Determination of Intrafraction Prostate Motion During External Beam Radiation Therapy With a Transperineal 4-Dimensional Ultrasound Real-Time Tracking System

To determine intrafraction prostate motion during volumetric modulated arc therapy (VMAT) using transperineal ultrasound (US) real-time tracking.770 US monitoring sessions in 38 prostate cancer patients' VMAT treatment series were retrospectively evaluated. Intrafraction motion assessment of the prostate was based on continuous position monitoring with a 4-dimensional US system along the 3 directions: left-right (LR), anterior-posterior (AP),...