Evaluation of Mean Glandular Dose from Digital Mammography Exams at Qatar and Compared with International Guidelines Levels.

ABSTRACT

The primary objective of this study was to measure the mean glandular dose (MGD) from craniocaudal (CC) and mediolateral oblique (MLO) views from mammography patients in Hamad Medical Corporation (HMC) in the state of Qatar and to compare them with the international guidelines levels as well as to establish Dose Reference Level (DRL) for the country by applying the quality control (QC) protocol for the Digital mammography units and to reduce the patient dose and improve the image quality. All patients data was taken from two Selenia digital mammography units for 18 months period. Quality control was implemented for the two mammography machines and corrective actions have been done for the image quality evaluation with rejected film analysis. The total number of collected patient data was 4085 mammography exams which considered as around 93% of the overall mammography procedures done in Qatar during that period. Based on the IAEA selection criteria of breast thickness between 2-7 cm and kV machine value from 26 to 33 kV, only 3280 mammography procedures satisfies the above criteria and are analysed accordingly, National Centre for Cancer Care & Research (NCCCR) 949 and Hamad General Hospital (HGH) 2331 exposures. The present study revealed that there were significant differences between the MGD values for the CC and MLO views (p <0.006). Referring to the limiting dose values in the European guidelines, the results from the two mammography units showed that 94.5% and 99.7% of the mean glandular doses are acceptable from NCCCR and HGH respectively. Due to compression devise error in the NCCCR mammography machine, the MGD for some patients became more than the acceptable values especially at small breast thickness values (0-3 cm) which it seems 0% in the acceptable range.