Evaluation of the accuracy and efficiency of the in vivo dosimetry systems for whole brain cancer patients

In external beam radiotherapy quality assurance is carried out on the individual components of the treatment chain. The patient simulating device, planning system and linear accelerators are tested regularly according to set protocols developed by national and international organizations. In-vivo dosimetry measures the dose to the target volume through indirect measures therefore the most likely method for picking up errors which might occur earlier in the chain. In vivo dosimetry, using diodes or thermoluminescent dosimeters (TLDs) is performed in many radiotherapy departments to verify the dose delivered during treatment. In vivo dosimetry is applied to evaluate the delivered dose to critical organs or in complex geometries where the dose is hard to predict from the treatment. The aim of this study was to verily the response of TLDs type (LiF) use in radiotherapy, using Thermoluminescence detectors to establish calibration procedure for TLDs and to evaluate admission dose obtained by the treatment planning system with measured dose.