空腔和非均匀组织对不同照射技术的剂量学影响  

Dosimetry influence of different radiotherapy technologies caused by cavity and inhomogeneous tissues

作　　者：李建[1] 康盛伟[1] 祁国海[1] 吴大可[1] 钟海洛[1] 王培[1] 

机构地区：[1]四川省肿瘤医院放疗中心,成都610041

出　　处：《中华放射肿瘤学杂志》2014年第5期437-440,共4页Chinese Journal of Radiation Oncology

基　　金：四川省科技厅支撑项目课题（2008SZ0189）

摘　　要：目的 使用仿真人体模型,研究空腔及非均匀组织结构对不同照射技术的剂量学影响.方法 利用成都剂量体模,制作具有4cm×4cm×3 cm空腔结构的头颈部模体和胸部切片肺组织模体,按照实际治疗流程进行定位CT扫描和模拟定位机复位,在空腔和非均匀组织结构边界处及其内部粘贴3.2 mm ×3.2 mm ×0.8 mm超薄型热释光剂量片,采用不同照射技术设计治疗计划并在直线加速器上进行实际照射,对热释光剂量片数值进行分析.结果 头颈部仿真模体,单野、两野对穿和7个野IMRT计划照射测量结果均存在显著的空腔效应,并且随射野增加和放疗技术的复杂性,空腔效应有减小趋势;对胸部肺组织仿真模体,也存在类似空腔效应.结论 对人体组织内部空腔结构或非均匀组织结构,设计计划时应考虑空腔效应影响,给予更多射野或使用更加复杂的照射技术来减小空腔效应影响.Objective To investigate influence on dose distribution due to cavity and inhomogeneous structures using thermoluminescence dosimeters （TLD） and Chengdu phantoms.Methods A cavity 4 cm × 4 cm × 3 cm was made by a head and neck phantom and a lung phantom was cut into slices which were got a CT scanning and setup in a digital simulator.The TLD were pasted on edge and in the center of cavity structure and inhomogeneous structures.Treatment plans of different radiotherapy technologies were made generated and delivered on a linear accelerator.Then the TLD were read and analyzed.Results There were remarkable cavity effects of conventional single field,opposite fields and IMRT plans with 7 fields for head and neck phantom.There is similar effect in lung phantom.The more complexity the radiotherapy technology was the less cavity effect.Conclusions It is necessary to consider using more advanced radiotherapy technology or applying more fields to make treatment plans in order to decrease the cavity effect or similar effect when there are inhomogeneous structures.

关 键 词：成都剂量体模 空腔 非均匀组织 热释光 

分 类 号：R730.55[医药卫生—肿瘤]