Effects of dispersed radiation on the thyroid and the gonads during mammography
Background: The study aimed to explore effects of dispersed radiation on radiosensitive organs during mammography. The thyroid and the gonads are determined as key organs for exploration of dispersed radiation: the first one due to its vicinity to the dispersion zone and the second ones due to their symmetrical position in regard to the thyroid, which enables an assessment of distribution of dispersed radiation in regard to a compression plate. Materials and Methods: Entrance skin doses were defined during diagnostic procedures, using thermoluminescent dosimeters attached to the skin surface above the thyroid and the gonads for the purpose of exploration of dispersed radiation effects. Results: Results obtained indicate that medium entrance skin doses on skin around the thyroid were 0, 211 ± 0, 107 mGy per woman and 0, 017 ± 0, 012 mGy per woman on skin around the gonads. Measuring confirms that there is a significant correlation between entrance skin doses for the thyroid and total applied mAs during mammography (r = 0, 802, p<0, 01). Conclusion: Measuring defined that most of dispersed radiation was directed towards the area above breasts and the thyroid and only a small amount covered the area under the breasts and went towards the gonads. Entering skin doses for the thyroid ranged from 0.10 to 0, 51 mGy while the dose received by the thyroid varied from 0, 7 % to 1, 6 % of the MGD dose. Entrance skin doses for the gonads can be 13 times less than the thyroid dose and cannot be concerned dangerous for the gonads.