Effective Dose Estimation and Cancer Risk Assessment Due To Some Selected Ct Examinations at Sweden Ghana Medical Centre (SGMC)

Abstract

In this study, the effective dose and its associated cancer risk were estimated for adult patients undergoing the five most common types of CT examinations (head, neck, chest, abdomen and pelvis) at Sweden Ghana Medical Centre (SGMC) in the Greater Accra Region of Ghana. Two main methods were employed in the study: patients’ data collection and phantom measurement to verify the patient data. The effective doses were estimated using the dose length product (DLP) from the control console of the CT machine and the anatomic region specific conversion factors. The lifetime attributable risk of cancer incidence and cancer mortality for each patient for a particular examination were both determined from the effective dose, age and sex of each patient with the help of BEIR VII report. The effective doses were all within the range of typical effective doses (1-10mSv) for CT examinations. The abdominal scan recorded the highest mean effective dose of 7.01 mSv with the minimum effective dose of 1.00 mSv and maximum effective dose of 24.46 mSv. The average risk for all the examinations was observed to be low (1 in 10 000 to 1 in 1000). The average lifetime attributable risk of cancer incidence was 0.049% (1 in 2041) and in the range of 0.004% (1 in 25000) and 0.267% (1 in 375). For the lifetime attributable risk of cancer mortality, the average was also 0.030% (1 in 3333) in the range of 0.003% (1 in 33333) and 0.124% (1 in 807).