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Ablation for Kidney & Liver Tumors

Percutaneous ablation is a minimally invasive procedure where small needles are inserted through the skin under imaging guidance. The needles are directed toward tumors, which can be in the liver, kidney, bone, or lung. Once the needles are in place, the tumors are destroyed by either heating or freezing the cancer cells.

These treatments are faster and safer than traditional surgery. For many types of cancers, our results with ablation are equivalent to traditional surgical approaches. Apart from these benefits, many of our patients can go home the same day or the next day with only a band aid. Thus, our recovery time is much faster than traditional surgical approaches.

In this segment, Dr. Andrew Gunn discusses ablation for kidney & liver tumors and when to refer to a specialist.
Ablation for Kidney & Liver Tumors
Featured Speaker:
Andrew Gunn, MD
Andrew Gunn, MD graduated magna cum laude from Brigham Young University in Provo, UT earning a BS in exercise physiology with a minor in sociology. He then returned home to South Dakota to attend medical school at the University of South Dakota. During medical school, he participated in the competitive Howard Hughes Medical Institute – National Institutes of Health Research Scholars Program and was awarded the Donald L. Alcott, M.D. Award for Clinical Promise. He graduated summa cum laude in 2009. He completed his diagnostic radiology residency at the Massachusetts General Hospital of Harvard Medical School in Boston, MA followed by a fellowship in vascular and interventional radiology at the Johns Hopkins Hospital in Baltimore, MD where he served as chief fellow.

Learn more about Andrew Gunn, MD 

Dr. Gunn has the following financial relationships with commercial interests:

Support for Travel to Meetings or Other Purposes - Merit Medical, Medtronic Inc., Cook Medical

Dr. Gunn does not intend to discuss the off-label use of a product. No other speakers, planners or content reviewers have any relevant financial relationships to disclose.

There is no commercial support for this activity.

Melanie Cole (Host): Percutaneous ablation is a minimally invasive procedure where small needles are inserted through the skin under imaging guidance. These needles are directed towards tumors which can be in the liver, kidney, bone or lung. Once the needles are in the place, the tumors are destroyed by either heating or freezing the cancer cells. There treatments can be faster and safer than traditional surgery. My guest today is Dr. Andrew Gunn. He’s an interventional radiologist at UAB Medicine. Welcome to the show. Explain a little bit about ablation therapy. It’s typically been used in many different conditions such as AFIB or varicose veins. When did this become something that can be used to treat cancer?

Dr. Andrew Gunn (Guest): Thanks for having me on the podcast. Ablation therapy, as you said, has been around for a long time. In interventional radiologist, we’ve been using percutaneous ablation for kidney tumors and liver tumors for almost 30 years at this point. We've been able to have very good results with both liver and kidney tumors and be able to treat patients in a minimally invasive manner in which they can avoid the risk associated with traditional surgery.  

Melanie: What kind of cancers can be treated with ablation therapy?

Dr. Gunn: We’re starting to find out that almost any type of cancer can be treated with ablation therapy. We have the longest history with renal tumors and with liver tumors, but we’re expanding ablative therapies into bone cancers and also into pancreatic cancers and into certain types of lung cancers as well. Even researchers actually are looking into percutaneous ablation for small breast cancers as an alternative to lumpectomies. Pretty much if there's a small tumor that we can see under imaging guidance and we can reach it with a needle, people are looking into ablating it. That being said, we have our best results and our best data with our kidney tumors and our liver tumors.

Melanie: What's the influence for clinical indications as their lesion size or comorbidities of the patient? Speak about some of these clinical indications?

Dr. Gunn: For kidney cancers, we have the best data for kidney tumors that are about three centimeters or less sized. Certainly, there are some patients – for example, patients who might not be surgical candidates because of other medical comorbidities or for patient preference that we’re certainly about to ablate large lesions than that – but for the most part, a lot of times we’re looking at these lesions that are about three centimeters in size. They often get referred to us because the patient’s either don’t want to undergo traditional surgery or because they're not good surgical candidates. In the liver, it’s the same. Our liver cancers are really managing a multidisciplinary conference, so we sit down with surgeons and medical oncologists and radiation oncologists and interventional radiology determine which tumors would be best for ablation versus intra-arterial therapy versus surgical resection. Again, even in liver tumors, we’re looking at the tumors that are about three centimeters in size, maybe up to three of those lesions in which we can do percutaneous ablation.

Melanie: Is there a need for a pre-ablation biopsy?

Dr. Gunn: That depends. For our liver cancer patients, we often don’t do a biopsy beforehand because these patients often just by imaging characteristics that’s diagnostic for liver cancer or some other type of cancer that they have, so we often don’t do a biopsy for our liver cancer patients. For our renal cancer patients, we often do a biopsy at the same time and that helps to influence the type of follow-up that they get, but usually by the time they get to us, people are pretty convinced by the imaging characteristics that they have either renal cancer or liver cancer.

Melanie: What are some current issues in procedural planning and technical considerations for radiofrequency ablation? Speak about the anatomic location of the kidney to the adrenal gland and as a consideration of all these things.

Dr. Gunn: Technically, there's still some debate about what type of ablative therapy is to be used. Certainly, as you just mentioned, radiofrequency ablation is the thing that has been around for the longest, but mostly physicians for renal tumors are moving away from radiofrequency ablation. The newer ablative technologies that are out there include microwave ablation, cryoablation – which is where you freeze the tumor – or irreversible electroporation, IRE – which destroys the tumor by destabilizing the cell. A lot of the research that’s out there is looking at different ablative technologies – which ones are better and which ones may kill the tumor better – so when you're talking about technical approaches, for us, you may want to use something like IRE if there's structures nearby that you don’t want to damage in the ablative zone like the aorta or the inferior vena cava or adjacent bowels. A lot of the times we’re using cryoablation and able to safely ablate by using things like hydro-dissection, which is where we instill fluid to protect adjacent structures from the ablative zone, or pneumo-dissection, where we put air in there to move the ablative zone away from any structures that we don’t want to damage.

When we sit down with a patient in our clinic, we go over these different kinds of issues whether or not they're safe for the percutaneous route – are we going to have to do any adjunctive measures and whether or not we think we can cover the whole lesion in one session or maybe will need to use two sessions. Those are the things technically that we’re really talking about as we consider renal tumors. For liver tumors, the biggest thing is for a lot of times, we’re using microwave ablation for these just because it’s quicker and we can get a bigger ablation zone with a single probe. Again, you want to make sure that you're not damaging any adjacent structures like the portal vein or the gallbladder or the biliary system. A lot of this for us is treatment planning where we can safely access and how much we can safely ablate without causing damage to any adjacent structures.

Melanie: What about follow-up imaging?

Dr. Gunn: It’s different for each tumor. For our renal tumors, we usually see them in about three months, and I think if you look around, institutional people and nationwide people easily use three or six months as a first follow-up after ablation for renal cell cancer. If things look good, they usually get scanned at three months and again at nine months and again at a year. If we don’t see anything at that point, we usually get yearly scans for anywhere from three to five years out. For our liver tumor patients, a lot of these patients are looking towards getting transplants for their liver, and so we follow them a little bit closer. We usually get a scan at about one month and again at three months, and if they're a transplant candidate, we usually get them about every three months, and if not, usually about every six months for the liver cancer patient.

Melanie: What does current research indicate for future developments in these types of treatments? Give us a little blueprint for future research.

Dr. Gunn: I think future research is going to focus on different ablative technologies. I think that’s one way, like we IRE versus radiofrequency ablation versus cryoablation. I think another area would be combined technologies. For example, for liver cancer patients, we can do intra-arterial therapy like chemoembolization or radioembolization and follow that up with percutaneous ablation and does that give patients better survival, longer progressive survival or time to progression? The same thing with renal cell cancer patients. We’re looking into if we do a combined trans-arterial therapy like embolization or radioembolization up front and then treat with percutaneous ablation and is that going to give us longer survivals. We don’t really know the answers to those things yet, but I definitely think those combined therapies are very interesting and exciting and things that people are going to be looking at going forward.

Melanie: In summary, tell other physicians what you'd like them to know about the ablation of kidney and liver tumors and when to refer to a specialist.

Dr. Gunn: One thing that I would like physicians to know is that we can do it. I think that there's a general lack of awareness of what interventional radiology can provide for patient care. Your patients have options, so if you see a patient and someone says their only option is surgery, you can send them over to us and maybe we can do a percutaneous ablation, have them avoid that bigger procedure and we can do something that’s more minimally invasive with a shorter recovery time, less hospital stays and may have just as good clinical results. Another thing I’d want people to understand is that we can do this and you should send them over to us to discuss this. The patients that they should be thinking about sending over to us would be patients that have lesions that are less than three centimeters in size, patients who may have multiple comorbidities where potentially they might not do well with general anesthesia or might not do well with a big surgery, and patients who just generally do not want to undergo a large surgery just because of their lifestyle. We see patients all the time that don’t want to be down for four to six weeks – they want to be down for a week – they don’t want to miss that much work, they don’t want to miss a vacation or Christmas or all these other things with their families. Those are the patients that we should be talking to because we have options for them.

Melanie: Tell us about your team. Why is UAB so great to work with?

Dr. Gunn: Our team is all board certified interventional radiologists. We’re the experts in this field and definitely in this area. Anything big and complicated comes to UAB and so we see everything. We have lots of experience in this area and also clinical trials that we’re rolling people for that might not be available at other centers. I think the fact that we treat patients with a wide variety of problems that we do so in a multidisciplinary manner with support from world class physicians from surgery, transplant, urology and gastroenterology and we collaborate so closely with them in the ability to enroll patients in clinical trials that aren’t available at other centers is a huge benefit for patients.

Melanie: Thank you so much for being with us today. A community physician can refer a patient to UAB Medicine by calling the MIST Line at 1-800-UABMIST. That’s 1-800-822-6478. You're listening to UAB Medcast. For more information on resources available at UAB Medicine, you can go to That’s This is Melanie Cole. Thanks so much for listening.