CAJ | 학술논문

目的：研究不同施源器对192 Ir源近距离治疗剂量分布的影响。方法核通公司＃101?001、＃084?350柱形施源器内管分别为塑料和不锈钢，串球为塑料，串球半径为1?00、1?25、1?50、1?75 cm。利用EGSnrc程序模拟体模中有施源器时的剂量分布，对比计划系统计算结果，分析材料、厚度和源驻留点个数不同情况下施源器对剂量分布影响。结果由两种施源器产生的剂量偏差与施源器半径之间无明显关系，有施源器存在时患者实际受量比计划量小，施源器＃101?001产生的剂量偏差≤1％，施源器＃084?350产生的剂量偏差接近3％，改变驻留点个数剂量偏差保持不变。结论对现阶段近距离治疗，在条件允许情况下尽量选用塑料材质施源器，长远来看为提高近距离治疗精确性，对现有剂量计算算法进行改进，考虑含有不锈钢等金属施源器对剂量分布的影响。
목적：연구불동시원기대192 Ir원근거리치료제량분포적영향。방법핵통공사＃101?001、＃084?350주형시원기내관분별위소료화불수강，천구위소료，천구반경위1?00、1?25、1?50、1?75 cm。이용EGSnrc정서모의체모중유시원기시적제량분포，대비계화계통계산결과，분석재료、후도화원주류점개수불동정황하시원기대제량분포영향。결과유량충시원기산생적제량편차여시원기반경지간무명현관계，유시원기존재시환자실제수량비계화량소，시원기＃101?001산생적제량편차≤1％，시원기＃084?350산생적제량편차접근3％，개변주류점개수제량편차보지불변。결론대현계단근거리치료，재조건윤허정황하진량선용소료재질시원기，장원래간위제고근거리치료정학성，대현유제량계산산법진행개진，고필함유불수강등금속시원기대제량분포적영향。
Objective To study the impacts of different applicators on dose distribution in 192 Ir brachytherapy. Methods The inner tubes of two cylinder applicators from Nucletron,#101?001 and#084?350, were made of plastic and stainless steel, respectively. The cylinder parts of them were made of plastic, and had four different radiuses:1?00 cm, 1?25 cm, 1?50 cm, and 1?75 cm. EGSnrc program was used to simulate dose distribution when applicators were present in a phantom, and the results calculated by the treatment planning system were compared with the results of EGSnrc. The impacts of applicators on dose distribution were analyzed with different materials, thickness, and numbers of resident source. Results There was no significant relationship between dose deviation and the radius for the two applicators. When an applicator was present, the actual dose delivered to a patient was smaller than the planned dose. The dose deviation of the applicator#101?001 was no more than 1%, while the dose deviation of the applicator#084?350 was close to 3%. The dose deviation remained the same when the number of resident source changed. Conclusions The plastic applicator, if possible, is the best choice for brachytherapy right now. In a long term, in order to promote the accuracy of brachytherapy, current dosimetry algorithm should be improved, and the impacts of the applicator made of metal, such as stainless steel, on dose distribution should be taken into account.