Gammaknife Radiosurgery for Small Cell Lung Cancer

Abstract

Small cell lung cancer (SCLC) has traditionally been treated with whole brain radiation (WBRT) secondary to concerns about high rates of CNS failure. For other histologies, including non-small cell lung cancer, stereotactic radiosurgery (SRS) has been shown to have less toxicity and no detriment to overall survival. Evaluation of SCLC patients treated with SRS on a prospective SRS database. A total of 70 patients were evaluated. Forty-five had received previous WBRT and 25 were treated with SRS alone and had not had any previous WBRT. The median number of treated CNS mets was 4 (range 1 to 29). Median follow-up for all patients was 116 days. Median survival was 149 days. For patients that had not had previous WBRT, the one-year distant failure rate was 52% with 7 distant CNS failures, median time to distant failure was 467 days. For all patients there were 2 local failures. There were no differences in survival between patients treated with SRS alone versus having previous WBRT. Number of treated CNS mets was associated with different CNS control rates with a one-year control rate of 40% for 1-2 mets, 30% for 3-5 mets and no patients without CNS failure with more than 5 treated CNS mets at one year. Systemic disease control was not associated with difference in CNS control. SCLC has a higher likelihood of CNS recurrence when treated with SRS alone but still appears to be an effective option, especially for patients with < 5 CNS mets.