Good morning, I'm here to deliver a talk today on radiotherapy in cervical cancer. And to ask the question, are our processes adaptable for every situation in every country around the world? Here in Melbourne, we have access to MRI, PET-CT and CT planning. We utilize volumetric contouring, deliver our external beam radiotherapy using VMAT or IMRT techniques, go on to deliver brachytherapy using image guided adaptive techniques. And whilst we have access to many of the resources available in the modern era around the world, we certainly don't have all of them. So I asked the question, what do we need? And what is actually aspirational? In Australia, a woman diagnosed with cervical cancer, it is recommended that the Cancer Australia optimal care pathway should be followed. This usually means that upon presentation to a GP and the suspicion of a cervical cancer being found, patient is usually referred on to a gynecologist who will undertake a number of simple tests and procedures to confirm that diagnosis before referring on to a gynecologist. Further investigations will then be undertaken before the patient is discussed at a gyne-oncology multidisciplinary team meeting to plan the treatment pathway. Most commonly, women with a phagostage 1B2 or greater tumour are referred on for chemo radiotherapy and brachytherapy as their definitive management for the cancer. Referral to a radiation oncology and medical oncology team usually follows. And once treatment is completed, we like to follow up and assess our success or otherwise with a PET-CT. So here we have a common case, 49-year-old woman with a phagostage 1B3 SCC of the cervix. We can see from this MRI that the tumour is well-defined in the cervix. There's no involvement of the parametria, vagina, bladder, rectum, and no anatomically unusual pelvic lymph nodes. We confirm this with a PET-CT, which shows only avidity within the cervix and certainly no distant metastatic disease. To undertake volumetric contouring, consensus guidelines were published in 2011, which have defined how we undertake this process To achieve this, we will fuse the MRI, the PET-CT with our planning CT. And our protocol here at Peter Mac is to treat using bladder full. We also want to look at what happens when the bladder is empty because the uterus can move. And for that reason, we will undertake a bladder empty scan and fuse that as well. We define the nodal volumes, the primary tumour volumes on the MRI, both planning CT scans and the PET scan, as well as outline our organs of risk. These include the bladder full, the bladder empty, the rectum, sigmoid colon, non-rectal bowel, and the femoral heads. We import all of this into our planning system and formulate a VMAT plan. The aim in this case is to deliver 44 gray in 22 fractions to the tumour. We use this as our COVID protocol. Normally we would not use, normally we would use 45 gray in 25 fractions with weekly cisplatin. We set a number of plan objectives to ensure we minimise the dose to our organs at risk and check this using our dose volume histograms. We then go on to deliver the adaptive brachytherapy and the estro guidelines are now our gold standard published back initially in 2005. We're all aware that this treatment should be delivered based on a planning MRI. And you can see with the same patient here that the MRI done at time of brachytherapy shows that the tumour has already started to respond to the initial external beam radiotherapy, which is why adaptive brachytherapy is so important. But do you need an MRI with every treatment? We have the privilege of an exceptional brachytherapist, Dr. Sylvia Van Dyck, who has been instrumental in developing what we call the Melbourne Protocol, which is an ultrasound strategy for the delivery of adaptive brachytherapy. And in this particular paper, she asked the question, why has ultrasound been so slow to be utilised in cervical cancer when it is state-of-the-art in prostate cancer because it so clearly outlines soft tissue? And we can see from these images, we know that the uterine tandem is well placed within the uterine canal. We know we can centre it. We are able to see where our ovoids are placed and ensure that they've not accidentally crossed over. We can also clearly see the outlines of the uterus, the cervix, the bladder, the rectum, and even sigmoid colon on the ultrasound. Critical to delivery of radiotherapy, particularly in external beam radiotherapy, is measurement. Tolerances are set with a maximum of usually five millimetres but more commonly, two to three millimetres. But we don't necessarily utilise this when we do brachytherapy because we're so reliant on having an MRI with every treatment. However, if we ask the question, why can't we use the ultrasound to determine if we can accurately replicate the MR plan? And you can see from this particular image that by taking measurements along the course of the uterine tandem of the uterus and comparing them with what we see at time of the MR plan brachytherapy, we can replicate this with every brachytherapy fraction. We've published this information widely and our data has actually shown that our local control rates, our survival rates, patterns of failure and complication rates are readily comparable with those achieved by the GEC-ESTRO consortia. We know that our local control rates at five years are 86 to 87% plus, and that we can deliver a dose to the HRC-TV of a mean 80 grey, but now trending towards the expected 84, 85 grey in most cases. So the question can be asked, where is it possible to use these sort of techniques in low and middle income countries who may not be as well resourced as we are here in the developed world? This particular paper looks at these questions and also raises the issue of ultrasound and its adaptability. The comment is made that ultrasound is useful in staging and also quotes Sylvia and her use of ultrasound in brachytherapy treatment. The American Brachytherapy Society produced some brachytherapy treatment recommendations that could be utilised in low and middle income countries. And again, quote Sylvia's technique, which would hint that using a readily available resource does mean that you can deliver this fantastic treatment even if you don't have access to an MRI at all times or even at all. So what do you really need to deliver your treatment? First and foremost, the personnel. Well-trained doctors, radiation oncologists, anesthetists, gynae oncologists. Here in Australia, we have radiation therapists who are well-trained in both delivery of radiotherapy but also planning the radiotherapy and some of whom go on and train as specific brachytherapists. But this may not always be readily available and other countries rely more heavily on their medical physicists. You may also need to utilise sonographers and radiographers to get the imaging you need. And we can never forget the importance of our nursing staff in caring for these women. The equipment, X-ray, CT, ultrasound. Is your linear accelerator able to withstand the rigours of your environment? We all know that they're fairly fragile pieces of equipment needing steady states of temperature and power which may not always be available. So perhaps the Cobalt-60 machine is more appropriate for your situation. Similarly with brachytherapy, you have to ask the question, whilst we can access an Iridium-192 source every three months, can you? And is a Cobalt-60 source more appropriate which only needs replacement every five years? What equipment do you have available? Simple tandem and ovoids or tandem and ring may be all that's required to deliver your treatment effectively. And then there's always the planning software. Everything else could be considered aspirational. So yes, you can deliver optimal radiotherapy care for these women with cervical cancer. We just need to be able to adapt. Thank you.

radiotherapy

cervical cancer

adaptability

MRI

PET-CT