A dose-response relationship for time to bone pain resolution after stereotactic body radiotherapy (SBRT) for renal cell carcinoma (RCC) bony metastases.

ABSTRACT

BACKGROUND: To investigate the utility of stereotactic body radiotherapy (SBRT) in the treatment of painful renal cell carcinoma (RCC) bone metastases, and for a possible dose effect on time to symptom relief. MATERIAL AND METHODS: Eighteen patients with 24 painful osseous lesions from metastatic RCC were treated with SBRT. The most common treatment regimens were 24 Gy in 3 fractions and 40 Gy in 5 fractions. The times from treatment to first reported pain relief and time to symptom recurrence were evaluated. Median follow-up was 38 weeks (1-156 weeks). RESULTS: Seventy-eight percent of all patients had pain relief. Patients treated with a BED > 85 Gy achieved faster and more durable pain relief compared to those treated with a BED < 85 Gy. There was decrease in time to pain relief after a change in treatment regimen to 8 Gy × 5 fractions (BED = 86). There was only one patient with grade 1 skin toxicity. No neurological or other toxicity was observed. CONCLUSIONS: SBRT can safely and effectively treat painful RCC bony metastases. There appears to be a relationship between radiation dose and time to stable pain relief.