Comparison of radiotherapy dosimetry for 3D-CRT, IMRT, and SBRT based on electron density calibration

13th South-East Asian Congress of Medical Physics 2015

物理学;医药卫生

Kartutik, K.^1 ; Wibowo, W.E.^2 ; Pawiro, S.A.^1

Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia^1

Department of Radiotherapy, National General Hospital Dr. Cipto Mangunkusumo, Jakarta, Indonesia^2

关键词: Accurate calculations;    Calibration curves;    Dose distributions;    Inverse planning;    Linear calibration curve;    On-electron density;    Radiation field;    Radiotherapy planning;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/694/1/012017/pdf
DOI  :  10.1088/1742-6596/694/1/012017

学科分类：卫生学

来源: IOP

【 摘 要 】

Accurate calculation of dose distribution affected by inhomogeneity tissue is required in radiotherapy planning. This study was performed to determine the ratio between radiotherapy planning using 3D-CRT, IMRT, and SBRT based on a calibrated curve of CT-number in the lung for different target's shape in 3D-CRT, IMRT, and spinal cord for SBRT. Calibration curves of CT-number were generated under measurement basis and introduced into TPS, then planning was performed for 3D-CRT, IMRT, and SBRT with 7, and 15 radiation fields. Afterwards, planning evaluation was performed by comparing the DVH curve, HI, and CI. 3D-CRT and IMRT produced the lowest HI at calibration curve of CIRS 002LFC with the value 0.24 and 10. Whereas SBRT produced the lowest HI on a linear calibration curve with a value of 0.361. The highest CI in IMRT and SBRT technique achieved using a linear calibration curve was 0.97 and 1.77 respectively. For 3D-CRT, the highest CI was obtained by using calibration curve of CIRS 062M with the value of 0.45. From the results of CI and HI, it is concluded that the calibration curve of CT-number does not significantly differ with Schneider's calibrated curve, and inverse planning gives a better result than forward planning.