Stereotactic body radiation for early-stage, inoperable non-small cell lung cancer yields high overall survival rates and low toxicity compared to conventional radiotherapy, according to the results of a study presented at the annual meeting of the American Society for Radiation Oncology in Boston, Massachusetts. In fact, the approach doubled overall survival rates historically achieved with conventional radiation.
Lung cancer is a major cause of death worldwide, with over one million deaths per year. Non–small cell lung cancer (NSCLC) is the most common type of lung cancer. Early-stage NSCLC is most often treated with surgical resection with or without the addition of radiation therapy and/or chemotherapy. In some cases, patients may not be able to undergo surgery to remove their cancer due to underlying conditions such as emphysema or heart disease. Treatment of early-stage NSCLC patients who are unable to undergo surgery may include radiation therapy or observation.
Strategies to improve treatment for this group of patients include stereotactic radiation therapy. Stereotactic radiation therapy involves the very precise delivery of a large dose of radiation to a tumor while sparing normal tissue. Stereotactic radiation therapy is delivered from multiple angles and planes, which allows the delivery of the larger dose. Sessions can be delivered over 2 to 2.5 weeks instead of the typical 8-9 week regimens associated with conventional techniques.
Researchers from Japan conducted a phase II study to evaluate the safety and efficacy of stereotactic body radiation therapy. The study included 100 patients with stage I inoperable NSCLC who were treated in 15 institutions throughout Japan between 2004 and 2008. Median follow-up was 37 months.
After three years, the overall survival rate was 59.9 percent, compared to historical rates of 31-39 percent with conventional radiation. At the three-year follow-up, progression-free survival was 49.8 percent, local progression-free survival was 52.8 percent, and event-free survival was 46.8 percent. Treatment was associated with mild toxicity. The five-year overall survival rate was 40.8 percent, compared with historical rates of 13-22.2 percent.
The researchers concluded that stereotactic body radiation therapy for inoperable stage I NSCLC is highly effective with mild toxicity. They suggest that it should become the new standard treatment, replacing conventional radiation therapy in this population.
Nagata Y, Hiraoka M, Shibata T, et al. Stereotactic Body Radiation Therapy For T1N0M0 Non-small Cell Lung Cancer: First Report For Inoperable Population Of A Phase II Trial By Japan Clinical Oncology Group. Presented at the 54th Annual Meeting of the American Society for Radiation Oncology. October 28-31, 2012 Boston, Mass. Abstract 115.