Servicio de Oncología Radioterápica, Hospital Quirónsalud, Barcelona, Spain; Servicio de Oncología Radioterápica, Hospital Quirónsalud, Málaga, Spain.
Servicio de Oncología Radioterápica, Hospital Quirónsalud, Barcelona, Spain.
Phys Med. 2022 Oct;102:19-26. doi: 10.1016/j.ejmp.2022.08.016. Epub 2022 Aug 26.
To investigate the feasibility of using the free PRIMO Monte Carlo software for independent dose check of cranial SRS plans designed with the Varian HyperArc (HA) technique.
In this study, the PRIMO Monte Carlo software v. 0.3.64.1800 was used with the phase-space files (v. 2, Feb. 27, 2013) provided by Varian for 6 MV flattening-filter-free (FFF) photon beams from a Varian TrueBeam linear accelerator (linac), equipped with a Millennium 120 multileaf collimator (MLC). This configuration was validated by comparing the percentage depth doses (PDDs), lateral profiles and relative output factors (OFs) simulated in a water phantom against measurements for field sizes from 1 × 1 to 40 × 40 cm. The agreement between simulated and experimental relative dose curves was evaluated using a global (G) gamma index analysis. In addition, the accuracy of PRIMO to model the MLC was investigated (dosimetric leaf gap, tongue and groove, leaf transmission and interleaf leakage). Thirty-five HA SRS plans computed in the Eclipse treatment planning system (TPS) were simulated in PRIMO. The Acuros XB algorithm v. 16.10 (dose to medium) was used in Eclipse. Sixty targets with diameters ranging from 6 to 33 mm were included. Agreement between the dose distributions given by Eclipse and PRIMO was evaluated in terms of 3D global gamma passing rates (GPRs) for the 2 %/2 mm criteria.
Average GPR greater than 95 % with the 2 %(G)/1 mm criteria were obtained over the PDD and profiles of each field size. Differences between PRIMO calculated and measured OFs were within 0.5 % in all fields, except for the 1 × 1 cm with a discrepancy of 1.5 %. Regarding the MLC modeling in PRIMO, an agreement within 3 % was achieved between calculated and experimental doses. Excellent agreement between PRIMO and Eclipse was found for the 35 HA plans. The 3D global GPRs (2 %/2 mm) for the targets and external patient contour were 99.6 % ± 1.1 % and 99.8 % ± 0.5 %, respectively.
According to the results described in this study, the PRIMO Monte Carlo software, in conjunction with the 6X FFF Varian phase-space files, can be used as secondary dose calculation software to check stereotactic radiosurgery plans from Eclipse using the HyperArc technique.
研究使用免费的 PRIMO 蒙特卡罗软件对瓦里安 HyperArc（HA）技术设计的颅 SRS 计划进行独立剂量检查的可行性。
本研究使用了 PRIMO 蒙特卡罗软件 v.0.3.64.1800，并结合瓦里安提供的适用于 6MV 无均整滤过（FFF）光子束的相空间文件（版本 2，2013 年 2 月 27 日），这些文件来自配备了 Millennium 120 多叶准直器（MLC）的瓦里安 TrueBeam 直线加速器。通过将水模体中的模拟和测量的百分深度剂量（PDD）、侧向轮廓和相对输出因子（OF）进行比较，验证了这种配置。对于 1×1 至 40×40cm 的射野大小，使用全局（G）伽马指数分析评估了模拟和实验相对剂量曲线之间的一致性。此外，还研究了 PRIMO 对 MLC 建模的准确性（剂量学叶片间隙、舌槽、叶片传输和叶片间泄漏）。在 PRIMO 中模拟了 35 个在 Eclipse 治疗计划系统（TPS）中计算的 HA SRS 计划。在 Eclipse 中使用了 Acuros XB 算法 v.16.10（介质剂量）。包含了 33 个直径为 6 至 33mm 的靶区。使用 2%/2mm 标准评估了 Eclipse 和 PRIMO 给出的剂量分布之间的一致性。
在每个射野大小的 PDD 和轮廓上，都获得了大于 95%的平均 GPR，符合 2%/1mm 标准。除了 1×1cm 的射野，PRIMO 计算的和测量的 OF 之间的差异在 0.5%以内，差异为 1.5%。关于 PRIMO 中的 MLC 建模，计算剂量与实验剂量之间的差异在 3%以内。对于 35 个 HA 计划，PRIMO 和 Eclipse 之间的一致性非常好。靶区和外部患者轮廓的三维全局 GPR（2%/2mm）分别为 99.6%±1.1%和 99.8%±0.5%。
根据本研究中描述的结果，PRIMO 蒙特卡罗软件结合瓦里安 6XFFF 相空间文件，可作为用于检查使用 HyperArc 技术的 Eclipse 立体定向放射外科计划的二次剂量计算软件。
