Dosimetric predictors of esophageal toxicity after stereotactic body radiotherapy for central lung tumors.

ABSTRACT: Stereotactic body radiotherapy (SBRT) to central lung tumors can cause esophageal toxicity, but little is known about the incidence or risk factors. We reviewed central lung SBRT patients to identify dosimetric factors predictive of esophageal toxicity.We assessed esophageal toxicity in 125 SBRT patients. Using biological equivalent doses with ?/?=10 Gy (BED??), dose-volume histogram variables for the esophagus (Dv and Vd) were assessed for correlation with grade ?2 acute toxicity.Incidence of grade ?2 acute toxicity was 12% (n=15). Highly significant logistic models were generated for D?cc and Dmax (p<0.001). To keep the complication rate <20%, the model requires that D?cc?26.3 BED??. At 2 years, the probability of complication with BED??D?cc>14.4 Gy was 24%, compared to 1.6% if ?14.4 Gy.This novel analysis provides guidelines to predict acute esophageal toxicity in lung SBRT. Dose to the hottest 5cc and Dmax of the esophagus were the best predictors of toxicity. Converting the BED?? limits to physical doses, D?cc to the esophagus should be kept less than 16.8, 18.1 and 19.0 Gy for 3, 4, and 5 fractions, respectively, to keep the acute toxicity rate <20%.

SUBMITTER: Wu AJ 

PROVIDER: S-EPMC4254177 | biostudies-literature | 2014 Aug

REPOSITORIES: biostudies-literature