Abstract
Esophagitis is common in patients treated with definitive radiotherapy for local-regional advanced non small cell lung cancer (NSCLC). The purpose of this study was to estimate the dose-effect relationship using clinical and dosimetric parameters in patients receiving intensity modulated radiotherapy (IMRT) and concomitant chemotherapy (CCT).
Between 2009 and 2013, 117 patients with stages IIB-IIIB NSCLC were treated in a multicenter randomized phase II trial with 2 cycles of induction chemotherapy followed by IMRT and CCT. The esophagitis was prospectively scored using the Common Toxicity Criteria 3.0. Clinical and dosimetric variables were analyzed for the correlation with grade ⩾2 esophagitis through logistic regression.
Grade 2 esophagitis was experienced by 31 (27%). All models including gender, institution, a dosimetric parameter and a position parameter were significantly associated with esophagitis. The two models using the relative esophagus volume irradiated above 40 Gy (V40, OR=2.18/10% volume) or the length of esophagus irradiated above 40 Gy (L40, OR=4.03/5 cm) were optimal. The upper part of esophagus was more sensitive and females experienced more toxicity than men.
V40 and L40 were most effective dosimetric predictors of grade ⩾2 esophagitis. The upper part of esophagus was more sensitive.