Cosimo di Maggio

Digital breast tomosynthesis versus digital mammography: a clinical performance study

ObjectiveTo compare the clinical performance of digital breast tomosynthesis (DBT) with that of full-field digital mammography (FFDM) in a diagnostic population.MethodsThe study enrolled 200 consenting women who had at least one breast lesion discovered by mammography and/or ultrasound classified as doubtful or suspicious or probably malignant. They underwent tomosynthesis in one view [mediolateral oblique (MLO)] of both breasts at a dose comparable to that of standard screen-film mammography in two views [craniocaudal (CC) and MLO]. Images were rated by six breast radiologists using the BIRADS score. Ratings were compared with the truth established according to the standard of care and a multiple-reader multiple-case (MRMC) receiver-operating characteristic (ROC) analysis was performed. Clinical performance of DBT compared with that of FFDM was evaluated in terms of the difference between areas under ROC curves (AUCs) for BIRADS scores.ResultsOverall clinical performance with DBT and FFDM for malignant versus all other cases was not significantly different (AUCs 0.851 vs 0.836, p = 0.645). The lower limit of the 95% CI or the difference between DBT and FFDM AUCs was −4.9%.ConclusionClinical performance of tomosynthesis in one view at the same total dose as standard screen-film mammography is not inferior to digital mammography in two views.

Serum proteomic analysis identifies a highly sensitive and specific discriminatory pattern in stage 1 breast cancer

BackgroundMass spectrometry (MS)-based profiling was used to determine whether ion fingerprints could distinguish women with stage 1 breast cancer from women without breast cancer.MethodsThe initial study population consisted of 310 subjects: 155 women with yearly negative breast examination and negative mammography findings for at least 4 years, and 155 women undergoing surgery for pathology-proven stage 1 invasive ductal carcinoma. High-resolution SELDI-TOF (surface-enhanced laser desorption ionization–time of flight) analysis was performed on serum obtained from blood samples collected before mammography in controls, and before surgery in patients with breast cancer. Samples were divided into a training (109 controls and 109 cancers) and blinded (46 controls and 46 cancers) testing set; each group had similar age demographics. In addition, an independent study set of 46 serum samples was analyzed 14 months after the initial study to validate the robustness of the classifier.ResultsA discriminatory profile consisting of seven ion peaks found in the training set, when applied to the blinded test set, achieved a sensitivity and specificity of 95.6% and 86.5%, respectively. This same seven-peak profile achieved a 96.5% sensitivity and 85.7% specificity, with correct identification of all of 17 T1a tumors when applied to the validation study set.ConclusionsMass spectrometry profiling of human serum generated a robust classifier composed of seven low-molecular-weight ions that yielded a highly sensitive and specific diagnostic procedure for the discrimination of women with stage 1 breast cancer compared with women without breast cancer in this research study set.

Dose comparison between screen/film and full-field digital mammography

The study purpose was the comparison between doses delivered by a full-field digital mammography system and a screen/film mammography unit, both using the same type of X-ray tube. Exposure parameters and breast thickness were collected for 300 screen/film (GE Senographe DMR) and 296 digital mammograms (GE Senographe 2000D). The entrance surface air kerma (ESAK) was calculated from anode/filter combination, kVp and mAs values and breast thickness, by simulating spectra through a program based on a catalogue of experimental X-ray spectra. The average glandular dose (AGD) was also computed. Results showed an overall reduction of average glandular dose by 27% of digital over screen/film mammography. The dose saving was about 15% for thin and thick breasts, while it was between 30% and 40% for intermediate thicknesses. Full-field digital mammography dose reduction is allowed by wider dynamic range and higher efficiency of digital detector, which can be exposed at higher energy spectra than screen/film mammography, and by the separation between acquisition and displaying processes.

State of the Art of Current Modalities for the Diagnosis of Breast Lesions

With the availability of numerous diagnostic techniques comes the possible risk of the unjustified use of such techniques and a lack of rational clinical application. Clearly, errors of this nature would affect the diagnostic accuracy and therefore reduce the possibilities for treatment. It is not uncommon for women and also for general practitioners to be misinformed about which is the most suitable technique or rather, which is the best combination of the various techniques. For this reason, inappropriate tests are often requested or, conversely, there is failure to request tests which would in fact make a useful contribution to safeguarding the patient’s health. This work has the following aims: (a) to set out precisely the real diagnostic contribution of each method, both radiological and otherwise, and suggest methods of application and indications consistent with the state of the art, and (b) to suggest the most effective and rational combinations of the various techniques and organisation of diagnostic activities.

Combination of one-view digital breast tomosynthesis with one-view digital mammography versus standard two-view digital mammography: per lesion analysis

AbstractObjectiveTo evaluate the clinical value of combining one-view mammography (cranio-caudal, CC) with the complementary view tomosynthesis (mediolateral-oblique, MLO) in comparison to standard two-view mammography (MX) in terms of both lesion detection and characterization.MethodsA free-response receiver operating characteristic (FROC) experiment was conducted independently by six breast radiologists, obtaining data from 463 breasts of 250 patients. Differences in mean lesion detection fraction (LDF) and mean lesion characterization fraction (LCF) were analysed by analysis of variance (ANOVA) to compare clinical performance of the combination of techniques to standard two-view digital mammography.ResultsThe 463 cases (breasts) reviewed included 258 with one to three lesions each, and 205 with no lesions. The 258 cases with lesions included 77 cancers in 68 breasts and 271 benign lesions to give a total of 348 proven lesions. The combination, DBT(MLO)+MX(CC), was superior to MX (CC+MLO) in both lesion detection (LDF) and lesion characterization (LCF) overall and for benign lesions. DBT(MLO)+MX(CC) was non-inferior to two-view MX for malignant lesions.ConclusionsThis study shows that readers’ capabilities in detecting and characterizing breast lesions are improved by combining single-view digital breast tomosynthesis and single-view mammography compared to two-view digital mammography.Key Points• Digital breast tomosynthesis is becoming adopted as an adjunct to mammography (MX) • DBT(MLO)+MX(CC)is superior to MX(CC+MLO)in lesion detection (overall and benign lesions) • DBT(MLO)+MX(CC)is non-inferior to MX(CC+MLO)in cancer detection • DBT(MLO)+MX(CC)is superior to MX(CC+MLO)in lesion characterization (overall and benign lesions) • DBT(MLO)+MX(CC)is non-inferior to MX(CC+MLO)in characterization of malignant lesions

Grid removal and impact on population dose in full-field digital mammography

The study purpose was to determine the impact of anti-scatter grid removal on patient dose, in full field digital mammography. Dose saving, phantom based, was evaluated with the constraint that images acquired with and without grid would provide the same contrast-to-noise ratio (CNR). The digital equipment employed a flat panel detector with cesium iodide for x-ray to light conversion, 100 microm pixel size; the x-ray source was a dual-track tube with selectable filtration. Poly(methyl-emathocrylate) (PMMA) layers in the range 20-70 mm were used to simulate the absorption of different breast thickness, while two Al foils, 0.1 and 0.2 mm thick were used to provide a certain CNR. Images with grid were acquired with the same beam quality as selected in full automatic exposure mode and the mAs levels as close as possible, and the CNR measured for each thickness between 20 and 70 mm. Phantom images without grid were acquired in manual exposure mode, by selecting the same anode/filter combination and kVp as the image with grid at the same thickness, but varying mAs from 10 to 200. For each thickness, an image without aluminum was acquired for each mAs value, in order to obtain a flat image to be used to subtract the scatter nonuniformity from the phantom images. After scatter subtraction, the CNR was measured on images without grid. The mAs value that should be set to acquire a phantom image without grid so that it has the same CNR as the corresponding grid image was calculated. Therefore, mAs reduction percentage was determined versus phantom thickness. Results showed that dose saving was lower than 30% for PMMA equivalent breast thinner than 40 mm, decreased below 10% for intermediate thickness (45-50 mm), but there was no dose gain for thickness beyond 60 mm. By applying the mAs reduction factors to a clinical population derived from a data base of 4622 breasts, dose benefit was quantified in terms of population dose. On the average, the overall dose reduction was about 8%. It was considered small, not sufficient to justify a clinical implementation, and the anti-scatter grid was maintained.

Are phantoms useful for predicting the potential of dose reduction in full-field digital mammography?

A phantom study was performed in full-field digital mammography to investigate the opportunity and the magnitude of a possible dose reduction that would leave the image quality above the accepted thresholds associated with some classical phantoms. This preliminary work is intended to lay the groundwork for a future clinical study on the impact of dose reduction on clinical results. Three different mammography phantoms (ACR RMI 156, CIRS 11A and CDMAM 3.4) were imaged by a full-field digital mammography unit (GE Senographe 2000D) at different dose levels. Images were rated by three observers with softcopy reading and scoring methods specific to each phantom. Different types of data analysis were applied to the ACR (American College of Radiology) and the other two phantoms, respectively. With reference to the minimum acceptance score in screen/film accreditation programmes, the ACR phantom showed that about 45% dose reduction could be applied, while keeping the phantom scores above that threshold. A relative comparison was done for CIRS and CDMAM, for which no threshold is defined. CIRS scoring remained close to the reference level down to 40% dose reduction, the inter- and intra-observer variability being the main source of uncertainty. Contrast-detail curves provided by CDMAM overlapped down to 50% dose reduction, at least for object contrast values ranging between 30% and 3%. This multi-phantom study shows the potential of further reducing the dose in full-field digital mammography beyond the current values. A common dose reduction factor around 50% seems acceptable for all phantoms. However, caution is required before extrapolating the results for clinical use, given the limitations of these widely used phantoms, mainly related to their limited dynamic range and uniform background.

Clinical Performance of Digital Breast Tomosynthesis Versus Full-Field Digital Mammography: Preliminary Results

Preliminary results of a clinical study designed to compare clinical performance of digital breast tomosynthesis (DBT) versus standard full-field digital mammography (FFDM) in a diagnostic population are presented and discussed. Paired tomosynthesis and mammography examinations were analyzed by three experienced radiologists. One hundred single-breast cases were analyzed. Findings were rated in terms of lesion conspicuity, classified using the ACR BIRADS scale and compared with the truth. Statistically significant differences were found in lesion conspicuity for all radiologists, showing tomosynthesis superior to mammography. Finding classifications (BIRADS) were evaluated by ROC analysis. The results obtained from tomosynthesis images were consistently superior to FFDM for all readers. The difference was statistically significant for one radiologist. The results demonstrated DBT superiority for conspicuity of findings and showed potential for superior clinical performance.

Correlation between magnetic resonance imaging and histopathological tumor response after neoadjuvant chemotherapy in breast cancer.

AIM To evaluate the accuracy of magnetic resonance imaging in assessing tumor response following neoadjuvant chemotherapy in patients with locally advanced breast cancer. MATERIALS AND METHODS Twenty-six patients entered a phase II study of neoadjuvant chemotherapy, undergoing bilateral breast magnetic resonance imaging before therapy and before surgery. Tumor response was classified using RECIST criteria, using tumor size at magnetic resonance imaging. The latter was then compared to residue found at histopathological examination. RESULTS Magnetic resonance imaging showed 6 (23%) complete responses, 17 (65%) partial responses, 3 (11.5%) disease stabilizations and no disease progressions. Twenty-three tumors (88.5%) were considered responsive and 3 (11.5%) unresponsive. Pathological tumor response was: 6 complete responses (23%), 17 partial responses (65%), 2 stable disease (8%), 1 progression (4%). When results of the preoperative magnetic resonance imaging were compared to pathological tumor response, magnetic resonance imaging overestimated tumor size in 12 cases (46%) and underestimated it in 9 (35%). However, preoperative magnetic resonance imaging failed to detect invasive tumor in 2 false-negative cases (8%), 1 of which was multifocal. Mastectomy was performed in 12 cases: 1 case of disease progression even though the neoplasm appeared smaller at magnetic resonance imaging, 3 cases with stable disease, and 4 cases with T3 or T4 disease. The 9th patient was T2N2 with initial retroareolar disease and negative magnetic resonance imaging after chemotherapy. The 10th patient, affected by lobular cancer, was in partial remission but was T3N1. The 11th patient was 57 years old but was not interested in conservative surgery. The 12th patient requested bilateral prophylactic mastectomy due to her positive family history of breast cancer. CONCLUSIONS Magnetic resonance imaging of the breast allowed conservative surgery in 54% of the patients. This low value is primarily due to overestimation of tumor size, with a negative predictive value of 67% in our population. However, surgeons were able to choose conservative surgery with relative safety in cases of small residual disease.

Application of dual-energy techniques to digital mammography

A dual-energy technique which employs the basis decomposition method is being investigated for application to digital mammography. A three-component phantom was doubly exposed with the digital mammography system manufactured by General Electric. The “low” and “high” energy images were recorded with a Mo/Mo anode-filter combination at 25 kV and a Rh/Rh combination at 40 kV, respectively. The total dose was kept within the acceptable levels of conventional mammography. The first hybrid image obtained with the dual-energy algorithm is presented in comparison with a conventional radiograph of the phantom.