Radiotherapy to bone has utility in multifocal metastatic renal carcinoma

Renal cell carcinoma metastases to bone are classically considered radioresistant. We reviewed 28 patients who underwent irradiation for metastatic renal cell carcinomas to bone to test the hypothesis that irradiation of renal metastases to bone provides adequate palliation in carefully selected patients. Metastases were multifocal in all patients. All patients were followed until death. Overall, 36 index radiotherapy treatments were given as palliative initial treatment for 36 osseous metastatic sites. Twenty-five of 36 sites (69.5%) had no subsequent radiotherapy. Eight sites (22.2%) underwent repeat radiotherapy at a mean 28.9 weeks after treatment. Two (5.6%) additional sites underwent surgery at the site at an average 74 weeks later, and a pathologic fracture occurred at one (2.8%) site 3 weeks after irradiation. Overall, 33 of 36 (91.7%) sites had only radiotherapy as their source of palliation. Median times to return to pretreatment pain and functional levels, however, were 2 months and 1 month, respectively. Radiotherapy to osseous sites appears to control pain for the short term and generally prevents fractures and avoids the need for surgery in renal cell carcinoma patients with multiple bone metastases.