ABSTRACT
Objective:To analyze whether involved-field irradiation (IFI) was associated with improved survival and reduced treatment-related adverse events compared with elective nodal irradiation (ENI) in Chinese patients with esophageal squamous cell carcinoma receiving radiotherapy.Methods:Literature review was conducted from CNKI, Wanfang Data, PubMed, Embase, Web of Science and Cochrane Central databases (until July 31, 2022). Relevant data were collected according to the inclusion and exclusion criteria. Primary outcomes included overall survival (OS) rate and treatment-related adverse events. Secondary outcomes included progression-free survival (PFS) rate and local control rate (LCR). Risk of bias was assessed using the Cochrane Risk of Bias tool. The quality of the results was assessed by using the meta analysis of Evidence Evaluation and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) methods.Results:A total of 7 articles with 918 patients were included of which 465 received IFI and 453 received ENI. The 1-, 2-, 3-and 5-year OS rates in the IFI group were not significantly different from those in the ENI group (1-year OS rate: RR=1.00, 95% CI=0.94-1.07, P=0.97, high certainty; 2-year OS rate: RR=1.01, 95% CI=0.90-1.13, P=0.90, high certainty; 3-year OS rate: RR=0.86, 95% CI=0.71-1.05, P=0.14, high certainty; 5-year OS rate: RR=0.76, 95% CI=0.42-1.37, P=0.36, low certainty). In the IFI group, patients with ≥grade 2 acute radiation esophagitis ( RR=0.71, 95% CI=0.58-0.87, P=0.001, high certainty), ≥grade 3 acute radiation esophagitis ( RR=0.39, 95% CI=0.24-0.64, P<0.001, high certainty) and ≥grade 2 acute radiation pneumonitis ( RR=0.72, 95% CI=0.52-0.99, P=0.04, high certainty) were significantly lower compared with those in the ENI group. However, no significant differences were observed in the incidence of ≥grade 3 late radiation esophagitis, ≥grade 3 acute radiation pneumonitis and ≥grade 3 late radiation pneumonitis between two groups. No significant differences were noted in the 1-, 2-, 3-PFS rates and LCR between two groups. Conclusions:For Chinese patients with esophageal squamous cell carcinoma, IFI and ENI yield similar efficacy in terms of OS, PFS and LCR. However, IFI has a lower incidence of ≥grade 2 acute radiation esophagitis, ≥grade 3 acute radiation esophagitis and ≥grade 2 acute radiation pneumonitis than ENI.