An interview with Timothy Clark, MD, Director, Interventional Radiology, Penn Presbyterian Medical Center, Division of Interventional Radiology, Department of Radiology, University of Pennsylvania.
Why did you choose to move into interventional oncology?
It has always been a big part of my practice. There are some interventional radiologists who have moved into interventional oncology (IO) to the exclusion of almost everything else. I wouldn’t want to characterize myself in that way; I still have a busy arterial and venous vascular practice. Interventional oncology is something that I was trained in as a resident and as a fellow, so I have been embedded since I finished my training 17 years ago. Over the years, IO has gone from being used as a salvage or last-ditch therapy to being increasingly utilized at earlier stages in a patient’s cancer care, and in some situations, as first-line therapy. It’s been great to see IO therapies incorporated into multiple practice guidelines for specific cancers, such as those produced by the National Comprehensive Cancer Network (NCCN) and the United Organ Sharing System (UNOS).
Has the percentage of your practice devoted to IO grown over the past 17 years?
Yes. IO is now one of the main pillars of interventional radiology. It used to be limited to a relatively small number of centers around the country and was consolidated mainly at bigger teaching hospitals; now, interventional oncology can be found in community hospitals and the quality of interventional oncology care is also something that has grown in leaps and bounds, because fellows are entering practice well-trained in all the different therapies that we can offer to interventional oncology patients. The technologies that we use — the tools in the toolbox, if you will — have also gotten a lot better. And there are more of them, so we are able to offer more for patients than we could previously.
How do oncology patients come to you?
Certainly a large number of patients continue to come through what is now the standard route, the multidisciplinary tumor board, now a fixture in all hospitals offering cancer care. The multidisciplinary tumor boards are where new patients and follow-up patients are discussed in a setting of medical oncologists, surgical oncologists, radiation oncologists, and interventional oncologists. Often a diagnostic radiology physician is present as well, to guide people through all the imaging.
Interventional oncologists have an advantage in some respects, in that we are often involved in multiple points of care for the oncology patient such as placing a chemotherapy port. We view every chemotherapy port placement as an opportunity for an interventional oncology consultation. We will review why the patient is getting the port. Maybe the patient is relapsed for their metastatic colorectal cancer, they have failed multiple courses of systemic therapy, and are about to embark upon another course of systemic therapy, and the treating oncologist hasn’t had it occur to them that an IO therapy may be helpful. We will review the imaging, review the patient’s history, and if it seems like they are appropriate for an IO therapy such as an ablation or a transarterial therapy, or a combination of the two, we will go ahead and place the port. But we will bring them back and see them in the office as a separate encounter with the endorsement of their oncologist or oncologic team, so that everybody is kept in the loop. That has been very helpful from a practice-building standpoint.
How much outreach do you need to do to other oncologists?
Medical oncology has been another field that has undergone a huge transformation. The historic medical oncology approach has been to administer cytotoxic drugs to kill the cancer cells, but these can poison the patient, too. Over the last 10 years, the transformation that has occurred in medical oncology has been through the widespread availability of biologic therapies that are not nearly as toxic to the body. It’s not enough that oncologists have to be familiar with basic mechanisms of cellular proliferation as it occurs in various cancers. They have to have an intimate knowledge of all of the molecular biology and biochemistry as it pertains to all of these therapeutic options. Today, we have small molecular weight tyrosine kinase inhibitors, a vast array of monoclonal antibodies, and drugs that can knock out specific metabolic pathways pertaining to angiogenesis.
There are now so many therapeutic targets for medical oncologists that it has become a huge amount of information to master. For that reason, they may not be as familiar with some of the interventional oncology options that are out there, particularly some oncologists who have been out in practice for a while, who have had a hard enough time trying to keep abreast of the sheer volume of developments in the field of medical oncology. So in answer to your question, outreach is something one always has to do and that is not just for interventional oncology, but for all aspects of your interventional radiology practice. We will do outreach particularly to our medical and surgical oncology colleagues, since they are the ones that are the most receptive to the role of interventional oncology therapies in the contemporary paradigm of cancer patient management.
Do you have suggestions for how fellows can grow their practice?
Yes, I do. I think the message from the leadership from interventional radiology and interventional oncology is fairly consistent this way. First, it is not enough just to have the technical skills to be able to offer interventional oncology therapies. You have to be very familiar with the cancer biology. Even if your knowledge is not to the same extent as your medical oncology colleagues, you have to know what relevant tumor markers are. You have to have a reasonable working knowledge of what certain genetic predispositions a patient may have as it pertains to optimal therapeutic plans. For example, it appears that patients with mutant KRAS status may not respond as well to liver-directed therapy of colorectal metastases as do patients with wild-type KRAS.
To be a worthwhile addition to the whole oncology team, you have to be able to function as a consultant. That doesn’t mean going around saying every patient should undergo some kind of embolization or ablation; it is important to know the cancer biology, the natural history of each specific cancer, and where it is appropriate to offer an IO therapy and where it isn’t. There are certain cancers that become metastatic to the liver and will present with what we call oligometastatic disease. Those patients are often appropriate candidates for locoregional therapy from interventional oncologists. There are other forms of cancer that when they spread to the liver will typically have a much more widespread, diffuse metastatic pattern, and offering an interventional oncology therapy may not be appropriate. So, to gain trust and credibility among your oncology colleagues, you have to be able to judiciously recommend IO therapies, and that also means knowing when it is important to say IO is not appropriate for a particular patient. That would be the first thing, knowing how to talk the talk and walk the walk, not just being a catheter jockey or ablation jockey, but someone who has invested the time and energy to know enough about cancer to have a meaningful discussion with your oncology colleagues.
The second thing is to make sure you are a fixture at your multidisciplinary tumor boards. It is important to develop the relationship with your oncology colleagues, and tumor boards are one of the best forums for doing so. Sometimes the tumor boards are held in the middle of the day and on a busy day, it can be a challenge to make it to those meetings, but it is important to structure your schedule to make sure that you and your colleagues are there.
The third piece of advice is to approach every patient having a lesion biopsied or having a vascular access device placed for chemotherapy, and consider this patient holistically. Don’t just do the biopsy. Think about how you may be able to help that patient. A patient incapacitated by SVC syndrome may benefit from stenting, or a patient with intractable malignant ascites may get profound relief from a tunneled peritoneal catheter. We always need to consider whether there is something else we can offer to help improve their care by reducing suffering and prolonging survival, or that will improve their outcomes in some other, meaningful way.