Welcome everyone, or good morning, good afternoon, good evening, depending on where you are in the world. This is the radiation oncology webinar, looking at ultrasound in image guided brachytherapy where everything old is new again. I'm Perley Core, I'm the Associate Professor and Lead Radiation Oncologist for the Gynae Tumour Stream at the Peter MacCallum Cancer Centre in Melbourne, Australia. And I'm also the current Chair of the IGCS Education Radiation Oncology Work Group. Thank you so much for joining us today for this webinar. The aim of this webinar is to share the Peter Mac ultrasound program and the impact that it's had on being able to deliver image guided adaptive brachytherapy, improving the technical quality of brachytherapy implants in the treatment of patients with locally advanced cervical cancer. We have a pretty impressive faculty lined up for you today. Our first speaker is Dr. Sylvia Van Dyke. She is our Head Brachytherapist at the Peter MacCallum Cancer Centre, and she has been the pioneer in developing this particular program and instrumental in educating a vast number of radiation oncologists and radiation therapists along the way in her very illustrious career. Our second speaker is Dr. Kelvin Yu. He is a Radiation Oncologist at the University of Santo Tomas Hospital in Manila, Philippines. And our third speaker is Dr. Ryan Urban, who is a Radiation Oncologist at the BC Cancer Centre in Vancouver, Canada. Both Kelvin and Ryan have both spent some time at Peter Mac where they were both fellows and enjoyed being part of the brachytherapy program at Peter Mac and we're honoured to count them as one of our fellow alumni. And our final panelist is Dr. Aninye Balagon, who is a Radiation Oncologist leading the GYNI program at the Will Cornell Centre in Brooklyn, New York. So, today, we will have a variety of insights into the usefulness of ultrasound in delivering adaptive brachytherapy, and I thank everyone for joining us for this presentation. Now, before we get started, just a couple of small housekeeping items. Firstly, the recording will be available, I think, next week on the IGCS Education 360 Learning Portal. We do ask that you please submit any questions via the Q&A feature, rather than the chat function. The webinar etiquette is to try and fit everything to your window. Unfortunately, only the presenters will be able to speak and everybody else's microphones will be muted, so for that reason, please use the Q&A function for any questions that you have. And we will do our best to answer them along the way. Otherwise, we'll address as many as possible in the panel session at the end. So, without further ado, I'm going to hand over to Dr. Sylvia Van Dyke for our first presentation. Thank you. Hi, thanks, Pearlie. I'll just get my screen up and share that. How's that looking? Can you see me? Okay, there. All right, thank you, everybody, and thank you for the lovely invitation to come and join you this evening. It's an absolute pleasure and honour for me to do this on behalf of the Peter Mac brachytherapy team. As Pearlie said, I'm Sylvia Van Dyke, the lead radiation therapist in brachytherapy at Peter Mac. I'm very proud to be sharing this forum with our two recent fellows who were really a joy to work with and a joy to share knowledge with, and we shared a lot of knowledge back and forth and it's lovely to see them presenting with us today. I've got a contingent of Peter Mac brachytherapy personnel online tonight, and I want to say hi to them. I haven't seen you for a while, but I wanted to make a special call out to Mr. Angelo Savaras, who's actually looking after the service at the moment. Angelo has been instrumental in helping me with this ultrasound guided brachytherapy, and I want to congratulate him because he's recently obtained his graduate certificate in medical ultrasound. So now I'm going to take you on a little journey as to how we do ultrasound guided brachytherapy at Peter Mac. First of all, we'll have a little look at some historical pictures and of course, like everywhere, it's the resources, infrastructure, past work practices that influence how we work, and they continue to do that to this day. So back in the day, early 2000s, late 1990s, we were treating cervix cancer with LDR. The ladies would come to theatre, get their applicators inserted, and then they would go to the radiotherapy department for some AP and lateral films, where we'd create a point A template based plan, and then we'd transfer the patients to the ward for 24, 36 hours while they underwent cesium treatment. In the late 90s, Peter Mac bought an HDR unit and there was nowhere to put it. The ward, shielded rooms in the wards were being used with cesium. There was no spare bunker. So they put the HDR afterloader into the theatre because they wanted to start offering a prostate brachytherapy program. So we quickly adapted to that. It was a lovely way to introduce HDR brachytherapy for our gynae patients, but we had to make some adjustments. So we, of course, brought the ladies to theatre, inserted the applicators under anesthesia, as we had been for LDR. We then got the CR in to take our AP and lateral films so we could continue using Fletcher implant rules to get a good quality implant. We digitized the implants into Plato and we created a template based plan and treated the patient while she was asleep on the table. So we're sort of matching our prostate program. And that's an important point, I think, to take forward is that whatever practices you do, whatever tumour streams you're working in, there's always space for cross-pollination. Along the way, two of our senior oncologists, Professor Narayan and Professor Burnshaw, had started asking for some MRI scans of these ladies undergoing HDR brachytherapy. And back in the day, early 2000s, we would get a hard copy coronal and sagittal film of the implant. And the professors wanted these images to look at tumour characteristics and behaviour. So they both bearded gentlemen, they would stroke their beards and go, hmm, endophytic, poor response, exophytic, good response, and then put the films away in the bag. But I had a light bulb moment, and that's what the light bulbs are there for. And I said, why don't you put the isodose lines on and see what you're treating? And they were both amazed that that was possible. And of course, it was possible. I just plotted the isodose plot at the magnification of the MR films, which is about 1.4, it was gigantic. And we looked at the coverage that we were achieving with these point A template based plans. Most of the time, coverage of the cervix was good to generous, but often too much, there was too much dose in the organs at risk. And occasionally, coverage was skimpy with a point A plan, and we had to do something about that. So we started adjusting these point A plans for the subsequent brachytherapy fractions. In those days, we were doing five fractions. So for fractions two, three, four, and five, we'd adjust the plan based on what we saw on MRI. And you can see those images there on the middle row of that slide. So we started doing conformal planning. After that, because we needed the sonographer so much more often for five fractions, I would start scanning the patients, because they were often held up in their own diagnostic departments. And as I was scanning a patient one day, and I'm looking at the light box with the MRI image on the light box, I turned to the professors and said, you know, we could do conformal planning from fraction one by using ultrasound. I can measure the cervix and uterus on ultrasound. It's the same as MRI. And that was another light bulb moment for us. And we started to do that. Fortunately, we could print out the ultrasound image, and you can see an ultrasound image here. And I'd plot the isodose plot at about a magnification of 0.6 and lay it over. And you can see a young Dr. Kaur there doing exactly that, lying the isodose plot over the ultrasound image to check coverage. And that's how we developed the technique that we still use to this day. We've got a little bit more modern with more modern computers. We're able to upload our ultrasound images into the planning system. And we've got some lovely tools in there to help make this a faster, more accurate process. But that's the genesis of where we started from in brachytherapy. So today's talk, the overview is, this is the overview, talk about the importance of the technical quality of implants and the value that ultrasound brings to that in the resources and environment that we work within at Peter Mac and how we've made that work for us. I'm not going to read through all these quotes. These are old quotes about the need to use brachytherapy. We're all very familiar with these quotes. And we understand that we must incorporate brachytherapy into a treatment course for these patients to cure them. And to do that, we have to also be sure that the implants are of adequate technical quality to make sure that the brachytherapy is effective. That's what we are trying to do with what we do with ultrasound is to achieve the highest quality implant using the resources available. Now, technical quality in this era of these papers was more about the relationship of applicators to each other and the bony pelvis. And of course, we have expanded that now with soft tissue imaging to also consider the relationship of the radiation, the applicators to the tumour itself. So why do we worry? Why use imaging? Well, mainly, and it's pretty blunt, we want to see what we're doing, avoid perforation, avoid abandoned treatment, treat disease and avoid normal structures. And this is just some images to just point out. Sorry, I'm going to grab the laser pointer. Some images showing what a perforation looks like on laparoscope. There's the tandem protruding from the uterus there. This is a sagittal MRI, a CT view of an applicator that's perforated the posterior wall of the cervix. And this is an ultrasound view from Peter Mack. And the tandem is actually in the uterus, but it's not all the way into the canal. It's going to sort of break through the top end of the uterus there. So seeing what you're doing is absolutely vital to getting a high quality implant. Our use of ultrasound has extended beyond just avoiding a perforation. We now use it in all these manners to assess anatomy, guide applicator placement, verify at each insertion. And that's a really strong point that I want to make throughout the presentation, that verification is so vitally important on the journeys that we take these patients through. And we also use it now to help us report those symmetry. So it has a lot of uses in each of those subcategories there as well. The incidence of uterine perforation ranges from about 2% up to 30% when we start using soft tissue imaging. And you can see from these somewhat old studies, old ultrasound studies, and then the more recent CT studies when CT was starting to be brought in, that they probably range from about 10 to 15%. It's not just perforations that detract from the quality of the implant. Perforations tend to amount to complete geographic miss of the cervix and uterus. But you can have myometrial penetrations and suboptimal placements. And in the study done by Granai back in the 90s with ultrasound, he discovered that up to 68% of their implants were subpar. And that's what we want to correct with imaging. So I'm going to take you through a few images now just to highlight how important it is to see the anatomy that we're trying to implant. And these are just standard anatomical variations of the uterus and cervix. Over here is a sagittal CT. There's the vagina with the applicator in the vagina. And the tandem has gone through the cervix and perforated outside the posterior wall. Now, this is just a normal antiverted uterus. The cervix is about 90 degrees to the vagina. There's no way that tandem can turn that corner and end up in the uterus. This panel A up here is a transvaginal ultrasound of one of our patients. And it's the same orientation as that CT. This is the ultrasound probe in the vagina. The angle between the vagina and the cervix is 90 degrees. And we would struggle to get a tandem in that as well. After we've assessed the patient with transvaginal ultrasound to see the position of the uterus, we then change to transabdominal ultrasound. We fill up the bladder to create a lovely acoustic window into the pelvis. And we open up the angle between the vagina and the cervix to about 130 degrees, 140 degrees. And that makes for applicator insertion far easier and much more safe because we can see the canal all the way. Similarly, another very common anatomical variation is the retroverted uterus. This is a transvaginal image here. You can see the relationship between the vagina and the cervix is quite simple to see. But the body of the uterus is very retroflexed and hanging into the back of the pelvis. It's the same patient. We've switched to transabdominal ultrasound, big acoustic window via the bladder there. Got a speculum in the vagina. And the line between the vagina and the cervix is almost 180 degrees. Easy for applicator insertion. But the uterine body is still hanging down into the pelvis. So we've used ultrasound to inch the tandem in slowly and then reposition the uterus for treatment. So very important to be able to see what we're doing. If not, this scenario could easily have happened. The tandem would have gone into the bladder. There are lots of anatomical variations in uteruses by corneate, corneate, septate, partial septate. I haven't got time to show you my gallery of all of them. So I'll just show you the partial septate one. We see that quite often in the clinic. And these are some lovely ultrasound, transabdominal ultrasound pictures showing the bicorneate uterus in the axial orientation. And here we've got the tandem, which is this hyper-echoic little artifact here with a shadow artifact behind it in the patient's right cornea. The image below, the tandem's in the left cornea. And that's how we elected to treat the patient. And that's what it looked like on MRI. We had a better fit with a longer tandem. And we established that with ultrasound at the time of applicator insertion. This is the axial MRI image, that dark void. There's the tandem. And it agrees very well with the ultrasound image there. So we see the same thing, of course, with ultrasound and MRI. But sometimes it takes a little while to convince people that that's what we do see. We also use ultrasound to assess the response to EBRT. A very important consideration. And here we have an unfortunate patient whose tumor did not respond well to 45 gray. We could tell clinically that there was still tumor present. And then when we looked with ultrasound, there was still exophytic and infiltrative tumor in her bladder wall and vagina. This is an old image. And we only had intracavitary available to us at this point. And we could not cover that extent of disease with brachialone. So we abandoned and sent the lady for her MRI scan so that she could be replant and have additional chemo and external vein. But it's a very important consideration. Because using ultrasound to assess tumor response helps us determine the technique and the type of applicator that we might want to use. Here's a patient whose tumor responded well. The whole tumor was taking over the whole cervix at pretreatment. After 45 gray, the cervix is back to normal shape. And again, this is a transvaginal ultrasound in the same orientation as your sagittal MRI view. It then told us we only need to use intracavitary applicators for this patient. And this is the transabdominal scan. I've just rotated it so that you can orientate yourself with the sagittal MRI. One of the most asked questions that we encounter is what ultrasound technique can be used in brachytherapy. Of course, you can use any transabdominal, transvaginal, transrectal. And they can all be used to assess the cervix and disease at the time of brachytherapy. We find transabdominal to be most effective to assess target dimensions and verify applicator placement. So we predominantly use that. But I've got a few images of some of the other modalities as well. We did get out our transvaginal ultrasound, our transabdominal ultrasound and our transrectal ultrasound to basically help ourselves understand what we're looking at with these different modalities and image orientations. So in this first image, we were measuring the cervix, the anterior-posterior dimensions of the cervix using transvaginal ultrasound here. And then we moved this. It's the same patient. We just went to transabdominal, filled up the bladder, created that acoustic window and measured the cervix in that direction and then verified it and verified it with MRI later on. So it gave us confidence that we were measuring the right things with ultrasound. Similarly, we went to measure the width of the cervix with TRUS, transrectal ultrasound that's used quite extensively in some European centres. It's good for looking at the cervix and measuring width. It's not as useful when the applicators are in situ. But again, we found good agreement between the different modalities and that gave us confidence to proceed. So we'll get to the environment that we now have at Peter Mac. We had new hospitals built for us about seven years ago. And in that hospital, we got two brachytherapy suites, so two shielded theatres inside the operating suite. So same scenario, same sort of infrastructure as the previous old photos that you saw at the beginning, but much more purpose built this time with a much greater emphasis on radiation safety for both ourselves and our patients. Much greater emphasis on source security. That first afterloader was just plugged into an electric socket in the corner of the room. Nowadays, of course, it's under so many levels of security as you can see there on the image, quite a different scenario. But it's a lovely suite. There are pros and cons to these types of suites, but we find that pros outweigh the cons by far. We have full anaesthetic and recovery services and we are better placed to deal with emergency procedures, be they medical, software, mechanical or radiation. This is The top panel here is that theatre again without the bed in it. There's our little afterloader in the radiation cupboard. The bottom picture is our co-located brachytherapy control room. That sits behind this cupboard where the afterloader is. It's a very well-shielded cupboard. We're very safe on the other side of that wall. In this co-located room, which is literally just around the corner, we have our planning computer and lots of space for the team, which can get quite large. This is our team, the brachy. We've got a good suite of applicators available to us for gynaecological brachytherapy. We do still use the standard CTMR, fixed tandem and ovoids, very basic geometry, but very reliable and very reproducible in our setting, as well as some of the more advanced applicators like the Geneva, the vaginal multichannel and the Venezia, although we haven't used that with ultrasound just yet. It's a big team. We have the anaesthetic team, of course, the scout scrub team, the radonc team, maybe an RO or two and a registrar and a fellow, or there may be all four of them present during a session. We have three brachytherapists, a physicist and a theatre tech. Often the whole team are in theatre together, so it can be quite a crowd. We treat around 50 cervix patients per year and each patient gets three fractions of treatment. We only get access to our theatre, purpose-built and spectacular as it is, we only get two sessions a week to access that. If patients come are referred slowly, we can manage our workload quite well with that sort of access. If we get an influx of referrals, we sometimes struggle and we have to try and negotiate a bit more access. If we had unfettered access, we could treat many more patients in this environment. Our imaging resources, we, of course, use the ultrasound machines that were purchased for the prostate program and they're actually wonderful, these BK machines. We, of course, purchased some extra probes, a large curvy linear array for trans-abdominal work. This is the endocavity small curvy linear array that we use for transvaginal work. Of course, the dual array that we use for prostate work that usually is transrectal. We use it in the vagina as well sometimes to look at urethra. We have a range of phantoms to do our simulation-based education training and we have access to the CRM. We only get three MRI slots a week on our MRI, so each patient gets one MRI per course of brachytherapy on a Monday or a Friday. We do have simulators, of course, in our radiotherapy department, but they're booked out all of the time and we rarely get access to them. If we can't get MRI, we often are quite satisfied with ultrasound alone, particularly in intracavitary alone brachytherapy. I've drawn a big red circle around this chronoscene. This is a very important component of the whole ultrasound-based picture and that is to have in place a way to clean and reprocess probes that's quick and efficient. Previously, we used Cydex, which is a little bit dangerous with the fumes and things, but we've moved to this high-level ultraviolet disinfection process that only takes 90 seconds per probe. If you're considering buying ultrasound, don't forget the equipment to help you clean it after use. Just a quick overview again of what we do with ultrasound at Peter Mac. We use 2D, 3D, 4D imaging and PowerDoppler for both prostate and gynae and we do try to cross-pollinate across the two streams. We often think if it's possible in prostate, why isn't it possible in gynae and vice versa? We use it to guide applicator insertion. We integrate our software. We have a standalone prostate system that we wheel into theatre. Quite often when we're doing intracavitary alone, we do the planning in the control room, but for intracavitary interstitial hybrid implants, we would log into the PC in the theatre and do live planning inside theatre, just like we do for prostate brachytherapy. Of course, we've got our afterloader, our co-located control room, our sterile core with all of our applicators, which is right next door to our control room. These are the planning constraints that we use for gynae. I'm not going to go into every single one of them. I'm sure you're all quite familiar with the Jeck Estro Embrace 2 protocol and I've just benchmarked us against that. We're a little bit more conservative in total dose for both target volumes and organs at risk, but get more confident as time goes on to push those doses a little higher. So we're certainly playing in the same field. This is a typical patient journey in our department. Patient comes in at about 7am. We hope to start the procedure at 8.30am. That's in scanning the patient with transvaginal ultrasound to have a look at the lay of the land, if you like, the topography of the pelvis. We then go to transabdominal ultrasound, have a look around again, guide applicator insertion. We start planning at around 9.15am and at 10 o'clock start treatment. Treatment's usually done within half an hour and the patient then departs the theatre, gets woken up, departs theatre and heads over to the MRI scanner. She should be back in recovery by about midday and ready for early discharge in the early afternoon. Now that changes, this is a pretty straight, if we get a straight run for intracavitary brachytherapy, we can do that within that timeframe. If we're using interstitial hybrid brachytherapy, we take a little longer in theatre and we push our MRI out to midday so the patient doesn't actually leave the hospital to late afternoon. But it's a very efficient process and we've been very fortunate in that this protocol was developed with the Peter McCallum anesthetist for expedited transfer to the imaging suite. So we do the minimum requirement of observations in recovery and then get these patients off to MRI. They normally have a spinal on board for that first insertion to keep them comfortable throughout that journey. As I said, we predominantly use trans-abdominal ultrasound for intracavitary and hybrid brachy and that requires the full bladder. You'll hear me go on about the full bladder a lot because it creates that acoustic window into the pelvis and it really does help you get a good quality image if you've got a lovely acoustic window. It helps move the small bowel away from the uterus. Bowel is full of gas. Gas is the enemy of ultrasound. That's why you can't see anything when you first put a probe on somebody's tummy if the bladder is not full. The full bladder can help, as you've seen, change the position of the uterus from anteverted and avoid perforating posterior wall and similarly with the retroflexed uterus. And it also provides the largest field of view and the most anatomical detail. This is what it looks like. So here we have a small bladder. These are sagittal ultrasounds. This is superior here, inferior here. This is the vagina here. This is the uterus here, but we can't see it all because gassy bowel is covering the top of the uterus. But as we increase the bladder volume, increase the acoustic window, we see more and more and more. And I've overdone it on this image here on panel D just to highlight how clearly you can see. You'll notice that underneath the bladder, the whole image is a little bit brighter. It's because the bladder is anechoic. The sound's not being absorbed. It's going straight through and allowing us to see deep into the pelvis. And that's what we're aiming to do. And we always fill the bladder to just beyond the thunder. So normally we'd work with this type of image, but sometimes get a bit carried away and just forget to clamp the bladder off. The brachytherapy sonographer and the people that do the sonography now in brachytherapy at Peter Mac are the RTs who specialise in brachytherapy. So they're radiation therapists who are like medical dosimetrists. We do planning and treatment at Peter Mac. We go into brachytherapy, we learn that. And now on top of that, we're also learning ultrasound. So it's new to us to learn this imaging modality. And the brachytherapy sonographer is constantly talking to the radonc as they're scanning, explaining the orientation of the view that they're showing the doctor and conferring with them and letting them know what direction they're pointing in. So this picture looks like you'd be forgiven for thinking that this sagittal ultrasound view, the vagina there, there's the uterus there. I'll just outline it for you. There's the canal. We focus on finding the canal for the radonc so that they can sound the uterus. This image would, you'd be forgiven for thinking that this uterus was in midline because it's in the middle of the screen, but that's not necessarily so. Not many uterus is a textbook in midline. Most of them wander off somewhere. And this one was wandering off to the patient's left shoulder. So it's the job of the brachysonographer to talk to the radonc. It's a very collaborative process saying, I'm pointing my probe at her right left shoulder. That's let the sound go to the left shoulder if that's what you feel when you insert the sound into the canal. We then change over to the dilator. That's what that looks like, a thicker dilator. There's the uterus. And then we swap over and put the applicator into the canal. While we're doing this, we will change orientation from sagittal to axial to confirm that the applicator is optimally placed within the uterus left to right. So you can get a mid-sagittal plane, but it's easy to drift off and get a parasagittal plane. If we see the applicator on the parasagittal plane, we have to confirm that actually is in the center of the uterus. Otherwise you can get yourself into the realms of suboptimal implants. So we always go orthogonal or right angles to the tandem and confirm in the axial plane that the tandem is optimally placed. It's really important to be familiar with the dimensions, geometry and composition of the applicators that you use so that you can help identify them in the ultrasound image. So here we can see a straight applicator. Here we can see a curved applicator, and that's the standard CTMR and the vaginal CTMR applicator. And that's often very helpful for newcomers to brachytherapy to see me do that so they can picture what they're looking at when they're looking at these images and identify the applicator within the image as well. Hybrids presented a new challenge. We had another dimension to the applicators. They had little bits hanging out the side, but they're pretty easy to see. They create a nice hypoechoic artifact, the needles. They're very echogenic but not echo abstractive, which is helpful because it's still plastic. So we see a nice white artifact and that's what that applicator would look like. The hybrid applicators are a bit more challenging because they're off axis from the tandem. The tandem is quite easy to find in these slices. And we want to check them both in the sagittal plane and in the axial plane. And occasionally we'll call on transrectal ultrasound to check the separation of the needles as we insert them into beyond the cervix. And that's what this image at the end here is, just us checking the separation. Although on this image here, panel A, you can see that the separation between the needles is very uniform and agrees with the geometry of the applicator itself. We do use Color Flow for all of our hybrid implants to check nearby vessels and make sure we don't go anywhere near them, don't perforate them, don't push them. We just stop short of them and it's very useful. So the ultrasound along with Color Flow dictates the depth of the needle insertion when we're inserting these parametrial needles. Using ultrasound to plan gynae. So we take an ultrasound view along the tandem. The region of interest is in the centre of the ultrasound field of view and across the screen. So on this panel here, the bed would be parallel with the vaginal spatula. The tandem is at an angle because the uterus is at an angle from the vagina. So what we do is we hold the probe at an angle. We don't hold it vertical on the patient. We hold it at an angle so that the sound propagation is orthogonal to the tandem. That gives us the best way of measuring, most accurate way to measure the dimensions of the cervix and uterus. And that is displayed on an ultrasound screen as if the uterus is parallel to the bed. It's not. So we often have to explain that to the ranog as we're scanning. So looking at this image, you'd think this uterus was parallel to the bed. It's not. It's at an angle in the patient's pelvis, but the image is displayed this way on the ultrasound unit. And that takes a little bit of getting used to when you're doing scanning that we have to sometimes remind the ranogs that you're pointing too low. You need to point a bit more anterior because the uterus is actually angled in the patient's pelvis. So we think of the ultrasound as like a torch, a beam of light, and we're shining that into the pelvis and having a look around. After we've got a lovely sagittal view, we go axial and try to get the axial views as orthogonal to the tandem as possible. So we get a true cross section in the actual orientation through that uterus. We take an image through the tip of the tandem and just above the flange at the external loss. And we can scan along the tandem and get all sorts of axial images. But unfortunately, along the tandem and get all sorts of axial images. But unfortunately, one of the downfalls of 2D keyhole ultrasound is that there's no coordinate system that we can spatially allocate those images to. So we just stick with the two cardinal images we can absolutely identify, which is at the tip of the tandem and at the external loss. We can now upload these images into our planning system. And that's been revolutionary for us. And it really has expedited our planning processes and made them more accurate. So we started by uploading the two axial images as a data set. So there's only two images in this data set. They're spaced five centimetres apart. That's the length of the tandem in this patient. If we used a six centimetre tandem, they'd be six centimetres apart. We then upload the sagittal ultrasound image and co-register that to the axial images. And this image here down here in the bottom corner there, that's a coronal reconstruction between the two axial images. And unfortunately, you can see there's a fair bit of missing information there. And this is what we're aiming for one day to be able to see an image like that. And we could do a lot of wonderful conformal planning with a basic data set like that. We then translate our applicator into the data sets using applicator modelling, that lovely integrated applicator reconstruction software that is now available. This is the Electa system on Centra. I believe Varian has it as well. It really does change things and makes for very accurate, fast reconstruction. And then we start optimising our plan on the ultrasound images. So we cover the cervix. We adjust the isodose lines by covering the cervix. We do a lot of the planning based on the sagittal view, because we can see the whole uterus. And we're very particular about the radiation to the posterior wall of the cervix, because beyond that is potentially rectum and bowel. We do use ion dose shaper, but we also fine tune with manual dwell weights. We recheck everything, of course, after every little change that we make. We check the dose, that the ingress of iso lines into the bladder. We find that ultrasound over calls bladder dose because of transducer pressure. So we allow a little bit of iso ingress into their bladder, but knowing that when we're treating, there is no transducer pressure. And we know that, and we've confirmed that with our MRI scans taken a little bit later. We spare the rectum. We always use a spatula in the vagina. It makes for very reproducible setups from implant to implant, and perhaps different practitioners doing different implants for patients. And we review all our dwell times and positions and aim for steady modulation to avoid necrosis. That process was wonderful using the two limited data sets for ultrasound. But when we had some new influx of new staff, it took a little bit long for them to master obtaining all those scans and also then the registration within the planning system. So we made a call to just upload the sagittal ultrasound alone and use the information from the axial ultrasounds to guide our iso coverage by using measures or rulers on the coronal reconstruction, as you can see here. So we make sure the width of the cervix is measured and shown on this image, and the width of the uterus at the tip of the tandem. And we iso shape based on the sagittal ultrasound view. And that has expedited the planning process a little bit so we can stay on time in our very short access list that we have. Ultrasound is also good to assess intrafraction changes. So in a typical workflow where the applicators are inserted in theta, you might see a lovely picture like this where the applicator, the flange is at the ass, the tip is at the end of the canal. It looks perfect. And then patients get transferred to MRI for their planning views. And this would be quite disheartening, disappointing to see. If the applicator position was checked just prior to MRI, that may have been able to be remedied. Now, this applicator has slipped because it really probably wasn't secured well enough. And so it wasn't usable for us because we only use that to show the plan that we have already delivered. But in a forward sort of planning environment on a typical patient journey, that's almost next to useless as well. You don't have a planning scan that actually indicates where the applicator is. If you did try to plan on that scan, you'd have to verify at the point of treatment that the applicator was still in that position. And that's often a missing link as well in many programs. Once we've got the MRI after the first fraction of treatment, we upload that to Oncentra and do the contouring on MRI. And then we back project the plan onto the MRI images to see what we covered based on the ultrasound alone. And eventually we do also co-register all the ultrasound images to all the ultrasound images to check the changes over time. So we do look at 4D applicator volume and isodose verification. We look at the interfraction changes by uploading each ultrasound to that MRI data set after each insertion. And just have a look if there's been much change in the size and shape and dimensions of the cervix and uterus. And does the plan that we had used from fraction one still adequate or do we have to adapt ISO coverage? For our basic intracavitary work, we never had to make too many changes for fractions three and four. We do find we do more replanning, of course, with interstitial. When hybrid applicators came along, it was just a brand new challenge. And we had to work out if it was possible to use these applicators in our environment. And it was absolutely imperative that we develop a workflow that was safe, accurate and efficient. And some quality criteria to maintain the technical quality of implants that we'd been achieving with intracavitary over the past so many years. So we developed a few protocols around this. We keep a record of applicator use, needle use, needle depths, needle contributions and dose metrics. And we brought the Geneva applicator into being in December, 2021. The qualitative assessment that we undertake for the Geneva's is based on our intracavitary qualitative assessments. We've just added another parameter to it. So we always check that the flange is against the external loss with ultrasound when we're doing both intracavitary and interstitial. And we always check that the tandem is centred in the uterus. And we introduced, of course, another measure that we identify the needles on ultrasound and MRI and that the location and depths were both the same. You can see here, this is a very beautiful picture of a parasagittal ultrasound showing the needles. And this is the corresponding MRI from that patient. So we do check all that is in agreement. I'll quickly go through how we plan a hybrid in our integrated theatre. I won't dwell too much on the details. Suffice to say, she had a horrible large infiltrating ectosurvex up to five centimetres long. We start with transvaginal ultrasound. This is the sagittal transvaginal ultrasound. This is ant and post. The cervix is actually much smaller ant to post. So she's had a response. There was a marked reduction in the mass. But when we rotated the transvaginal probe to get a coronal view through the uterus, we could see it was still bulky on the left. So that immediately told us that we'd have to go to a hybrid technique that helps us choose the applicator. We went for a Geneva and we started planning immediately. We moved to transabdominal, started filling the bladder, inserted the sound, check that it was centred and then inserted applicators. And we selected a six centimetre Geneva tandem and 30 millimetre ovoids. And that's the picture with the tandem in situ there and the ovoids. Ultrasound's really good at helping to check that the ovoids are locked in properly. We found the Geneva has a tendency for the ovoids to slip underneath the phalange. Even though the phalange is very large, they can slip under and we've detected that with ultrasound by looking just underneath the pubic bone. And we're able to correct that because we know that's what it should look like. This nice little rectangle, when you look at the ovoids locked together when you're external to the patient, that's what they should look like. So we can check the applicator is, it has a good relationship to itself and we don't see something untoward. One of the quality checks that we do use throughout hybrid is keeping an eye on the tip of the tandem to fundus as a quality control measure. When you start inserting hybrid applicators and needles, there's a tendency for, I'm gonna move my hands up into the camera for the radons to lift the tandem up so they can see what they're doing, push the needles in. That often makes the tandem slip out a little bit. And we saw that happen a couple of times. So now we use this little measurement here between every needle insertion before and after and make sure the tandem's still where we want it to be because we wanna treat the uterus, cervix and uterus predominantly with the tandem and ovoids and then boost the dose to the parametrium with the needles. So the tandem needs to be optimally placed and we need to maintain that technical quality. As soon as we start, make the decision to do a hybrid insertion, we start planning. We call up an in silico plan. That just means a computer-based plan. We create an empty data set in Oncentra and this is also one of those light bulb moments we knew we needed a data set, but of course we don't have one. We created an empty one, Oncentra lets you do that. And then we could put the applicators into the empty data set and start planning that way. We load a library template. We've created templates for every tandem and ovoid combination for every applicator type that we have and there's a little, that's what it looks like in Oncentra. And we just load the dwell positions and point A's and some surface points on the ovoids and the ICRU rectal point comes in with that template. And it means that it's quick to start planning. It's consistent, all planners use the same dwell positions to start with, very efficient way of getting started. Once we've loaded the template, it's not a plan. There's no optimisation in this. It means nothing at the moment. We update the prescription dose, the treatment date and the time. And then we start iso-shaping if you like. And we do it the same way. There are three sonographers, three RTs in the room. One of them scanning the patient, measuring the distance from the tandem to the posterior surface of the cervix and uterus. One of them's at the planning computer, creating this plan and putting the same measures on the plan and then starting to iso-shape. And the third one tends to sort of run between the two documenting everything on our worksheets. And then we iso-shape like we would with a standard intracavitary plan to this uterus and cervix and get the best coverage that we can get with the intracavitary component of the implant. Once we've achieved that, we start inserting needles. The needles are added to this virtual plan because it's a virtual plan in the planning system as they're being inserted. And the insertion depth is based on the ultrasound measurements. So if we decided we were going to put, in this lady's instance, three needles through the left ovoid to treat that still bulky parametrial disease on the left side of her cervix, we put three needles quickly in through those ovoids. And that's what they look like when they're reconstructed in the planning system. We have our ultrasound images that dictate the depth because we use ColorFlow to help us with that. So they're all about, I think, 25 millimetres in this instance. And we update our worksheets as we're going along. And it's very important, of course, to keep good record of where the needles are going. And they are in this system. Needles are identified by catheter number, channel number and coordinate. And we label the needles in the patient, the external part, the free length with the coordinates so we can cross-check before we treat the patient. We start iso-shaping. We activate the needles with n equals two, that's two millimetres between each source position. And we offset the dwell positions from the ovoid surface so we don't heat the vagina up too much. And we iso-shape based on the measurements that the sonographer RT is telling us. The weightings in the needles are typically weighted low and they're all the same to start with and we might manually adjust them. We keep a very close eye on the hyperdose sleeve, the 200% isodose line. We're trying to spread the 100% isodose line out to cover this bulky disease. We don't need to blow it up with 200% of dose. It's a very high dose. We check coverage. We check the doses to our organs at risk. The contribution to the needles, we tend to use around the 10 to 20% contribution, which is sort of standard in the literature. The RO reviews the plan with us. They are in the room while we're doing this, calling out measurements and making decisions. We send the plan to it for an independent red calc check and then we send it to the TCC and we're ready to treat. And this would have taken all in all probably an hour or less than an hour, 45 minutes. Patient's ready for treatment. We tell the anaesthetist the treatment time so they can adjust the anaesthetic drugs. We clear the room. We clear a pathway from the afterloaded to the cupboard. So in case of emergency and we leave the room. We cross-check the plans at the TCC with our physicist. The physicist monitors the source. RT1 monitors the patient and the anaesthetic slave, which is here. That's RT2 completes QA. After treatment, the bladder is drained and the amount's noted because we refill it again at MRI and the patient's transferred to the trolley. We fix a sign that says, keep the patient flat. There are brachytherapy applicators in situ so that some poor nurse doesn't inadvertently sit the patient up and break the applicators. And a brachytherapist always accompanies our patient from theatre to MRI. And that's, again, to maintain the technical quality of that implant and for patient reassurance. We're also escorted by a nurse for medical help if we should need it. Once we've got the MRI data set, we then back project the plan that we just delivered onto the MRI. So RT1 reconstructs the applicator and needles and contours the organs at risk. RT2 checks that reconstruction and contouring and the radonc contours the high-risk CTV. And we check the coverage with the radonc. So the plan you're seeing on the screen was generated with ultrasound alone in the theatre and was delivered at fraction one. See, there's been a little bit of convergence of the needles here on the left ovoid and we will account for that and try to reproduce that next time or we'll make adjustments based on that. This plan achieved a high-risk CTV D90 of 8.5 gray for that fraction. And when we extrapolate that for the three fractions, gave us a D90 of 83.6 gray, which was a bit undercooked for us. And we could see also that we could have done maybe with some needles on the right side. So the radonc requested for needles to be inserted on the right side as well for fractions two and three. So we do that by creating a virtual plan on the MRI data set. So we copy that plan, add three more needles, recalculate the plan and see what we can come up with. And on this virtual replan, we achieved 8.8 gray per fraction. So if we added that to fraction one and added another two times 8.8 for fractions two and three, we could achieve a D90 of 85 gray. So when we go to theatre for fraction two, it's a reverse process. We open the MRI data set, we open the case with the fraction two plan with the virtual needles, and we replicate that with ultrasound in the patient. And we can cross check all those measurements and dimensions and adjust the depth and trajectory of the needles based on the ultrasound views. We adjust them in the MRI data set and we recalculate and replan interoperatively as the needles are inserted. Excuse me, I'm gonna get a sip of water. So this is what the ultrasounds look like when we added the three needles on the right side, that little marker there is a stent in the lady's right ureter. So we start with the most posterior, use transabdominal parisagittal view, start with the most posterior needle, then go to the middle needle and then most anterior needle so that we don't block the view. As we're inserting the needles, and that's the left ovoid inserted, very clear pictures. And you see, we don't really need transrectal in this instance to see the separation between the needles and see it very clearly on the parisagittal views. Whoops. So in total, we actually did adjust the plan again for fraction three on this patient. We didn't change the needle positions or trajectories, but we did up the weightings in some parts of the applicator and were able to achieve 9.7 gray for a total of D90 over all three fractions of 87 gray. So it was a pretty good result based on this hybrid planning method that we've used. We do our plan evaluation and reporting is via a chart round. And that's great because we have the whole team present and everybody has input into how to problem solve, how to move ahead, what we can do better next time. And then in terms of recording, the parameters are reported in EQD2 and all data is saved in our planning system and as a PDF report in Mosaic. And we do have an ethics approved database to collect all of our patient data. In terms of reporting dose, those parameters are universal to whatever technique that we use. And if we have an MRI, we then have these dose metrics that are extrapolated from that one MRI across the three fractions. If we don't have an MRI for some reason, occasionally that does happen, patient can't go to the MRI and the MRI is broken and it's intracavitary, we would just report on minimum target coverage based on width, height and thickness of coverage of the cervix in those two dimensional images that we take. We have reported clinical outcomes from our ultrasound guided brachytherapy. It's really important for us to do that, to look back and see what we did achieve. You can see it's from mid 2000s there, we'd done a lot of development of our technique, we'd sort of smoothed out the rough edges and felt that this was good to have a look at this group of patients. And we'd certainly been collecting their data prospectively from that time and we found very acceptable local control rates and minimal toxicity. And just to compare that to the other literature at the time and other practices in a similar timeframe, we thought we were tracking pretty well then, but I have tacked on the EMBRACE study right at the bottom there, which has moved the dial a little bit higher for us to aim for. So ours was using intracavitary alone. And of course, with the EMBRACE, there's a much greater percentage of hybrid implants that give you that better dose coverage. It was important for us to do an audit of our Geneva applicator. We had all these protocols in place, but we needed to make sure that there was no protocol. Individually, we felt each patient was doing well, but we wanted to check, of course, that there's no protocol drift along the way. So we elected a timeframe with one of our newer fellows and wrote this up. And now the aims were to look at the technical quality of our implants, the dose metrics, local control and complications. And we found, of course, technical implant quality was very high. There was only one fraction treated with suboptimal positioning of the flange against the os. We'd selected a tandem, it was a little bit too long and the flange stood off the os. So we changed that to the subsequent fractions. It was rectified on the patient at times. And when we did our audit and looked back, that was the only time we didn't meet that criteria for one fraction on one patient. Dose metrics were within our planning criteria. Local control was good. Medium follow-up of 11 months, all patients received a PET at six months and 81% of them had a complete metabolic response in the pelvis. There are only two instances of bleeding on needle removal, and that's also an important consideration to have strategies in place to manage bleeding should it occur post removal. And they were controlled with a vaginal pack. So very happy with our audit. One of the most difficult things, of course, for any programme, and I'm sure there are lots of people watching and who'll agree with this and recognise this, that how difficult it is to maintain and sustain an education programme in brachy and ultrasound. Brachy tends to be a little offshoot from the main radiotherapy department. People are often deployed in both areas. We're fortunate at Peter Mac, we have a specialised brachy team, so we can really put effort into a sustainable education programme. But having said that, it's still not easy. We always feel short. And it takes a long time to train people in brachytherapy and now in ultrasound use as well. We teach brachy on the job for radiation therapists. I do have a curriculum there. I have readings, we do pracs, we do tutorials, always supervised clinical work. We do encourage, well, it's mandatory to attend an Australian brachy group workshop that's held biannually and conferences where possible and site visits so that people who get inculcated in the brachytherapy way at Peter Mac understand different workflows in different departments. And we're very fortunate that we have a department down the road that helps facilitate that for us so our therapists can see what most of the world do. And that hospital also comes and visits us to see how we do it at Peter Mac. Ultrasound has also been tricky on the job. We do on the job training. And I used to run a workshop through the Australian School of Medical Imaging. It was a private ultrasound school, but unfortunately it ceased in 2020 due to the pandemic. And so we've just kept our training in-house, but we do make it mandatory that somebody in the team has formal brachy ultrasound qualifications. That was me, and it's now myself and Angelo. It's important to develop ultrasound-based protocols if you're going to go down this road. It's so easy to wheel an ultrasound unit into a department, put a probe on somebody's belly and see something, but what are you seeing? Do you understand what you're seeing? So we've built protocols around all these parameters you see on the screen. When somebody comes to brachytherapy, they probably have a little bit of university experience. So we have to tap into that prior knowledge in terms of anatomy and pathology, but often requires a bit of revision as well, particularly in the context of recognising anatomy and pathology on ultrasound. They've got new knowledge to learn, brachytherapy, the physics of it, applicators, the geometry, dimensions, composition, assembly, disassembly, and ultrasound. As I said, formal training is mandated in our department. It's absolutely essential to learn how to use this device and this modality properly. It's very limited scope training. We, Angelo and I have both gone through university and we've got graduate certificates in medical ultrasound. So we cannot go out and be diagnostic sonographers, but we can use it for this sort of, for verification and identification. And of course we do on the job training. It's also important to keep up with the ongoing credentialing in brachytherapy. When scans are performed by outside people, people who aren't specialising in ultrasound, you really need some sort of mechanism to make sure that you stay up to date and that everybody's on the same page. Everything's consistent, it's systematic, and we're all recognising the same thing. Post-treatment protocols are equally important. Again, wheeling in a little portable ultrasound is very easy, but you need to make sure that there are daily, weekly, monthly, yearly brachytherapy and ultrasound QA programme. And this little table down the bottom is very important, particularly admin, that you've developed your workflow, you do reports, you keep records, you keep images. There's structured education, training, credentialing and skill maintenance. If you walk away from ultrasound, you have to come back and get refreshed. It just doesn't come back to you automatically. And again, quality, doing those clinical audits, keeping an eye that there's no drift from protocol, using these newer modalities. Quality assurance in an integrated suite is also very important, and we learnt this when we started prostate brachytherapy, real-time ultrasound-guided prostate brachytherapy. In the radiotherapy world, planner creates a plan, they get a colleague to check their calculations, they then send it off to a charge or a senior physicist to check the dosimetry, and then it gets sent to the machines. And that's over a few days. There's time. In an integrated suite, real-time planning, while the patients sleep on the bed and you've got a very limited window of access, we have to do all this quality assurance in a way that is safe, but that doesn't take hours or days. And so we've built this program built on the pilot, co-pilot, check pilot type scenario, based on the airline industry. So the Radonc's the pilot, brachytherapist number one's a co-pilot, and brachytherapist number two is a check pilot. And it's all about communication, taking notice of your protocols, having relevant checklists covering all aspects of the procedure, use of clear diction and standard phraseology, and it makes it fast, efficient, accurate, precise. We have that feedback system, we talk to each other, we acknowledge and verify, and it's not a command control environment. It's all about the team, everybody contributing their specialities. And it's been working really well for us. And we stick to this and we bring it up time and time again, and sometimes even to the point where we identify who's the pilot, the co-pilot and the check pilot at each list. Something that's vitally important and hopefully we'll get touched on in the discussion, especially with Dr. Balagan present, is patient comfort and the effect of that on implant quality. So we know that implant quality is dependent on patient comfort. If the patient moves, the implant can move. We will need to keep the patient comfortable and pain free. And most of our patients are treated while they're asleep, except for fraction one when they have to go to MRI, and we try to keep them under spinal coverage there. But for a normal sort of more traditional workflows, it becomes much more important to keep the patient pain free as they transition from the OR to the recovery to the imaging suite to the treatment room. We need to think about that. And I've put a citation there from the Kurchina paper that talked about PTSD. I won't go into it now. We may get some time to go into that in the panel discussion after this. Can we do any better? We're nearly there, folks. Can we do any better with 3D ultrasound? We certainly believe that we can at Peter Mac. There are lots of technical challenges. With 3D, Angelo has been instrumental in helping us navigate the challenges, but there's still lots of them there. DICOM format from an ultrasound machine is not compatible with Oncentra. Use of third-party software is necessary to facilitate transfer of data. We've been told that's not legal in our hospital. We have to sort this stuff out. The voxel square and what's the orientation of the image? But I think you'll agree with me, this is a 3D volume which would be absolutely ideal for localised planning, even at a minimum, to get the 3D reconstruction so we can see that coronal view in our planning system and help iso-shape. And this is a true patient. It's the same patient. I got my hands on one 3D probe once and was able to create that image and upload it to the planning system, co-register it and see what the plan looked like on the ultrasound coronal view. And if we can achieve these sort of views using 3D ultrasound, these were generated with transvaginal. Of course, we can't do that. Our applicators are in the vagina, but we could do it with transabdominal. When gynaecologists check the placement of IUDs, well, that to me is just a tandem that needs checking. So we have done a proof of concept study using 3D ultrasound. And Angela was instrumental in that and we hope to start a pilot study soon. But what we do is need help from industry, the ultrasound vendors, the brachytherapy vendors. They need to talk to each other better. We need local help from our physicists, those gurus in the imaging department, our IT department, and also the sonographers in our diagnostic imaging department. So to end up, we've been using the resources that we have, along with some light bulb moments, and try to get the most out of the equipment that we have to ensure that we're doing high quality implants for the patients that come to us for treatment at Peter Mac. Point of care ultrasound allows us to assess the anatomy and give us the confidence that we've put the tandem in the right place at the point of treatment, which is a point that I'm trying to hammer home. It's so important. It's not normally part of the... Ultrasound is not normally part of the remit of the radiotherapy teams. So it really needs to be well addressed. Training and education needs to be well addressed in that. And we think, you know, 3D real-time ultrasound guided prostate brachytherapy is considered the gold standard in imaging for prostate. And we think that can be also achievable with gynae. And on that note, thank you. That's it. Thank you, Sylvia. In the essence of time, I'm going to go straight through to Kelvin. Kelvin has spent some time at Peter Mac, as I've said before, as our fellow, and is now going to give us a bit of an insight into how he's managing to adapt this system for his home environment. All right. Thank you, Pearlie. So greetings to everyone. My name is Kelvin Yu. I'm a practicing radiation oncologist here in the Philippines and was a previous fellow here at McCallum Cancer Center. So today I will be speaking about the process of adapting the Peter Mac ultrasound image guided adaptive brachytherapy to our setting. Just as short background, the Philippines is classified as a low to middle income country and limited resources often lead to challenges in healthcare access. Cervical cancers rank second as the most common cancer in women in our country. And most of the cases that we see are locally advanced. Our public health insurance provides coverage for both EBRT and brachytherapy. However, since it has only been a few years since we started doing IGBT, even though 20% of the centers are capable, currently there's still no public health insurance for coverage for IGBT. This means that any additional costs would have to be paid out as an out-of-pocket expense by the patients. As a result, majority of our brachytherapy that we do here is film-based. So how can the use of ultrasound fit our setting? Ultrasound is now more widely available and affordable. You can now get a very portable ultrasound that connects to your phone or laptop like this model here on the right, which was used to get the ultrasound picture in my title slide. Ultrasound is very useful in brachytherapy as it provides us with soft tissue information. Not only can guide us in our tandem positions during hard insertions, but it can also potentially be used as an image guidance during plan optimization. Additionally, it's also logistically friendly as it can be done bedside without any need for patient transfers. However, the main disadvantage of ultrasound is that it's very user-dependent, and it requires a well-trained person to be able to get good quality images for the brachytherapy procedure. So where are we currently? Currently, we are in the very early stages of incorporating ultrasound into our brachytherapy protocols. We have started doing simulations on actual patients to demonstrate the concept to the staff, establish workflows, and identify challenges that are unique to our setting. Here is a case example. This was a 40-year-old female with cervical cancer. In the initial IE, there was a 4-by-4-centimeter fungating cervical mass and bilaterally dodural parametria. This patient can't afford to do any additional scans and was clinically staged. At the time of the CT-SIM, there were enlarged nodes that were noted, so this patient was upstaged to stage 3C1. After concurrent chemo to 45 gray, there was a good response and a pre-brachytherapy examination showed a 2-by-2-centimeter slightly nodular mass in the cervix and resolution of the parametrial extension. She then proceeded with brachytherapy, 7 gray times 4 fractions prescribed to point A. This was the actual plan with the reconstructed isodose lines. The red line corresponds to the prescription dose of 700 to point A with an estimated EQD2 of 85 gray to the tumor, and the blue is the 60 gray EQD2 isodose line. For this plan, point A received about 7 gray, and we tried to keep the bladder and rectal dose to less than or equal to 80% of the prescription dose. This plan was then reviewed with ultrasound images. So with ultrasound data, it seems that we have good coverage of the cervix. However, doses to the OAR might have been quite high. As you can see, the 7 gray isodose line goes beyond the uterus. So with this data, we did some optimization to keep the 7 gray isodose line within the uterus and the best effort to keep the 90 gray and the 75 gray EQD2 dose away from the bladder and rectum, respectively, while maintaining good coverage of the cervix. So this was the optimized plan, and just comparing it with the initial plan. So with this optimized plan, as you can see, the point A dose significantly decreased because of the optimization, and it's only now about 4 gray. So with these simulations, we have encountered several challenges. So first is the difficulty of using the radiograph with ultrasound images in the TPS. Different centers here have different TPS depending on the supplier, and there were also different policies on data transfer in each center, some of which don't allow USBs due to the risk of introducing computer virus. To address this, we have currently resorted to doing manual measurements with a tandem as a reference point and optimizing the isodoses based on these numbers. Next is the staff. We need a trained staff who can get the ultrasound images that we need, which will require experience and training in the use of ultrasound. So currently in our center, I'm the only one who can get the required images. So we're starting to train staff to gain the experience in getting the ultrasound. Finally, if we are delivering the optimized plan in an actual setting, then how are we supposed to communicate our prescription in a way that will avoid confusion? So here we are all used to looking at the 0.8 dose and reporting the 0.8 dose of the optimized plan might give the wrong impression to other additional oncologists who are going to see the report and they may have this misinterpretation that the plan was underdosed. So for our future plan, we are looking into the addition of a single CT scan during the first fraction to be able to report the dose to HRCTV and implement the same plan by replicating the position of the tandem ovoids in the subsequent fractions. So for that, we have to establish workflows and create worksheets and finally need to be able to find a workaround for that added cost of that CT scan. So that's the end of my presentation. Thank you very much for listening. Thank you. Apology. Thank you so much for that, Kelvin. My apologies to everyone online, but we are running a little overtime and for that reason and because it is a ridiculous hour in the morning for Vancouver, Ryan had recorded his presentation and rather than play it now, we are going to post it on the Education360 portal for you to view and I would strongly recommend that you go across there and have a look at Ryan's fantastic presentation of how he started to use some of these principles back home in Vancouver. I'm now going to move quickly on to the Q&A panel before we wrap up this webinar. I quickly want to thank both Sylvia and Kelvin for their presentations and I understand, Kelvin, that you may have to jump off soon to get to a meeting. So thank you very much again for being here. I'd like to welcome Dr. Onyinye Balagon to the panel. Onyinye found out about this program some time ago and has been in contact with Sylvia and we had the pleasure of hosting her on a very short sabbatical not that long ago and hope to have her back again soon in the future. So I'm going to open the Q&A by asking Onyinye to just give us a bit of an insight into what actually attracted you to our program. Thank you so much for the opportunity to be a part of this. So I think the thing that attracted me the most is, you know, I perform brachytherapy and we always want to do it to the best of our abilities and looking at the Geck Estro guidelines and seeing persistently that MRI is the gold standard, I couldn't help but think about colleagues with whom I work closely in low and middle income countries and also some colleagues in the United States who do not have ready access to MRI. In fact, MRI is only available in about 30% of countries. So I was thinking a lot about the fact that we already have an ultrasound that we use to guide placement at the time of implantation. Why not also use it for planning? And so when I started to dig around and I came across your work at Peter Mac, I said, Peter Mac is the best of the best. If ultrasound is good enough for them and even not just good enough, but I have to thank you for the body of work that you've put out that shows, you know, your local control rates, that your survival rates are comparable, you know, to what you would have with, you know, the papers with Potter and using MRI regularly. So I wanted to come and see for myself how it was done. And I was so impressed because, again, you're making sure that you, one, keep the patient safe. And when I talk about safety, I'm talking about perforation. You're decreasing the risk of perforation. You're making sure that I think about safety in terms of pain. You referred to this, Sylvia. Some of the research that I have done of late with one of my partners, we were trying to also construct a new brachytherapy device. And my eyes were opened to the fact that 40% of patients have PTSD because of their experience with brachytherapy. And part of it is the pain of the procedure. And we know that pain regimens just vary widely in all these different settings. Even in the United States, people might be, some people are using general anesthesia. Others are just giving an Ativan. So being able to use ultrasound that's right there, you expedite the process. And so for all those reasons, I was really impressed with your operation at Peter Mac. And I hope that we can move towards implementing it, especially in low middle income and rural settings. Thank you for that, Onunye. Sylvia, do you have anything to add to that? No, it was a great summary. Thanks, Onunye. Yeah, we would hope that this could help people. Like Kelvin was a fantastic example. The majority of patients, x-ray based plant point A, and he can see just using a little bit of his handheld ultrasound unit that he bought while he was here in Australia, that, you know, just that helps him conform. So reduce toxicity, increase accuracy, reduce toxicity. And I think, you know, it's a simple thing to roll out. And when I first saw the title of this talk, what's old is new again, I thought, what are you talking about? We're brand new, but we're not. Ultrasound was used in the 70s, and it's probably a little bit more in the endometrial space for intracapillary endometrial space. They did take measurements, and that's what we built on as well. So, yes, it is old is new again, but much better than it used to be. So I think it is the answer, but like at the end there, we do need help from industry. So that Kelvin's struggling with a whole lot of technical roadblocks, like we are with 3D ultrasound. And that should, we should be able to overcome that very quickly and very easily. I want to echo that. Oh, no, I wanted to echo that because I was excited to try and start using the technique immediately. And Oncentra, you know, has that ability, but, you know, not all other manufacturers do. And I think it speaks to a point of equity. We talk a lot about the, you know, prostate breaking. They've optimized the systems, right, for prostate breaking. Men are put under, you get everything done, you plan right there. We need that also for women. We know that cervical cancer survival, at least in the U.S. for sure, survival has gotten worse. Between 1970s to now, survival has gotten worse. So we need to see all the ways that we can improve the treatments that we offer to women. I see it as a point of health equity that they have to just make these systems available. I think that brings us to a very interesting question that's been posed as well. Sylvia, you might be able to help answer this. It's about bladder filling. And it covers a bit of what both of you have been saying. And the second part of this question is if we do it without anesthesia, what do you recommend the bladder filling to be balancing great view versus comfort? And I guess my first thought there is please don't do it without anesthesia unless you absolutely have to. But what do you think with regard to bladder filling? I mean, I know we don't have an absolute number that we fill the bladder to, but what would you recommend would be a minimum volume that you need to fill the bladder to, Sylvia? There is no answer to that, Pearlie. You've got to be able to see the uterus. So you fill the bladder until you can see the uterus. On a small uterus, that may be 250 mils. But we routinely put three, 350 in. And sometimes we need a little bit more. Now, sometimes we put a bit too much in. And if you had a conscious patient, of course, you'd be much more cognizant of that. But you can't compromise on the view. Why use ultrasound if you're not going to see properly? Because all that people will say is ultrasound doesn't work. Can't see. It's like a snowstorm. Well, that's because you don't have that acoustic window into the pelvis. So to optimize the use of it, anesthesia would be better. And like Onyunye says, gold standard prostate treatment is asleep for the whole time while we do all sorts of things via the rectum and the perineum. We're doing that to women, but they're awake. And if I may add, I think, you know, it sounds like the person is in a setting that doesn't have necessarily access to anesthesiologists who can come for general anesthesia. We have to broaden our scope and training when it comes to managing pain. For instance, they don't have to have general anesthesia. Maybe you can do a local anesthesia. Maybe you can do a local block, a cervical block, you know. But like Pearlie said, something. So it doesn't have to be general. Ideally, it would be general or something to put them under so they're not really aware. But think about what else can you do? Can you give them something oral, right? And then also do a local block. But yeah, those are some of my suggestions. And like Sylvia said, we have to see the uterine fundus. Even when I'm just trying to make sure I'm properly placing the tandem, we have to fill until I see the uterine fundus. Otherwise, you're not going to get a proper placement. Yeah. So I think that's answered much of the questions that came through on the Q and A. And I'd like to thank everyone for staying with us because I know we've run well over time. Thank you everyone again for being part of this presentation. And please do go across to the Education360 portal. Please do take the time to hear Ryan. He has a wonderful presentation. And just as a quick promo for Ryan, like myself, Ryan and I both started life as radiation therapists. So a lot of what Sylvia has said today resonates with us because we've been there too. And that's possibly why a lot of this makes sense. We thank Sylvia for pioneering this program at Peter Mac. And we hope that we've given you some insight into how you could use it at your centre. Please do reach out to us if you'd like to learn more or even for just a little bit of advice. We're very happy to help. And thank you again to everyone and we'll leave it there. So I just want to thank you for the opportunity of me being able to present my experience, Lessons in Ultrasound Guidance at Peter MacCallum Cancer Centre. My name is Ryan Urban. I'm one of the radiation oncologists at BC Cancer here in Vancouver, Canada. And unfortunately, I couldn't join the live webinar due to the time zone differences. But hopefully this recording will add to the conversation today. So just an overview of my time, fellowship experience at Peter MacCallum Cancer Centre. I was there in 2022 and mainly focused on gynae and GU brachytherapy. Nothing but great things to say about Peter MacCallum, the entire team there and the learning experience that they provide and the care that they provide to their patients. These are a few of the snapshots. I was able to participate in a few demos with phantoms. This is an HDR prostate type of example, but we did some demos with gynecological brachytherapy. And it's really just a beautiful building and such a cutting-edge centre in the world and a real privilege to be able to gain some experience there. Most of my time in gynae brachy involved using the Electa Geneva applicator depicted here. And this is a combined intracavitary interstitial applicator. You can see two ovoids and a tandem. And then these ovoids have these small channels, which allows you to use the interstitial capability if you choose to use or if you need to do that for your particular patient. And then here's the rectal paddle behind it. So Peter MacCallum is a high volume centre. And we did a variety of cases during my time there, both just standard intracavitary where there's no needles required. And here's the applicator all set up within the operating room. And then also for more complicated tumours, either because of the size or the asymmetry of it, using more interstitial capability to better cover the tumour and improve your dosimetry. And which I'm sure you'll learn a lot more about during this webinar is the way ultrasound is used for the brachytherapy practice at Peter MacCallum. So they use a variety of trans-abdominal, trans-rectal, trans-vaginal ultrasounds to not only plan for the brachytherapy, but then also facilitate the brachytherapy during the procedure, verify the positioning, which just gives you so much more confidence during the procedure. It's much safer and allows you to have more effective brachytherapy implants. This is a particular example of a trans-abdominal axial view of a patient with a cervical tumour. And we're using interstitial capabilities on her right to deposit these needles. You can see the ureter with a stent here just shows you how crisp the images can be. If your ultrasound program is set up, it just, again, gives you so much more confidence while you're in there. You're doing the right thing. You know where these needles are going. So when I came back to BC Cancer after my time at Peter MacCallum, we previously had used a variant system, which included mostly a tandem and ring. And we completely converted over to Electa in the winter of 2023. And so we've been using it for roughly a year and a half now, the Electa-based system. Mostly we've used the Geneva and multi-channel cylinder. We did purchase the Venetia and we're commissioning that. We haven't had an opportunity to use that. I know when I was in Australia at Peter Mac, they also had the Venetia, but I don't believe it was commissioned yet. I'm curious if that has been done since I've left. But essentially this one has these semi-lunar rings, sort of like a semi-lunar ring ovoid with the interstitial capability that are not only parallel to the tandem, but there are some oblique channels. And then there's this perineal template, which allows you to do some more perineal interstitial needles if needed. So one of the things that we've adopted based on the experience at Peter Mac is using more ultrasound modalities and different ways of using the ultrasound. One of the ones is the transrectal ultrasound approach. And this is helpful for me. I do a lot of prostate brachytherapy as well. So I'm used to doing transrectal ultrasound in patients with prostate cancer. And we're trying to adopt that into the gynecological world as well. This is just an example of what that could look like. This is an example of a 72-year-old female with a previous history of a hysterectomy in 2012 for an early stage endometrial cancer. And then unfortunately had a right supravaginal recurrence as depicted on this MRI. And she was planned for radiation with brachytherapy. And this is her brachytherapy implant. We use some interstitial needles to cage the tumor, as you can see on the axial views, these interstitial needles. And we use that transrectal ultrasound, and it was quite helpful. So that's a skill that our team is continuously trying to build with the experience from Peter Mac and how they've used it routinely. Some of the challenges that we've had here. So at Peter Mac, we did a lot more complicated perineal templates. And a lot of the cases that required that from surrounding hospitals in the area around Peter Mac, they would get referred to Peter Mac for some of these implants. So this is a particular example of a patient with a SIAD template, a variety of interstitial needles, and actually some freehand needles through the vulva. And not infrequently for some of these implants, we would actually have the assistance from gynecology of doing a laparoscopy to see where some of these needles are going in to make sure we're not perforating bowel or adjacent structures, or even sometimes putting a layer of omentum in this area to just give us a little bit more room for the dosimetry in some of these cases. Unfortunately, in BC Cancer, we don't have the inpatient resources right now to effectively support these complicated implants over several days. And we don't unfortunately have the gynecology support to do some of these laparoscopic assisted brachytherapy procedures. One of our provincial institutions has a particular interest in the perineal templates, and it is an option. However, it's about a four or five hour drive away, and patients for a variety of reasons, family reasons, or just being close to their loved ones, sometimes don't really want to travel. And therefore, we have to come up with some new approaches. And so what are the things that we have done to kind of mitigate some of those things? And some of these cases that I'll present will kind of highlight that. So the first case is a 52-year-old female. She had a subtotal hysterectomy in 2007 for fibroids at the time of a C-section. She then presented with some post-coital bleeding and was ultimately diagnosed with an invasive adenocarcinoma of her cervical stump. An MRI in PET showed a relatively small primary, about two centimeters, with some possible perimetral invasion. And her PET unfortunately showed some retroperitoneal lymphopathy. And she was planned for chemo radiation with a brachytherapy boost. So this is her MRI sagittal at time of diagnosis. You could see the cervical stump. There's no more uterus here. She has a small primary. But because she had a cervical stump and some lymph nodes, she was planned for chemo radiation with brachytherapy. Now, here we give five weeks of radiation with the chemotherapy. And we often start brachytherapy depending on how many patients are currently getting scheduled for brachytherapy, but often during sometimes week fives or sometimes just shortly after finishing external beam as the tumor shrinks. And to prepare for that, we were anticipating this might be a little bit more challenging than a standard cervix brachytherapy implant. We obtained a pre-brachytherapy MRI, which is something that Peter Mac does not infrequently as well, just to give us some more confidence and plan for what we're going to do in the OR at the time of her first brachytherapy fraction. So this is a fraction of 20 to 25, so roughly four weeks done of radiation. She had a good response. So her cervical lesion is now only measuring about a centimeter in size. And what I did here was actually in the vault room where we do her adjuvant vaginal vault brachytherapy, so just a shielded room with no anesthesia, I inserted, did a pelvic exam, inserted the electro-ovoids based on her anatomy, and actually just put a blunt tandem in to see, and then obtained an MRI to see exactly where that Electa Geneva haplocator is sitting, and then give me an idea of whether I could put some needles in and how deep I could put them in. So what I learned from this is you can see a nice cervical canal here, which unfortunately we don't have a tandem that's that small, but I had a blunt tandem in. I could possibly feed a blunt needle through the end of the blunt tandem and use that as a sound. And then I could measure how deep from one of the needle channels could I go with an interstitial needle to be safe and to avoid going in this region where there could be bowel that I don't want to perforate. So that was the plan. After reviewing this, I saw this small channel. I said, okay, maybe let's try a 1.5 centimeter blunt end needle from the blunt tandem and use that as a sound to sound this cervical stump. And then I could possibly put two needles in to roughly about 1.5 centimeters safely. So at the time of her first brachytherapy fraction, that's what we did. This sort of diagram depicts that. So we use the 25 millimeter ovoids in this case, the blunt tandem. Within that blunt tandem, I put the 15 millimeter blunt needle in, use that to sound, and you could see the transabdominal here, the bladder, Foley catheter, and then the remnant cervix. And right in the middle, you can see the blunt needle going in right in the center. And that actually went in quite easily under anesthesia. And then I used these two anterior medial needle channels to put those needles in about 15 millimeters as well. And this is the transabdominal sagittal of me putting in the needles. Now in our post procedure MRI, so we get both an MRI for at least one or two fractions of the brachytherapy, and we also get a CT scan to help plan. This is her fraction one brachytherapy MRI. You could see the ovoids in, the rectal paddle in, packing, and then the blunt needle is sort of a little bit under some tension here, but within that cervical canal of the remnant cervix. The needles are a little bit more difficult to see on this sequence. So on the coronal of the CT, you can see these interstitial needles. The one on her right didn't go as deep as I had hoped, but you can see depicted on here. Once we've contoured the high-risk CTV on the MRI, we convert that to our CT, and that's depicted here in this blue. So that's our target. And then the red is our 100% isodose. And you can see that's covering the target well, and just avoiding the draping sigmoid that's just above the cervical remnant. Then we continued with that for her three fractions, and we actually didn't need one of the needles for her remaining two fractions, because we just didn't end up using it significantly during the first fraction. And this is our dosimetry sheet, which we track every patient's external beam and brachytherapy doses. And you can see her D90 that we achieved was quite high, 94.1. And I know my Australian colleagues probably think that's probably unnecessarily high, but nevertheless, her OAR doses, so both the bladder, rectum, sigmoid, bowel, all well below our hard constraints. Like ideally, we'd get less than these, but all much below. And she tolerated this quite well and has had a great clinical response. The second case is somewhat similar. This particular patient was a 77-year-old female, so in her late 70s. She had a prior hysterectomy and vaginal excision in 2017 for H-cell. At the time, there was concern of invasive disease, but actually on pathology, just H-cell was found. And then a few years later, she had acute cholecystitis, and at the time of imaging for that, had this incidental finding of this left supravaginal mass, which was worked up with MRI and PET, showing this mass and also a pelvic lymph node. And on exam, her vaginal mucosa on that particular side appeared normal. You could only really feel this mass on pelvic rectal. And a biopsy through the vagina did confirm an HPV-associated squamous cell carcinoma. So because she was node positive, again, planned for chemo radiation with Brachy boost. Now, this is a particular patient that probably would have gotten a perineal implant to adequately implant this, but she was in her late 70s, going through a perineal implant, and especially here, traveling to go do that can be quite difficult. She elected to have treatment with us, so we had to improvise, okay, how are we going to effectively implant this? So this is her time of Brachytherapy, and it's a bit interesting, you can see from this actual MRI, this is one of the ovoids from the Geneva, and the other side it's absent. So what we did, we actually put a blunt tandem, there's nothing to sound. And then one of the ovoids on the left side where the tumor was, and then on the other side just packed. So everything was held into place. And then within this lateral middle channel, a little bit more difficult to see, but on this sagittal MRI, we fed a needle right into, an interstitial needle right into the tumor. And this is the trans-abdominal sagittal view, showing this needle going nicely into the tumor. And then on our post-treatment, or post-implant CT, you could see the needle into the mass, again the blue depicting our target, our HRC-TV, and then the red being our 100% isodose, nicely covering this, and avoiding the adjacent OARs. And on her final dosimetry, you know, her D90 that we achieved was, you know, in the high 80s. And again, OAR constraints, you know, below our hard cutoffs. So it just shows you that sometimes you can achieve good brachytherapy without a huge invasive implant, especially for patients, you know, in their late 70s where that would be quite difficult to tolerate. And in our resource limited settings, sometimes this is the alternative that we have to go with. So just some conclusions and some tips. And, you know, what I've learned at Peter Mac is the pre-brachytherapy MRI is very helpful. They would do that not infrequently, especially for these complicated implants. And it just gives you another bit of information of how to plan what you're going to do during that fraction one. And, you know, you can do a lot of measurements on there of, you know, how deep you think you can go. And you can use that with your clinical exam, your ultrasound and time of fraction one, and everything should be concordant. I hope you learned that ultrasound guidance is key. The ultrasound program at Peter Mac with Sylvia Van Dyck and the entire team is second to none. They are really experts at all the different modalities, whether it be transabdominal, transrectal, transvaginal, and like learning from that team has been excellent. And I hope what I really like about brachytherapy is, and I hope that I've depicted here is really it's continuous learning, imagination and creativity, sometimes trying new things, seeing how they work is how we adapt to challenges. And you really need to surround yourself with a team that's motivated to do that, to improve care to patients. And Peter Mac is the epitome of that team. So thank you very much. Say hi to all my Australian colleagues and thanks for allowing me to present today.

radiation oncology

webinar

ultrasound

image-guided brachytherapy

Peter MacCallum Cancer Centre

cervical cancer

applicator placement

transabdominal ultrasound

transvaginal ultrasound

3D ultrasound

resource-limited settings

brachytherapy protocols

patient cases

treatment precision