Evaluation of 3D Gamma index calculation implemented in two commercial dosimetry systems

8th International Conference on 3D Radiation Dosimetry

Xing, Aitang^1 ; Arumugam, Sankar^1 ; Deshpande, Shrikant^1 ; George, Armia^1 ; Vial, Philip^1 ; Holloway, Lois^1,2,3 ; Goozee, Gary^1

Liverpool and Macarthur Cancer Therapy Centres, Ingham Institute, Liverpool Hospital, NSW, Australia^1

Institute of Medical Physics, School of Physics, University of Sydney, NSW, Australia^2

Centre for Medical Radiation Physics, University of Wollongong, Wollongong

NSW, Australia^3

关键词: Additional datum;    Clinical routine;    Gamma indices;    Local methods;    Pass rate;    Patient specific;    Tomotherapy;    VeriSoft;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/573/1/012054/pdf
DOI  :  10.1088/1742-6596/573/1/012054

来源: IOP

【 摘 要 】

3D Gamma index is one of the metrics which have been widely used for clinical routine patient specific quality assurance for IMRT, Tomotherapy and VMAT. The algorithms for calculating the 3D Gamma index using global and local methods implemented in two software tools: PTW- VeriSoft® as a part of OCTIVIUS 4D dosimeter systems and 3DVHTMfrom Sun Nuclear were assessed. The Gamma index calculated by the two systems was compared with manual calculated for one data set. The Gamma pass rate calculated by the two systems was compared using 3%/3mm, 2%/2mm, 3%/2mm and 2%/3mm for two additional data sets. The Gamma indexes calculated by the two systems were accurate, but Gamma pass rates calculated by the two software tools for same data set with the same dose threshold were different due to the different interpolation of raw dose data by the two systems and different implementation of Gamma index calculation and other modules in the two software tools. The mean difference was -1.3%±3.38 (1SD) with a maximum difference of 11.7%.