Determination of output factor for 6 MV small photon beam: comparison between Monte Carlo simulation technique and microDiamond detector

13th South-East Asian Congress of Medical Physics 2015

物理学;医药卫生

Krongkietlearts, K.^1 ; Tangboonduangjit, P.^1 ; Paisangittisakul, N.^2

Department of Radiation Therapy, Ramathibodi Hospital, Mahidol University, 270 Rama 6 Road, Phayathai, Bangkok

10400, Thailand^1

Department of Physics, Faculty of Sciences, Chulalongkorn University, 254 Phayathai Road, Patumwan, Bangkok

10330, Thailand^2

关键词: Cancer patients;    Intensity-modulated radiation therapy;    Modern techniques;    Monte carlo simulation technique;    Output factor measurements;    Output factors;    Synthetic single crystals;    Volumetric modulated arc therapy;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/694/1/012019/pdf
DOI  :  10.1088/1742-6596/694/1/012019

学科分类：卫生学

来源: IOP

【 摘 要 】

In order to improve the life's quality for a cancer patient, the radiation techniques are constantly evolving. Especially, the two modern techniques which are intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) are quite promising. They comprise of many small beam sizes (beamlets) with various intensities to achieve the intended radiation dose to the tumor and minimal dose to the nearby normal tissue. The study investigates whether the microDiamond detector (PTW manufacturer), a synthetic single crystal diamond detector, is suitable for small field output factor measurement. The results were compared with those measured by the stereotactic field detector (SFD) and the Monte Carlo simulation (EGSnrc/BEAMnrc/DOSXYZ). The calibration of Monte Carlo simulation was done using the percentage depth dose and dose profile measured by the photon field detector (PFD) of the 1010 cm2field size with 100 cm SSD. Comparison of the values obtained from the calculations and measurements are consistent, no more than 1% difference. The output factors obtained from the microDiamond detector have been compared with those of SFD and Monte Carlo simulation, the results demonstrate the percentage difference of less than 2%.