The esophageal dose-volume parameters for predicting Grade I-II acute esophagitis correlated with weight loss and serum albumin decrease in lung cancer radiotherapy.

Abstract

Acute esophagitis (AE) is a commonly encountered side effect of curative thoracic radiotherapy (CTRT) for lung cancer patients. Nevertheless, its identification for widely used scoring systems depends on patients' statements. It is aimed to evaluate the correlation between the esophagus doses during CTRT and Grade 1-2 AE, weight change, and change in serum albumin (Alb) levels. The data collected from 124 lung cancer patients treated with ≥60 Gy CTRT were evaluated retrospectively. Weight and serum Alb level difference of each patient, throughout CTRT, were calculated. The percentage of the esophagus volume receiving ≥5 Gy (V5), V10, V35, V50, and V60; the absolute esophagus volume receiving ≥60 Gy (V60(cc)); the length of esophagus receiving ≥60 Gy (L60); the average esophagus dose (Dmean); and the maximum esophagus dose (Dmax) were the dose parameters calculated. The correlations were performed by Spearman's rank correlation coefficient. Grade 1 and Grade 2 AE were reported in 62 and 25 patients, respectively. All of the dose parameters were correlated with Grade 1-2 AE (P < 0.001) and weight loss (P < 0.001 for all, except Dmax P = 0.018). Decrease in serum Alb level was significantly correlated with all the parameters, but V5 and V10. Receiver operating characteristic curve analysis was performed for five parameters with the highest correlation coefficient (V35, V50, V60(%), V60(cc), and Dmean), and the cutoff values were 39.5%, 28.17%, 2.21%, 0.5cc, and 26.04 Gy, respectively. The correlation of the dose parameters that might be effective on Grade 1-2 AE with the weight loss and Alb loss was investigated, and the cutoff values corresponding to the best sensitivity and specificity were identified.