Stereotactic body radiation therapy (SBRT) for central early stage non-small cell lung cancer: results of a prospective phase I/II trial
Mené sur 74 patients atteints d'un cancer non à petites cellules et de stade précoce de la région centrale du poumon, cet essai de phase I/II (durée médiane de suivi pour la phase II : 27 mois) détermine la dose maximale tolérée d'une radiothérapie corporelle stéréotaxique puis évalue l'efficacité, du point de vue du contrôle local de la maladie et de la survie globale à 2 ans, et la toxicité de ce traitement
Introduction : We report results from a prospective phase I/II trial for patients with centrally-located, early-stage non-small cell lung cancer (NSCLC) receiving stereotactic body radiation therapy (SBRT). Methods : Eligible patients were medically inoperable with biopsy-proven NSCLC within 2 cm of the proximal bronchial tree or 5 mm of the mediastinal pleura or parietal pericardium. Phase I had 4 dose levels using 5 fractions: 9, 10, 11, and 12 Gy per fraction. The primary phase II objective was to determine if the maximum tolerated dose in phase I achieved local control >80% at 2 years. Results : Seventy-four patients were enrolled; 23 to phase I and 51 to phase II. Two phase I patients treated with 10 Gy x5 developed unrelated acute grade 3 lung toxicities which resolved. The phase II dose level selected was 11 Gy x5 fractions. The median follow-up for living phase II patients was 27 months (range: 9-58). Two-year local control using 11 Gy x5 fractions was 85% (95% CI: 62-95%). Two-year overall survival was 43% (95% CI: 28-57%). Three patients (6%, 95% CI: 1-17%) experienced acute grade 3 and 4 cardiac or pulmonary toxicities. Of the 41 patients evaluable for late cardiac and pulmonary toxicity, 11 (27%, 95% CI: 14-43%) developed grade 3, 5 (12%, 95% CI: 4-26%) developed grade 4, and 1 (4%, 95% CI: 0-13%) died of grade 5 toxicity. Conclusion : SBRT for central NSCLC using 11 Gy x5 fractions is tolerable and has excellent local control, but is associated severe late toxicity in some patients.