Basic characteristic of a prototype tissue equivalent phantom thermoluminescence dosimeter (TEP-TLD)

• Published in: Radiation measurements 2011-12, Vol.46 (12), p.1912-1915
• Main Authors: Shinsho, Kiyomitsu, Tomizawa, Yuji, Horikawa, Hiroki, Miyajima, Satoshi, Saitoh, Hidetoshi, Urushiyama, Akio
• Format: Article
• Language: English
• Subjects: 3D dose distribution; Correlation; Dosimeters; Earth sciences; Earth, ocean, space; Exact sciences and technology; Geochronology; Ion chambers; Irradiation; Isotope geochemistry. Geochronology; Prototypes; Slabs; TEP-TLD; Thermoluminescence; Three dimensional
• ISSN: 1350-4487; 1879-0925
• DOI: 10.1016/j.radmeas.2011.05.023

We have researched the feasibility of using a newly developed 3D thermoluminescence dosimeter as a tissue equivalent phantom (TEP-TLD) for verification of high precision radiotherapy treatments, such as IMRT etc. Our system is low cost, has a simple construction, is reusable and 3D dose distribution can be obtained with a single irradiation. In this paper, we demonstrate the correlation between the response of our system and that of a system based on an ion chamber dosimeter. Our prototype TEP-TLD comprises a stack of 32 square slabs of thickness 2.5 mm, producing a phantom volume of 80 mm × 80 mm × 80 mm which was exposed to x-ray radiation. The exposed slabs were individually heated and the thermoluminescence was captured using a digital camera and subsequently analyzed. The dose response of the TEP-TLD was found to be highly linear in the range of 500 mGy ˜50 Gy and the off axis ratio showed close correlation to that of ion chamber. By controlling the time and temperature between irradiation and measurements the response was shown to have a high repeatability, with standard deviation of 2%.