Planning, delivery, and quality assurance of intensity-modulated radiotherapy using dynamic multileaf collimator: A strategy for large-scale implementation for the treatment of carcinoma of the prostate
Planning, delivery, and quality assurance of intensity-modulated radiotherapy using dynamic multileaf collimator: A strategy for large-scale implementation for the treatment of carcinoma of the prostate
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DOI：
10.1016/s0360-3016(97)00458-6
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发表时间：
1997-11-01
影响因子：
7
通讯作者：
Ling, CC
中科院分区：
文献类型：
--
作者：
Burman, C;Chui, CS;Ling, CC
目的：为了改善前列腺癌患者的局部控制，我们实施了调强放射治疗（IMRT），以提供81戈伊的处方剂量。这种方法是基于逆规划和使用动态多叶准直器（DMLC）。由于调强放射治疗是一种新的治疗方式，因此主要强调过程中每个组成部分的质量保证和患者安全。在这篇文章中，我们详细描述了我们的程序和质量保证program.Methods和Materials：使用逆算法，我们已经制定了一个治疗计划，包括五个强度调制（IM）的光子领域，提供与DMIC。在计划阶段，计划员指定射束的数量及其方向，以及目标、正常器官和“重叠"区域的期望剂量。然后，逆算法设计最符合指定标准的强度分布。第二种算法确定将产生设计的强度图案的叶片运动，并产生DMLC文件作为MLC控制计算机的输入。我们针对计划和治疗提供过程的质量保证计划包括以下组成部分：1）验证定位舱胶片上的DMLC射野边界，2）验证DMLC文件的叶片运动是否产生计划的剂量分布（独立计算），3）在相同的实验条件下，将DMLC在平板模体中产生的剂量分布与治疗计划计算机计算的剂量分布进行比较，4）计划的叶运动与实施的治疗（如MLC日志文件上记录的）的比较，5）通过记录和验证系统确认每个场的MLC的初始和最终位置，以及6）体内剂量measurements.Results：使用五场IMRT计划，我们定制了剂量分布以符合并向PTV提供81戈伊。此外，在PTV和直肠之间以及PTV和膀胱之间的重叠区域中，剂量保持在相应器官的耐受范围内。我们的QA检查表明，计划和实施的叶片运动之间的协议是可以接受的。相应地，胶片和胶片剂量测定表明，输送的剂量与计划剂量一致，在2%以内。截至1996年9月15日，我们已经治疗了8例患者81戈伊与IMRT.Conclusion：对于复杂的规划问题，周围正常组织的处方剂量的严重限制，IMRT提供了一个强大而有效的解决方案。如果有一个全面和严格的质量保证计划，强度调制场可以有效和准确地提供使用DMLC。调强放射治疗现在已经准备好在我们的诊所进行大规模的常规实施。(C)1997年爱思唯尔科学公司
Purpose: To improve the local control of patients with adenocarcinoma of the prostate we have implemented intensity modulated radiation therapy (IMRT) to deliver a prescribed dose of 81 Gy. This method is based on inverse planning and the use of dynamic multileaf collimators (DMLC). Because IMRT is a new modality, a major emphasis was on the quality assurance of each component of the process and on patient safety. In this article we describe in detail our procedures and quality assurance program.Methods and Materials: Using an inverse algorithm, we have developed a treatment plan consisting five intensity-modulated(IM) photon fields that are delivered with DMIC. In the planning stage, the planner specifies the number of beams and their directions, and the desired doses for the target, the normal organs and the ''overlap'' regions. Then, the inverse algorithm designs intensity profiles that best meet the specified criteria. A second algorithm determines the leaf motion that would produce the designed intensity pattern and produces a DMLC file as input to the MLC control computer. Our quality assurance program for the planning and treatment delivery process includes the following components: 1) verification of the DMLC field boundary on localization pod film, 2) verification that the leaf motion of the DMLC file produces the planned dose distribution (with an independent calculation), 3) comparison of dose distribution produced by DMLC in a flat phantom with that calculated by the treatment planning computer for the same experimental condition, 4) comparison of the planned leaf motions with that implemented for the treatment (as recorded on the MLC log files), 5) confirmation of the initial and final positions of the MLC for each field by a record-and-verify system, and 6) in vivo dose measurements.Results: Using a five-field IMRT plan we have customized dose distribution to conform to and deliver 81 Gy to the PTV. In addition, in the overlap regions between the PTV and the rectum, and between the PTV and the bladder, the dose is kept within the tolerance of the respective organs. Our QA checks show acceptable agreement between the planned and the implemented leaf motions. Correspondingly, film and TLD dosimetry indicates that doses delivered agrees with the planned dose to within 2%. As of September 15, 1996, we have treated eight patients to 81 Gy with IMRT.Conclusion: For complex planning problems where the surrounding normal tissues place severe constraints on the prescription dose, IMRT provides a powerful and efficient solution. Given a comprehensive and rigorous quality-assurance program, the intensity-modulated fields can be efficaciously and accurately delivered using DMLC. IMRT treatment is now ready for routine implementation on a large scale in our clinic. (C) 1997 Elsevier Science Inc.