William Kennedy, MD

As a leader in radiation oncology, Dr. William Kennedy is singularly focused on successfully treating patients’ brain, spine, and head and neck tumors and preserving their quality of life. 

At the Ivy Brain Tumor Center at Barrow Neurological Institute, Dr. Kennedy specializes in the treatment of these central nervous system tumors using noninvasive radiosurgery, including Gamma Knife and CyberKnife radiosurgery, stereotactic body radiation therapy (SBRT), and image-guided, intensity-modulated radiation therapy (IMRT). 

Dr. Kennedy utilizes cutting-edge technology and tools to meticulously plan radiation treatment, map the anatomy of the brain, spine, and head and neck, and digitally arrange radiation beams. 

“Radiation therapy is not a one-size-fits-all approach,” he says. “That’s the advantage of being here at the Ivy Brain Tumor Center. We have all the tools to deliver cutting-edge radiosurgery treatments in brain and spine tumors that are highly individualized to the patient.”

Dr. Kennedy completed his radiation oncology residency at Washington University School of Medicine. Prior to that, he attended medical school at the University of Florida where he was awarded the Radiation Oncology Merit Award. He was also the recipient of the Roentgen Resident Research Award and the Trainee Research Prize from the Radiological Society of North America.

Dr. Kennedy’s research efforts are focused on developing novel uses of stereotactic radiosurgery and the development of clinical trials for the management of primary and metastatic CNS tumors. He is the author of many peer-reviewed articles on the subjects of stereotactic radiosurgery, quality improvements in the treatment and planning of radiotherapy, and patient-reported quality of life and survivorship. 

The opportunity to make a difference in a patient’s life is what drew Dr. Kennedy to the profession.  

When his father was diagnosed with kidney cancer, which eventually metastasized to his brain, the care he received throughout his journey made an impression on a young Dr. Kennedy. He wanted to provide that same kind of care to other families faced with similar situations. 

“My career aspirations are to be the best radiation oncologist and, above all, the best advocate I can be for my patients. If I can help make their journey better, that’s what I care about at the end of the day,” says Dr. Kennedy.

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Radiation Oncologist Q&A with Dr. Kennedy

How does radiation work? 

Radiation, in the setting of brain tumors, is often given after surgery. There’s no radioactivity, despite the name. It’s using high-energy, very focused lightwaves generated with electricity by a machine called a linear accelerator. We use these machines to deliver radiation from many different angles to the area where the tumor is or was, at the areas at risk for tumor regrowth or to treat areas that a surgeon couldn’t safely get to. That’s when radiation comes into play. It’s our best local therapy for brain tumors alongside surgery. 

Radiation can be thought of like lights on a stage – there are many different lights on a stage, and none of them individually are very bright, but when they all meet in the center it’s very bright. Using many different angles, we deliver a significant dose of radiation to a target without causing damage to nearby normal tissues. The directed radiation causes DNA damage and causes tumor cells to die off as they try to divide, which can happen over the course of days, weeks or even months after radiation is delivered.

Does radiation therapy use radioactivity? 

No, there is no radioactivity in most kinds of radiation therapy, such as Cyberknife, ZAP-X and Truebeam treatments. The only treatment we sometimes use that has actual radioactive material in it is a machine called Gamma Knife.

What’s the biggest challenge in radiation oncology? 

The biggest challenge in radiation oncology is delivering enough dose to a tumor to be effective while also minimizing radiation exposure to the surrounding normal tissues. 

In a patient’s imaging, how do you differentiate between treatment effects and tumor regrowth? 

After treatment, particularly for some types of brain tumors, it can be difficult to separate treatment effects versus tumor regrowth on surveillance imaging. We compare prior imaging and look for changes over multiple scans. We consider whether the patient has any new symptoms. We’ll use additional, specialized techniques, like perfusion imaging, to get another view. Our multidisciplinary team reviews each patient’s images together to help sort these differences out.

Patients always ask about diet. What do you recommend?  

We know there’s a link between nutrition and health, cancers included. Patients are looking for a cause and effect and, right now, we really don’t know. There isn’t enough evidence to make a clear connection, only many good leads. The reason for that is that tumors are very complicated. We’re talking about thousands of different diseases with many thousands of genetic changes, and we’re asking how much does diet influence a tumor’s growth. Designing studies to test certain aspects of diet are hard to do because patients, like most human beings, don’t do very well on a strict diet. 

For example, a ketogenic diet has a lot of interest in cancer research. Some preclinical data in mouse models show that it may be effective, and we are still trying to see if that connection is true in humans. There are ongoing studies looking into this and once we have more meaningful data I can hopefully give my patients a better answer because I want to know as much as they do. For now, the best thing I recommend for my patients is to eat a nutritionally diverse, predominantly plant-based diet, and that doesn’t mean to cut out meat entirely, just the more green (or colors other than beige) on your plate, the better. 

What are your research interests? 

We’re trying to implement better imaging studies, such as PET scans, into our clinic to help better identify microscopic tumors and pinpoint radiation. We’re doing a randomized study in our department looking at the fluciclovine PET tracer in treatment for gliomas. My personal interests lie in stereotactic radiosurgery treatment planning and clinical trial design. For example, identifying different tools or planning parameters that can improve the planning process to make radiosurgery even safer, more efficient and effective. I’m also interested in looking at the genetic or molecular data from gliomas and meningiomas to help better cater treatments.

What’s the biggest change you see coming in your field in the next decade? 

The biggest change I see coming to radiation oncology is the continued huge improvements in the efficiency, quality, and safety of radiation therapy. My goal in the next decade is to find a way to improve treatment outcomes for patients with brain tumors, through continued dedication and research. 

Click here to learn more about the Ivy Center’s robust clinical trial program which includes a series of studies designed to identify new therapies that will enhance the effects of radiation in brain tumor patients.