Phase 2 Study of Stereotactic Body Radiation Therapy and Stereotactic Body Proton Therapy for High-Risk, Medically Inoperable, Early-Stage Non-Small Cell Lung Cancer

Poor accrual, due to lack of volumetric imaging and insurance coverage for proton therapy, led to early closure of the trial and precluded accurate assessment of efficacy and toxicity. Comparable maturity of 2 radiation therapy modalities, particularly on-board imaging, and better insurance coverage for SBPT should be considered for future studies.