Involved-field high-dose chemoradiotherapy with respiratory motion management for esophageal squamous cell carcinoma

We investigated the clinical outcomes of involved-field high-dose (≥66 Gy) chemoradiotherapy (CRT) combined with respiratory motion management for esophageal squamous cell carcinoma (ESCC).

Patients who underwent definitive CRT for histologically confirmed ESCC in our department between 2012 and 2018 were retrospectively analyzed. Respiratory motion management strategies included breath-holding (63%) and mask immobilization (29%) based on individual measurements of respiratory tumor motion using radiographic fluoroscopy with endoscopically placed clip markers as landmarks. We evaluated patient characteristics, treatment efficacy, failure patterns, and toxicities.

We enrolled 35 patients with a prescribed dose of 66-70 Gy in 33-35 fractions. The overall response rate within 6 months post-CRT was 94.3%; the median follow-up period for survivors was 43 months. The 2-year overall survival (OS), progression-free survival, and locoregional failure-free survival rates were 51.4%, 42.9%, and 42.9%, respectively. A significant difference in OS was observed between patients with and without esophageal fistulas after CRT (p = 0.002, log-rank test). Disease failure occurred in 16 patients (45.7%), including one (2.9%) with out-of-field regional nodal failure. Major grade 3 or higher toxicities included decreased white blood cell count (48.6%), neutrophil count (34.3%), and esophageal stenosis (31.4%). No grade 3 or higher cardiopulmonary toxicities were observed. Bronchial/tracheal tumor compression and a higher radiotherapy dose (70 Gy) were significantly correlated with esophageal fistulas.

Involved-field high-dose CRT with respiratory motion management may be a feasible treatment option for ESCC. However, a comprehensive assessment of esophageal fistula risk is required to identify suitable candidates.