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

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 were acute 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- year and 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- year and 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. (authors)