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Melanie Cole (Host):  For some patients, kidney cancer can be effectively treated without surgery. According to the Society of Interventional Radiology’s first ever position statement on the role of percutaneous ablation in the treatment of renal cell carcinoma. Welcome to UAB Med Cast. I’m Melanie Cole and today, we have Dr. Andrew Gunn. He’s an Interventional Radiologist at UAB Medicine. Dr. Gunn, welcome to the show. So, before we get into the percutaneous ablation, for renal cell carcinoma, tell us about the prevalence of kidney cancer. What are you seeing in the trends?

Andrew Gunn, MD (Guest):  Well kidney cancer affects about 60 or 70,000 individuals every year. It results in anywhere between 15 and 20,000 deaths a year. We’re actually seeing an increase in the incidence of kidney cancer and that’s because we’re using more imaging like ultrasound, CT and MRI looking at other indications and so we’re actually finding more of these kidney cancers, almost by accident and what I mean by that is kidney cancers that are not symptomatic. Patients aren’t having pain, or they are not having blood in their urine yet we find these kidney cancers because they’re being imaged for some other reason and so because of that, we’re seeing an increase in the incidence of kidney cancers.

Host:  That’s interesting that you’re finding them incidentally and that you’ve got this imaging that’s augmenting your ability to diagnose these. So, what has been the thought on treatment as far as surgery in the past? What’s different now that you are doing?

Dr. Gunn:  So, primarily, the gold standard for treatment for kidney cancer would be surgery. And that involves - traditionally has involved what’s called a nephrectomy where they go in and they take out the whole kidney. In the past several years, there has been a movement towards what’s called nephron sparing surgery. Or surgeries or interventions that actually spare most of the kidney because we want to preserve as much kidney function as possible. And so even in the urology literature, there has been a movement towards what’s called partial nephrectomy where they only remove a part of the kidney and try to leave as much of the kidney there as possible. And so that’s where we come in in interventional radiology what we do is we use imaging guidance either with CT or with ultrasound and we place needles through the skin and with those needles we can either burn or we can freeze that kidney cancer to death without removing the entire kidney. And what we’ve been able to know over the years is that the imaged guided ablation of kidney cancer has less complications, it preserves the renal functions to a greater degree compared to surgery and patients stay in the hospital for less period of time compared to traditional surgery. So, there’s been more of a movement towards these minimally invasive approaches to kidney cancer compared to years past.

Host:  It’s fascinating. So, tell us about the position statement that you were one of the authors of that was published and how it establishes performance thresholds for patient safety. Tell us a little bit about that.

Dr. Gunn:  Yeah, so there’s a couple exciting and new things about it compared to where we have been in the past. First, it’s always been difficult to perform a randomized controlled trial comparing partial nephrectomy or radical nephrectomy the surgical approaches to percutaneous ablation and that’s because both treatment strategies work really, really well. And so in order to do a large trial, we’d have to have a high, high number of patients in order to accomplish that and so, what’s good about this position statement and these quality improvement guidelines is it actually includes data from what are called metanalyses and population based studies where researchers have looked at national cancer databases to be able to compare outcomes for image guided ablation versus partial nephrectomy and like I mentioned earlier, this position statement includes some of this most recent work looking at these population based studies in which we’ve been able to show that our clinical and our technical outcomes for percutaneous ablation or image guided ablation are very – or nearly equal to partial nephrectomy especially for tumors that are less than four centimeters in size. And so including that information is one thing that is new and exciting about this position statement.

The second thing is that the society has been able to take a position on larger tumors. So, tumors that are greater than four centimeters in size. And so, previously, these were basically left to surgery and said image guided ablation is not a great option for that because recurrence rates could be a little bit higher, complications can be a little bit higher but in the last several years, including here at UAB, many series have been published showing that percutaneous ablation even for tumors larger than four centimeters can be accomplished both safely with high rates of technical success and good oncologic outcomes. And so this position paper is really the first one from our society to lay out that data for people to look at and be able to use for payers and be able to talk at tumor boards to their referring physicians.

And so, the third thing about it is how we set those thresholds. What we do is we take a look at all the numbers that are reported our in the literature and we take those numbers and we take the average of those numbers and we look at the range of those numbers and then we look at the deviation, what’s called the standard deviation. We take two standard deviations above and below what’s reported – the reported average that’s out in the literature and we use those to set thresholds. So, for example, we want to say for technical success and give the threshold which should really be 90+ or 95%+ technical success for image guided ablation and your complications should be less than 6% overall.

And so, we use those for people to be able to do quality improvement of their own practices and say if I’m having more complications than this, then we probably need to take a look and see how we’re doing the procedure or if our technical success isn’t as high as what’s reported out there, what’s the threshold that I need to go back and start to look at how I’m performing those cases to be able to make sure I’m doing the right thing for my patient. So, those are really the three big areas that I would say is different than what we’ve done in the past through the society.

Host:  Well you got to my next question on accompanying quality improvement document and what that entailed so thank you for that. Now define for us the patient population. Who might benefit from this procedure? Tell us a little bit about patient selection and has that changed?

Dr. Gunn:  You know – so first of all, patient selection has traditionally been patients who for some reason or the other can’t undergo partial nephrectomy or radical nephrectomy. So, a lot of times, in the interventional radiology literature, we’re looking at patients who might be a little bit older, patients who might have more medical comorbidities than the average patient, patients who have multiple renal cell carcinomas, patients who might have reduced kidney function at baseline. Those are traditionally the patients that we’ve been seeing in interventional radiology. And I would say how has patient selection changed? I would say it’s changed more in the sense that more patients I think are opting to go to image guided ablation compared to partial nephrectomy and so there’s – I am seeing personally, at least, a higher number of patients who are hearing both options and are choosing to go to the image guided or the needle based treatment as compared to traditional surgery just because the recovery time is quicker, it’s less morbid, there are fewer complications and so, I feel like our patient population is trending just ever so slightly a little bit younger than what has been in the past. But typically, I would say the traditional patient that we see in interventional radiology for this procedure is someone who either can’t or doesn’t want to undergo traditional surgery for their kidney cancer.

Host:  What have your outcomes looked like Dr. Gunn?

Dr. Gunn:  So, I mean our outcomes have been good here at UAB. When you look at nationally our technical success rates for tumors that are less than four centimeters in size are very close to 98 or 99%. Which basically means can we treat the tumor and on our first follow up imaging, do we see any tumor left? So, in that sense, the technical outcomes are really good. Major complications have been reported in anywhere between three and five percent of patients. We’re certainly at that threshold or below here at UAB. And I would say our oncologic outcomes which what I mean by that is recurrence rates, when the cancer – the timing of the cancer coming back if at all, survival rates both cancer specific survival and overall survival. When you look at that for tumors that are less than four centimeters in size, we see that percutaneous ablation is very similar within one or two percentage points of partial nephrectomy and all of those outcomes. With the advantages we talked about of having less complications, and a shorter hospital stay. So, the outcomes in that sense are really good.

The other thing that we are seeing more is these larger tumors, especially as the population gets older and has more medical comorbidities; we’re definitely seeing larger tumors in our practice and that has been good to look at the national literature and see that our technical success rates are 90+%. They are in the ball park. And when you consider repeat ablations, people that have to come back and clean up a small little area that might have gotten left behind or didn’t get adequately treated in the first one, the technical success gets into the 95% range. Even for those larger tumors.

Now of course, when we’re looking at those larger tumors, the complication rates tick up by a few percentage points and the time to recurrence or time that tumors might come back is a little bit shorter compared to the smaller tumors but regardless, I still think that for patients who are appropriately selected patients, percutaneous ablation can be a good treatment option for even those larger tumors.

Host:  So, as you tell us some technical considerations, that you might like to share with other providers, tell us about the anatomic and physiologic considerations unique to the kidney that have to be kept in mind. This is for other providers for effective and safe percutaneous ablation.

Dr. Gunn:  Well the first thing that I would say is that the vast majority of patients can be successfully treated with percutaneous ablation. If you think that it’s an option. What I would say if you’re listening to the podcast is that if you have a question about whether or not your patient is a candidate for percutaneous ablation, the answer is probably yes. And that we would be happy to see them in clinic. The technical considerations are always that tumors that are smaller, any tumor that is smaller, any tumor that is more on the outside of the kidney compared to being more centrally located within the kidney and tumors that are on the backside of the kidney, posterior located versus anterior located. So, those are always the easier more technically straightforward cases. So, if they are smaller, they are more on the outside of the kidney and they are more on the back of the kidney. So, that’s one thing we’re always looking at inside of our clinic is to see those critical questions about the location of the tumor.

That being said, even tumors that are larger, tumors that are more centrally located, tumors that are more on the anterior side of the kidney; we have several techniques whether it’s placing fluid in between the kidney and the colon or placing stents in the ureter to protect the renal collecting system. We have several of these adjunctive maneuvers that we can perform so that we can perform this procedure safely for the vast majority of patients. As far as risk factors go, bleeding is by far an away the number one complication from this procedure. So, it’s always something that we’re very cognizant about and that we’re very – watch patients after the procedure to make sure that we don’t have any evidence of bleeding. Other complications such as damaging some sort of adjacent structure like the bowel or the ureter or a nerve are very low, well less than one percent of all cases.

And so, those are really the big considerations that we’re looking at when we are evaluating patients for this procedure.

Host:  And Dr. Gunn, the statement used a multidisciplinary group of experts including interventional radiologists such as yourself, and urologists. Why is it so important to consult that multidisciplinary group for this procedure?

Dr. Gunn:  Really, I would say that a multidisciplinary approach for all patients with cancer is a good approach. And it’s not just kidney cancer. It’s all sorts of cancer and I think that that’s one thing about being at a large cancer center like UAB that is quite beneficial is the fact that you’ll get a consultation with a medical oncologist, and with a radiation oncologist, or with surgery or with interventional radiology and I think the important thing is that the patient is presented with all of their options and I think that the patient has to also apply their own beliefs and values and priorities to those treatment decisions as well. So, it’s never really a one size fits all approach for any one patient. And so when a patient comes in, especially when it comes to kidney cancer, some patients might prefer to have surgery and that’s fine and some patients might prefer to have the more needle based approach that we offer in interventional radiology which is also fine. But what we have to do as physicians is provide them with all of their options and so to be able to be at a place where all of those options are and have that multidisciplinary approach where the patient can be presented with all of their different options and with our recommendations, I think is a real advantage.

Host:  Well it certainly is. What a fascinating topic. Dr. Gunn, wrap it up for us. What would you like other providers to know about percutaneous ablation in the treatment of renal cell carcinoma and what you’re doing at UAB? What would you like to share? Wrap it up for us.

Dr. Gunn:  Yeah, I would say percutaneous ablation especially for those smaller tumors is safe, it’s effective and its outcomes are nearly equivalent to partial nephrectomy. And it would be with the caveats that we have. Quicker recovery times, we keep people out of the hospital, and we have a less detriment to patients’ renal function. So, if it’s something that you are at all considering for your patient, please send them over to have a consultation with us. The other thing that I would say to wrap it up is even with these larger tumors, for the appropriately selected patients, percutaneous ablation is not contraindicated. We can still do it. It just may require some more technical considerations, but I would never consider it contraindicated in those larger tumors. And so, I think that’s something important for other referring providers to hear.

Host:  Well it certainly is and thank you Dr. Gunn for joining us today and sharing your incredible expertise in this fascinating topic. A community physician can refer a patient to UAB Medicine by calling the MIST line at 1-800-UAB-MIST. That concludes this episode of UAB Med Cast. For more information on resources available at UAB Medicine, please visit our website at www.uabmedicine.org/physician. Please also remember to subscribe, rate and review this podcast and all the other UAB podcasts. I’m Melanie Cole.