Normal tissue complication models for clinically relevant acute esophagitis (≥ grade 2) in patients treated with dose differentiated accelerated radiotherapy (DART-bid)

• DOI: 10.1186/s13014-015-0429-1
• Publication Date: 2015-05-27T14:39:02Z
• Authors: Franz Zehentmayr; Matthias Söhn; Ann-Katrin Exeli; Karl Wurstbauer; Almut Tröller; Heinz Deutschmann; Gerd Fastner; Christoph Fussl; Philipp Steininger; Manfred Kranzinger; Claus Belka; Michael Studnicka; Felix Sedlmayer
• Keywords: Esophagitis; Eosinophilic Esophagitis; Dart

One of the primary dose-limiting toxicities during thoracic irradiation is acute esophagitis (AE). The aim this study to investigate dosimetric and clinical predictors for AE grade ≥ 2 in patients treated with accelerated radiotherapy locally advanced non-small cell lung cancer (NSCLC). 66 NSCLC were included present analysis: 4 stage II, 44 IIIA 18 IIIB. All received induction chemotherapy followed by dose differentiated (DART-bid). Depending on size (mean three perpendicular diameters) tumors binned four groups: <2.5 cm 73.8 Gy, 2.5–4.5 79.2 4.5–6 84.6 >6 90 Gy. Patients 3D target splitting technique. In order estimate normal tissue complication probability (NTCP), two Lyman models cutoff-logistic regression model fitted data as statistical endpoint. Inter-model comparison was performed corrected Akaike information criterion (AICc), which calculates model’s quality fit (likelihood value) relation its complexity (i.e. number variables model) dataset. Toxicity documented prospectively according RTOG. median follow up 686 days (range 84–2921 days), 23/66 (35 %) experienced 2. actuarial local control rates 72.6 % 59.4 at 3 years, regional 91 both time points. Lyman-MED (D50 = 32.8 m 0.48) cutoff (Dc 38 Gy) provide most efficient current On multivariate analysis V38 (volume esophagus that receives Gy or above, 95 %-CI 28.2–57.3) significant predictor (HR 1.05, CI 1.01–1.09, p 0.007). Following high-dose rate slightly lower than reported concomitant radio-chemotherapy additional benefit markedly increased loco-regional tumor control. patient cohort found be V38. A second clinically useful parameter treatment planning may MED esophageal dose).