NRG Oncology RTOG 0915 (NCCTG N0927): A Randomized Phase II Study Comparing 2 Stereotactic Body Radiation Therapy (SBRT) Schedules for Medically Inoperable Patients with Stage I Peripheral Non-Small Cell Lung Cancer
Mené sur 94 patients inopérables atteints d'un cancer non à petites cellules de la région périphérique du poumon et de stade I (durée médiane de suivi : 30,2 mois), cet essai de phase II compare, du point de vue du taux de survie sans maladie et du taux de survie globale à 2 ans, l'efficacité de deux protocoles de radiothérapie stéréotaxique corporelle
Purpose : To compare 2 stereotactic body radiotherapy (SBRT) schedules for medically inoperable early-stage lung cancer to determine which produces the lowest rate of grade ≥ 3 protocol-specified adverse events (psAEs) at 1 year. Methods : Patients with biopsy-proven peripheral (greater than 2 cm from the central bronchial tree) T1/T2, N0 (clinically node negative by positron emission tomography), M0 tumors were eligible. Patients were randomized to receive either 34 Gy in one fraction (Arm 1) or 48 Gy in 4 consecutive daily fractions (Arm 2). Rigorous central accreditation and quality assurance confirmed treatment per protocol guidelines. This study was designed to detect a psAEs rate > 17% at a 10% significance level (1-sided) and 90% power. Secondary endpoints included rates of primary tumor control (PC), overall survival (OS) and disease-free survival (DFS) at 1 year. Designating the better of the two regimens was based on pre-specified rules of psAEs and PC for each Arm. Results : Ninety four patients were accrued between September 2009 and March 2011. Median follow up time was 30.2 months. Of 84 analyzable patients, 39 were in Arm 1 and 45 in Arm 2. Patient and tumor characteristics were balanced between Arms. Four (10.3%) patients on Arm 1 (95% confidence interval (CI): 2.9%-24.2%) and six (13.3%) patients on Arm 2 (95% CI: 5.1%-26.8%) experienced psAEs. The 2-year OS rate was 61.3% (95% CI: 44.2%-74.6%) for Arm 1 patients and 77.7% (95% CI: 62.5%-87.3%) for Arm 2. The 2-year DFS was 56.4% (95% 39.6%-70.2%) for Arm 1 and 71.1% (95% CI: 55.5%-82.1%) for Arm 2. The 1-year PC rate was 97.0% (95% CI: 84.2%-99.9%) for Arm 1 and 92.7% (80.1%-98.5%) for Arm 2. Conclusions : 34 Gy in 1 fraction met pre-specified criteria and of the two schedules, warrants further clinical research.