Stereotactic Radiosurgery for Brainstem and Thalamic Metastases

Abstract

Some lesions situated in sensitive areas of the brain are potentially dangerous to treat with any modality. This study reviews one institution's experience with the use of stereotactic radiosurgery (SRS) for brainstem and thalamic metastases to evaluate its efficacy in treating such lesions. Between October 1989 and January 1998, 20 patients (9 men, 11 women) underwent linear accelerator SRS for metastases in the brainstem or thalamus. A retrospective chart and radiographic analysis was performed on these patients. The mean patient age at the time of SRS was 55.9 years (range 34–76). The median dose of SRS was 1600 cGy (range 1200–2000) to the 80% isodose line, although the isodose line varied somewhat. Of the 20 lesions, median patient survival from the time of SRS was 27.2 weeks (mean 39.7, range 5.4–216). Reliable evaluation of neurological status after SRS was obtainable in 17 patients and radiographical follow-up in 12. The rate of clinical control of symptoms was 88.2% (15/17) and radiographical control was 100% (12/12). Complications occurred in two patients (11.8 %). Our results indicate outcomes that are similar to those in a previous report of SRS for metastatic lesions of the brainstem and thalamus, with survival shorter than that for other cerebral lesions. SRS for metastases of the brainstem and thalamus is a safe and effective treatment option, but does not offer as favorable an outcome as SRS for lesions in other areas of the brain.