Analysis of dose–volume histogram parameters for radiation pneumonitis after definitive concurrent chemoradiotherapy for esophageal cancer

PurposeTo evaluate dose–volume histogram (DVH) parameters as predictors of radiation pneumonitis (RP) in esophageal cancer patients treated with definitive concurrent chemoradiotherapy.Patients and methodsThirty-seven esophageal cancer patients treated with radiotherapy with concomitant chemotherapy consisting of 5-fluorouracil and cisplatin were reviewed. Radiotherapy was delivered at 2 Gy per fraction to a total of 60 Gy. For most of the patients, two weeks of interruption was scheduled after 30 Gy. The percentage of lung volume receiving more than 5–50 Gy in increments of 5 Gy (V5–V50, respectively), and the mean lung dose (MLD) were analyzed.ResultsTen (27%) patients developed RP of grade 2; 2 (5%), grade 3; 0 (0%), grade 4; and 1 (3%), grade 5. By univariate analysis, all DVH parameters (i.e., V5–V50 and MLD) were significantly associated with grade ⩾2 RP (p < 0.01). The incidences of grade ⩾2 RP were 13%, 33%, and 78% in patients with V20s of ⩽24%, 25–36%, and ⩾37%, respectively. The optimal V20 threshold to predict symptomatic RP was 30.5% according to the receiver operating characteristics curve analysis.ConclusionDVH parameters were predictors of symptomatic RP and should be considered in the evaluation of treatment planning for esophageal cancer.