Shinhaeng Cho1, Nuri Lee2, Sanghyeon Song3, Jaeman Son4, Haksoo Kim1, Jong Hwi Jeong1, Se Byeong Lee1, Youngkyung Lim1, Sunyoung Moon5, Myonggeun Yoon5, Dongho Shin1. 1. Proton Therapy Center, National Cancer Center, Goyang, Korea. 2. Department of Radiation and Oncology, National Medical Center, Seoul, South Korea. 3. Department of Radiation and Oncology, Soon Chun Hyang University Hospital, Seoul, South Korea. 4. Department of Radiation and Oncology, Seoul National University Hospital, Seoul, South Korea. 5. Department of Bio-Convergence Engineering, Korea University, Seoul, Korea.
Abstract
PURPOSE: Fabricate an acrylic disk radiation sensor (ADRS) and characterize the photoluminescence signal generated from the optical device as basis for the development and evaluation of a new dosimetry system for pencil beam proton therapy. METHODS: Based on the characteristics of the proposed optical dosimetry sensor, we established the relation between the photoluminescence output and the applied dose using an ionization chamber. Then, we obtained the relative integral depth dose profiles using the photoluminescence signal generated by pencil beam irradiation at energies of 99.9 and 162.1 MeV, and compared the results with the curve measured using a Bragg peak ionization chamber. RESULTS: The relation between the photoluminescence output and applied dose was linear. In addition, the ADRS was dose independent for beam currents up to 6 Gy/min, and the calibration factor for energy was close to 1. Hence, the energy dependence on the optical device can be disregarded. The integral depth dose profiles obtained for the ADRS suitable agreed with the curve measured in the Bragg peak ionization chamber without requiring correction. CONCLUSIONS: These results suggest that the ADRS is suitable for dosimetry measurements in pencil beam scanning, and it will be employed as a low-cost and versatile dosimetry sensor in upcoming developments.
PURPOSE: Fabricate an acrylic disk radiation sensor (ADRS) and characterize the photoluminescence signal generated from the optical device as basis for the development and evaluation of a new dosimetry system for pencil beam proton therapy. METHODS: Based on the characteristics of the proposed optical dosimetry sensor, we established the relation between the photoluminescence output and the applied dose using an ionization chamber. Then, we obtained the relative integral depth dose profiles using the photoluminescence signal generated by pencil beam irradiation at energies of 99.9 and 162.1 MeV, and compared the results with the curve measured using a Bragg peak ionization chamber. RESULTS: The relation between the photoluminescence output and applied dose was linear. In addition, the ADRS was dose independent for beam currents up to 6 Gy/min, and the calibration factor for energy was close to 1. Hence, the energy dependence on the optical device can be disregarded. The integral depth dose profiles obtained for the ADRS suitable agreed with the curve measured in the Bragg peak ionization chamber without requiring correction. CONCLUSIONS: These results suggest that the ADRS is suitable for dosimetry measurements in pencil beam scanning, and it will be employed as a low-cost and versatile dosimetry sensor in upcoming developments.