Preliminary evaluation of postoperative radiotherapy with small T-shaped field in thoracic esophageal squamous cell carcinoma.

Abstract

The optimal extent of clinical target volume (CTV) for postoperative radiotherapy in complete resection thoracic esophageal squamous cell carcinoma (ESCC) patients remains controversial. This study aimed to evaluate the primary outcome of postoperative radiotherapy with small T-shaped field encompassing the tumor bed, positive lymph node areas, bilateral supraclavicular areas, and upper and middle mediastinal areas. A total of 96 thoracic ESCC patients were enrolled, with 49 and 47 cases in the small T-shaped field group and tumor bed field group, respectively. All of the patients received intensity-modulated radiotherapy (IMRT), and chemotherapy was administrated concurrently or sequentially. The median time of follow-up was 25 (range, 7-47) months. At the end of the follow-up period, in the small T-shaped field group, 8 (16.3%) patients had locoregional recurrence (LRR) and 12 (24.5%) had distant metastasis (DM), while in the tumor bed field group, 15 (31.9%) patients had LRR and 11 (23.4%) had DM. Although the rates of LRR and DM were not statistically different, LRR incidence in the mediastinal lymph nodes of the small T-shaped field group was strikingly lower than that of the tumor bed field group. The overall survival (OS) of the small T-shaped field group was higher than that of the tumor bed field group, but the difference was not statistically significance. In addition, we observed grade 2 radiation pneumonitis and grade 2 radiation esophagitis in both groups; all of these side effects were tolerable and controllable, and none of the patients experienced ≥ grade 3 pneumonitis, esophagitis, esophageal stricture, or life-threatening hemorrhage. In conclusion, radiotherapy with small T-shaped field might be a feasible and efficacious postoperative approach for ESCC patients.