NIPAM polymer gel dosimetry for IMRT four-field box irradiation using optical-CT scanner

7th International Conference on 3D Radiation Dosimetry

Yao, C.H.^1,2 ; Hsu, W.T.^2,3 ; Hsu, S.M.^1,2 ; Ma, P.Y.L.^3 ; Hsieh, B.T.^4 ; Chang, Y.J.^5,6

Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan^1

Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan^2

Department of Radiation Oncology, Puli Christian Hospital, Nan Tou, Taiwan^3

Department of Medical Imaging and Radiological Science, Central Taiwan University of Science and Technology, Taichung, Taiwan^4

Institute of Biomedical Engineering and Material Science, Central Taiwan University of Science and Technology, Taichung, Taiwan^5

Department of Management Information Systems, Central Taiwan University of Science and Technology, Taichung, Taiwan^6

关键词: Dose profile;    Gel phantom;    N-isopropylacrylamides;    Optical computerized tomography;    Polymer gel dosimeter;    Polymer gel dosimetry;    Polymer gels;    Reproducibilities;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/444/1/012030/pdf
DOI  :  10.1088/1742-6596/444/1/012030

来源: IOP

【 摘 要 】

The study assessed the dosimetric characteristics of the N-isopropylacrylamide (NIPAM) polymer gel dosimeter. Experiments on the intra-dosimeter consistency and reproducibility of NIPAM polymer gels were performed. A cylindrical NIPAM gel phantom measuring 10 cm (diameter) by 10 cm (height) by 3 mm (thickness) was irradiated using the four-field box treatment with a field size of 3 cm x 3 cm. A fast, optical computerized tomography scanner was used to scan the gel phantoms. The results showed that the dose profiles were consistent at various depths. The isodose lines agreed quantitatively with the calculated TPS dose and the measured NIPAM polymer gel dose within the 30 to 90 percentage isodose lines. In addition, the Gamma pass rates were determined to be 94.9%, 95.2%, and 95.7% at depths of 40 mm, 45 mm, and 50 mm, respectively, using 5% dose difference and 5 mm distance-to-agreement criteria. Using the same Gamma criteria, the Gamma pass rates were 95.1%, 95.3%, and 95.7% for the three replicated. The results indicated that the NIPAM polymer gel dosimeter was stable and reliable. The dosimetric characteristics highlighted the potential of NIPAM polymer gel dosimeter in radiotherapy.