Increased Risk of Biochemical and Clinical Failure for Prostate Patients with a Large Rectum at Radiotherapy Planning: Results from the Dutch Trial of 68 GY Versus 78 Gy

Purpose: To investigate whether a large rectum filling visible on the planning CT scan was associated with a decrease in freedom from any failure (FFF) and freedom from clinical failure (FFCF) for prostate cancer patients. Methods and Materials: Patients from the Dutch trial (78 Gy vs. 68 Gy) with available acute toxicity data were analyzed (n = 549). A 10-mm margin was applied for the first 68 Gy and 0–5 mm for the 10-Gy boost. The dose in the...