Standard radiotherapy (RT) for locally advanced NSCLC (LA-NSCLC) employs a uniform dose of approximately 60 Gy. Recent trials demonstrated that radiotherapy dose escalation may not improve outcomes and may cause added toxicity. XXX previously performed a single-arm trial testing a personalized, risk-adapted, and de-intensified RT strategy. We now report findings from a randomized trial testing this novel approach. LA-NSCLC patients with ECOG performance status 0-2 were eligible for this trial. Metabolic tumor volume (MTV) for each pulmonary tumor and involved lymph node was calculated using FDG-PET. Participants were randomized 1:1 to receive standard RT (60 Gy in 30 fractions delivered to pulmonary tumors and involved lymph nodes) versus dose-painted RT (55 Gy delivered to tumors and lymph nodes with metabolic volume exceeding 20 cm3 and 44-48 Gy to other lesions, all in 20 fractions). Concurrent chemotherapy and standard adjuvant therapy were given in both arms. The primary objective was to characterize patient-reported outcomes utilizing PRO-CTCAE. Secondary objectives included comparing outcomes between study arms. Fifty patients were enrolled. The most common grade 3 patient-reported adverse events within 90 days of RT completion were dysphagia (38%), fatigue (38%), cough (32%), and wheezing (28%). The median progression-free survival (PFS) duration is 18 months, and the median overall survival (OS) duration is 42 months. PFS and OS rates are similar across study arms (logrank p=0.562 and 0.765, respectively). There have been three cases of in-field disease progression, with one in the control arm and two in the dose-painted arm. Grade 3-4 lymphopenia was reduced with dose-painted RT (48% v. 81%, chi-square p=0.012). High-grade patient-reported toxicity in LA-NSCLC patients who are treated with concurrent chemoradiotherapy is common. We found no evidence that risk-adapted radiotherapy de-escalation compromises clinical outcomes. Follow-up studies testing the ability of this approach to improve the safety profile of chemoradiotherapy are warranted.
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