Acrylonitrile Butadiene Styrene (ABS) plastic-based low cost tissue equivalent phantom for verification dosimetry in IMRT
Acrylonitrile Butadiene Styrene (ABS) plastic-based low cost tissue equivalent phantom for verification dosimetry in IMRT
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DOI：
10.1120/jacmp.v11i1.3030
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发表时间：
2010-01-01
影响因子：
2.1
通讯作者：
Mayya, Y. S.
中科院分区：
文献类型：
--
作者：
Kumar, Rajesh;Sharma, S. D.;Mayya, Y. S.
设计并制作了一种新型调强放射治疗体模。与辐射相互作用和剂量测定相关的ABS塑料的物理特性与常用的放射治疗剂量测量体模材料进行了比较。ABS IMRT体模可容纳各种类型的探测器，如离子室、射线照相/辐射变色胶片、TLD、MOSFET和凝胶剂量计。采用ABS和Scanditronix-WellhoferRW 3型调强放射治疗体模对5例前列腺癌患者进行了调强放射治疗前剂量验证的相关测量。点剂量数据采集使用电离室和EBT光盘，而Gafchromic EBT和射线EDR 2电影用于生成2D剂量分布。治疗计划系统（TPS）在ABS塑料和RW 3 IMRT体模中计算和测量的剂量在+/-2%范围内一致。使用ABS和RW 3体模采集的给定患者某个点的剂量值在1%范围内具有可比性。TPS生成的这些患者的通量图和剂量分布与ABS IMRT体模中测量的通量图和剂量分布在数值和空间上也具有可比性。本研究表明，ABS塑料调强放射治疗体模是一种组织等效体模，在剂量学上，它类似于固体/塑料水调强放射治疗体模。虽然这种材料被证明用于IMRT剂量验证，但它也可以用作放射治疗中其他剂量测定目的的组织等效体模材料。
A novel IMRT phantom was designed and fabricated using Acrylonitrile Butadiene Styrene (ABS) plastic. Physical properties of ABS plastic related to radiation interaction and dosimetry were compared with commonly available phantom materials for dose measurements in radiotherapy. The ABS IMRT phantom has provisions to hold various types of detectors such as ion chambers, radiographic/radiochromic films, TLDs, MOSFETs, and gel dosimeters. The measurements related to pretreatment dose verification in IMRT of carcinoma prostate were carried out using ABS and Scanditronix-Wellhofer RW3 IMRT phantoms for five different cases. Point dose data were acquired using ionization chamber and TLD discs, while Gafchromic EBT and radiographic EDR2 films were used for generating 2D dose distributions. Treatment planning system (TPS) calculated and measured doses in ABS plastic and RW3 IMRT phantom were in agreement within +/- 2%. The dose values at a point in a given patient acquired using ABS and RW3 phantoms were found comparable within 1%. Fluence maps and dose distributions of these patients generated by TPS and measured in ABS IMRT phantom were also found comparable both numerically and spatially. This study indicates that ABS plastic IMRT phantom is a tissue-equivalent phantom and, dosimetrically, it is similar to solid/plastic water IMRT phantoms. Although this material is demonstrated for IMRT dose verification, it can also be used as a tissue-equivalent phantom material for other dosimetry purposes in radiotherapy.