Proton Arc Reduces Range Uncertainty Effects and Improves Conformality Compared With Photon Volumetric Modulated Arc Therapy in Stereotactic Body Radiation Therapy for Non-Small Cell Lung Cancer

Stereotactic body radiation therapy with proton arc and Photon-VMAT generate significantly more conformal high-dose volumes than standard proton SBRT, without loss of coverage of the tumor and with significant sparing of nearby organs, such as chest wall. In addition, both proton arc approaches spare the healthy lung from low-dose radiation relative to photon VMAT. Our data suggest that IMPT-Arc should be developed for clinical use.