Detailed Organ Contouring Guidelines

All manual contours were drawn by an experienced radiation oncologist following the guidelines of the RTOG [12 , 13 (link)] using Oncentra Masterplan by Elekta AB, Sweden. Lungs: All inflated and collapsed, fibrotic and emphysematic lungs were contoured including small vessels extending beyond the hilar regions; hilars and trachea/main bronchus were not included. Heart: Contoured along the pericardial sac. The superior aspect (base) began at the level of the inferior aspect of the pulmonary artery passing the midline and extend inferiorly to the apex of the heart. Bladder: Contoured inferiorly from its base, and superiorly to the dome. Rectum: Contouring ended inferiorly from the lowest level of the ischial tuberosities (right or left), and superiorly before the rectum lost its round shape in the axial plane and connected anteriorly with the sigmoid.