MEAN GLANDULAR DOSE FOR AUGMENTATION MAMMOGRAPHY

Lilian Soares Couto, Ruffo de Freitas Jr, Rosangela da Silveira Corrêa, João Emílio Peixoto, Cláudio Domingues Almeida, Marcelo Vilela Lauar, Danielle Cristina Netto Rodrigues, Daniele Machado Mendonça

Institution: Hospital das Clínicas de Goiânia

“OBJECTIVE: The patients with cosmetic breast augmentation receive higher radiation doses during the exam than women without implants. In this study we evaluated the mean glandular dose (MGD) for exam and if the position with the implant has relationship with dose. METHODS: The MGD to the breast during screening mammography was measured for 335 women who had breast implants. Effective tube current (mAs), peak kilovoltage (kV) breast thickness (mm) and mean glandular dose were collected directly from each image produced. For 2,680 images being 1340 images from the standard position and 1340 with implant displacement (Eklund maneuver) four-view each one. RESULTS: The position of the implant was retroglandular in 283 (85%) retropectoral in 48 (14.4%) and not defined in two (0.6 %) women. The average thickness of the breast in standard craniocaudal (CC) view was 76.7±9.4 mm (p = 0.292) and mediolateral oblique (MLO) was 76.1±10.8 mm (p = 0.961). In the Eklund the average in CC and MLO were 34,6mm (p = 0.316) and 42.2 mm (p = 0.009) respectively. The average MGD in the standard images in the CC view was 3.3 mGy and MLO was 3.4 mGy, in the Eklund the average MGD was 1.4 mGy to the CC view and 1.7 mGy to the MLO. The average MGD of the four standard images was 3.3 mGy and the maneuver was 1.6 mGy.The average dose applied, considering the eight images in the augmentation mammography, were 19,59±3, for exam to an average thickness of 57.4 mm. The average MGD according to the implant position showed no significant difference (p=0.482). CONCLUSION: Mean glandular dose per breast from four-view augmentation mammography averaged 19,6 mGy which is 6.5 times higher than the 3 mGy at this thickness according to the European Guidelines, for conventional two-view mammography of breasts without implants.

Key words: Breast cancer, Breast Implants, Augmentation Mammography, Radiation Protection”

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