So, this is the overview of this presentation. In the past, we used 2D radiotherapy, and now we have 3D brachytherapy. And I will reveal the experience of image-guided adaptive brachytherapy on survival cancer in Queen Mary Hospital, and talk about our local data, and have two cases for presentation. So why we changed from 2D to 3D? In the past, we used a rotoderm system. We put in the ovoids and the tubes, and then we used a POND-A and POND-B. So, for the ovaries, we just use a POND dose for the rectum, which is around 0.5 cm posterior to the wall of the ovoid, and use the bladder wall, that is the foley, to account for the bladder dose. With 2D technique, we use x-ray, and then we count the dose. However, there's some problem with 2D technique. With 2D technique, the anatomy actually overlaps, and the cargots and the organs actually cannot be seen on the x-ray. Those prescriptions often are assumed to be in standard geometry, but actually, in the real-world setting, the tumor may extension maybe to one side, to the left or to the right, or more anterior and posteriorly. So, the isodose distribution cannot be seen clearly, and no dose-volume information can be given. Nowadays, we use a 3D image-guided radiotherapy. We put in the tubes and the rein or ovoid, and then we will do MRI or CT. In that case, we can have a cross-sectional imaging of each cut of the applicators put in, and then we know the tumor volume, and we know the target that we would like to have a radiation in high dose. With the image-guided break-in therapy, we can verify the applicator positions, especially we can know whether the applicator is within the uterine canal and there's no false track, to give accurate definition of the normal tissue dosimetry. For example, the bladder, the rectum, and the sigmoid and small bowels, and then we know the dose to each part of this organ at risk. We can provide a conformal dose distribution to the tumor volume and the organ at risk, and especially if the tumors are not symmetrical, and then we can have a dose modification. As well, we can have dose escalation. For example, some areas are more at risk, and then we can give a higher dose. The GEC Astro working group also published several recommendations in the past, recommending the dose and the concept of a 3D image-guided break-in therapy, how we calculate the dose, how we do the dosimetry for the physicists. So how we do the image-guided break-in therapy in Cranberry Hospital? Usually we have the external beam radiotherapy, around fourth grade in transfection, 3D technique, and then we have the break-in therapy for four sections. We will give a 6.5 grade in 4-faction usually on Monday and Thursday, under general anesthesia. There are many things to prepare before the break-in therapy. First the patient needs to have the MRI, pelvis, and the CT abdomen and pelvis before the external beam radiotherapy. And then we'll have our analyst to assess the patient, whether the patient is a bit more general anesthesia or spinal anesthesia. And then after the external beam radiotherapy, we'll schedule the patient for a pre-break-in MRI. Usually the MRI will be done in the final two to three factions of the radiotherapy, so that we can know whether the tumor is straight well or not. And then using the pre-break-in planning MRI, we'll review the MRI and we'll have physical examination to check the latest size of the tumor, whether there's easy bleeding, any vaginal involvement. And then we will decide on whether we need any needles and the size of the applicators. This is what we often do, we'll correlate. This is what I drew for the patients. After the MRI, I will review the tumor size from the cervix, neck, and then up to the uterus. And then here is a tumor, and then we will measure from the ulcer and then to the edge of the tumor, anteriorly, posteriorly, and also left and right. And then how much away from the bladder and rectum, and then calculate whether we need to have any needles. For example, here in this case, this is a cervical tumor and this is the bladder and rectum. And then I will calculate which site may be far away from the tubes and may need a higher dose and may need needles. And this is the range that we'll put in, which position and how long I should insert the needles. So for the break-in therapy, we often involve our clinical oncologists, physicists, radiation therapists, our audiologists, anesthesiologists, and also sometimes our gynecologists who always help us to get a biopsy or if there's any massive bleeding and they will come in and help us and save us and save the patient as well. This is the old system using an ovoid and tubes, the rotoderm system. Now we have this system with a uterine tube, vaginal ovoids, and range. And here you can see that from the range, we'll have the needles come out. And now we have this kind of needle that is an oblique needle, especially for those patients with a very bulky and financial involvement that we need to put in a needle on the side so that we have enough dose to the tumor. This is our OT suite, where we have the privilege to have the CT scans on the side of the operation theater. So the patient does not need to move from the OT theater to a long way to the other side of the hospital. So the patient can now move just one to two meters to this CT scans and have the CT scans immediately. And so the whole process can be done very quickly. So we put in the applicators and now we also have ultrasound to see if the applicators are put in the right positions, whether there's a false track and whether there's any perforation. Patient goes into the CT scans and after that, we will contour the tumor and calculate dose. So for the whole process, it takes around two hours. We need to prepare the patient for GA, insertion of the applicators, the CT scans and contour the targets of the wrist and checking tables for the treatment and removal of the applicators. So how's the results in Queen Mary? We have a total of 135 patients in 2014 to 2019 with median age of 56 years old. Most of the patients are squamous cell carcinoma and around 20% of the patient had adenocarcinoma. And 68% of the patients are with positive pelvic limb dose on presentation. So all patients except one had pre-brachial MRI. So the average tumor size is around 4.9 cm diagnosis. The mean volume of the HRC-TV is 41 cc. And starting from 2016, we started to use interstitial needles and we put in needles as well. And 40 patients needed interstitial needles insertions. We do not put in needles for all patients. Why? Because for those small tumors, there's no need for needles. Usually those with large tumors, we need to have the needles to have enough dose to the site or to the bulk area. So this is the dosimetry that we had in the past. In the past, with no needles, the HRC-TV doses are only around 75. But after the needles, we have a better learning curve and the dose is increased and escalated to around 88, 90 grade, which is the recommended dose from your RC-TV. And the dosimetry compared with other studies also is comparable. And how about the local control and overall survival with a median follow-up of three years with local recurrence, only 16 patients. We differentiate whether a squamous cell customer of adenocarcinoma. Adenocarcinoma obviously had a poor prognosis with a higher risk of local recurrence. For patients who cannot attain complete remissions after radiotherapy or brachytherapy, five patients had self-aged surgery. For distance recurrence, actually, we had quite good results. For distance recurrence, only 13.3%. And the three-year overall survival is around 82%. And compared with retro-embryo study, which is the largest European study, the local control is around 91%. We are close to it. And for the three-year overall survival, also, we had a comparable overall survival. And I also compared our study together with other studies. Actually, compared with PORTER, that is the retro-embrace one. This is the retro-embrace one. This is the embrace one study. And also, there are some studies from France. And here is the study from the UK. Actually, our local control and overall survival is actually quite good. The adverse effects are some... One of the highest adverse effects is usual perforations in our case. In our case, it's around 11 of our patients got a uterine perforation during the operation. However, we need to know that in the past, sometimes, even we put in the PORTER system, we didn't have the CT scan, and we don't know we perforate. Sometimes we perforate, but we don't know. However, the other thing is that for uterine perforation, if there's only a very minor one, that's the... Actually, the uterus can't heal itself, and there's no need for operations. So most of our patients even have minor perforation after antibiotics can heal rapidly and can still go on to the next fraction of brachytherapy. Some patients have GI toxicities in non-one with radiation protitis. 0.7% of patients had bladder toxicity with hematuria. One of our patients had a pelvic insufficiency fracture. So there's a case for sharing. This is a 68-year-old, Madam Wong. She was diagnosed to have endocardial surface. Face examination at that time was a 5cm tumor in the surface. The MRI showing a large cervical mass at the lower half of the uterus, pelvic needle positive. After the external beam radiotherapy, this is a pre-brachy MRI. Actually, you can see that tumor is still very big, occupying the whole surface and the lower uterus. Here, the tumor, you can see a very thick wall. This is our dosimetry. We didn't put in any needles. And if we just put in the tube and over without any loading of the side needles, we can see that the HRCT redose is only 4.5 grade. We need to aim at 6.5 grade. But here, it's very low. Because here, the tumor is over here. A large part of the tumor, that is the dotted line, we would like to have high dose. It's underdosed. We need to see the red line to cover the dotted red line. So after we load the needles, here, we can see that the dose, now the red line can cover the red dotted line here. Well covered. And here also, the tumor PVC, just a very regular P-shaped. Now, we'll put in the needles, and the dose can cover the whole tumor, the bulky area over the right side. And we can see that the HRCT, after putting in the needles, can go higher than our minimum dose of 6.5 grade. Actually, not just for large tumors. Sometimes, in some of the cases, if the tumor is very close to some open areas, we may also use needles to help. For example, like this case, this is a 65-year-old lady with squamous cell carcinoma of the cervix. A physical examination found a 3CM tumor at the cervix, extending to one-third of the vagina on presentation. After external beam radiotherapy, actually, the tumor is only some nodularity and cannot be seen clearly on the MRI. So, we put in our applicators. You can see that here, the 100% isodose, actually, beyond the tumor. Moreover, it also goes up to the bladder. There's a high dose to the bladder. And with such a high dose to the bladder, the patient may have a high risk of radiation cystitis after brachydectomy. You see that the bladder is a high dose. So, what we did is that we reduced the tube dose. Yes, we decreased the tube dose, but then we can have dose modification and reduce the dose to the bladder. So, we also had some local presentation before using 2D and 3D technique and compare the dose. For example, polydose and D90 dose. And a large tumor will usually have a lower 0.8 dose because the 0.8 is a fixed dose. So, as a large tumor, usually a 0.8 dose will be lower. And also, in the past years, we also have some bladder volume control. And we put in 15 mL water and sometimes 100 mL water in order to have a consistent bladder dosage and to have a consistent... Putting some water into the bladder can also control the dose to avoid too much fluid in the bladder and to have a static dose to the gross tumor volume. So, this is what we think as a participant's purpose before. As I've said before, previously in the first few years, the dose to HR-CGV is not so good. And now we have very good HR-CGV and we can have a very good low control. And so, always practice makes perfect. And we need to start things early and then to practice in order to make ourselves even better. So, that's all for my presentations. And I would like to thank our teammates and our gynecologists and physicists and radiation therapists. Thank you very much. Thanks, Wendy, for the excellent talk.

3D brachytherapy

cervical cancer

Queen Mary Hospital

image-guided brachytherapy

tumor visualization

radiation dose