Ge-doped optical fibres as thermoluminescence dosimeters for kilovoltage X-ray therapy irradiations

Abstract

Abstract We investigate key dosimetric parameters for the thermoluminescence (TL) of Ge-doped silica optical fibres irradiated by X-rays generated at 90 and 300 kVp. The parameters include dose response, reproducibility and fading. Relative dose measurements were performed, obtaining central axis percentage depth dose (PDD) values, use being made of doped fibres irradiated in water and solid water phantoms. TL yields were compared with published data and ionisation chamber measurements. Linearity to dose was demonstrated over the investigated range (0.1–6 Gy), with reproducibility to within±2%. TL fading was found to be minimal, at