Single-fraction radiosurgery for treatment of spinal and cerebral metastases from renal cell carcinoma under systemic tyrosine kinase inhibition.

Abstract

4625 Background: Angiogenic therapy shows promising treatment effects in patients with metastatic renal cell carcinoma (RCC). Limited response has been documented for metastatic lesions in the brain and spine. High-dose local radiation treatment (stereotactic radiosurgery, or SRS) was added for selected patients to improve local control and overall survival. We report on toxicity and local tumor control in patients with metastatic renal cell carcinoma who were simultaneously treated with angiogenic therapy and aggressive local irradiation. Methods: 88 patients with spinal (n=47) or cerebral (n=41) metastatic lesions from RCC and an eastern cooperative oncology group (ECOG) status of 0 or 1 were treated systemically with sorafenib or sunitinib and additional SRS. Patients with surgically removable cerebral lesions were not included. Dose was not withheld or delayed while patients were simultaneously treated with SRS. Results: Median time from initial diagnosis to metastatic spread was 0.6 years (range 0 - 3.5 years). Median follow-up was 14.7 months (range 1-42 months). Twenty-seven patients were treated with sunitinb (50 mg pod, 4 weeks on 2 weeks off) and 61 patients were treated with sorafenib (400 mg bid). One patient suffered a tumor hemorrhage after SRS that did not require treatment. No skin toxicity occurred after SRS, and SRS did not alter the side effect profile of systemic angiogenic therapy. Neither neurotoxicity nor myelopathy was observed. Local tumor control 15 months after SRS was 98% (95% CI: 89-99%). The median pain score on the visual analogue scale before spinal treatment was 5 (range 1-8). After SRS the median pain score was significantly lowered to 0 (range 0-2, p<0.001). There were no treatment related deaths, and late complications after SRS were not noted so far. Conclusions: Systemic angiogenic therapy and SRS for selected RCC patients with cerebral and spinal metastases is safe and effective. Single-fraction delivery as an outpatient procedure allows for convenient integration of SRS into various oncological treatment concepts. Further studies are needed to determine the limits of SRS for RCC metastases outside the brain and spine. No significant financial relationships to disclose.