Mean glandular dose in digital mamography in women with breast implants

Abstract

Purpose: Mean Glandular Dose (MGD) is the quantity related to the risk of radiation-induced breast cancer. This study aimed to evaluate the MGD in screening mammography for women with breast implants. Methods: This retrospective study used data of 2680 mammographies of 335 asymptomatic women with mammary implants examined in a digital direct x-ray unit. Each woman had a total of eight images: four in standard views and four with posterior displacement of the implant (ID). Data on kV, mAs, target/filter combination, compressed breast thickness and MGD were obtained from the DICOM header of the stored images. Quantitative variables were presented through descriptive statistics for median (5th–95th percentiles); and the qualitative variables were presented by numbers and percentages. Mean glandular doses of standard views and ID views were compared and statistical analysis was used to assess the influence of implant position, breast glandularity and thickness on mean glandular doses. Results: Median MGD for standard views were 3.30 (2.60–4.00) mGy for CC and 3.31 (2.70–4.20) mGy for MLO. For ID views, median were 1.20 (0.90–2.20) mGy and 1.40 (0.97–3.74) mGy for CC and MLO views, respectively. Median MGD for the whole examination of women with breast implants was 9.60 (7.92–12.07) mGy, ranging from 6.25 to 21.50 mGy. When comparing MGD median for standard and ID views it was found a statistically significant difference (p < 0.05), with higher doses for the standard views due to the greater compressed breast thickness in these views. It was observed that, in the standard views, MGD decreases with increasing breast thickness due to the manual radiographic techniques used to expose the women. It was also observed that implant position does not affect MGD in breast augmentation mammography. Conclusion: Mammography of women with mammary implants gives higher radiation doses when compared with those without implants. For more accurate dose assessment in augmented breast mammography, it is necessary that specific conversion factors for the calculation of MGD based on air kerma at entrance of breasts with implants are made available.

Estudo sobre fatores intrínsecos a paciente que influenciam na dose glandular média em exames de tomossíntese de mama

“…Esse resultado concorda com outros encontrados na literatura [13,24]. A mesma tendência de aumento da DGM em mamas de maior densidade também foi observada em mulheres com implantes mamários [25]. No entanto, em todas as faixas de EMC para a modalidade 2D (Figura 6) e na faixa 40 < EMC [1,9,25].…”

“…A mesma tendência de aumento da DGM em mamas de maior densidade também foi observada em mulheres com implantes mamários [25]. No entanto, em todas as faixas de EMC para a modalidade 2D (Figura 6) e na faixa 40 < EMC [1,9,25]. A maior diferença nos coeficientes de correlação para a DGM e a DVM, para as duas modalidades, ocorre nas duas menores faixas de EMC.…”

Diagnostic value of a spiral breast computed tomography system equipped with photon counting detector technology in patients with implants

“…Mammography, which presents the screening method of choice for women with implants in some countries, [ 5 , 6 ] comes with the disadvantage of a higher mean glandular dose in augmented breasts due to decreased compression as well as radiation absorption of the implant itself. [ 7 , 8 ] Recommended four-view augmentation mammography is associated with a more than threefold mean glandular dose (10.7 mGy) compared to conventional two-view mammography (3.4 mGy). [ 8 ] For the breast CT, we found an average dose of 6.45 mGy (SD 0,36; range 5.81 7.28 mGy) in women with implants.…”

“…[ 5 , 6 ] Augmentation mammography comes with the disadvantage of a higher mean glandular dose due to decreased compression as well as radiation absorption of the implant itself. [ 7 , 8 ] The discomfort caused by compression during mammography can be particularly enhanced in women with implants. Mammography cannot, in most of the cases, detect intracapsular ruptures, which account for the majority of implant failures.…”

Coeficientes de Conversão do Kerma no Ar Incidente para a Dose Glandular Média em Mamografia de Mulheres com Implantes Mamários: Estudo Preliminar

“…Tendo em vista que o exame radiográfico das mamas de mulheres portadoras de implantes mamários inclui um maior número de imagens, elas recebem doses maiores em relação às que não possuem 2 . Assim, torna-se relevante a estimativa da DG nas oito incidências do exame, principalmente nas quatro com a presença dos implantes mamários, e a consequente avaliação do risco para estas mulheres.…”