鼻腔副鼻窦肿瘤的“靶中靶”适形治疗计划研究

The "Target in Target" Model of 3D Conformal Treatment Plan for Paranasal Sinuses and Nasal Cavity Carcinomas

目的:探讨"靶中靶"三维适形治疗计划在提升复杂鼻腔副鼻窦癌靶区剂量和优化剂量分布的作用。方法:以6例鼻腔副鼻窦肿瘤病例的CT定位数据图像资料为研究对象。在同一软件上分别进行常规方法和"靶中靶"方法的三维适形治疗计划设计,并对剂量分布和体积剂量直方图(DVH)结果进行分析。常规计划为单一等中心,3-5个共面或非共面适形野。靶中靶计划由一个简单化的常规计划和一个补丁计划融合而成。结果:总体上靶剂量分布及DVH靶中靶计划优于常规计划。V90(被90%等剂量包络的靶体积的百分率)和D90(包络90%靶体积的剂量百分率)靶中靶计划均高于常规计划。6/6靶中靶计划和3/6常规计划达到CTV平均剂量>66Gy、危及器官的平均受照剂量<54Gy的目标。分别有3/6靶中靶计划和1/6常规计划出现小范围高剂量区,1/6靶中靶计划和5/6常规计划出现低剂量区。结论:靶中靶方式适形治疗计划可以适用于比较复杂的鼻腔副鼻窦肿瘤,能有效改善靶区剂量分布和提升靶区剂量。

Objective： Try to assess the 3D conformal treatment planning with a ＂target in target＂ model for improving dose distribution and boosting targets dose in patients with complex nasal cavity and paranasal sinus carcinomas. Methods： This study based on the digital CT images of six patients with nasal cavity and paranasal sinus carcinomas. Conventional conformal treatment plans （CCTPs） and ＂target in target＂ conforrnal treatment plans （TITCTPs） were designed respectively with same software and their results of dose distributions and dose-volume histograms （DVH） were analyzed. CCTPs consist of 3-5 irregular fields （coplanar or non-coplanar） with one isocenter. TITCPs consist of a simplified conventional plan and a mend plan with second isocenter. Results： In general, TITCTPs excelled CCTPs in dose distribution and DVH. V90 （percentage of target volume encompassed by 90% isodose） and Dg0 （percent isodose of covering 90% target volume） in TITCTPs were better than them in CCTPs, respectively. 6/6 TITCTPs and 3/6 CCTPs had achieved average dose 〉66 Gy in targets and 〈54 Gy in organs at risk, respectively. There were part target volume overdose in 3/6 TITCTPs and 1/6 CCTPs, and part target volume underdos in 1/6 TITCTPs and 5/6 CCTPs, respectively. Concludes： TITCTPs is an available mode for optimizing dose distribution and boosting target dose in complex nasal cavity and paranasal sinus carcinomas.