engleski

Is there still a place for the spot view in the evaluation of mammographically detected noncalcified abnormality?

Supplementary mammographic views have been an important part of the assessment process in women recalled following an abnormal screening mammogram. They are performed in addition to the standard mediolateral oblique and craniocaudal views to confirm the presence and characterize a true breast lesion rather than a pseudoabnormality simulated by summation of normal breast tissue. Traditionally, the spot view (SV) has been one of the most commonly used supplementary mammographic view in the assessment of abnormalities detected on a screening mammogram. With the incorporation of digital breast tomosynthesis into clinical use in 2011, the use of additional mammography images, including the spot view, is increasingly being questioned [1]. Furthermore, studies have shown that digital breast tomosynthesis is at least equivalent to the use of standard supplementary mammographic views in the assessment of noncalcified abnormalities (masses, distortions, and asymmetries) [2-7]. Digital breast tomosynthesis was introduced in the workup of screen-detected noncalcified abnormalities in the Department for Diagnostic and Interventional Radiology at the University hospital centre Zagreb in January 2017. During the initial learning period with digital breast tomosynthesis, standard spot compression views were also performed. Since we had spot compression views and two-view digital breast tomosynthesis available for all patients during the initial period, we compared their diagnostic value in the assessment of noncalcified abnormalities. Moreover, as an abnormal finding observed in 2D mammography or digital breast tomosynthesis requires further confirmation through breast ultrasound, and sometimes even breast magnetic resonance imaging. As both breast ultrasound and breast magnetic resonance imaging are time demanding, in this pilot study, we investigated whether the diagnostic results of the spot view (SV) performed after digital breast tomosynthesis could reduce the need for further diagnostic evaluation. This retrospective study included 62 female patients with a mammographically detected noncalcified abnormality. Digital breast tomosynthesis and the SV were performed in all patients and breast ultrasound was performed in 44 patients. All breast imaging findings were evaluated by a radiologist with 10 years of experience in breast imaging. Findings were classified according to Breast imaging-reporting and data system (BI-RADS) classification having categories 3-5 positive and 1-2 negative. The final diagnosis was established based on histopathological results when a tissue specimen was available ; otherwise, a clinical follow-up was required for at least one year to confirm the benign radiological findings. The mean age of the patients was 59 years (range, 41 - 85 years). The final histopathological analysis revealed six malignant breast lesions, four of which were presented as a mass and two as an architectural distortion. There was no significant difference between digital breast tomosynthesis and SV in mass characterization, and both digital breast tomosynthesis and SV showed high sensitivity and negative predictive value (NPV) for the detection of breast carcinoma. Nevertheless, SV showed greater overall specificity in comparison to digital breast tomosynthesis (84% to 50%) as shown in Fig 1. Even though in the case of a negative SV finding, the overlap of negative SV and breast ultrasound findings was 100%, breast ultrasound has shown greater specificity than SV for the detection of breast cancer (87% vs 77%) at the same level of sensitivity and negative predictive value as shown in Fig 2. In 29% (18/62) of the patient, the availability of SV after digital breast tomosynthesis eliminated the need for ultrasound as a part of the diagnostic process. Our results have shown that SV underperforms breast ultrasound within the standard diagnostic algorithm in case of a BI-RADS 3-5 assessment observed on SV. Nevertheless, in the case of a BI- RADS 1-2 assessment, SV may reduce the need for breast ultrasound. Furthermore, as SV resulted in better diagnostic performance than digital breast tomosynthesis on our dataset, it can be considered as an option in a case digital breast tomosynthesis is not available. Also, we would like to emphasize that we are aware that the results of the studies mentioned in the introductory part are not consistent with our results. By analyzing our results, we concluded that our study has limitations that are primarily due to limited experience in patient positioning and small sample size. SUMMARY STATEMENT: Comparison of digital breast tomosynthesis, breast ultrasound and spot compression view over 62 patients having mammographically detected noncalcified abnormality confirmed that breast ultrasound is an indispensable part of the diagnostic algorithm in the case of BI-RADS 3-5 findings observed on SV.

breast ; mammography ; MR ; ultrasound ; comparative studies ; cancer

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