Strategies for Online Organ Motion Correction for Intensity-Modulated Radiotherapy of Prostate Cancer: Prostate, Rectum, and Bladder Dose Effects

With online correction of both translations and rotations, a 4-mm margin was sufficient for 15 of 19 patients, whereas the remaining four patients had an underdosed CTV volume <1%. Margin reduction combined with online corrections resulted in a similar or lower dose to the rectum and bladder. The more advanced the correction strategy, the better the planned and accumulated dose agreed.