[多叶准直器定位精度对医科达直线加速器治疗宫颈癌容积调强弧形治疗计划质量控制的影响]
[Impact of multi-leaf collimator positioning accuracy on quality control of volumetric modulation arc therapy plan for cervical cancer treated with Elekta linear accelerator].
作者信息
Liang J, Yu F, Zhu J, Song T
机构信息
School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China.
State Key Laboratory of Oncology in South China//Department of Radiotherapy, Sun Yat-sen University Cancer Center, Guangzhou 510060, China.
出版信息
Nan Fang Yi Ke Da Xue Xue Bao. 2022 Jul 20;42(7):1089-1094. doi: 10.12122/j.issn.1673-4254.2022.07.19.
OBJECTIVE
To investigate the influence of positioning accuracy of the multi-leaf collimators (MLC) on the passing rate of the plan dose verification for volumetric modulation arc therapy (VMAT) of cervical cancer using an Elekta linear accelerator.
METHODS
The dose distributions were measured using Sun Nuclear's Mapcheck and Arccheck semiconductors matrix before and after MLC calibration in30 cervical cancer patients undergoing VMAT. Dosimetric comparisons were performed with 2D and 3D gamma passing rates of 3%, 3 mm and 2%, and 2 mm. The 3D gamma distribution was reconstructed with respect to the patient's anatomy using 3DVH software to evaluate the possible influence of MLC positioning accuracy.
RESULTS
Before and after MLC calibration, the gamma passing rates of Mapcheck were (88.80±1.81)% and (99.25 ± 0.53)% under 3% and 3 mm standard, respectively, with an average increase of 10.45%. The corresponding gamma passing rates of Arccheck were (87.61±1.98)% and (98.13±0.99)%, respectively, with an average increase of 10.52%. The gamma passing rates of 3DVH were (89.87±2.28)% and (98.3±1.15)%, respectively, with an average increase of 8.43%.
CONCLUSION
The MLC positioning accuracy is one of the main factors influencing dosimetric accuracy of VMAT for cervical cancer. The application of Autocal software facilitates MLC calibration and improves the accuracy and safety of VMAT delivery for cervical cancer.
目的
探讨使用医科达直线加速器时，多叶准直器（MLC）的定位精度对宫颈癌容积调强弧形治疗（VMAT）计划剂量验证通过率的影响。
方法
在30例接受VMAT的宫颈癌患者中，使用Sun Nuclear公司的Mapcheck和Arccheck半导体矩阵在MLC校准前后测量剂量分布。采用3%、3mm和2%、2mm的二维和三维伽马通过率进行剂量学比较。使用3DVH软件根据患者解剖结构重建三维伽马分布，以评估MLC定位精度可能产生的影响。
结果
MLC校准前后，在3%和3mm标准下，Mapcheck的伽马通过率分别为（88.80±1.81）%和（99.25±0.53）%，平均提高了10.45%。Arccheck相应的伽马通过率分别为（87.61±1.98）%和（98.13±0.99）%，平均提高了10.52%。3DVH的伽马通过率分别为（89.87±2.28）%和（98.3±1.15）%，平均提高了8.43%。
结论
MLC定位精度是影响宫颈癌VMAT剂量学精度的主要因素之一。Autocal软件的应用有助于MLC校准，并提高宫颈癌VMAT治疗的准确性和安全性。
Zotero 插件