Estimation of radiation dose to the lens of eyes of patients undergoing cranial computed tomography in a teaching Hospital in Osun state, Nigeria

Background: One of the means of assessing dose to patients from Computed tomography (CT) procedure is through the determination of the skin entrance dose (ESD) with the appreciation of the concern that ocular exposure effects from CT scan includes possible induction of cancer and cataract. Due to the relatively more recent introduction of CT scans, little work has been done in this area in the country including exposure dose on the lens of the eyes of patients undergoing Cranial Computed Tomography (C-CT). Materials and Methods: The Entrance Surface Dose (ESD) to the lens of eyes of 26 patients who had cranial CT procedures at a University Teaching Hospital in Ile-Ife, Nigeria has been determined in order to assess the level of radiation protection compliance and optimization of radiation safety at the hospital. Results: Results indicate that the doses to the patients ranged between 17.13 mGy and 51.98 mGy within the period under study. The average doses obtained for the pediatric patients (1.5-18 yrs), young adults (19-49 yrs) and adults (&ge50 yrs) were 31.14 ±11.02 mGy, 41.81±12.60 mGy and 31.97 ± 11.31 mGy respectively. The mean dose obtained in this study was lower than threshold for lens damage, therefore the dose recorded in this study is clinically safe. Conclusion: This study represents a requisite pedestal on the need for a nation-wide evaluation and investigation of optimization of procedures in radiological examinations with a view to establishing a national dosimetry protocol and reference dose level or guidance level in the country.