Senzitivnost digitalne tomosinteze u odnosu na digitalnu mamografiju

Objective To explore the sensitivity of digital breast tomosynthesis in relation to digital mammography and to assess diagnostic value of digital tomosynthesis. Methods Systematic data research in PubMed and Medline publications from 2009 to 2016 using the key words: digital breast tomosynthesis, digital mammography and sensitivity, as well as review of the relevant bibliography. The results are provided in narrative form mainly because the studies are heterogeneous which makes them difficult to compare statistically. Results Digital tomosynthesis can definitely have potential clinical benefits. Firstly, it reduces recall rates regarding breast density, especially in cases of extremely dense breasts. It has been determined that tomosynthesis is particularly beneficial in regard to visibility of noncalcified breast cancer on scattered and heterogeneously dense breasts. It is possible to resolve problems arisen from overlapping tissue which is the main reason of recall and additional screening on 2D mammography (that can result in improved cancer detection). Furthermore, it can result in less biopsies because the enhanced visualisation of suspicious structure reduces the biopsy rates. Since the images are shown with less overlapping tissue and forest structure, it is expected that the images will be more visible and with improved clarity which leads to more reliable results interpretation. In the early phase of tomosynthesis development it was suggested that images should be in only one view, namely mediolateral-oblique because it is in the nature of tomosynthesis image to view breasts from multiple angles. Such image generation wasn't sufficient because there are pathologies extended on a flat surface or in a non-spherical shape that can be detected much better screened in one orientation rather than the other. Specifically, a recent study shows that 9% of malignant breast tumors that have been detected in craniocaudal position weren't visible in mediolateral-oblique view. One-view tomosynthesis imaging (CC or MLO) is a process of lower dosage in comparison to two-view imaging but it has been proven that they are less clinically efficient. Substantial evidence shows the enhanced sensitivity of both of these views. Some studies point out the importance of including CC view in tomosynthesis and conclude that getting both views is optimal for tumor visualization. Tomosynthesis screening combined with conventional mammography results in significantly higher cancer detection rates, 40% or even bigger increase in invasive cancer detection without increase in ductal carcinoma in situ detection (DCIS). This represents one of the key advantages of digital tomosynthesis – a potential for early detection of invasive cancer, particularly those cancer types that can become life threatening if not timely detected. The increase of sensitivity with use of digital tomography in comparison to digital mammography amounted to 43% with significant increase of cancer detection rate with only one-view tomosynthesis as an independent modality of screening as opposed to two-view digital mammography. Sensitivity rises by adding two-view digital tomography in contrast to digital mammography and the recall rate for false positive cases is reduced for 19% when comparing two-view DBT to digital mammography itself. For diagnostic purposes, tomosynthesis results in improved characterisation and classification of benign and malignant lesions and enables local breast cancer grading. In breasts of high density diagnostic results of tomosynthesis are better than those of 2D digital mammography. The main limitation is additional radiation exposure that arises from this technique. Areas where comprehensive research and development efforts are focused on creating 2D images generated from 3D data are essential for reduction of exposure and dosage, shorter time and increased patient comfort due to shorter time of compression. This software enables digital tomosynthesis in the same dosage as in conventional digital mammography. With technical evolution and the rising application of tomosynthesis in clinical practice, all towards the improvement of the workflow and the enhancement of diagnostic accuracy as well as clinical application, it is important to mention 3D guided biopsy and contrast-enhanced imaging technology. Conclusions Digital breast tomosynthesis is an extraordinary technological advancement that has shown its value in screening and diagnostic assessments. Improvements in clinical performance in relation to 2D mammography are substantial. Many studies show that two-view tomosynthesis offers improved cancer detection rates and recall reduction in comparison to conventional mammography. Clinical studies using 3D mammography system have shown superior performance in mass and architectural distortion detection, the same or somewhat better performance in microcalcification detection with use of 2D plus tomo imaging as opposed to 2D alone. Both 3D tomosynthesis views (MLO and CC) and both 2D mammography views (MLO and CC) offer superior performances in comparison to 2D mammography alone. Furthermore, using only MLO tomosynthesis with both 2D CC and MLO also offers better performance in relation to 2D alone. Finally, an addition of 3D imaging to conventional 2D imaging enables enhanced sensitivity with fatty and dense breasts, especially with the latter ones. The use of C-View software enables generation of 2D images from 3D data which reduces the amount of radiation during tomosynthesis to that extent that it is almost the same as with conventional mammography.