ACR guidelines, Cohort study, Compressed breast thickness, Mammography, Mean glandular dose
Citation Information :
Singla V, Singh T, Prabhakar N, Singh G, Kang M, Khandelwal N. Internal Audit of Factors Affecting Mean Glandular Dose of Mammography in a North Indian Cohort. J Postgrad Med Edu Res 2019; 53 (3):113-117.
Aim: Increasing use of screening mammography has led to the speculation of increased incidence of radiation-induced cancer of the glandular breast tissue. The present study aimed to estimate the mammographic mean glandular dose (MGD) in North Indian females and establish the various factors which affect the radiation dose and compare it with global results.
Materials and methods: Four hundred and ninety consecutive females referred for diagnostic and screening mammography were enrolled in the study over four months duration. Standard two mammographic views of bilateral breasts, viz., mediolateral oblique (MLO) and craniocaudal (CC) views were taken generating a total of 1960 views. The tube voltage (kV), current (mA) [available as automatic exposure controls (AEC)], and other variables such as compressed breast thickness (CBT), applied compression force (CF), and MGD per projection for each breast available as digital readouts were evaluated.
Results: The mean CBT was 5.1 ± 1.7 cm in CC views and 5.72 ± 1.8 cm in MLO views. The mean CF was 99.8 ± 35.9 N and 117.7 ± 36 N in CC and MLO views respectively. The average MGD per view in CC and MLO views was 1.11 ± 0.41 mGy and 1.27 ± 0.47 mGy respectively; and the mean MGD per woman for four views was 4.76 mGy. Mean glandular dose was found to be directly proportional to the CBT, which was seen to be inversely related to age.
Conclusion: The mean MGD per view in the present study was 1.19 mGy, which is lower than average global values and is well within the stipulated guidelines of 3 mGy set by the American College of Radiology (ACR).
Clinical significance: As there is a trend of rising incidence of breast cancer in younger women in India, this study might help to allay fears concerning radiation risk during mammography in the minds of patients, referring surgeons, gynecologists, technologists, and radiologists.
Murthy NS, Agarwal UK, et al. A study on time trends in incidence of breast cancer—Indian scenario. Eur J Cancer Care (Engl) 2007;16:185–186. DOI: 10.1111/j.1365-2354.2006.00761.x.
Agarwal G, Ramakant P. Breast Cancer Care in India: The Current Scenario and the Challenges for the Future. Breast Care (Basel) 2008;3:21–27.
The 2007 Recommendations of the International Commission on Radiological Protection PUB, 103, Ann. ICRP. 2007;37:1–332.
Klein R, Aichinger H, et al. Determination of average glandular dose with modern mammography units for two large groups of patients. Phys Med Biol 1997;42:651–671. DOI: 10.1088/0031-9155/42/4/004.
Beckett JR, Kotre CJ. Dosimetric implications of age related glandular changes in screening mammography. Phys Med Biol 2000;45:801–813. DOI: 10.1088/0031-9155/45/3/316.
American College of Radiology Committee on Quality Assurance in Mammography. Mammography quality control manual, medical physicist's section. Reston, VA: ACR; 1999.
Heggie JC. Survey of doses in screening mammography. Australas Phys Eng Sci Med 1996 Dec;19(4):207–216.
Sookpeng S, Ketted P. Mean Glandular dose from routine mammography. Naresuan Univ J 2006;14:19–26.
Gentry JR, DeWerd LA. TLD measurements of in vivo mammographic exposures and the calculated mean glandular dose across the United States. Med Phys 1996 Jun;23(6):899–903. DOI:10.1118/1.597824.
Jamal N, Ng KH, et al. A study of mean glandular dose during diagnostic mammography in Malaysia and some of the factors affecting it. Br J Radiol 2003;76:238–245. DOI: 10.1259/bjr/66428508.
International Atomic Energy Agency. International basic safety standards for protection against ionising radiation and for the safety of radiation sources, Safety Series no. 115–1. Vienna, Austria: IAEA; 1996.
Dance DR, Skinner CL, et al. Additional factors for the estimation of mean glandular breast dose using the UK mammography dosimetry protocol. Phys Med Biol 2000;45:3225–3240. DOI: 10.1088/0031-9155/45/11/308.
Young KC. Radiation doses in the UK trial of breast screening in women aged 40–48 years. Br J Radiol 2002;75:362–370. DOI: 10.1259/bjr.75.892.750362.
Eklund S, Thilander A, et al. The impact of anatomic variations on absorbed radiation doses in mammography. Radiat Prot Dosimetry 1993;49:167–170. DOI: 10.1093/rpd/49.1-3.167.
Burch A, Goodman DA. A pilot survey of radiation doses received in the United Kingdom Breast Screening Programme. Br J Radiol 1998;71:517–527. DOI: 10.1259/bjr.71.845.9691897.
Wu X, Barnes GT, et al. Spectral dependence of glandular tissue dose in screen-film mammography. Radiology 1991;179:143–148. DOI: 10.1148/radiology.179.1.2006265.
Rosenstein M, Andersen LW, et al. US Department of Health and Human Services. Handbook of glandular tissue doses in mammography, p. 16. FDA Report 1985;85-8239.
Dance DR. Monte Carlo calculation of conversion factors for the estimation of mean glandular breast dose. Phys Med Biol 1990;35:1211–1219. DOI: 10.1088/0031-9155/35/9/002.
Du X, Wang J, et al. Investigation of mean glandular dose in diagnostic mammography in China. Biomed Environ Sci 2014;27:396–399.
Leyton F, Nogueira Mdo S, et al. Mean glandular dose in six digital mammography services in Santiago, Chile: preliminary reference levels. Radiat Prot Dosimetry 2015;165:115–120.
Nguyen JV, Williams MB, et al. Do women with dense breasts have higher radiation dose during screening mammography? Breast J 2018;24:35–40. DOI: 10.1111/tbj.12833.