Diagnostic reference levels for mammography examinations in North Eastern Nigeria

Background: Diagnostic reference levels (DRLs) plays an important role in health-care delivery and radiation safety of patients. This study was carried out as part of a comprehensive project to establish DRLs for the radiological examinations for the first time in North Eastern Nigeria. Objective of the Study: The aim is to establish DRL for mammography examination in North Eastern Nigeria and to compare it with other established works. Materials and Methods: This study is a prospective cross-sectional study conducted in two university teaching hospitals in North Eastern Nigeria. Sixty patients were recruited for the study. Thermoluminescent dosimeter (TLD) chips were exposed for craniocaudal (CC) and mediolateral examinations to record the entrance skin dose (ESD). TLD readings were obtained at the Center for Energy Research and Training Zaria, Kaduna State, Nigeria. Dance formula was used to convert ESD to mean glandular dose (MGD). Student's t-test was used to determine the relationship between the mean ESD obtained in the two centers and Pearson's correlation was used to determine the relationship between the MGD and anthropotechnical parameters. Statistical significance was set at P < 0.05. Results: The total MGD for this study was 0.31 ± 0.05 mGy and 0.69 ± 0.11 mGy for CC and mediolateral oblique (MLO), respectively. DRL was 0.63 mGy and 1.04 mGy for CC and MLO, respectively. There was no statistically significant relationship (P > 0.05) between the MGD and anthropotechnical parameters. The DRL in this work were higher when compared with international established work. Conclusion: There is need for optimization of our radiology practice in North Eastern Nigeria and most centers in Nigeria.