ESTIMATION OF ENTRANCE SURFACE RADIATION DOSE TO THYROID REGION IN COMPUTED TOMOGRAPHY BRAIN EXAMINATION
Objective: The objective of this study was to estimate the entrance surface radiation dose to the thyroid region in a computed tomography (CT) brain scan.
Methods: Unfors Multi-O-Meter equipment was used to measure the entrance surface at the thyroid region of adult patients ranging from 18 to 70 years of age. A total of 115 patients were included in the study based on convenience sampling. The Multi-O-Meter was kept at the thyroid region during the scan, and the values for entrance surface dose (ESD) were noted from its monitor after the scan was complete.
Results: The obtained data were analyzed and violate normal distribution; therefore, the median and quartiles were computed. The overall median (Q1, Q2), ESD of the patients, was 1.335 (1.213, 1.529) mGy. The minimum and maximum dose values recorded were 1.015 mGy and 1.964 mGy, respectively.
Conclusions: The result showed a significant amount of entrance surface radiation dose to the thyroid region while taking a brain scan. This data can be used for optimization of radiation protection while undergoing CT scans of brain to reduce exposure to thyroid region.
2. Bianchi J, Goggins W, Rudolph M. In vivo, thyroid and lens surface exposure with spiral and conventional computed tomography in dental implant radiography. Oral Surg Oral Med Oral Pathol 2000;90:249-53.
3. Sherer MA, Visconti P, Ritenour ER, Haynes K. Radiation Protection in Medical Radiography. 6th ed. Philadelphia, PA: Elsevier-Health Sciences Division; 2010.
4. Nour AH, Khan M, Sulaiman AZ, Batool T, Nour AH, Khan MM, et al. In vitro anti-acetyl cholinesterase and antioxidant activity of selected Malaysian plants. Asian J Pharm Clin Res 2014;7:93-7.
5. Gupta M, Dahiya J, Marwaha RK, Dureja H. Therapies in cancer treatment: An overview. Int J Pharm Pharm Sci 2014;7:1-9.
6. Guo-Qing H, Ying L, Di-Fei C, Yu G, Dan S, Jin-Hai Z, et al. Advances in tumor markers for the early diagnosis of papillary thyroid carcinoma. Int J Pharm Pharm Sci 2016;8:47-51.
7. Hall EJ. Radiation biology. Cancer 1985;55:2051-7.
8. Kilfoy BA, Zheng T, Holford TR, Han X, Ward MH, Sjodin A, et al. International patterns and trends in thyroid cancer incidence, 1973- 2002. Cancer Causes Control 2009;20:525-31.
9. Su YP, Niu HW, Chen JB, Fu YH, Xiao GB, Sun QF. Radiation dose in the thyroid and the thyroid cancer risk attributable to CT scans for pediatric patients in one general hospital of China. Int J Environ Res Public Health 2014;11:2793-803.
10. Parry RA, Glaze SA, Archer BR. The AAPM/RSNA physics tutorial for residents. Radiographics 1999;19:1289-302.
11. Ribeiro LP, Entradas DC, Abrantes AF, Rodrigues SI, Reis MV. Evaluation of use of thyroid shield in mammography: A preliminary study. Int J Radiol Radiat Ther 2017;3:2-4.
12. Beaconsfield T, Nicholson R, Thornton A, Al-Kutoubi A. Would thyroid and breast shielding be beneficial in CT of the head. Eur Radiol 1998;8:664-7.
13. Mortazavi SM, Ghiassi-Nejad M, Bakhsi M, Jafari-Zadeh M, Kavousi A, Ahmadi J, et al. Entrance surface dose measurement on the thyroid gland in orthopantomography: The need for optimization. Iran J Radiat Res 2004;2:21-6.
14. Al Senan R, Mueller DL, Hatab MR. Estimating thyroid dose in pediatric CT exams from surface dose measurement. Phys Med Biol 2012;57:4211-21.