Fateme Asghari - Student Research Committee, Babol University of Medical Sciences, Babol, Iran
Kourosh Ebrahimnejad Gorji - Babol University of Medical Sciences
Rahele Mehraeen - Department of Radiology, Babol University of Medical Sciences, Babol, Iran
Mohammad Kiapour - Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, Iran
Hoda Talebian - Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, Iran
Ali Shabestani Monfared - Department of Medical Physics & Radiation Biology, Faculty of Medicine, Babol University of Medical Sciences, Babol, Iran

Introduction: The present study aimed to assess the reduction of breast surface dose, breast radiation-induced cancer incidence, and mortality risks when the lead apron shielding was positioned on the chest regions during head computed tomography (CT). Material and Methods: In this study, routine head CT scans were performed on ۲۸ female patients with a mean body mass index (BMI) of ۲۵.۲ ± ۲.۸ kg/m۲. The common lead aprons (۰.۵ mm thicknesses) were folded and positioned in the chest regions. The breast surface doses were measured using six thermoluminescent dosimeters (TLD-۱۰۰), three TLDs were located above the apron and three ones positioned under the apron. Breast radiation-induced cancer incidence and mortality risks were estimated using the Biological Effects of Ionizing Radiation (BEIR-VII) model. Finally, the measured doses and cancer/mortality risks were compared using Paired sample T-Test in SPSS software. Results: The breast surface doses under and over the apron were obtained at ۰.۱۸±۰.۰۶ and ۰.۴۹±۰.۱۳ mGy, respectively, (P-value<۰.۰۵). Although all cancer/mortality risks for both groups (over and under the apron) were very low, using the lead apron could decrease (significantly) breast cancer incidence risk ([۱.۲۴±۰.۳۲]×۱۰-۳ % over the apron vs. [۰.۴۶±۰.۱۵] ×۱۰-۳ % under the apron) and mortality risk ([۰.۳۰±۰.۰۸]×۱۰-۳ % over the apron vs. [۰.۱۱±۰.۰۴] ×۱۰-۳ % under the apron) about ۶۳% in all patients. Conclusion: The use of common lead aprons in the chest regions for patients undergoing head CT scans could significantly reduce the breast surface doses and radiation-induced cancer/mortality risks.

Computed Tomography, Radiation Protection, Head, Breast, Thermoluminescent Dosimetry