Keeping PACE.

Here’s how radiation was planned and delivered in PACE-B. Fiducials and MRI were strongly encouraged. Patients were asked to use an enema and maintain a full bladder. The clinical target volume (CTV) was the prostate for low-risk patients with the addition of the proximal 1 cm of seminal vesicles for intermediate-risk disease. In the CF/HF arm, the planning target volume (PTV) margin was 5 to 9 mm (3 to 7 mm posteriorly). In the SBRT arm, it was 4 to 5 mm (3 to 5 mm posteriorly). For SBRT, 95% of the PTV received >36.25 Gy, and 95% of the CTV received >40 Gy and 98% >34.4 Gy. Dmax was <48 Gy and D2% <42.8 Gy. Treatment could be delivered daily or every other day. The SBRT arm originally only allowed CyberKnife, but opened to other platforms part-way through. Interestingly, CyberKnife afforded significantly lower acute GU toxicity. You can also find rectal and bladder constraints here. TBL: As you integrate prostate SBRT, take note of the differences in treatment planning details among trials. | PACE-B Protocol 2019