Halo-Vest支架对颈椎原发恶性肿瘤放疗剂量分布的影响  

Effect of Halo-Vest on dose distribution of radiotherapy for primary cervical spine malignant tumors

作　　者：张喜乐[1] 杨瑞杰[1] 孟娜[1] 李孟昭 王俊杰[1] 庄洪卿[1] 田素青[1] Zhang Xile;Yang Ruijie;Meng Na;Li Mengzhao;Wang Junjie;Zhuang Hongqing;Tian Suqing(Department of Radiation Oncology,Peking University Third Hospital,Beijing 100191,China)

机构地区：[1]北京大学第三医院肿瘤放疗科,100191

出　　处：《中华放射医学与防护杂志》2020年第8期612-617,共6页Chinese Journal of Radiological Medicine and Protection

基　　金：北京市自然科学基金(7202223);北京市科技计划课题(Z201100005620012);首都卫生发展科研专项(2020-2Z-40919)。

摘　　要：目的探讨Halo-Vest支架对颈椎原发恶性肿瘤不同放疗技术剂量分布的影响。方法选择10例曾接受Halo-Vest支架手术后进行放射治疗的颈椎原发恶性肿瘤患者进行回顾性研究,使用Monaco计划系统,在勾画Halo-Vest支架结构外轮廓的CT序列图像上设计调强放疗(IMRT)和容积旋转调强放疗(VMAT)计划,然后复制相同射野参数的IMRT和VMAT计划到不勾画Halo-Vest支架结构外轮廓的CT序列图像上重新计算剂量分布,比较靶区、危及器官和正常组织的剂量分布差异。结果对于VMAT计划,两组计划的计划靶区(PTV)和计划肿瘤靶区(PGTV)的剂量学参数除PGTV107%外的各参数平均差异均<1%。相比外轮廓勾画Halo-Vest支架,外轮廓不勾画支架的图像计算的脊髓和脊髓-PRV平均最大剂量分别增加0.38和0.42 Gy(Z=-2.803、-2.803,P<0.05),脊髓和脊髓PRV Dmean分别增加0.35和0.37 Gy(Z=-2.703、-2.801,P<0.05)。黏膜、甲状腺、腮腺、下颌骨、下颌关节和正常组织的V5、V30和Dmean最大差异为0.74%。对于IMRT计划,两组计划的PTV和PGTV间剂量学参数差异较VMAT技术的差异增大,大部分差异超过1%,最大差异为4.55%。相比外轮廓勾画Halo-Vest支架,外轮廓不勾画支架的图像计算的脊髓平均最大剂量和脊髓-PRV最大剂量分别增加0.48和0.59 Gy(P>0.05),脊髓和脊髓PRV的平均Dmean分别增加0.57和0.59 Gy(Z=-2.293、-2.293,P<0.05)。其他危及器官的最大差异为1.98%。结论CT图像外轮廓勾画或不勾画Halo-Vest支架结构,VMAT计划间剂量差异很小,临床上可以忽略,但IMRT计划间剂量差异偏大,需要考虑忽略或部分勾画Halo-Vest支架结构的外轮廓时对剂量分布带来的影响。Objective To investigate the effect of Halo-Vest on the dose distribution of different radiotherapy techniques for primary cervical spine malignant tumors.Methods Ten patients with primary cervical spine malignancies who underwent radiotherapy after Halo-Vest surgery were retrospectively studied.The IMRT and VMAT plans were designed on the contoured CT images including Halo-Vest delineations using Monaco planning system.The IMRT and VMAT plans with the same field parameters were duplicated to the CT images without the Halo-Vest delineations,and the dose distribution was recalculated.The dose distribution of the target,organs at risk and normal tissues was analyzed and compared for the plans with and without the Halo-Vest delineation.Results For most dosimetric parameters of VMAT plans,the mean deviations induced by the Halo-Vest were less than 1%,except for PGTV107%.Without Halo-Vest delineation,the mean maximum dose of spinal cord and spinal cord-PRV increased by 0.38 Gy and 0.42 Gy(Z=-2.803,-2.803,P<0.05),respectively.The mean Dmean of spinal cord and spinal cord PRV increased by 0.35 Gy and 0.37 Gy,respectively(Z=-2.703,-2.701,P<0.05).The maximum deviation observed in the mean V5,V30,and Dmean of mucosa,thyroid,parotid gland,mandible,mandibular joint,and normal tissues was 0.74%.For IMRT plans,larger dosimetric deviations than VMAT plans were observed in PTV and PGTV,most of which were more than 1.0%and the maximum deviation was 4.55%.The absence of Halo-Vest delineation increased the mean maximum dose of spinal cord and spinal cord-PRV by 0.48 Gy and 0.59 Gy(P>0.05),respectively.The mean Dmean of spinal cord and spinal cord PRV increased by 0.57 Gy and 0.59 Gy,respectively(Z=-2.293,-2.293,P<0.05).The maximum deviation of other organs at risk was 1.98%.Conclusions There are no clinically significant dose differences for VMAT planning with or without Halo-Vest delineation on the CT images.But the dosimetric impact of absent or partial Halo-Vest delineation on IMRT planning is relatively large and should be cons

关 键 词：HALO-VEST支架 外轮廓 容积旋转调强放射治疗 固定野调强放射治疗 剂量 

分 类 号：R730.55[医药卫生—肿瘤] R738.1[医药卫生—临床医学]