Implementation of Photon Treatment Back-up Workflow at a High-Volume Proton Center: Safety, Quality, and Patient Considerations

A tiered system established by disease site, number of fractions, and individualized circumstances is used to prioritize patients. Proton-photon backup planning strategy and physics check details were described. This article provides an overview of workflow of conversion of PBT to photon when the PBT machine is down. Specific needs of patients undergoing proton beam therapy are addressed.