Radiation doses to the uterus and ovaries in abdominopelvic computed tomography in a Nigerian Tertiary Hospital

Abstract

Background: Computed tomography (CT) has remained an important tool in medical diagnosis. However the radiation dose imparted to patients, especially to radiosensitive organs during a CT scan, continues to raise concern. Our aim was to determine the radiation dose to the ovary and the uterus during routine abdomen/pelvis CT examinations at the University College Hospital, Ibadan, Nigeria using appropriate dose computational methods. Materials and Methods: Technical factors and parameters were obtained for three groups of 60 randomly selected patients who had abdominal CT examinations using three machines, namely; the CT/e, BrightSpeed S and Toshiba Aquilion 64. The scanning parameters were used to estimate the patient organ doses using measurements of CT dose indexes and organ doses obtained with the aid of the ImPACT CT Dosimetry Calculator SpreadSheet based on National Radiological Protection Board conversion factors. Results: The mean total organ dose from the CT/e machine to the ovary was 11.15 ±2.48 (mGy) and to the uterus was 12.10 ±2.57 (mGy), and the mean total organ dose from the BrightSpeed S machine to the ovary was 39.2 ± 22.66 (mGy) and to the uterus was 43.05 ±24.88 (mGy), while the mean total organ dose from the Toshiba Aquilion 64 to the ovary was 33.07 ±16.86 (mGy) and to the uterus was 33.85 ±18.58 (mGy). These values were mostly comparable to but slightly higher than values of similar organ doses reported in the literature for Tanzania, the United Kingdom, Germany, and Japan. The doses to the ovary and uterus obtained varied from other international surveys by 3.8–12.9 mGy and 3.17–15.07 mGy, respectively, representing a 25–50% dose increase. Conclusion: The organ doses to the ovary and the uterus at our facility are higher than those obtainable in other countries; however, this could be substantially minimized through optimization of CT scanning protocols.