The Implication of Failure Patterns After Neoadjuvant Chemoradiation Therapy With Small Involved Field in Esophageal...

This study evaluated the feasibility of involved-field irradiation (IFI) with a small margin (SM) in patients with esophageal squamous cell carcinoma (ESCC) undergoing neoadjuvant chemoradiotherapy.

We retrospectively reviewed 511 patients with ESCC who underwent neoadjuvant chemoradiation therapy followed by radical esophagectomy between 2016 and 2022. The IFI was routinely applied. The clinical target volume was defined as the primary gross tumor volume plus a 2.0 to 3.0 cm longitudinal and 0.5 to 1.0 cm circumferential margin, and the nodal gross tumor volume plus a 0.5 to 1.0 cm margin, with modifications. Patients receiving a 2 cm longitudinal margin without further extension were classified as the SM group (n = 366); the others comprised the large-margin group. With radical esophagectomy, 3-field lymph node (LN) dissection was performed in 212 patients (41.5%), whereas 296 patients (57.9%) underwent 2-field LN dissection. Failure patterns, locoregional control, and survival outcomes were analyzed. Regional recurrence included LN defined by the American Joint Committee on Cancer eighth edition and supraclavicular nodes.

During the median follow-up of 44.8 months, 213 patients (41.7%) experienced recurrence. First recurrences were locoregional recurrence (LRR) in 120 (23.5%), nonregional LN in 56 (11.0%), and distant metastases in 153 (29.9%) patients. Among LRR cases, 52 patients (10.2%) had infield failures, 28 (5.5%) had both infield and outfield failures, and 40 (7.8%) had outfield failures. Isolated outfield LRR occurred in only 17 patients (3.3%), of whom only 4 would have had their lesions covered by elective nodal irradiation. Locoregional control, progression-free survival, and overall survival did not differ between the SM and large-margin groups.

IFI with SM demonstrated favorable outcomes and minimal isolated outfield recurrence, supporting its feasibility as a neoadjuvant setting for ESCC.