Iranian Journal of Medical Physics

Iranian Journal of Medical Physics

Patient-Specific Radiation Dose and Cancer Risk in Computed Tomography Examinations in Ondo, Nigeria

Document Type : Original Paper

Authors
Tajudeen Ayinde Olaniyan 1
Caleb Ayoade Aborisade 1
Fatai Akintunde Balogun 2
Sulaiman Ogunsina 1
Aminu Saidu 3
Mark Ibrahim 1
1 Department of Physics, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Nigeria
2 Centre for Energy Research and Development, OAU, Ile-Ife. Nigeria
3 Department of Physics, Faculty of Science, Usmanu Danfodiyo University, Sokoto Nigeria
10.22038/ijmp.2018.23516.1234
Abstract
Introduction: The dose in computed tomography (CT) often approach or exceed the optimum levels, thereby increasing the probability of cancer induction. With wide application of this diagnostic test, it is expedient to determine the effective dose (ED) for each patient to estimate their cancer risk. This study was conducted to investigate the patient-specific dose (PSD) and cancer risk in CT examinations in Ondo, Nigeria.
Material and Methods: The study was conducted on 160 patients undergoing eight most common types of CT examinations performed at the center, from December 5, 2015 to February 28, 2016. Body mass index (BMI) was calculated for each patient using demographic data, PSD was determined and estimation of the lifetime attributable risk (LAR) of cancer was accomplished using the Biologic Effects of Ionizing Radiation VII (2006) report phase 2 models.
Results: From the results, radiation doses varied significantly within and between the types of CT examinations. The mean ED was 5.88±3.75 mSv in a range of 0.78-19.00 mSv. The mean PSD was 0.274±0.229 mSv/kgm-2 in a range of 0.024-1.555 mSv/kgm-2 and the mean LAR of cancer incidence was 0.04861±0.03996 Sv-1 in a range of 0.00004-0.21942 Sv-1.
Conclusion: ED and PSD varied within and across the CT examinations. In this regard, the coefficients of variation of ED for abdominal, cranial, craniocervical, abdomen/pelvis, thoracic, thoracoabdominal, cervical spine, and pelvis were 5.7%, 6.6%, 3.9%, 8.9%,3.7%, 6.0%, 44.7%, and 19.2%, respectively. Accordingly, the coefficients of variation of PSD were 9.0%, 7.9%, 7.0%, 10.1%,5.6%,23.8%, 47.7%, and 14.2%.
Keywords
Computed Tomography (CT)
Radiation Protection
Eeffective Dose
BEIR VII Model
Risk Assessment
Subjects

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Iranian Journal of Medical Physics
Volume 16, Issue 1 - Serial Number 1
January and February 2019
Pages 85-90

  • Receive Date 01 April 2018
  • Revise Date 21 June 2018
  • Accept Date 22 June 2018