Involved-field irradiation in definitive chemoradiotherapy for locally advanced esophageal squamous cell carcinoma

BACKGROUND Since there is high local failure and poor survival for unresectable esophageal squamous cell carcinoma (ESCC), the necessity of elective node irradiation is controversial. The purpose of this study was to investigate the failure patterns and survival in patients with locally advanced ESCC receiving involved-field irradiation (IFI). METHODS A retrospective study was preformed on the clinical records of patients with locally advanced ESCC, who have received IFI with concurrent chemotherapy between January 2003 and January 2009. Comparing the target volume and first sites of failure, patterns of failure were defined as in-field, out-of-field regional lymph node and distant failure. The survivals were analyzed by different patterns of failure. RESULTS Eighty patients were included in our study. With a median follow-up of 52.6 months, failures were observed in 76 patients. In-field recurrence, distant metastasis, and out-of-field regional failure were seen in 53.75%, 41.25%, 30% patients, respectively. There were significant differences in OS for patients with and without in-field (median OS 14.2 vs.17.4 m, P=0.01)or distant failure(13.2 vs.15.9 m, P ≤ 0.0001), but not for out-of-field regional lymph node failure(both 14.5 m, P=0.665). CONCLUSIONS The solitary regional nodal failure of out-of-field was acceptable in advanced ESCC patients treated with IFI. In-field and distant failures remained the predominant patterns and negatively impacted survival more significantly. Further investigation is needed to establish the optimal radiotherapy field for these patients at advanced stage.