Involved field irradiation (IFI) versus elective nodal irradiation (ENI) in combination with concurrent chemotherapy for esophageal thoracic squamous cell cancer: a prospective, randomized, multicenter, controlled study

Abstract

Objective This study was conducted to evaluate treatment-related toxicities, the patterns of failure, overall survival (OS) and progression-free survival (PFS) by comparing IFI with ENI in combination with chemotherapy. Methods Eligible patients were treated with concurrent chemoradiotherapy and randomized into either an IFI or ENI arm. The primary end points wereacute treatment-related toxicities. The secondary end points were patterns of failure, OS and PFS. Kaplan-Meier survival rate of the method for calculating the Logrank test difference method. Results Between April 2012 and October 2016, a total of 228 patients were enrolled from nine centers in china. Grade≥3, Grade≥2 radiation esophagitis and pneumonitis in the IFI arm were significantly lower than that of the ENI arm (P=0.018, 0.027). No significant differences were observed in overall failure rates, loco-regional failure, distant failure rates, in-field and out-field lymph node failure between the two arms (P=0.401, 0.561, 0.510, 0.561, 0.681). The 1-, 2-, 3-, 4-yearand median OS in the ENI arm and IFI arm were 84.1%, 57.3%, 39.4%, 31.6%, 28 months and 83.6%, 62.1%, 44.5%, 31.5%, 32 months (P=0.654), respectively. The 1-, 2-, 3-yearand median PFS in the ENI arm and IFI arm were 71.9%, 42.3%, 32.7%, 20 months and 70.1%, 45.0%, 35.9%, 22 months (P=0.885), respectively. Conclusions Compared to ENI, IFI resulted in decreased radiation pneumonitis and esophagitis without sacrificing loco-regional lymph nodal control, PFS and OS in thoracic ESCC. Clinical Trial Registry Chinese Clinical trail registry, registration number: NCT01551589. Key words: Esophageal neoplasms/radiotherapy; Elective nodal irradiation; Involved field irradiation; Toxicities; Patterns of failure