Do the patients with esophageal cancer benefit from higher radiation dose?——Dose escalation of 3-D conformal radiation therapy in the patients with esophageal cancer

Background and purpose:It may improve local control to increase radiation dose for esophageal cancer.The purpose of the study is to obtain the maximum tolerance dose(MTD)and assess toxicity of 3-D conformal radiation therapy(3-DCRT)for esophageal cancer.Methods:The scheduled dose escalation ranged from 70 Gy to 76 Gy.All patients received conventional fractionation irradiation to a dose of 46 Gy/23 Fx/4.5 weeks,followed by accelerated hyperfractionation irradiation using reduced fields,1.5 Gy twice a day,to a dose of 24 Gy/16 Fx.The criteria for stopping dose escalation was grade ≥3 radiation-induced toxicity in ≥15% patients.Results:From July,2000 to July,2001,18 patients were enrolled.Five patients completed a total dose of 70 Gy and an additional 5 patients received 73 Gy.Eight patients completed a total dose of 76 Gy.No patient occurred grade ≥3 radiation-induced toxicity at the level of 70 Gy.Four patients(80%)experienced grade ≥3 radiation-induced late toxicity(2 patients died of late radiation-induced pneumonitis)at the level of 73 Gy.Five patients(62.5%)experienced grade ≥3 radiation-induced acute toxicity and 6 patients(75%)had grade≥3 late toxicity(1 patients died of late radiation-induced esophagitis,and 2 patients died of late radiation-induced pneumonitis)at the level of 76 Gy.Conclusions:Based on the clinical trial,there were more severe radiation-induced toxicities when the patients with esophageal cancer received more than 70 Gy.