Evaluation of Standard Beam Delivery Devices in Proton Radiosurgery

Abstract

Abstract Purpose: To evaluate the use of standard apertures and range shifters for the treatment of brain metastasis in proton stereotactic radiosurgery. Materials and Methods: Nine patients with localized brain metastasis who had been previously treated using our intracranial proton stereotactic radiosurgery procedure (ie, with a custom aperture and bolus) were randomly selected from our patient cohort. The custom aperture and bolus treatment plans were used as the standard of care in this case and comparative treatment plans using the standard aperture and range shifter concept were generated. Gantry/table angle and the number of treatment beams were optimized as part of this study to evaluate the ability of the standard aperture/range shifter system to deliver a comparable treatment to the patient. Conformity index, homogeneity index, isodose volumes, and integral dose were all evaluated to determine the degree of conformity of the plans created and for comparison to the custom aperture/bolus treatment...