Immunotherapy and Image-Guided Therapy: Are There Synergies?

RillingImmunotherapy is revolutionizing cancer care, and its success has led interventionalists to wonder how it might pair with image-guided therapy in the future. Despite some concerns in the field that immunotherapy might replace image-guided therapy, William Rilling, MD, sees an opportunity for collaboration and additional opportunities for interventional oncology to flourish. Dr. Rilling is an interventional radiologist at the Medical College of Wisconsin in Milwaukee, Wisconsin, and he is speaking about immunotherapy on Sunday, February 4th at the Symposium on Clinical Interventional Oncology (CIO).

Will immunotherapy replace image-guided therapy?

We definitely need to be knowledgeable about immunotherapy, the revolution that’s happening in that space, how patients can benefit, and how we might integrate immunotherapy with image-guided therapy. However, although some in the field have talked about how immunotherapy may replace image-guided therapy, I don’t think that scenario will happen. For many of the diseases we treat, a relatively small number of patients are actually going to benefit from immunotherapy in a significant way. In the new data on hepatocellular cancer, the patients who responded were in the 15% to 20% range. In patients who did see a benefit, there was a sustained benefit, but they still comprise a small minority of the overall patient population.. There are many patients who will still need locoregional therapy. We shouldn’t despair over the fate of our field. Rather, we should investigate synergies between immunotherapy and image-guided therapy.

What are some areas in which there might be synergies?

I think we’re just beginning to approach synergies of IO therapies and immunotherapy in a scientific manner. A number of ongoing pilot studies are studying ways that we could enhance immunotherapy with our techniques from the standpoint of cancer antigen presentation of the immune system. For example, one interesting area is how ablative therapies can help in presenting tumor antigens in a more efficient, effective way to the immune system. Both heat-based (microwave and radiofrequency) and cryoablation therapies can augment the host immune response, and there is a lot of investigation into that area.

The research is at an early stage, so we’ll know more in the next few years. I think we will be seeing significant progress though because there’s so much excitement and energy in this area right now. Once a signal is found in the pilot studies, we’ll see some larger scale phase II studies soon afterwards. I encourage everyone to closely watch the results of published studies and be aware of this fascinating and rapidly evolving field.

What do you think might lead some practitioners to believe that immunotherapy might replace the current therapies offered by interventional oncologists? 

Immunotherapy works extremely well for some of the patients with challenging diseases, such as melanoma, for which we previously had only very poor systemic therapies. In those cases, we’re seeing a complete revolution in therapy. However, in most diseases that we treat, only a small fraction of patients experience a large benefit. That small fraction is still significant, but more conventional therapy is needed for the other 80% to 90% of patients. Additionally, immunotherapies are incredibly expensive and, as a result, are not going to be used in all circumstances.

What diseases do you think will be the first ones targeted by potential trials looking at combining immunotherapy with locoregional therapy?

Hepatocellular carcinoma (HCC) is an attractive target for a number of reasons. It remains a significant problem worldwide, and its incidence is continuing to increase. Although there have been 3 new drugs recently approved for HCC, most drugs for HCC up until this point in time have had very modest, at best, efficacy and have significant toxicities

Outside of immunotherapy, are there any areas of interventional oncology that you feel aren’t getting enough attention but still have great potential?

A lot of work is being done to improve our locoregional and drug delivery platforms. Conventional chemoembolization has been around in its current form for more than 20 years, and we have multiple drug-eluting bead platforms that all have very similar basic pharmacokinetics. It is disappointing that we have not made further progress with improved efficacy and new drugs for locoregional delivery. There is very interesting work  being done, but it’s coming at a slower rate than I would have preferred. Still, the attention is there. Multiple companies are working on new platforms and better pharmacokinetics.

Do you think prostate cancer has potential to be a large part of interventional oncology going forward?

Prostate cancer does have potential to be treated with image-guided techniques. The current treatment paradigms and patient selection are challenging—it’s difficult to pick the right patients with the right amount of disease and treat it with the right amount of aggressiveness. However, I think that there are significant benefits to applying image-guided therapy to prostate cancer. The United Kingdom, for example, is ahead of us with high-intensity focused ultrasound treatment for prostate cancer. They are achieving some impressive results and are preserving sexual function and continence while maintaining excellent disease control. I think prostate cancer is a very interesting area for interventional oncology.

Where do you think the future, the promise, lies in interventional oncology?

Hopefully we will see some refinement in the delivery platforms, and I also hope that we start to look at locoregional therapy in new diseases and organ systems in which there may be some additional unmet needs. Musculoskeletal disease is a huge area of opportunity and can make a big difference to patients. We’re seeing a ton of growth in that area in our practice and other practices around the world. There’s still a lot of work ahead of us to understand which techniques will be effective in the more complicated, non-isolated blood supply of a soft tissue sarcoma, for example, but it’s exciting to start applying what we’ve learned so far in the liver, kidney, and lung and move on to problems in other organ systems.

Regarding lung metastases, I think we could make a significant impact and should probably have a bigger role than we currently do. Overall access to therapy with interventional oncology in that area is still an issue, and many patients aren’t afforded the advantages of locoregional therapy, particularly from a quality-of-life perspective.

Many of the palliative interventions that we can do to help improve quality of life are underestimated and underappreciated. As patients are living longer, they have detriments to their quality of life that we can assist in mitigating, including general pain, pain control from a bad bone metastasis, or a celiac plexus block, and management of malignant pleural effusions and malignant ascites. We can have a significant impact on patients’ lives not necessarily by prolonging their survival but by improving their quality of life.