Abstract
To measure integral doses in image-guided radiation therapy, we developed an integral condenser dosimeter comprising a disposable USB-A mini-substrate with a 0.1-µF condenser and a silicon X-ray diode (Si-XD), a microcomputer (mbed) dock, and a personal computer (PC). The Si-XD is a high-sensitivity photodiode selected for detecting X-rays. The USB-A substrate with dimensions of 24 × 14 mm2 is inserted into the microcomputer dock, and the condenser is charged to 3.23 V through a 10-kΩ resistor. The condenser charging voltage is subsequently measured directly using an analog–digital converter (ADC) in mbed. When the condenser is fully charged, the microcomputer dock is switched to high impedance, and the substrate is removed. Subsequently, the substrate is exposed to an X-ray source, and the condenser is discharged via the photocurrent flowing through the Si-XD. The substrate is inserted into the dock again, and the charging voltage is measured. The dock is connected to a PC through a mini-USB cable, and integral doses are shown on the PC monitor. The doses were proportional to decreases in the charging voltage, and the calibrated doses corresponded well to those obtained using a typically available ionization chamber.
Similar content being viewed by others
References
Gööket A, Geerts W, Hambsch FJ, Oberstedt S, Vidali M, Zeynalov Sh. A position-sensitive twin ionization chamber for fission fragment and prompt neutron correlation experiments. Nucl Instrum Methods A. 2016;830:366–74.
Gaudefroy L, Roger T, Pancin J, Spitaels C, Aupiais J, Mottier J. A twin Frisch-grid ionization chamber as a selective detector for the delayed gamma-spectroscopy of fission fragments. Nucl Instrum Methods A. 2017;855:133–9.
Avila ML, Rehm KE, Almaraz-Calderon S, Ayangeakaa AD, Dickerson C, Hoffman CR, Jiang CL, Kay BP, Lai J, Nusair O, Pardo RC, Santiago-Gonzalez D, Talwar R, Ugalde C. Study of (a,p) and (a,n) reactions with a multi-sampling ionization chamber. Nucl Instrum Methods A. 2017;859:63–8.
Matsushita R, Sato E, Yanbe Y, Chiba H, Maeda T, Hagiwara O, Matsukiyo H, Osawa A, Enomoto T, Watanabe M, Kusachi S, Sato S, Ogawa A, Onagawa J. Low-dose-rate computed tomography system utilizing 25 mm/s-scan silicon X-ray diode and its application to iodine K-edge imaging using filtered bremsstrahlung photons. Jpn J Appl Phys. 2013;52:032202-1-5.
Sato Y, Sato E, Ehara S, Oda Y, Hagiwara O, Matsukiyo H, Enomoto T, Watanabe M, Kusachi S. Development of a dual-energy silicon X-ray diode and its application to gadolinium imaging. Radiat Meas. 2015;77:12–7.
Arakawa Y, Sato E, Kogita H, Hamaya T, Nihei S, Numahata W, Kami S, Oda Y, Hagiwara O, Matsukiyo H, Osawa A, Enomoto T, Watanabe M, Kusachi S, Sato S, Ogawa A. Investigation of X-ray photon-counting using ceramic-substrate silicon diode and its application to gadolinium imaging. Jpn J Appl Phys. 2014;53:072201-1-5.
Kanamoto M, Miyati T, Terashima K, Suga D, Fuwa N. Preliminary study of apparent diffusion coefficient assessment after ion beam therapy for hepatocellular carcinoma. Radiol Phys Technol. 2016;9:233–9.
Onizuka R, Araki F, Ohno T, Nakaguchi Y, Kai Y, Tomiyama Y, Hioki K. Accuracy of dose calculation algorithms for virtual heterogeneous phantoms and intensity-modulated radiation therapy in the head and neck. Radiol Phys Technol. 2016;9:77–87.
Takakura T, Ito Y, Higashikawa A, Nishiyama T, Sakamoto T. Verification of the dose attenuation of a newly developed vacuum cushion for intensity-modulated radiation therapy of prostate cancer. Radiol Phys Technol. 2016;9:270–6.
Groh BA, Siewerdsen JH, Drake DG, Wong JW, Jaffray DA. A performance comparison of flat-panel imager-based MV and kV cone-beam CT. Med Phys. 2002;29:967–7.
Thapa BB, Molloy JA. Feasibility of an image planning system for kilovoltage image-guided radiation therapy. Med Phys. 2013;40:061703-1-10.
Cederlund J. A three-electrode ionization condenser chamber. Br J Radiol. 1960;33:105–9.
Measure works; 2017. https://www.measureworks.co.jp/Directreadingdosimeter.htm. Accessed 17 Oct 2018.
Acknowledgements
This work was supported by Grants from Keiryo Research Foundation, Promotion and Mutual Aid Corporation for Private Schools of Japan, Japan Science and Technology Agency (JST), and JSPS KAKENHI (17K10371, 17K09068, 17K01424, 17H00607). This was also supported by a Grant-in-Aid for Strategic Medical Science Research (S1491001, 2014–2018) from the Ministry of Education, Culture, Sports, Science and Technology of Japan.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Ethical approval
This article does not contain any studies on animals or human participants.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Yamaguchi, S., Sato, E. Product development of a condenser dosimeter using a skin-insulated USB-A-substrate with a silicon X-ray diode. Radiol Phys Technol 12, 69–75 (2019). https://doi.org/10.1007/s12194-018-00493-4
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12194-018-00493-4