Mohandass P, Khanna D, Manigandan D, Bhalla Narendra Kumar, Puri Abhishek
Department of Radiation Oncology, Fortis Cancer Institute, Fortis Hospital, Mohali, Punjab, India.
Department of Physics, School of Engineering and Technology, Karunya Institute of Technology and Sciences, Coimbatore, Tamil Nadu, India.
J Med Phys. 2018 Apr-Jun;43(2):93-99. doi: 10.4103/jmp.JMP_7_18.
Validation of a new software version of a Monte Carlo treatment planning system through comparing plans generated by two software versions in volumetric-modulated arc therapy (VMAT) for lung cancer.
Three patients who were treated with 60 Gy/30 fractions in Elekta Synergy™ linear accelerator by VMAT technique with 2% statistical uncertainty (SU) were chosen for the study. Multiple VMAT plans were generated using two different software versions of Monaco treatment planning system TPS (V5.10.02 and V5.11). By keeping all other parameters constant, originally accepted plans were recalculated for the SUs of 0.5%, 1%, 2%, 3%, 4%, and 5%. For plan evaluation, the metrics compared were conformity Index (CI), homogeneity Index (HI), dose coverage to planning target volume (PTV), organ at risk (OAR) doses to spinal cord, pericardium, bilateral lungs-PTV, esophagus, liver, normal tissue integral dose (NTID), volumes receiving dose >5 and >10 Gy, calculation time (tCT), and gamma pass rates.
In both versions, CI and HI improved as the SU increased from 0.5% to 5%. No significant dose difference was observed in Dmean to PTV, bilateral lungs-PTV, pericardium, esophagus, liver, normal tissue volume receiving >5, and >10 Gy and NTID. It was observed that while the tCT and gamma pass rates decreased, the maximum dose to PTV increased as the SU increased. No other significant dose differences were observed between the two MC versions compared.
For lung VMAT plans, in both versions, SU could be accepted up to 3% per plan with reduced tCT without compromising plan quality and deliverability by accepting variations in point dose and an inhomogeneous dose within the target. The plan quality of Monaco™V5.10.02 was similar to Monaco™TPS-V5.11 except for tCT.
通过比较蒙特卡罗治疗计划系统两个软件版本在肺癌容积调强弧形治疗（VMAT）中生成的计划，验证该系统新软件版本。
选择3例在医科达Synergy™直线加速器上采用VMAT技术接受60 Gy/30分次治疗且统计不确定性（SU）为2%的患者进行研究。使用Monaco治疗计划系统TPS的两个不同软件版本（V5.10.02和V5.11）生成多个VMAT计划。在保持所有其他参数不变的情况下，针对0.5%、1%、2%、3%、4%和5%的SU重新计算最初接受的计划。对于计划评估，比较的指标有适形指数（CI）、均匀性指数（HI）、计划靶体积（PTV）的剂量覆盖、脊髓、心包、双侧肺 - PTV、食管、肝脏等危及器官（OAR）的剂量、正常组织积分剂量（NTID）、接受剂量>5 Gy和>10 Gy的体积、计算时间（tCT）以及伽马通过率。
在两个版本中，随着SU从0.5%增加到5%，CI和HI均有所改善。在PTV、双侧肺 - PTV、心包、食管、肝脏、接受>5 Gy和>10 Gy的正常组织体积以及NTID的平均剂量（Dmean）方面，未观察到显著剂量差异。观察到随着SU增加，tCT和伽马通过率降低，而PTV的最大剂量增加。比较的两个蒙特卡罗版本之间未观察到其他显著剂量差异。
对于肺部VMAT计划，在两个版本中，每个计划的SU可达3%，同时通过接受靶区内点剂量变化和不均匀剂量，在不影响计划质量和可交付性的情况下降低tCT也可接受。除tCT外，Monaco™V5.10.02的计划质量与Monaco™TPS - V5.11相似。
