剂量计算算法的影响螺旋式二极管阵列使用体积调制弧线疗法用于小目标
Tomohiro Ono1, Hideaki Hirashima1, Takanori Adachi1
1Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Journal of applied clinical medical physics
|February 16, 2024
概括
剂量计算算法对小目标的患者特异性质量保证有重大影响. 阿库罗斯XB (AXB) 在窄光束的准确性较低,影响了VMAT小目标测量中的马传递率.
科学领域:
- 医学物理 医学物理
- 辐射瘤学 辐射瘤学
- 剂量测量方法 剂量测量方法
背景情况:
- 针对患者的质量保证 (PSQA) 对于放射治疗中的小目标至关重要.
- 剂量计算算法 (DCAs) 可以影响PSQA中的剂量分辨率和准确性.
- 评估不同的DCA对于可靠的小目标治疗验证至关重要.
研究的目的:
- 为了评估Acuros XB (AXB),异构分析算法 (AAA),光子蒙特卡洛 (pMC) 和崩圆 (CC) 剂量计算算法的影响.
- 为了评估这些算法在螺旋式二极管阵列使用体积调制弧线疗法 (VMAT) 对于小目标.
- 为了确定DCA特征对小目标的马传递率 (GPR) 的影响.
主要方法:
- 使用ArcCHECK探测器在2.9厘米的深度进行测量.
- 分析了矩形场 (2x100到100x100mm2) 和20个临床VMAT计划 (大脑转移,脊柱).
- 在TrueBeam STx系统上计算了AXB,AAA,pMC和CC的马传递率 (3%/2mm).
主要成果:
- 由于剂量分辨率较粗,Acuros XB (AXB) 在窄光束 (2x100,5x100mm2) 中表现出GPR<50%,而GPR<50%.
- 对于较大的场域 (>10x100mm2),GPR为>88.1%,并且在所有评估的DCA中都是可比的.
- 在临床VMAT计划中,GPR为79.1% (AXB),93.2% (AAA),94.9% (pMC) 和94.5% (CC).
结论:
- 在螺旋式二极管阵列上的小目标中,剂量分配行为在DCA之间有所不同.
- 在ArcCHECK测量中,Acuros XB的较粗的剂量分辨率可以导致VMAT小目标的GPR降低.
- 准确的剂量计算对于可靠的VMAT质量保证至关重要,特别是对于小型和复杂的目标.
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