摘要
目的研究碳纤维体位固定板对宫颈癌放疗剂量的影响。方法在RayStation计划系统中创建碳纤维体位固定板模型,比较计划系统中模型板和实际测量中真实板2种情况下得到的衰减系数差异,验证体位固定板模型准确性;选取10例宫颈癌患者,在不添加体位固定板模型的CT图像上设计无板模型计划,计算剂量;无板模型计划完成后将此计划移植到添加体位固定板模型的CT图像上得到有板模型计划,计算剂量,比较无板模型计划、有板模型计划靶区(PTV)和危及器官(OAR)的剂量学差异;RayStation计划系统中建立2个ArcCHECK验证模体,分别为添加体位固定板模型ArcCHECK验证模体和不添加体位固定板模型Arc-CHECK验证模体,将10例宫颈癌计划分别移植到2种验证模体中进行剂量计算,在新华加速器下将Arc-CHECK验证模体置于体位固定板上,执行验证计划,比较计划系统中体位固定板模型的添加与否,对验证计划伽马通过率的影响。结果对于计划系统中创建的体位固定板模型准确性:计划系统和实际测量2种情况下得到的衰减系数偏差(d)<0.3%;对于宫颈癌计划:与无板模型计划比较,有板模型计划PTV和OAR的受照剂量明显偏低,其中PTV受照剂量平均偏低1%左右,不同OAR偏低程度不同,范围在3%以内;对于宫颈癌计划验证:有板模型验证计划的伽马通过率显著高于无板模型验证计划,3 mm/3%、2 mm/2%通过率分别提高了0.69%、1.50%左右。结论碳纤维体位固定板对宫颈癌患者的放疗剂量有一定的影响,为确保PTV剂量准确性,建议在计划设计时加入体位固定板模型。
Objective To study the effect of carbon fiber postural fixation plate on radiotherapy dose of cervical cancer.Methods The carbon fiber postural fixation plate model was created in the RayStation planning system,and the difference of attenuation coefficient between the model plate in the planning system and the real plate in the actual measurement was compared to verify the accuracy of the position fixing plate model.A total of 10 patients with cervical cancer were selected,and the plate-free plan was designed on the CT image without the fixed plate model,and the dose was calculated.After the plate-free plan was completed,the plan was transplanted to the CT image with the fixed plate model to obtain the plate plan,and the dose was calculated.The dosimetric differences of target volume(PTV)and organ at risk(OAR)between the platefree plan and the plate plan were compared.Two ArcCHECK verification phantoms were established in the RayStation planning system,which were the ArcCHECK verification phantom with the postural fixation plate model and the ArcCHECK verification phantom without the postural fixation plate model.The 10 cervical cancer plans were transplanted into two verification phantoms for dose calculation.Under the Xinhua accelerator,ArcCHECK was placed on the postural fixation plate to perform the validation plan,and the effect of the postural fixation plate model in the planning system on the gamma passing rate of the verification plan was compared.Results For the accuracy of the position fixation plate model was created in the planning system:the deviation(d)of the attenuation coefficient obtained in the planning system and the actual measurement is less than 0.3%.For the cervical cancer plan:compared with the plate without plan,the dose of PTV and OAR in the plate with plan was significantly lower.The average dose of PTV was about 1%lower,and the degree of OAR was different,ranging within 3%.For cervical cancer plan verification:the gamma pass rate of the plate model verification plan was significantly h
作者
郑倩倩
高文超
陈文彰
ZHENG Qianqian;GAO Wenchao;CHEN Wenzhang(Department of Radiotherapy,Shijingshan Teaching Hospital of Capital Medical University/Beijing Shijingshan Hospital,Beijing 100043,China;Department of Radiotherapy,Fifth Medical Center,Chinese PLA General Hospital,Beijing 100071,China)
出处
《重庆医学》
CAS
2023年第23期3626-3631,共6页
Chongqing medicine
关键词
碳纤维
体位固定板
板模型
宫颈癌
放疗剂量
伽马通过率
carbon fiber
posture fixing plate
plate model
cervical cancer
radiotherapy dose
gamma pass rate
