Monaco计划系统中鼻咽癌患者颈部皮肤受量的剂量学研究  

Neck Skin Dose for Nasopharyngeal Carcinoma Patients in Monaco Radiotherapy Planning System:A Dosimetric Study

作　　者：陈伟[1] 何海[1] Chen Wei;He Hai(Department of Radiotherapy,The Second People's Hospital of Neijiang,Neijiang,Sichuan 641000,China)

机构地区：[1]内江市第二人民医院放疗科,四川内江641000

出　　处：《四川医学》2024年第9期951-954,共4页Sichuan Medical Journal

摘　　要：目的探索在Monaco计划系统中制定鼻咽癌放疗计划时,如何降低鼻咽癌患者颈部皮肤受照剂量。方法随机选取我院已完成治疗的中晚期鼻咽癌患者计划15例,将放疗靶区上下各1 cm范围内由系统自动生成的皮肤(Skin1)内缩3 mm形成新的皮肤轮廓(Skin2),并由二者通过减法运算得到一个厚度为3 mm的皮肤层环形结构(Skin3)。在Monaco计划系统中按处方要求重新制定放疗计划时,增加Parallel函数对该环形结构进行体积剂量的调控,并对两组计划的数据进行对比分析。结果两组计划的原发部位PGTVnx D_(95)、颈部淋巴结PGTVnd D_(95),高危淋巴引流区PCTV1 D_(95)的靶区剂量分布以及危及器官受照剂量相比较,差异均无统计学意义(P>0.05);两组预防照射区PCTV2 D_(95)和机器输出跳数(MU)相比较,差异有统计学意义(P<0.05),单独调控后机器的输出(MU)会增加6.15%;两组PCTV2的剂量分布适形度指数(CI)和皮肤受照剂量差异有统计学意义(P<0.05),单独调控后PCTV2 CI增加6.41%且皮肤受量下降明显,其中Skin3V 50下降71.56%。结论在Monaco计划系统中对鼻咽癌患者颈部皮肤进行剂量调控,虽然会在一定程度上引起机器输出的增加,但是会对靶区剂量分布进行再调整,剂量约束更加优化,皮肤受量也能得到很好的调控,这对于降低患者皮肤受量提高放疗质量能够起到相应的促进作用。Objective To investigate the method to reduce nasopharyngeal carcinoma patients neck skin radiation dose when making radiotherapy plan in Monaco system.Methods 15 patients with advanced nasopharyngeal carcinoma that had been treated were selected randomly.The neck skin generated automatically by the system within 1 cm above and below the radiotherapy target area was Skin1,Skin2 was formed by shrinking the skin1 into 3 mm,and then a 3 mm thick circular skin layer was obtained by subtracting skin1 and skin2(Skin3).In the Monaco planning system,radiotherapy plan was reformulated according to the prescription requirement,and the volume dose of the Skin3 was adjusted by using the Parallel function.Results There were no statistically significant differences(P>0.05)in the target dose distribution of the primary site(PGTVnx)D_(95),the cervical lymph nodes(PGTVnd)D_(95),and the high-risk lymphatic drainage area(PCTV1)D_(95),as well as the radiation dose to organs at risk.There were statistically significant differences(P<0.05)in the number of monitor units(MU)and the prophylactic irradiation areas(PCTV2)D_(95)between the two groups of plans,and the monitor units(MU)was increased by 6.15%after independent regulation.At the same time,the PCTV2 dose distribution conformity index(CI)and skin irradiation dose had statistically significant differences(P<0.05).After independent regulation,the CI of PCTV2 increased by 6.41%and skin irradiation dose decreased significantly,with Skin3V 50 decreased by 71.56%.Conclusion In the Monaco plan system,the dose control of the Skin3 would increase the monitor units,but the dose distribution would be adjusted and the dose restriction will be optimized,at the same time the skin dose could be well regulated,it is very important to reduce the skin dose and improve the quality of radiotherapy.

关 键 词：鼻咽癌 放射治疗 危及器官 颈部皮肤剂量 

分 类 号：R730.55[医药卫生—肿瘤]