Impact of stereotactic radiosurgery dose on control of cerebral metastases from renal cell carcinoma

Abstract

Aim: Renal cell carcinoma (RCC) is a relatively radioresistant tumor and may require for higher radiation doses than other tumor types.

Patients and methods: Nineteen patients treated with 20 Gy of stereotactic radiosurgery (SRS) alone for one to three cerebral metastases were compared to nine patients treated with 16-18 Gy.

Results: SRS with 20 Gy led to significantly better local control than did 16-18 Gy (81% vs. 50% at 12 months; p<0.001). Results were also significant on multivariate analysis (risk ratio: 6.30; p=0.033). SRS dose did not associate with freedom from new cerebral metastases (75% vs. 62% at 12 months; p=0.42) or survival (16% vs. 56% at 12 months; p=0.46). On multivariate analyses, better survival was associated with higher Karnofsky performance score (p<0.001) and absence of extracranial metastatic disease (p=0.006).

Conclusion: In patients treated with SRS alone, local control of cerebral metastases from RCC was better after 20 Gy than after 16-18 Gy.

Keywords: cerebral metastases; freedom from new cerebral metastases; local control; renal cell carcinoma; stereotactic radiosurgery; survival.