Evaluation of Use of Thyroid Shield in Mammography: A Preliminary Study

Abstract

Purpose: Verify if the use of thyroid shield was effective in reducing the radiation dose received by the thyroid in mammography. Materials and Methods: Using a General Electric Senograph DMR+mammographer with two bucky's, thermoluminescent dosimeters and two phantoms, one of body and the other of breast, were made measurements in cranio-caudal and medio-lateral oblique views. The variation was made with and without thyroid shield, and in the breast without shield, on both views. Results: After collecting and analyzing data it was verified an 89% reduction of the entrance skin doses on thyroid with protection. Conclusion: Given the significant reduction of the dose and the principle ALARA we can conclude that the shield should be used by the Radiology service. However the use of the shield may provide artifacts, making difficult the analysis of the breast tissue and leading to the examination repetition increasing the radiation from the mammary gland, as well as the other organs.