Stereotactic Radiosurgery Shows Promise for Kidney Cancer

This noninvasive therapy approach offers a new nonsurgical option for patients with this lethal illness who have scarce treatment opportunities.

Rod Ellis, MD, lead author of the study, along with Lee Ponsky, MD, who is the lead investigator, presented phase 1 clinical trial findings of 20 patients with localized primary renal cancer at the 54th annual meeting of the American Society for Radiation Oncology (ASTRO), held October 2012 in Boston (MA, USA).

Dr. Ellis presented data that 94% of patients treated in the study had decreased or stable disease, with limited side effects. “This trial shows that low to moderate doses of stereotactic radiosurgery are safe for renal cancer patients who typically do not have surgical options,” said Dr. Ellis, clinical director and vice chair for clinical affairs, department of radiation oncology at University Hospitals (UH) Case Medical Center (Cleveland, OH, USA) and associate professor of radiation oncology and urology at Case Western Reserve University School of Medicine (Cleveland, OH, USA). “Based on these findings, this treatment represents a promising therapeutic option. Further studies are needed to determine safe levels for the maximum dosage and by doing so, we hope to find increased response and cure rates with this method.”

“This study is a unique partnership between a surgeon and radiation oncologist, intended to offer patients a noninvasive, highly focused ablative radiation with surgical precision with little to no side effects,” said Dr. Ponsky, director, urologic oncology, and minimally invasive therapies at UH Case Medical Center and associate professor of urology at Case Western Reserve School of Medicine. “We are very excited about these results and cautiously optimistic about the future potential of this therapy.”

According to the American Cancer Society, there are approximately 65,000 new cases of kidney cancer each year in the United States and it is among the 10 most widespread cancers in both men and women. Treatment alternatives typically include surgery or cryoablation, which usies cold therapy to kill the tumor.

However, many patients are not suited for undergoing surgery and stereotactic radiosurgery provides a noninvasive alternative in just three treatments that requires no anesthesia or narcotics. Stereotactic radiosurgery is performed using Cyberknife, a robotic radiosurgery system that delivers targeted doses of radiation with submillimeter accuracy while minimizing damage to surrounding healthy tissue. This high-dose, focused radiation kills tumor cells and blocks cancer cells from growing.

The study tracked patients from two to 41 months after treatment employing a four-part dose escalation strategy. The response rate indicates that patients reacted well and had tolerable levels of treatment-related toxicity following stereotactic radiosurgery in all age groups from 58 to 92 years old. Based on these positive findings, Drs. Ellis and Ponsky and a group of researchers have initiated a follow-up phase two study for 12 additional patients with increased dosage to determine the most effective dosage. “This study builds upon our team’s previous work as we continue to evaluate and define the role of radiosurgery for the safe and effective treatment of kidney tumors,” said Dr. Ponsky.

“Radiosurgery delivers a higher and more effective dose directly to the tumor site with less side effects than conventional radiation and has been very effective in treating other hard-to-reach tumors,” concluded Dr. Ellis. “We are excited about its potential for kidney cancer patients and to be le to offer a non-invasive option.”

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University Hospitals Case Medical Center