Long-term outcomes after proton therapy, with concurrent chemotherapy, for stage II–III inoperable non-small cell lung cancer

Abstract

PurposeWe report long-term disease control, survival, and toxicity for patients with locally advanced non-small cell lung cancer prospectively treated with concurrent proton therapy and chemotherapy on a nonrandomized case-only observational study. MethodsAll patients received passive-scatter proton therapy, planned with 4D-CT–based simulation; all received proton therapy concurrent with weekly chemotherapy. Endpoints were local and distant control, disease-free survival (DFS), and overall survival (OS). ResultsThe 134 patients (21 stage II, 113 stage III; median age 69years) had a median gross tumor volume (GTV) of 70cm3 (range, 5–753cm3); 77 patients (57%) received 74Gy(RBE), and 57 (42%) received 60–72Gy(RBE) (range, 60–74.1Gy(RBE)). At a median follow-up time of 4.7years, median OS times were 40.4months (stage II) and 30.4months (stage III). Five-year DFS rates were 17.3% (stage II) and 18.0% (stage III). OS, DFS, and local and distant control rates at 5years did not differ by disease stage. Age and GTV were related to OS and DFS. Toxicity was tolerable, with 1 grade 4 esophagitis and 16 grade 3 events (2 pneumonitis, 6 esophagitis, 8 dermatitis). ConclusionThis report of outcomes after proton therapy for 134 patients indicated that this regimen produced excellent OS with tolerable toxicity.