Restricted bowel loop contouring: Improving efficiency in radiotherapy contouring for abdomino-pelvic Stereotactic Ablative Radiotherapy (SABR).

We present a time-saving alternative to individual bowel loop delineation for abdomino-pelvic Stereotactic Ablative Radiotherapy. Here, individual bowel loop contouring is only performed within a 3 cm circumferential and 2 cm superio-inferior expansion of the PTV. A bowel bag structure represents distal bowel.