THE RESPONSE BEHAVIOR OF LIF-MG, CU, P THERMOLUMINESCENCE DOSIMETERS TO HIGH-ENERGY ELECTRON-BEAMS USED IN RADIOTHERAPY

To ensure the effectiveness of radiation-therapy treatments, both in-p hantom and in-patient reliable dose measurements are required. Thermol uminescence dosimeters are used commonly for both applications. Among the various available materials, the relatively new LiF: Mg, Cu, P pho sphor is a suitable candidate for quality control of in vivo dosimetry in electron-beam therapy. The response behaviour of LiF:Mg, Cu, P chi ps to 6-21 MeV electron beams used in radiotherapy was studied. Batch homogeneity, dose linearity, sensitivity change after use, dose and do se-rate response, energy dependence and fading characteristics were in vestigated. The contribution from each factor to the overall uncertain ty in dose measurement was evaluated. The results of this work show th at the LiF:Mg,Cu,P chips are comparable to the commonly used LiF:Mg, T i ones, and support their use for in vivo electron-beam dosimetry to a n accuracy within +/-10%.