简化调强技术在胃癌术后放射治疗中的应用

Application of Simplified Intenstiy Modulated Radiation Therapy for Gastric Cancer

目的:研究评价简化调强技术在胃癌术后辅助放射治疗中的剂量学与应用特点。方法:采用10例胃癌术后辅助放疗的病人,分别设计7野IMRT计划和5野sIMRT计划,利用剂量体积直方图比较这两种计划的适形度指数(CI)、不均匀度指数(SI)、总跳数以及相关的正常组织的受照射剂量。结果:7野调强计划的适形度指数和不均匀度指数都好于简化调强计划,但是简化调强计划在肝脏的受照剂量上均好于7野调强计划,总跳数也少于前者。结论简化调强技术对正常组织的照射剂量与总机器跳数明显少于7野调强计划,虽然在靶区的适形度和均匀性上不如前者,但也能满足靶区剂量条件,所以简化调强技术在临床应用中具有更便捷且能降低放疗毒性的优势。

Objective： To investigate the dosimetry and application characteristic of the simplified intenstiy modulated radiation therapy for gastric cancer.Methods： Ten patients who treated with adjuvant radiaton therapy after surgery were enrolled in this study.7-field IMRT plan and 5-field sIMRT plan were performed for each patient and compared by the comformity index,heterogeneity index,total MU and irradiation dose of related normal tissue.Results： The comformity index and heterogeneity index of 7-field IMRT plans were superior to which of sIMRT plans,but sIMRT plans were better than 7-field IMRT plans in irradiation dose of liver and total MU.Conculsions： Although the CI and HI of sIMRT plans were inferior to 7-field IMRT plans, the irradiation dose of normal tissue and total MU were less than the former obviously and can meet the dose requisition for target volume.So,sIMRT technique can provid more effective and lower toxcity in clinical application.