Department of Radiation Oncology, the University of Texas MD Anderson Cancer Center, Houston, Texas.
Department of Radiation Physics, the University of Texas MD Anderson Cancer Center, Houston, Texas.
Pract Radiat Oncol. 2012 Oct-Dec;2(4):e145-e153. doi: 10.1016/j.prro.2012.03.010. Epub 2012 Apr 25.
The use of intensity modulated radiation therapy (IMRT) is becoming more commonplace in the treatment of central nervous system (CNS) malignancies. However, the determination of beam arrangements is still an empirical process, and optimization of any given plan may take hours on the part of the dosimetrist and the physician to achieve optimal conformity and normal tissue doses. Regional CNS class solutions (CS) for IMRT planning with the Philips Pinnacle treatment planning system (version 8.0; ADAC Laboratories, Milpitas, CA) have been in partial implementation at our institution since 2009. The purpose of this present work was to investigate their validity in clinical practice.
The plans of 55 patients treated for high-grade gliomas since 2009 were analyzed retrospectively. Thirty plans were categorized as having been planned with class solutions and 25 plans with user-defined optimization. Each plan was evaluated based on the following: (1) mean dose to the brain; (2) brain V30; and (3) Radiation Therapy Oncology Group (RTOG) conformity index (CIRTOG). These data were then compared with 140 historical benchmark plans that were generated using user-defined optimization prior to 2009.
The CS plans for gliomas in frontal, parietal-occipital, and temporal regions typically resulted in superior mean brain dose, brain V30, and conformity index when compared with user-defined plans. The CS plans for brainstem gliomas exhibited improved CIRTOG, but not brain V30 and brain mean dose. In trials of planning efficiency, the CS technique reduced treatment planning time by more than 2 times, independent of prior planning experience.
We have developed a CS protocol for IMRT planning of gliomas that has dramatically simplified this complex planning process, allowing dosimetrists of all levels of experience to produce highly conformal plans in a time efficient manner.
调强放射治疗（IMRT）在中枢神经系统（CNS）恶性肿瘤的治疗中越来越普遍。然而，光束排列的确定仍然是一个经验过程，并且任何给定计划的优化可能需要剂量师和医生数小时才能达到最佳的一致性和正常组织剂量。自 2009 年以来，我们机构一直在部分实施飞利浦 Pinnacle 治疗计划系统（版本 8.0；ADAC 实验室，米尔皮塔斯，加利福尼亚州）的中枢神经系统区域分类解决方案（CS）进行 IMRT 计划。本研究的目的是调查其在临床实践中的有效性。
回顾性分析了自 2009 年以来治疗高级别胶质瘤的 55 名患者的计划。将 30 个计划归类为使用分类解决方案进行规划，25 个计划使用用户定义的优化进行规划。每个计划都根据以下标准进行评估：（1）大脑的平均剂量；（2）大脑 V30；（3）放射治疗肿瘤学组（RTOG）适形指数（CIRTOG）。然后将这些数据与 2009 年之前使用用户定义的优化生成的 140 个历史基准计划进行比较。
与用户定义的计划相比，额、顶枕和颞区胶质瘤的 CS 计划通常导致大脑的平均剂量、大脑 V30 和适形指数更高。脑干胶质瘤的 CS 计划改善了 CIRTOG，但没有改善大脑 V30 和大脑平均剂量。在规划效率的试验中，CS 技术将治疗计划时间减少了 2 倍以上，而与之前的规划经验无关。
我们已经开发出一种用于胶质瘤的 IMRT 计划的 CS 方案，该方案极大地简化了这个复杂的计划过程，使各级经验的剂量师能够以高效的方式生成高度适形的计划。
