Radiosurgery for brain metastases from primary lung carcinoma.

PURPOSE: Brain metastases are a common problem in patients with lung cancer. This retrospective review was performed to describe the efficacy and toxicity of stereotactic radiosurgery for brain metastases from lung carcinoma and to evaluate prognostic factors for survival. PATIENTS AND METHODS: A retrospective review was performed of 113 patients with the diagnosis of lung carcinoma who underwent radiosurgery with or without whole-brain radiotherapy for management of newly diagnosed or recurrent, single, or multiple brain metastases from 1991 through 1998 at the University of California, San Francisco. Freedom from progression and survival were measured from the date of radiosurgery and estimated using the Kaplan-Meier method. Prognostic factors were evaluated with the log-rank test and Cox proportional hazards models.
RESULTS: The median patient age at the time of radiosurgery was 59 years (range, 37-82 years), and the median Karnofsky performance score was 90 (range, 50-100). The median survival time from radiosurgery was 12.0 months overall, 13.9 months for 41 patients treated with radiosurgery alone initially, 14.5 months for 19 patients treated with radiosurgery and whole-brain radiotherapy initially, and 10.0 months for 53 patients with recurrent brain metastases. Among newly diagnosed patients, multivariate analysis showed that improved survival was associated with absence of extracranial metastases and fewer brain metastases. Among patients with recurrent brain metastases, improved survival was associated with higher Karnofsky performance score, control of the primary tumor, and fewer metastases. Measured by lesion, 1-year local freedom from progression probabilities were 81% for radiosurgery alone, 86% for radiosurgery and whole-brain radiotherapy, and 65% for radiosurgery performed after recurrence. In patients with newly diagnosed brain metastases, there was a significantly greater risk of developing subsequent brain metastases and of worse overall brain freedom from progression after radiosurgery alone versus radiosurgery and whole-brain radiotherapy. One-year brain freedom from progression probabilities were 13% without salvage therapy and 62% with salvage therapy in the 41 patients treated initially with radiosurgery alone, versus 67% without salvage therapy and 89% with salvage therapy in the 19 patients treated initially with radiosurgery plus whole-brain radiotherapy. DISCUSSION: Radiosurgery is an effective therapy for selected patients with newly diagnosed or recurrent brain metastases from lung carcinoma. Initial whole-brain radiotherapy with radiosurgery appears to improve brain control but not survival. Prospective, randomized trials are needed to further investigate the role of radiosurgery with and without whole-brain radiotherapy for brain metastases.