Collapsed photonic crystal fibre thermoluminescence dosimetry for external beam radiotherapy

In measuring exposure to ionizing radiation various detectors and techniques have been developed. Current investigation is of key TL dosimetric responses of Ge-doped collapsed photonic crystal fibre (PCF), a form offering the advantage of greater sensitivity compared to more conventional single-mode optical fibers. The PCF samples that have been studied herein have been used to obtain external photon beam percentage depth doses (PDD), elevated sensitivity being desirable in providing a basis for the capture of the range of doses. Using a linac operated at 6 and 10 MV, the results show a favourable comparison with ionization chamber values (typically to within 5%). Threshold dose, reproducibility, and dose-rate dependency have also been characterized.