MRI-based treatment planning for radiotherapy: Dosimetric verification for prostate IMRT
MRI-based treatment planning for radiotherapy: Dosimetric verification for prostate IMRT
复制标题
DOI：
10.1016/j.ijrobp.2004.05.068
复制
发表时间：
2004-10-01
影响因子：
7
通讯作者：
Pollack, A
中科院分区：
文献类型：
--
作者：
Chen, LL;Price, RA;Pollack, A
目的：磁共振（MR）和计算机断层扫描（CT）图像融合以及基于CT的剂量计算是前列腺治疗计划的金标准。MR和CT融合以及基于CT的剂量计算已经成为Fox Chase癌症中心调强放射治疗（IMRT）治疗计划的常规程序。单独使用MRI进行治疗计划（或MRI模拟）将消除与图像融合相关的任何错误。此外，它将通过避免冗余的CT扫描来降低治疗成本，并节省患者、工作人员和机器时间。本研究的目的是探讨基于MRI的前列腺IMRT.Methods和材料的治疗计划的剂量学准确性：共30 IMRT计划15例，使用MRI和CT数据生成。使用供应商（Philips Medical System，Cleveland，OH）提供的梯度失真校正（GDC）软件校正MRI失真。配对计划使用相同的内部轮廓。在基于CT和基于MR成像的计划之间分别绘制外部轮廓，以评价任何残余失真对剂量测定准确性的影响。相同的能量、射束角度、剂量约束和优化参数用于使用治疗优化系统的每个配对计划的剂量计算。由此产生的计划进行了比较，在等剂量分布和剂量体积直方图（DVH）。使用相同的叶序列和相关监测单元（MU）为基于CT的计划和基于MR的计划生成混合体模计划。然后，使用相同的叶序列，以验证治疗plannes.Results的剂量准确性照射的物理体模：我们的研究结果表明，基于CT和基于MRI的计划之间的剂量分布是同样可以接受的，根据我们的临床标准。基于CT和MR的计划之间的绝对剂量协议的计划靶体积是在2%和3%之间的测量剂量和剂量预测的计划系统中的物理phantom.Conclusions：磁共振成像是一个有用的工具，放射治疗模拟。与基于CT的治疗计划相比，基于MR成像的治疗计划满足剂量计算的准确性，并为前列腺IMRT提供一致的治疗计划。由于基于MR成像的数字重建X线照片不能提供足够的骨结构信息，因此建议使用一种用于产生线框图像的技术，该技术旨在取代由CT信息制成的传统数字重建X线照片。(C)2004年爱思唯尔公司
Purpose: Magnetic resonance (MR) and computed tomography (CT) image fusion with CT-based dose calculation is the gold standard for prostate treatment planning. MR and CT fusion with CT-based dose calculation has become a routine procedure for intensity-modulated radiation therapy (IMRT) treatment planning at Fox Chase Cancer Center. The use of MRI alone for treatment planning (or MRI simulation) will remove any errors associated with image fusion. Furthermore, it will reduce treatment cost by avoiding redundant CT scans and save patient, staff, and machine time. The purpose of this study is to investigate the dosimetric accuracy of MRI-based treatment planning for prostate IMRT.Methods and Materials: A total of 30 IMRT plans for 15 patients were generated using both MRI and CT data. The MRI distortion was corrected using gradient distortion correction (GDC) software provided by the vendor (Philips Medical System, Cleveland, OH). The same internal contours were used for the paired plans. The external contours were drawn separately between CT-based and MR imaging-based plans to evaluate the effect of any residual distortions on dosimetric accuracy. The same energy, beam angles, dose constrains, and optimization parameters were used for dose calculations for each paired plans using a treatment optimization system. The resulting plans were compared in terms of isodose distributions and dose-volume histograms (DVHs). Hybrid phantom plans were generated for both the CT-based plans and the MR-based plans using the same leaf sequences and associated monitor units (MU). The physical phantom was then irradiated using the same leaf sequences to verify the dosimetry accuracy of the treatment plans.Results: Our results show that dose distributions between CT-based and MRI-based plans were equally acceptable based on our clinical criteria. The absolute dose agreement for the planning target volume was within 2% between CT-based and MR-based plans and 3% between measured dose and dose predicted by the planning system in the physical phantom.Conclusions: Magnetic resonnace imaging is a useful tool for radiotherapy simulation. Compared with CT-based treatment planning, MR imaging-based treatment planning meets the accuracy for dose calculation and provides consistent treatment plans for prostate IMRT. Because MR imaging-based digitally reconstructed radiographs do not provide adequate bony structure information, a technique is suggested for producing a wire-frame image that is intended to replace the traditional digitally reconstructed radiographs that are made from CT information. (C) 2004 Elsevier Inc.