Rotating pods for stationary gantries.

The purpose of this project was, for light ion beams, to increase the available solid angle for beam entry when using stationary gantries to match that available with rotating gantries. Pods for chest, abdomen, and pelvis (CAP) and head and neck (HN) patients were developed to register, immobilize, and rotate patients with respect to robotic patient positioners. Ancillary devices were developed for moving and exchanging the pods for planning and treatment. Registration and immobilization techniques were enhanced to support the use of pods. For head patients, a beam entry solid angle greater than 2 pi was achieved. For chest, abdomen, and pelvis patients, a full 360o rotation of the pods was obtained with the patient positioner providing additional rotation around a perpendicular axis but limited by collisions with the radiation head and imaging systems. The use of rotating pods with stationary gantries can achieve a similar beam entry solid angle to fully rotating gantries.