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

摘要

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%.