Targeting Tumors with Highly Focused Radiosurgery

RyuSamuel Ryu, MD
Professor and Chair, Department of Radiation Oncology
Deputy Director of Clinical Affairs 
Stony Brook Cancer Center

Tumors in or near the brain and spinal cord are among the most challenging to treat due to the delicate adjacent tissues. That’s why the recent advances in radio- surgery are so welcome. Stony Brook’s Dr. Samuel Ryu, the internationally renowned physician-scientist who made significant progress and pioneered this treatment for the spinal cord, discusses these beneficial advances.

What are the unique challenges of treating spine and cord tumors?
Most of the challenges stem from the location of the tumors. Often they are in places difficult to access through conventional surgery. Some tumors on the spine may be pressing against the spinal cord, which could interfere with function- ing and lead to symptoms such as tingling or numbness or even paralysis. Tumors in the brain may affect the sensory organs such as eyes and ears. A major goal of treatment is to not only address the tumor, but to help reduce the risk of the tumor interfering with normal physical movement and functioning.

What is radiosurgery and why is it such a breakthrough?
Stereotactic radiosurgery (SRS), also known as stereotactic body radiation therapy (SBRT), is a highly focused treatment, with very precise use of radiation to target tumors. Radiosurgery is a stand-alone treatment, and it also complements, rather than replaces other treatments, such as surgery or chemotherapy. Using radiosurgery to shrink tumors can sometimes help prevent more complicated surgeries, as well as preserve function, help better manage symptoms and improve outcomes. 

Is the major advantage of this approach a better quality of life? 
Exactly. Because of the precision in the delivery of radiation, only the tumor, not the surrounding tissue or organs, receives radiation. Say, for example, a brain tumor is on the optic nerve or visual pathway — an area that is very radiosensitive. Using radiosurgery can prevent or cut down on risk — in this case, potential blindness. In addition, radiosurgery is also used in benign (non-cancerous) tumors. For example, if there is a growth on the spine, even though it is benign, it can still interfere with movement. However, with radiosurgery, we can stop the tumor’s growth in the spinal cord and help preserve normal function of the back and limbs.

Are there side effects?
Because both the dosage and delivery are so precise, side effects rarely occur. It may vary depending on the parts of the body being treated. Also, patients don’t experience the symptoms, such as hair loss and nausea that sometimes accompany many cancer treatments. 

Can radiosurgery be used on other parts of the body?
Yes. We are also using it to help treat tumors of all sites, including the lungs, liver, pancreas and adrenal glands. These successes have led to a series of clinical trials, including a phase III clinical trial of radiosurgery for spine metastasis, in which I am the principal investigator. For example, at Stony Brook, we have treated many patients with early-stage lung cancers or metastatic cancers and analyzed the outcomes of the first 100 patients. Our outcome results have been documented as superior to other institutions. The treatment regimen may vary depending on the different types of tumors. Mostly, it is a much shorter course of treatment consisting of one to six noninvasive outpatient sessions. This makes it more convenient for patients and does not interfere with their other treatment schedules.

How does Stony Brook’s radiosurgery compare with the Gamma Knife® and CyberKnife®?
This is a frequent and interesting question. For example, look at the numerous car companies that produce different models. Likewise, there are several commercial radiosurgery products available. Those are the names of the products, which are all good. At Stony Brook, we use the most advanced radiosurgery equipment, called Novalis® (from BrainLab) and we are preparing for the installation of EdgeTM (from Varian). This cutting-edge equipment, with the ability to track organ movement, even uses a GPS system. The most important aspect in the comparison isn’t the equipment or computer, but the pioneering knowledge and experience of the physician. When treating patients, the thoughtful evaluation of their symptoms and tumors, with pertinent interpretation of imaging studies, and wise use of this precise radiosurgery/ SBRT technology are the critical components. Indeed, it’s an art of connecting medicine and technology.

For more information about the Department of Radiation Oncology, call (631) 638-1000.