CAJ | 학술논문

目的研究调强计划射野特征参数之间的关系,以及射野特征参数对调强计划绝对剂量验证准确性的影响.方法使用Pinnacle 7.6c治疗计划系统,直接子野优化方法设计43例调强放射治疗计划,移植到固体水模.使用0.13 cc Farmer型标准电离室(IBA Corp),DOSE1剂量仪测量绝对剂量.统计43例调强病例的射野特征参数,分析其相互关系,并统计验证误差,分析射野特征参数与验证结果的相关性.结果各射野特征描述参数之间存在相互联系(P＜0.05).测量偏差与各射野特征参数均显著相关.子野数大于80个的IMRT计划,剂量偏差值大于3％；子野数小于80,多数计划的剂量偏差值小于3％.子野数大于100个的IMRT计划,一部分计划的剂量偏差值大于4％；子野数小于100个时,剂量偏差值均小于4％.结论从治疗计划设计角度而言,应在临床可以接受的情况下,尽量减少总射野数和总子野数,总子野数应控制在80个以内,可减少调强放疗计划验证偏差.
목적 연구조강계화사야특정삼수지간적관계,이급사야특정삼수대조강계화절대제량험증준학성적영향.방법 사용Pinnacle 7.6c치료계화계통,직접자야우화방법설계43례조강방사치료계화,이식도고체수모.사용0.13 cc Farmer형표준전리실(IBA Corp),DOSE1제량의측량절대제량.통계43례조강병례적사야특정삼수,분석기상호관계,병통계험증오차,분석사야특정삼수여험증결과적상관성.결과 각사야특정묘술삼수지간존재상호련계(P＜0.05).측량편차여각사야특정삼수균현저상관.자야수대우80개적IMRT계화,제량편차치대우3％；자야수소우80,다수계화적제량편차치소우3％.자야수대우100개적IMRT계화,일부분계화적제량편차치대우4％；자야수소우100개시,제량편차치균소우4％.결론 종치료계화설계각도이언,응재림상가이접수적정황하,진량감소총사야수화총자야수,총자야수응공제재80개이내,가감소조강방료계화험증편차.
Objective To study the relationship between parameter settings in the intensity-modulated radiation therapy (IMRT) planning in order to explore the effect of parameters on absolute dose verification.Methods Forty-three esophageal carcinoma cases were optimized with Pinnacle 7.6c by experienced physicist using appropriate optimization parameters and dose constraints with a number of iterations to meet the clinical acceptance criteria.The plans were copied to water-phantem,0.13 cc ion Farmer chamber and DOSE1 dosimeter was used to measure the absolute dose.The statistical data of the parameters of beams for the 43 cases were collected,and the relationships among them were analyzed.The statistical data of the dosimetry error were collected,and comparative analysis was made for the relation between the parameters of beams and ion chamber absolute dose verification results.Results The parameters of beams were correlated among each other.Obvious affiliation existed between the dose accuracy and parameter settings.When the beam segment number of IMRT plan was more than 80,the dose deviation would be greater than 3％ ; however,if the beam segment number was less than 80,the dose deviation was smaller than 3％.When the beam segment number was more than 100,part of the dose deviation of this plan was greater than 4％.On the contrary,if the beam segment number was less than 100,the dose deviation was smaller than 4％ definitely.Conclusions In order to decrease the absolute dose verification error,less beam angles and less beam segments are needed and the beam segment number should be controlled within the range of 80.