Jules H. Sumkin

Digital Breast Tomosynthesis: Observer Performance Study

OBJECTIVE The purpose of this study was to compare in a retrospective observer study the diagnostic performance of full-field digital mammography (FFDM) with that of digital breast tomosynthesis. MATERIALS AND METHODS Eight experienced radiologists interpreted images from 125 selected examinations, 35 with verified findings of cancer and 90 with no finding of cancer. The four display conditions included FFDM alone, 11 low-dose projections, reconstructed digital breast tomosynthesis images, and a combined display mode of FFDM and digital breast tomosynthesis images. Observers rated examinations using the screening BI-RADS rating scale and the free-response receiver operating characteristic paradigm. Observer performance levels were measured as the proportion of examinations prompting recall of patients for further diagnostic evaluation. The results were presented in terms of true-positive fraction and false-positive fraction. Performance levels were compared among the acquisitions and reading modes. Time to view and interpret an examination also was evaluated. RESULTS Use of the combination of digital breast tomosynthesis and FFDM was associated with 30% reduction in recall rate for cancer-free examinations that would have led to recall if FFDM had been used alone (p < 0.0001 for the participating radiologists, p = 0.047 in the context of a generalized population of radiologists). Use of digital breast tomosynthesis alone also tended to reduce recall rates, an average of 10%, although the observed decrease was not statistically significant (p = 0.09 for the participating radiologists). There was no convincing evidence that use of digital breast tomosynthesis alone or in combination with FFDM results in a substantial improvement in sensitivity. CONCLUSION Use of digital breast tomosynthesis for breast imaging may result in a substantial decrease in recall rate.

Detection and Classification of Calcifications on Digital Breast Tomosynthesis and 2D Digital Mammography: A Comparison

OBJECTIVE The purpose of this article is to compare the ability of digital breast tomosynthesis and full field digital mammography (FFDM) to detect and characterize calcifications. MATERIALS AND METHODS One hundred paired examinations were performed utilizing FFDM and digital breast tomosynthesis. Twenty biopsy-proven cancers, 40 biopsy-proven benign calcifications, and 40 randomly selected negative screening studies were retrospectively reviewed by five radiologists in a crossed multireader multimodal observer performance study. Data collected included the presence of calcifications and forced BI-RADS scores. Receiver operator curve analysis using BI-RADS was performed. RESULTS Overall calcification detection sensitivity was higher for FFDM (84% [95% CI, 79-88%]) than for digital breast tomosynthesis (75% [95% CI, 70-80%]). [corrected] In the cancer cohort, 75 (76%) of 99 interpretations identified calcification in both modes. Of those, a BI-RADS score less than or equal to 2 was rendered in three (4%) and nine (12%) cases with FFDM and digital breast tomosynthesis, respectively. In the benign cohort, 123 (62%) of 200 interpretations identified calcifications in both modes. Of those, a BI-RADS score greater than or equal to 3 was assigned in 105 (85%) and 93 (76%) cases with FFDM and digital breast tomosynthesis, respectively. There was no significant difference in the nonparametric computed area under the receiver operating characteristic curves (AUC) using the BI-RADS scores (FFDM, AUC = 0.76 and SD = 0.03; digital breast tomosynthesis, AUC = 0.72 and SD = 0.04 [p = 0.1277]). CONCLUSION In this small data set, FFDM appears to be slightly more sensitive than digital breast tomosynthesis for the detection of calcification. However, diagnostic performance as measured by area under the curve using BI-RADS was not significantly different. With improvements in processing algorithms and display, digital breast tomosynthesis could potentially be improved for this purpose.

Digital Breast Tomosynthesis versus Supplemental Diagnostic Mammographic Views for Evaluation of Noncalcified Breast Lesions

PURPOSE To compare the diagnostic performance of breast tomosynthesis versus supplemental mammography views in classification of masses, distortions, and asymmetries. MATERIALS AND METHODS Eight radiologists who specialized in breast imaging retrospectively reviewed 217 consecutively accrued lesions by using protocols that were HIPAA compliant and institutional review board approved in 182 patients aged 31-60 years (mean, 50 years) who underwent diagnostic mammography and tomosynthesis. The lesions in the cohort included 33% (72 of 217) cancers and 67% (145 of 217) benign lesions. Eighty-four percent (182 of 217) of the lesions were masses, 11% (25 of 217) were asymmetries, and 5% (10 of 217) were distortions that were initially detected at clinical examination in 8% (17 of 217), at mammography in 80% (173 of 217), at ultrasonography (US) in 11% (25 of 217), or at magnetic resonance imaging in 1% (2 of 217). Histopathologic examination established truth in 191 lesions, US revealed a cyst in 12 lesions, and 14 lesions had a normal follow-up. Each lesion was interpreted once with tomosynthesis and once with supplemental mammographic views; both modes included the mediolateral oblique and craniocaudal views in a fully crossed and balanced design by using a five-category Breast Imaging Reporting and Data System (BI-RADS) assessment and a probability-of-malignancy score. Differences between modes were analyzed with a generalized linear mixed model for BI-RADS-based sensitivity and specificity and with modified Obuchowski-Rockette approach for probability-of-malignancy-based area under the receiver operating characteristic (ROC) curve. RESULTS Average probability-of-malignancy-based area under the ROC curve was 0.87 for tomosynthesis versus 0.83 for supplemental views (P < .001). With tomosynthesis, the false-positive rate decreased from 85% (989 of 1160) to 74% (864 of 1160) (P < .01) for cases that were rated BI-RADS category 3 or higher and from 57% (663 of 1160) to 48% (559 of 1160) for cases rated BI-RADS category 4 or 5 (P < .01), without a meaningful change in sensitivity. With tomosynthesis, more cancers were classified as BI-RADS category 5 (39% [226 of 576] vs 33% [188 of 576]; P = .017) without a decrease in specificity. CONCLUSION Tomosynthesis significantly improved diagnostic accuracy for noncalcified lesions compared with supplemental mammographic views.

Comparison of Two-dimensional Synthesized Mammograms versus Original Digital Mammograms Alone and in Combination with Tomosynthesis Images

PURPOSE To assess interpretation performance and radiation dose when two-dimensional synthesized mammography (SM) images versus standard full-field digital mammography (FFDM) images are used alone or in combination with digital breast tomosynthesis images. MATERIALS AND METHODS A fully crossed, mode-balanced multicase (n = 123), multireader (n = 8), retrospective observer performance study was performed by using deidentified images acquired between 2008 and 2011 with institutional review board approved, HIPAA-compliant protocols, during which each patient signed informed consent. The cohort included 36 cases of biopsy-proven cancer, 35 cases of biopsy-proven benign lesions, and 52 normal or benign cases (Breast Imaging Reporting and Data System [BI-RADS] score of 1 or 2) with negative 1-year follow-up results. Accuracy of sequentially reported probability of malignancy ratings and seven-category forced BI-RADS ratings was evaluated by using areas under the receiver operating characteristic curve (AUCs) in the random-reader analysis. RESULTS Probability of malignancy-based mean AUCs for SM and FFDM images alone was 0.894 and 0.889, respectively (difference, -0.005; 95% confidence interval [CI]: -0.062, 0.054; P = .85). Mean AUC for SM with tomosynthesis and FFDM with tomosynthesis was 0.916 and 0.939, respectively (difference, 0.023; 95% CI: -0.011, 0.057; P = .19). In terms of the reader-specific AUCs, five readers performed better with SM alone versus FFDM alone, and all eight readers performed better with combined FFDM and tomosynthesis (absolute differences from 0.003 to 0.052). Similar results were obtained by using a nonparametric analysis of forced BI-RADS ratings. CONCLUSION SM alone or in combination with tomosynthesis is comparable in performance to FFDM alone or in combination with tomosynthesis and may eliminate the need for FFDM as part of a routine clinical study.

Digital Breast Tomosynthesis in the Diagnostic Environment: A Subjective Side-by-Side Review

OBJECTIVE The purpose of our study was to subjectively compare additional mammographic views to digital breast tomosynthesis (DBT) in the characterizing of known masses, architectural distortions, or asymmetries. MATERIALS AND METHODS Four experienced radiologists serially reviewed the imaging studies of 25 women with known masses, including full-field digital mammography (FFDM), additional views, and DBT. After review of the examinations, radiologists rated their relative preference in terms of classifying the finding in question when aided by the additional views versus aided by DBT, their combined diagnostic BI-RADS rating of the finding when both examinations were available, and whether or not they felt comfortable eliminating ultrasound in the specific cases being evaluated as a result of the DBT. RESULTS FFDM and DBT (combined) were perceived to be better for diagnosis in 50% (50/100) of the ratings (25 cases x four readers = 100 ratings) compared with FFDM and additional diagnostic views. Over all readers, 92% of the ratings for verified cancer cases and 50% of the ratings for high-risk cases were rated as BI-RADS 4 or 5. In 12% (12/100) of the ratings, radiologists indicated that the availability of DBT would have eliminated the need for ultrasound as a part of the diagnostic process. CONCLUSION DBT may be an alternative to obtaining additional mammographic views in most but not all cases of patients with a lesion that is not solely calcifications. In a fraction of cases, the use of DBT may eliminate the need for ultrasound.

Sentinel lymph node biopsy in early-stage cervical cancer: Utility of intraoperative versus postoperative assessment

OBJECTIVE To determine the diagnostic accuracy of sentinel lymph node (SLN) detection using lymphoscintigraphy, intraoperative blue dye, and radiocolloid in patients with early-stage cervical cancer. METHODS Intra-cervical injection of technetium-99 sulfur colloid and lymphoscintigraphy were performed preoperatively. Isosulfan blue was injected intra-cervically immediately prior to surgery. SLNs were excised and examined intraoperatively (imprint cytology and frozen section) and postoperatively (H and E histology and immunohistochemistry (IHC) for cytokeratin). RESULTS Thirty eight patients were evaluable. Laparoscopy and laparotomy were performed in 28.9% and 71.1%, respectively. Subjects had squamous cell carcinoma (n=26), adenocarcinoma (n=10) or adenosquamous (n=2) histologies. 55.3% had cervical tumors <2 cm. The overall SLN detection rate was 92.1%. The external iliac region just distal to the common iliac bifurcation was the most common SLN location. A mean of 2.1 SLNs were detected per patient with bilateral SLNs observed in 47.4%. On final pathology, metastatic nodal disease was identified in 15.7% of patients. Of these, 83.3% were detected in the SLNs. Sensitivity of SLN detection of metastasis was 100% for patients with cervical tumors <2 cm. However intraoperative evaluation by imprint cytology and frozen section correctly identified lymph node metastasis in only 33.3%. CONCLUSIONS SLN detection is feasible and accurately reflects pelvic nodal basin status when performed in early-stage cervical cancer patients. However, while current intraoperative pathology techniques for assessing nodal metastases reliably detect metastases larger than 2 mm, they lack sufficient sensitivity to detect micrometastasis and isolated tumor cells.

Diagnostic Accuracy and Recall Rates for Digital Mammography and Digital Mammography Combined With One-View and Two-View Tomosynthesis: Results of an Enriched Reader Study

OBJECTIVE The purpose of this study was to compare two methods of combining tomosynthesis with digital mammography by assessing diagnostic accuracy and recall rates for digital mammography alone and digital mammography combined with one-view tomosynthesis and two-view tomosynthesis. SUBJECTS AND METHODS Three hundred ten cases including biopsy-proven malignancies (51), biopsy-proven benign findings (47), recalled screening cases (138), and negative screening cases (74) were reviewed by 15 radiologists sequentially using digital mammography, adding one-view tomosynthesis, and then two-view tomosynthesis. Cases were assessed for recall and assigned a BI-RADS score and probability of malignancy for each imaging method. Diagnostic accuracy was assessed using receiver operating characteristic (ROC) analysis. Screening recall rates were compared using pooled logistical regression analysis. A p value of < 0.0167 was considered significant. RESULTS The area under the ROC curve (AUC) for digital mammography (DM), DM plus one-view tomosynthesis, and DM plus two-view tomosynthesis was 0.828, 0.864, and 0.895, respectively. Both one-view and two-view tomosynthesis plus DM were significantly better than DM alone (Δ AUCs 0.036 [p = 0.009] and 0.068 [p < 0.001]). Average noncancer recall rates for digital mammography, DM plus one-view tomosynthesis, and DM plus two-view tomosynthesis were 44.2%, 27.2%, and 24.0%, respectively. Combined with DM, one-view and two-view tomosynthesis both showed significantly lower noncancer recall rates than digital mammography alone (p < 0.001). Digital mammography with two-view tomosynthesis showed a significantly lower recall rate than digital mammography with one-view tomosynthesis (p < 0.001). Diagnostic accuracy for dense (Δ AUC, 0.091%; p < 0.001) and nondense (Δ AUC, 0.035%; p = 0.001) breasts improved with DM plus two-view tomosynthesis compared with digital mammography alone. Compared with digital mammography, diagnostic sensitivity for invasive cancers increased with the addition of both one-view (Δ12.0%, p < 0.001) and two-view (Δ21.7%, p < 0.001) tomosynthesis. CONCLUSION The addition of one-view tomosynthesis to conventional digital mammography improved diagnostic accuracy and reduced the recall rate; however, the addition of two-view tomosynthesis provided twice the performance gain in diagnostic accuracy while further reducing the recall rate.

The clinical significance of lobular neoplasia on breast core biopsy

A core biopsy diagnosis of atypical ductal epithelial hyperplasia is upstaged on follow-up excisional biopsy (FUEB) to in situ or invasive carcinoma in about 20% of cases, thus prompting a FUEB. In contrast, upstaging information for a core biopsy diagnosis of pure lobular neoplasia (LN), without mass lesions or other risk-associated lesions is less clear. In this retrospective study, we report the largest consecutive series of patients who had a breast core biopsy diagnosis of LN and a FUEB. Core needle breast biopsies with a diagnosis of LN were retrieved from our files for the period 1999 to 2005, yielding 110 patients. One hundred and one patients had a follow-up surgical excision. Cases of LN with coexisting high-risk lesions (n=9, 10%) were excluded from the study. Patients with associated mass lesions all had benign findings (n=15, 16%) and had no impact on the study results. The remaining 77 core biopsies had no masses or risk lesions and were mammographically Breast Imaging Reporting and Data System 4 (BIRADS) for microcalcifications. Overall, 8/77 (10%) of patients with a radiographic BIRADS 4 image with calcifications and a core biopsy diagnosis of LN on core biopsy were upstaged on FUEB to ductal carcinoma in situ or invasive carcinoma. The numbers upstaged from core biopsies were as follows: atypical lobular hyperplasia (ALH) 4/52 (8%), mixed ALH/lobular carcinoma in situ (LCIS) 1/9 (10%), and pure LCIS 3/16 (19%). A core biopsy of LCIS with neoplastic epithelial calcifications was nearly 3 times more likely to be upstaged on FUEB compared with ALH. We conclude that a finding of LN on breast core biopsy in a patient with a BIRADS 4 image and calcifications is associated with a risk of 8% to 19% of upstaging to a treatable disease on FUEB.

Recall and detection rates in screening mammography: A review of clinical experience: Implications for practice guidelines

The authors investigated the correlation between recall and detection rates in a group of 10 radiologists who had read a high volume of screening mammograms in an academic institution.

Localized detection and classification of abnormalities on FFDM and tomosynthesis examinations rated under an FROC paradigm.

OBJECTIVE The purpose of our study was to assess diagnostic performance when retrospectively interpreting full-field digital mammography (FFDM) and breast tomosynthesis examinations under a free-response receiver operating characteristic (FROC) paradigm. MATERIALS AND METHODS We performed FROC analysis of a previously reported study in which eight experienced radiologists interpreted 125 examinations, including 35 with verified cancers. The FROC paradigm involves detecting, locating, and rating each suspected abnormality. Radiologists reviewed and rated both FFDM alone and a combined display mode of FFDM and digital breast tomosynthesis (DBT) (combined). Observer performance levels were assessed and compared with respect to the fraction of correctly identified abnormalities, the number of reported location-specific findings (both true and false), and their associated ratings. The analysis accounts for the number and locations of findings and the location-based ratings using a summary performance index (Λ), which is the FROC analog of the area between the receiver operating characteristic curve and the diagonal (chance) line. RESULTS Under the FROC paradigm, each reader detected more true abnormalities associated with cancer, or a higher true-positive fraction, under the combined mode. In an analysis focused on both the number of findings and associated location-based ratings, each of the radiologists performed better under the combined mode compared with FFDM alone, with increases in Λ ranging from 5% to 34%. On average, under the combined mode radiologists achieved a 16% improvement in Λ compared with the FFDM alone mode (95% CI, 7-26%; p < 0.01). CONCLUSION We showed that DBT-based breast imaging in combination with FFDM could result in better performance under the FROC paradigm.