Cutting edge.

Can SBRT be used for high risk prostate cancer? This study from the SHARP consortium analyzes individual patient data from 7 centers with prospective phase 2 trials or databases. In total, 344 men were included and 69% had grade group 4+ disease. The proximal seminal vesicles were covered in all studies, and prescription doses ranged from 8 Gy per fraction (44%) down to 7 Gy. Treatments were delivered daily in some studies and up to weekly in others. However, it must be recognized that there is wide variation in prescribing methods and dose heterogeneity with prostate SBRT. In other words, a “prescribed” dose of 8 Gy x 5 in one study may look different from 8 Gy x 5 in another study. Also, the use of ADT (72%) and duration (9 months) were less than one might typically see for high risk disease. At 4 years, bRFS and DMFS were 81.7% and 89.1%, which are comparable to rates seen in other studies of high risk disease. Grade 3+ GU and GI toxicity were 2.3% and 0.9%. Higher dose per fraction was associated with both improved biochemical control and increased late GI and GU toxicity. TBL: With increasing prospective data, SBRT may become a more standard option for men with high risk prostate cancer. | van Dams, Int J Radiat Oncol Biol Phys 2021