Beam direction arrangement using a superconducting rotating gantry in carbon ion treatment for pancreatic cancer
Beam direction arrangement using a superconducting rotating gantry in carbon ion treatment for pancreatic cancer
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DOI：
10.1259/bjr.20190101
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发表时间：
2019-01-01
影响因子：
2.6
通讯作者：
Yamada, Shigeru
中科院分区：
文献类型：
--
作者：
Koom, Woong Sub;Mori, Shinichiro;Yamada, Shigeru
目的：碳离子放射治疗提供了一个集中的剂量分布的目标，并有几个优点比光子放射治疗。本研究旨在评价碳离子笔形束扫描的最佳射束方向，并比较旋转机架系统（RGS）和固定射束端口系统（FBPS）的剂量分布。首先，在俯卧位7束方向的剂量体积参数进行了评价。第二，使用4束方向在RGS开发的复合计划进行了比较，使用FBPS开发的，在12 fractions.Results的总处方剂量为55.2戈伊（相对生物学有效性，RBE）：在复合计划的目标覆盖范围没有很大的差异。对于十二指肠的第一和第二段，D2 cc的平均剂量没有显著变化（RGS和FBPS分别为23.80 +/- 11.90戈伊[RBE]和25.63 +/- 10.41戈伊[RBE]）。然而，在RGS中的剂量-体积直方图曲线显示在低剂量区域显著的剂量降低。在胃、十二指肠第三和第四段以及脊髓中未观察到显著差异。结论：与FBPS相比，RGS俯卧位4束照射方式在达到相同靶区覆盖率的同时，对周围正常器官的剂量分布具有可比性或上级优势。此外，RGS还允许单个患者定位。知识的进步：RGS有利于将放射治疗剂量输送到十二指肠，并允许单个患者定位和简单的计划过程。
Objectives: Carbon ion radiotherapy provides a concentrated dose distribution to the target and has several advantages over photon radiotherapy. This study aimed to evaluate the optimal beam direction in carbon ion pencil beam scanning and compare dose distributions between the rotating gantry system (RGS) and fixed-beam port system (FBPS).Methods: Patients with locally advanced pancreatic cancer were randomly selected. First, dose-volume parameters of 7-beam directions in the prone position were evaluated. Second, a composite plan developed using 4-beam directions in RGS was compared with that developed using FBPS, with a total prescribed dose of 55.2 Gy (relative biological effectiveness, RBE) in 12 fractions.Results: Target coverages in the composite plan did not widely differ. For the first and second segments of the duodenum, the mean dose of D2cc was not significantly changed (23.80 +/- 11.90 Gy [RBE] and 25.63 +/- 10.41 Gy [RBE] for RGS and FBPS, respectively). However, the dose-volume histogram curve in RGS showed a prominent dose reduction in the low-dose region. No significant differences were observed in the stomach, third and fourth segments of the duodenum, and spinal cord. The mean dose of the total kidney was similar between RGS and FBPS.Conclusions: Compared with that of FBPS, the 4-beam arrangement in the prone position using RGS provides comparable or superior dose distribution in the surrounding normal organ while achieving the same target coverage. In addition, RGS allows for single-patient positioning.Advances in knowledge: RGS is beneficial in delivering radiotherapy doses to the duodenum and allows for single-patient positioning and a simple planning process.