An investigation of the thermoluminescence of Ge-doped SiO2 optical fibres for application in interface radiation dosimetry.

We investigate the ability of high spatial resolution (∼120 μm) Ge-doped SiO2 TL dosimeters to measure photoelectron dose enhancement resulting from the use of a moderate to high-Z target (an iodinated contrast media) irradiated by 90 kVp X-rays. We imagine its application in a novel radiation synovectomy technique, modelled by a phantom containing a reservoir of I2 molecules at the interface of which the doped silica dosimeters are located. Measurements outside of the iodine photoelectron range are provided for using a stepped-design that allows insertion of the fibres within the phantom. Monte Carlo simulation (MCNPX) is used for verification. At the phantom medium I2-interface additional photoelectron generation is observed, ∼60% above that in the absence of the I2, simulations providing agreement to within 3%. Percentage depth doses measured away from the iodine contrast medium reservoir are bounded by published PDDs at 80 kVp and 100 kVp.