Stereotactic radiosurgery without radiation therapy providing high local tumor control of multiple brain metastases from renal cell carcinoma.

The aim of this study was to analyse treatment effects after stereotactic radiosurgery (SRS) without whole brain radiation therapy (WBRT) as primary treatment for patients harboring brain metastases of renal cell carcinoma (RCC). During an 8-year period, 85 patients with 376 brain metastases from RCC underwent 134 outpatient SRS procedures. 65 % of all patients had multiple brain metastases. The median tumor volume was 1.2 cm (3) (range: 0.1 - 14.2 cm (3)). Mean prescribed tumor dose was 21.2 (+/- 3.2) Gy. Local/distant tumor recurrences were treated by additional SRS in cases of stable systemic disease. Overall median survival was 11.1 months after SRS. The local tumor control rate after SRS was 94 %. Most patients (78 %) died because of systemically progressing cancer. A KPS > 70 and RTOG class I were related to prolonged survival time. Patients of the RTOG groups I, II and III survived for 24.2 months, 9.2 months and 7.5 months, respectively. There was no permanent morbidity after SRS. 11 patients (12.9 %) showed transient radiogenic complications and 3 patients (3.5 %) died because of intratumoral bleedings after SRS. Stereotactic radiosurgery alone achieves excellent local tumor control rates for patients with small brain metastases from renal cell carcinoma.