Muñoz Luis, McLoone Peter, Metcalfe Peter, Rosenfeld Anatoly B, Biasi Giordano
Genesiscare Flinders Private Hospital, Bedford Park, SA, Australia.
Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia.
Phys Eng Sci Med. 2025 Jul 21. doi: 10.1007/s13246-025-01602-5.
This study assesses the updated Monaco TPS virtual source model (VSM) 2.0, which removes multileaf collimator (MLC) and jaw characterization as editable factors from the MLC geometry section within Monaco. The focus is on the impact of changes to stereotactic radiotherapy (SRT) cases for spinal and intracranial treatments for two beam matched linear accelerators. A validated custom VSM 1.6 model optimized for SRT was compared with the Elekta Accelerated Go Live 6 MV flattening filter-free (FFF) and VSM 2.0. Evaluations included measured MLC characteristics with a high-resolution detector, measured output factors (OPF), ion chamber fields in the thorax phantom, and recalculations of clinically relevant SRT cases. VSM 2.0 improves MLC modelling. Ion chamber measurements for IAEA TD1583 measurements were found to be within expected tolerances. Gamma pass rates for two matched LINACs evidenced improvement at 1%, 1 mm and 10% threshold for single and multi-SRS brain and SABR Spine treatments. VSM 2.0 represents a meaningful advancement in beam modelling within a Monte Carlo-based TPS environment, offering improved dosimetric performance and operational simplicity. Commercially available detectors were used to demonstrate that VSM 2.0 enhances agility MLC modelling, supporting more precise SRT and SABR delivery for matched LINACs. Removing configurable dependencies from the beam model will result in more consistent high quality beam models, an improves workflows for commissioning of the Monaco TPS.
本研究评估了更新后的摩纳哥治疗计划系统（TPS）虚拟源模型（VSM）2.0，该模型从摩纳哥治疗计划系统的多叶准直器（MLC）几何结构部分中移除了将MLC和光阑特性作为可编辑因素。重点在于两台束流匹配直线加速器对脊柱和颅内治疗的立体定向放射治疗（SRT）病例变化的影响。将针对SRT优化的经过验证的自定义VSM 1.6模型与医科达加速上线6兆伏无均整器（FFF）和VSM 2.0进行了比较。评估内容包括使用高分辨率探测器测量的MLC特性、测量的输出因子（OPF）、胸部体模中的电离室射野，以及对临床相关SRT病例的重新计算。VSM 2.0改进了MLC建模。发现国际原子能机构（IAEA）TD1583测量的电离室测量值在预期公差范围内。两台匹配直线加速器的伽马通过率证明，在单剂量和多分割立体定向放射外科（SRS）脑部治疗以及立体定向体部放射治疗（SABR）脊柱治疗的1%、1毫米和10%阈值下有改善。VSM 2.0代表了基于蒙特卡洛的治疗计划系统环境中束流建模的一项有意义的进展，提供了改进的剂量学性能和操作简便性。使用市售探测器证明VSM 2.0增强了MLC建模的灵活性，支持为匹配的直线加速器进行更精确的SRT和SABR治疗。从束流模型中去除可配置的依赖性将产生更一致的高质量束流模型，改善摩纳哥治疗计划系统的调试工作流程。
