Department of Medical Physics, Townsville University Hospital and Health Service, Townsville, QLD, 4814, Australia.
College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia.
Phys Eng Sci Med. 2022 Jun;45(2):429-441. doi: 10.1007/s13246-021-01085-0. Epub 2022 Apr 5.
During the adaptive workflow associated with MRgRT, a secondary dose calculation is required and MU2net (DOSIsoft, France) is one commercial option. The suitability of MU2net to be used in conjunction with the online Monaco treatment planning system of the Elekta Unity (Elekta AB, Stockholm, Sweden), is evaluated in this work. Monaco and MU2net point doses are compared for various fields on and off axis and at different SSDs. To investigate the comparative effects of attenuation due to the cryostat, couch and posterior coil, measured, MU2net and Monaco dose outputs at the isocentre, as a function of gantry angle, were compared. Point doses for the beams of nine step and shoot IMRT (SSIMRT) test plans (courtesy Elekta) were calculated with Monaco v5.4 and compared to corresponding doses computed with MU2net. In addition, Monaco v5.4 and MU2net point doses were compared for 1552 beams treated on the Unity at our facility. For the on-axis fields investigated the agreement between MU2net and measured data is acceptable. MU2net and Monaco point doses for the Elekta SSIMRT test plans were within ± 5.0% and ± 6.4% for beams delivered from gantry zero and at planned beam angles, respectively. For the 1552 beams delivered approximately 80.0% of MU2net and Monaco point doses agree within ± 5.0%, therefore it is recommended to correlate MU2net Dose Reference Points (DRPs) with pre and post treatment dosimetry verification. Computational accuracy of MU2net could be enhanced with improved modelling of attenuation due to the couch, cryostat and posterior MR imaging coil.
在与 MRgRT 相关的自适应工作流程中，需要进行二次剂量计算，MU2net（DOSIsoft，法国）是一种商业选择。本工作评估了 MU2net 与 Elekta Unity（瑞典斯德哥尔摩 Elekta AB）在线 Monaco 治疗计划系统联合使用的适用性。比较了 Monaco 和 MU2net 在轴上和轴外以及不同 SSD 处的各种野点剂量。为了研究由于冷阱、治疗床和后线圈引起的衰减的比较影响，测量了 MU2net 和 Monaco 在等中心处的剂量输出，作为旋转架角度的函数。使用 Monaco v5.4 计算了九个分步调强放疗（SSIMRT）测试计划（由 Elekta 提供）的束点剂量，并与 MU2net 计算的相应剂量进行了比较。此外，还比较了在我们机构的 Unity 上治疗的 1552 束的 Monaco v5.4 和 MU2net 点剂量。对于所研究的轴上野，MU2net 和测量数据之间的一致性是可以接受的。Elekta SSIMRT 测试计划的 MU2net 和 Monaco 点剂量，在从旋转架零位和计划的射束角度发射的射束中，分别在 5.0%和 6.4%以内。对于交付的 1552 束，大约 80.0%的 MU2net 和 Monaco 点剂量在 5.0%以内一致，因此建议将 MU2net 剂量参考点（DRP）与治疗前和治疗后剂量验证相关联。通过改进治疗床、冷阱和后磁共振成像线圈衰减的建模，可以提高 MU2net 的计算准确性。
