Simultaneous integrated boost intensity‐modulated radiotherapy with or without concurrent chemotherapy in patients with esophageal squamous cell carcinoma: A multicenter, open‐label, randomized, phase III clinical trial

This multicenter, randomized phase III clinical trial assesses the efficacy and toxicity of SIB-RT with/without concurrent chemotherapy in patients with inoperable esophageal squamous cell carcinoma (ESCC) in the era of intensity-modulated RT and was conducted between December 2017 and November 2020. Patients with inoperable clinical stage II-III diseases or clinical stage IV disease with metastatic lymph nodes in supraclavicular/celiac trunk area were enrolled and randomized to receive SIB-RT concurrent with chemotherapy (SIB-RT + CT arm, N = 82) or SIB-RT alone (SIB-RT arm, N = 82). Planning gross tumor volume and planning target volume were administered with 59.92 and 50.4 Gy of radiation, respectively, in 28 fractions. The concurrent chemotherapy regimen comprised weekly doses of paclitaxel and nedaplatin for 5 weeks. The primary endpoint was overall survival (OS). The secondary endpoints were treatment response, progression-free survival (PFS), quality of life (QoL), and toxicity profiles. The SIB-RT + CT arm exhibited a superior treatment response to that in SIB-RT arm (69.5% vs. 53.7%, p = .04). The 5-year OS in SIB-RT arm and SIB-RT + CT arm was 23.9% vs. 28.8% (p = .33). The 5-year PFS in SIB-RT arm and SIB-RT + CT arm was 23.9% vs. 27.4% (p = .22). The improvement of EORTC QLQ-OES18 dysphagia subscale score was higher in SIB-RT + CT arm compared with SIB-RT arm (p = .02). The incidences of grade 3 or higher leukopenia and nausea were higher in SIB-RT + CT arm (p < .01 and p = .01). SIB-RT should be realized as the essential treatment modality for inoperable ESCC. SIB-RT + CT should be the preferred treatment option, as it affords a superior treatment response and greater dysphagia relief.