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.