Comparison of dose distribufions between conformal and intensity-modulated radiotherapy for the upper esophageal carcinoma / 中华放射肿瘤学杂志

ABSTRACT

Objective To evaluate the optimized conformal and IMRT plans for the upper esophageal carcinoma. Methods Eight patients with upper esophageal carcinoma underwent CT simulation.GTV was contoured on the CT image,referring the esophagogram and endoscopy simuhaneously,then CTV and PTV were also defined using the same criteria.Different conformal radiotherapy plans consisting of 3 fields(F),4F or 6F,IMRT plans consisting of 3F,4F,5F,7F,9F or 11F,and a simplified IMRT(s-IMRT)plan were designed for these patients.The minimum prescription dose that 95%of PTV volume received was 6000 cGy.Dose distributions of the PTV and OARs in different 3 DCRT and IMRT plans were compared and the optimized plans for the upper esophageal carcinoma were then recommended. Resuits Dose and volume parameters of PTV were similar among the 3DCRT plans(P＞0.05).4F 3DCRT plan reduced lung V20 as compared to 6F plan(P＜0.05),and mean lung dose(MLD)of 3F and 6F 3DCRT plans were higher than that of4F plan(P＜0.05).PTV D100 of 3F IMRT plan was lower than that of 9F and 11F plans(P＜0.05).IV of 4F IMRT plan was larger than that of 9F and 11F IMRT plans(P＜0.05).PTV dose and volume parameters of the 9F IMRT and 1 1 F IMRT were similar comparing with 5F.7F and s-IMRT plans,and OARs dose was also similar among IMRT plans(P＞0.05).PTV CI,D100,D95,V100 and V95 of the 4F 3DCRT plan were all lower than those of 5F,7F and s-IMRT plans(P＜0.05).5F,7F and s-IMRT plans reduced lung V20 as compared to 4F 3DCRT plan(P＜0.05).Conclusions For the upper esophageal carcinoma.4F 3DCRT plan is recommended among the 3DCRT plans.5F.7F and s-IMRT plans are recommended among the IMRT plans,which are superior than 4F 3 DCRT plan.