“…We further attribute the difference in results between our current models and the prior literature to a combination of the different toxicity endpoint assessed (grade 3 vs. grade 2), variance in radiation techniques, and implementation of resampling. Previously published reports using models developed using a median cohort size of 141 (well below our actual cohort), and median rate of radiation esophagitis of 11.1%, used logistic regression approaches [1,9,12,17,31,32,34,36,37,39], while some other studies would fit Lyman-Kutcher-Burman (LKB) models, both using pre-IMRT era cohorts [14,33], which may not reflect the current risks of radiation-induced toxicity in a contemporary setting. A more recent study used lasso regularization using a smaller cohort of 94 patients, where 16% developed radiation esophagitis [35].…”