The development and dose-volume parameters of radiation esophagitis in patients with breast cancer undergoing hypofractionated regional nodal irradiation

Background: Radiation esophagitis (RE) is an acute toxicity of regional nodal irradiation (RNI) in breast cancer patients. Aims and Objectives: This study evaluated the incidence of RE and its association with esophageal dose-volume parameters inpatients receiving hypofractionated RNI. Materials and Methods: This prospective observational study was conducted and included 56 postmastectomy breast cancer patients receiving 40 Gy in 15 fractions with three-dimensional conformal radiotherapy. Acute symptomatic RE was assessed using Common Terminology Criteria for Adverse Events version 5.0. Esophageal volume, Dmean, Dmax, V10, and V20 were recorded. Categorical variables were compared using chi-square or Fisher’s exact test, and continuous variables using the Mann–Whitney U test. Results: The mean age was 54.8±8.7 years, and 37 (66.1%) patients received internal mammary nodal irradiation. Grade 2 RE (G2RE) developed in 21 (37.5%) patients, while 35 (62.5%) had no RE. No Grade 3–5 RE occurred. Onset occurred during the 2nd week, with a mean of 8.7±0.8 fractions. RE was more frequent with left-sided tumors than right-sided tumors (60.7% vs. 14.3%; P<0.001). Dmean, V10, and V20 were significantly higher in patients with RE (all P<0.001), whereas esophageal volume (P=0.338) and Dmax (P=0.056) were not significantly different. Conclusion: Acute G2RE occurred in 37.5% of postmastectomy patients receiving hypofractionated RNI. Left-sided treatment and higher esophageal Dmean, V10, and V20 were significantly associated with RE. These findings support consideration of esophageal contouring during RNI planning.