Patterns of locoregional failure in locally advanced non-small cell lung cancer treated with definitive conformal radiotherapy: Results from the Gating 2006 trial

• Published in: Radiotherapy and oncology 2018-02, Vol.126 (2), p.291-299
• Main Authors: Jouglar, Emmanuel, Isnardi, Vanina, Goulon, Dorothée, Ségura-Ferlay, Céline, Ayadi, Myriam, Dupuy, Claire, Douillard, Jean-Yves, Mahé, Marc-André, Claude, Line
• Format: Article
• Language: English
• Subjects: 18FDG PET-CT; Adult; Aged; Aged, 80 and over; Carcinoma, Non-Small-Cell Lung - diagnostic imaging; Carcinoma, Non-Small-Cell Lung - pathology; Carcinoma, Non-Small-Cell Lung - radiotherapy; Conformal radiotherapy; Disease-Free Survival; Dosimetric analysis; Female; Fluorodeoxyglucose F18; Humans; Locoregional failure; Lung cancer; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - pathology; Lung Neoplasms - radiotherapy; Male; Middle Aged; Neoplasm Recurrence, Local - pathology; Positron Emission Tomography Computed Tomography - methods; Prospective Studies; Radiopharmaceuticals; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Conformal
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2017.11.002

To determine the patterns of locoregional failure (LRF) in patients with locally advanced non-small cell lung cancer treated with definitive radiotherapy (RT). One hundred and fifty-four patients from the Gating 2006 prospective randomized trial were treated with conformal RT with or without respiratory motion management. For patients with a LRF as first event, treatment planning with simulation CT, pre-treatment 18FDG PET-CT and post-treatment images demonstrating recurrence were registered and analyzed. Measurable LRF was contoured (rGTV) and classified as in-field, marginal, or out-of-field. Median follow-up was 27.8 months. Forty-eight patients presented with LRF. One-year and 2-year locoregional disease-free survival rates were 77% (95% CI 70–83) and 72% (95% CI 64–79) respectively. 79% of the patients with LRF as first event relapsed within the RT field (55% isolated), 30% had marginal LRF component. Isolated out-of-field failure occurred in only 3% of all patients. The regions of highest FDG-uptake on pre-treatment PET-CT were located within the recurrence in 91% of patients with in-field LRF. In-field failure was the most common pattern of failure. Escalated dose RT with high-dose fractions guided by PET parameters warrants further investigation.