Stereotactic body radiotherapy for primary prostate cancer: a systematic review

Stereotactic body radiotherapy (SBRT) for prostate cancer allows overall treatment times to be reduced to as little as 1 week while maintaining a non-invasive approach. This study provides a comprehensive summary of the literature relating to SBRT in prostate cancer. A systematic review of the relevant literature was performed using structured search terms. Fourteen phase I-II trials and retrospective studies using SBRT for the treatment of prostate cancer were used. Three studies were identified which addressed cost. Dose fractionation, radiotherapy procedures, biochemical progression-free survival, toxicity, cost and quality of life were critically appraised. A total of 1472 patients were examined across studies. Median follow-up ranged from 11 to 60 months. The most common dose fractionation was 35-36.25 Gy in five fractions, used in nine out of 14 studies. Ten of 14 studies used CyberKnife. The overall biochemical progression-free survival ranged 81-100%. Acute grade 2 urinary and rectal toxicities were reported in 5-42% and 0-27% of patients, respectively. Acute grade 3 or more urinary and rectal toxicity were 0.5% and 0%, respectively. Late grade 2 urinary toxicity was reported in 0-29% of patients, while 1.3% had a late grade 3 urinary toxicity. There were no late grade 4 urinary toxicities seen. Late grade 2 rectal toxicity was reported in 0-11%, while 0.5% had a late grade 3 rectal toxicity. Late grade 4 rectal toxicity was reported in 0.2% of patients.