Determination of small field output factors in 6 and 10 MV flattening filter free photon beams using various detectors

13th South-East Asian Congress of Medical Physics 2015

物理学;医药卫生

Masanga, W.^1,3 ; Tangboonduangjit, P.^2 ; Khamfongkhruea, C.^3 ; Tannanonta, C.^3

Medical Physics School, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand^1

Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand^2

Department of Radiation Oncology, Chulabhorn Hospital, Bangkok, Thailand^3

关键词: Daisy-chaining;    Edge detectors;    Flattening filter free;    Indirect methods;    Microdiamonds;    Output factor measurements;    Output factors;    Photon beams;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/694/1/012027/pdf
DOI  :  10.1088/1742-6596/694/1/012027

学科分类：卫生学

来源: IOP

【 摘 要 】

The study aimed to determine appropriate detectors for output factor measurement of small fields in 6 and 10 MV flattening filter free photon beams using five different detectors. Field sizes were varied between 0.6 0.6 and 4.0 4.0 cm2. An indirect method (daisy-chaining) was applied to normalize the output factors. For the smallest field size, the variations of output factors compared among the detectors were 13%. Exradin A16 had the lowest output factor and increasing in sequence with CC01, microDiamond, microLion and EDGE detectors, respectively, for both energies. The similarity between CC01 and microDiamond output factor values were within 1.6% and 1% for all field sizes of 6 and 10 MV FFF, respectively. EDGE and microLion presented the highest values while ExradinA16 gave lowest values. In conclusion, IBACC01, Exradin A16, microLion, microDiamond and EDGE detectors seem to be the detectors of choices for small field output factor measurement of FFF beams down to 1.6 1.6 cm2. However, we could not guarantee which detector is the most suitable for output factor measurement in small field less than 1.6 1.6 cm2of FFF beams. Further studies are required to provide reference information for validation purposes.