Overall response rates to radiation therapy for patients with painful uncomplicated bone metastases undergoing initial treatment and retreatment.

Introduction: Radiation therapy has been shown to successfully palliate bone metastases. A number of systematic reviews and large clinical trials have reported response rates for initial treatment and retreatment.

Objective: To determine overall response rates of patients with painful uncomplicated bone metastases undergoing initial treatment and retreatment.

Methods: Intent-to-treat and evaluable patient statistics from a systematic review of palliative radiotherapy trials for initial treatment of bone metastases and a randomized clinical trial of retreatment were pooled and analyzed to determine the overall response rates for patients receiving initial treatment and retreatment.

Results: In the intent-to-treat calculation, 71-73% of patients had an overall response to radiation treatment and in the evaluable patient population; 85-87% of patients did so. Response rates varied slightly whether patients underwent single or multiple fractions in initial treatment or retreatment.

Conclusions: Single and multiple fraction radiation treatment yielded very similar overall response rates. Patients treated with a single fraction for both initial and repeat radiation experience almost identical overall response to those patients treated with multiple fraction treatment. It is therefore recommended that patients with uncomplicated painful bone metastases be treated with a single 8 Gy fraction of radiation at both the initial treatment and retreatment.