8th Baltic Congress of Radiology

Breast Radiology

oral abstract

Contrast-enhanced spectral mammography (CESM) is a novel breast imaging technique that combines mammography with the intravenous administration of contrast material. Similarly to MRI , it depicts enhancement differences between neoplastic and normal tissue, and has recently become a a clinically useful tool for presurgical breast assessment. Accurate assessment of the size and extent of the tumour is essential for planning treatment. Since tumor size and disease extent are important prognostic factors. The long-term outcome is directly related to the site of origin of cancers. Site of origin of cancers can be determined by analysing the mammographic tumor features the so-called imaging biomarkers. Breast cancers arise from three components of the fibroglandular tissue: the terminal ductal lobular units (TDLUs), the major lactiferous ducts, and from the stem cells of the mesenchyme. Breast cancers arising from the TDLU are acinar adenocarcinoma of the breast (AAB) and have four imaging biomarkers: powdery calcifications, crushed stone-like calcifications, stellate and circular shaped tumor mass. Breast cancers originating in the major lactiferous ducts are termed ductal adenocarcinoma of the breast (DAB). DAB has six imaging biomarkers: fragmented casting type calcifications, dotted casting type calcifications, skipping stone calcifications, string of pearl-like calcifications, architectural distortion with no associated calcifications and nipple discharge. Architectural distortion is the imaging biomarker of breast cancer of mesenchymal stem cell origin (BCMO). The long-term survival of women having 1-14 mm AAB without associated casting type calcifications (DAB) have good to excellent survival compared with those women whose DAB is associated with 1-14 mm AAB, suggesting that the DAB is currently underdiagnosed as DCIS and consequently, undertreated. Both the DAB and the BCMO are of stem cell origin and resist both screening and modern therapeutic regimens.

A single centre, retrospective study included patients with primary operable breast cancer who underwent CESM between 01.01.2021. and 31.12.2021. The patients were divided into three groups according to the site of origin of their cancers (AAB, DAB and BCMO) using the imaging biomarkers / mammographic tumour features . The CESM findings were scored using a 4-point scale depending on the degree of contrast enhancement (0 = no contrast enhancement, 1 = mild, 2 = moderate, 3 = marked). The size or disease extent and breast density/background parenchymal enhancement were analysed on mammography, ultrasound, and CESM examinations.

Our study included 176 females with mean age 62 (age range 31 to 83). In 69% (n = 121) of cases the tumors were palpable. In 9% (n=16) of the cases the patients had recurrent cancer after breast conserving therapy. The distribution of cancers according to their site of origin was as follows: 68% (n= 120) AAB, 18% (n= 32) DAB, 7% (n= 12) BCMO and 12% (n=12) were mammographically occult. The most common findings on mammograms in the AAB group were stellate lesions: 86% (n=103); spherical/round lesions: 7% (n=9); crushed stone-like calcifications: 7% (n=8). In the DAB group the most common findings were fragmented casting type calcifications: 55% (n=16); noncalcified architectural distortion: 38% (n=11); dotted casting-type calcifications (n=2); skipping stone-like calcifications: (n=2). The tumor size distribution measured on the FFDM mammogram was as follows: 1-14mm in 22% (n=38) of the cases, 15- 19 mm in 15% (n=27) and > 20 mm in 63% (n= 110) of the cases. Overall, the study shows that both tumor size and extent were measured larger in 37 cases after the CESM exam. Contrast enhancement was absent in 2% (n=4) of the cancer cases while 14% (n=25) had mild enhancement, 61% (n=107) had moderate enhancement, and 22% (n=39) had marked enhancement in CESM. Breast density, according to the BI-RADS classification was A, B, C and D for 11%, 48%,38% and 3% respectively.

CESM provides high sensitivity and clinically meaningful preoperative help in breast cancer staging and planning patient management.

Site of origin of cancers can be determined by analysing the mammographic tumor features the so-called imaging biomarkers. Currently MG examination can be performed with a new method - by intravenous administration of a iodine-containing contrast agent. The aim of the research is, by studying radiological biomarkers of breast cancer patients with the new contrast-enhanced spectral mammography (CESM) method, to establish in which biomarkers this method is useful for additional examination.

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