Dose-volume analysis and the temporal nature of toxicity with stereotactic body radiation therapy for prostate cancer

SBRT for prostate cancer appears well tolerated, with mostly transient low-grade toxicity. Urethral sparing should be used with a maximum point dose < 47 Gy, volume receiving 120 Gy < 50% of the prostate, and bladder volume receiving 19 Gy < 15 mL in 4 fraction treatments. Patients with prostate volumes ≥ 50 mL should be counseled regarding the increased risk of moderate-grade genitourinary toxicity.