ATLANTA, Sept. 23, 2013 /PRNewswire/ -- Treating inoperable early-stage non-small cell lung cancer (NSCLC) with a single session of stereotactic body radiation therapy (SBRT) may be a viable option in some cases, according to the results of a multi-institutional randomized phase II trial led by the Radiation Therapy Oncology Group (RTOG) and reported yesterday in a presentation at the 2013 ASTRO Annual Meeting.
The presentation summarized results from the RTOG 0915 trial that compared two stereotactic body radiation therapy (SBRT) schedules for medically inoperable patients being treated for stage I peripheral non-small cell lung cancer. One group of patients received treatment spread out over four treatment sessions or "fractions" on consecutive days; the other group received treatment in a single fraction—a practice sometimes referred to as "lung radiosurgery." The median length of follow-up was 20.6 months for all patients.
"An earlier RTOG study demonstrated that a three-fraction approach can achieve good tumor control and overall survival rates for medically inoperable lung cancer patients," said Gregory M. M. Videtic, M.D., principal investigator on the RTOG study and radiation oncologist at The Cleveland Clinic in Ohio. "This study was designed to explore other schedules for delivering lung SBRT, and to evaluate toxicity rates at one year between the one-fraction and four-fraction patient groups. Secondarily, the study also assessed tumor control and overall survival rates when comparing one versus the multiple fraction approaches."
The study enrolled 94 patients who were treated at 30 institutions between September 2009 and March 2011. It compared the cumulative rates of grade 3 or higher toxicities at one year after treatment, including compromised respiratory function, neuropathy, injury to soft tissues or the chest wall, and skin reactions. Treatment plans were designed to maximize dose to the targeted lung tumor while keeping the dose to normal structures, such as the spinal cord, esophagus, health lung, heart, trachea, ribs, skin, and stomach, below specified normal tissue tolerances."We predetermined that if we found that the two groups had similar toxicity rates at one year and then saw that tumor control rates were comparable between them, then the shortest treatment schedule (i.e., one fraction) would be declared the 'winner,'" said Videtic. "At one year, the patients who received the single-fraction treatment met the pre-specified criteria that we had set with respect to adverse events and primary tumor control. We hope to use these findings to further define the optimal approach for treating inoperable early-stage lung cancer with SBRT."