Development of an Innovative Daily QA System for Pencil-Beam Scanning Proton Therapy

The goal of this study is to create a simplified procedure for a scanning proton therapy machine daily QA according the requirements specified by American Association of Physics in Medicine Task Group Report 224 (TG 224). A novel phantom and methodology was created for the daily QA process consisting of (1) multiple rectangular homogeneous acrylic block columns; (2) an innovative multi-PTV proton plan; and (3) SunNuclear Daily QA3 multi-chamber detector array. The procedure validated the accuracy of proton beam output, energy/range, and pencil-beam spot positions. The QA tolerance levels outlined by the American Association of Physics in Medicine Task Group Report 224 (TG 224) can also be applied during analysis which can be triggered for pass/fail. By using this innovative Daily QA method, all essential dosimetric checks recommended by TG 224 were achieved with a simple setup and a single beam delivery. During initial tests and clinical practice, this innovative daily QA program has verified output, energy, and spot positions with high reproducibility and accuracy in a time efficient manner.