Bayesian Adaptive Randomization Trial of Passive Scattering Proton Therapy and Intensity-Modulated Photon Radiotherapy for Locally Advanced Non–Small-Cell Lung Cancer

PurposeThis randomized trial compared outcomes of passive scattering proton therapy (PSPT) versus intensity-modulated (photon) radiotherapy (IMRT), both with concurrent chemotherapy, for inoperable non–small-cell lung cancer (NSCLC). We hypothesized that PSPT exposes less lung tissue to radiation than IMRT and thereby reduces toxicity without compromising tumor control. The primary end points were grade ≥ 3 radiation pneumonitis (RP) and local failure (LF).Patients and MethodsEligible patients had stage IIB to IIIB NSCLC (or stage IV NSCLC with a single brain metastasis or recurrent lung or mediastinal disease after surgery) who were candidates for concurrent chemoradiation therapy. Pairs of treatment plans for IMRT and PSPT were created for each patient. Patients were eligible for random assignment only if both plans satisfied the same prespecified dose-volume constraints for at-risk organs at the same tumor dose.ResultsCompared with IMRT (n = 92), PSPT (n = 57) exposed less lung tissue to doses of 5 to ...