Single-center analysis of stereotactic radiosurgery for spinal metastases from prostate cancer

Spinal metastases may result in pain, neurological deficit, and vertebral body collapse. A retrospective analysis of a prospectively maintained database of University of Pittsburgh (PA) Medical Center evaluated stereotactic radiosurgery for spinal metastases from prostate cancer. The median tumor volume was 37.0 cc (range 2.9-263.3). The majority (71%) of lesions were treated in a single fraction (median 20 Gy; range 14-22.5); multi-fractionated treatment consisted of 21-30 Gy in 2-5 fractions. Median follow-up was 12 months (range 1-146). The local control rates were 97% at 6 months, 91% at one year, and 91% at two years. Hormone sensitivity was not associated with local control. The overall survival rates were 71% at 6 months, 56% at one year, and 32% at two years. Age > 70 years (p=0.048) and tumor volume > 30 cc (p=0.03) were associated with inferior overall survival rates. Complete or partial pain response was observed in 58% of patients. Adverse radiation effects were observed in 16% of patients, including vertebral compression fractures in 4%. The authors conclude that radiosurgery for prostate cancer spinal metastases confers durable local control and moderate pain relief with minimal toxicity.