The IAEA/WHO TLD Audit Program. The results of the TLD postal dosimetry audits in the National Centre for Radiotherapy and Nuclear Medicine Department, Korle-Bu, Accra (1998 to 2012)

During therapeutic procedures, the patient is always protected by the quality assurance program legitimately required for medical exposures. This comprehensive quality assurance programs, or quality management systems, include all components of radiation therapy practice, and has proven to be necessary in reducing the likelihood of dose misadministration. The aim of this paper is to gives a summary of various studies performed during the period of 15 years (1998-2012), and provides the results of a survey conducted by the IAEA. The methodology involve checking the beam output with its dosimeters, and to irradiate two TLD capsules in sequence in such a way that the irradiation time or monitor units calculation would deliver 200 cGy to a ‘tumour’ whose centre (the TLD capsule) is at 5 cm depth. Here, the irradiations were done in reference conditions using the agency’s Perspex holder, and the delivered dose is not a ‘given dose’ at the depth of maximum dose, but a dose at depth. The results of this study demonstrate that the QUATRO audit programme is a very useful tool for reviewing practices at our Centre, and shown beyond doubt to be effective in assuring the quality of dose determination at the Centre. Our study further indicates that it is possible to have the dose determination within acceptance limits by implementing correct procedures and cautiously performing dose calculations and measurements