Laura J. Horvath

Early Clinical Experience with Digital Breast Tomosynthesis for Screening Mammography

PURPOSE To examine recall rates from screening mammography and the mammographic findings that caused recall in women who underwent digital breast tomosynthesis with conventional mammography (referred to as two-dimensional [ 2D two-dimensional ] with three-dimensional [ 3D three-dimensional ] imaging [ 2D two-dimensional + 3D three-dimensional ]) and in women who underwent conventional mammography alone (referred to as 2D two-dimensional ). MATERIALS AND METHODS This was an institutional review board-approved, HIPAA-compliant study with waivers of informed consent. A retrospective review of 2D two-dimensional + 3D three-dimensional and 2D two-dimensional screening mammograms from August 1, 2011, to December 31, 2012, was performed. Recall rates and abnormalities that caused recall were compared by controlling for differences in patient age, breast density, and risk factors. Cancer detection rate was assessed from this time period and from 1 year before the introduction of tomosynthesis for a historic control. RESULTS This study included 17 955 screening mammograms; of the total, there were 8591 (47.8%) 2D two-dimensional + 3D three-dimensional screening examinations and 9364 (52.2%) 2D two-dimensional examinations. The recall rate was 7.8% (671 of 8592) for 2D two-dimensional + 3D three-dimensional and 12.3% (1154 of 9364) for 2D two-dimensional (P < .0001); the rate of recall was 36.6% lower in the 2D two-dimensional + 3D three-dimensional group than in the 2D two-dimensional group. Recall rates for the 2D two-dimensional + 3D three-dimensional group were significantly lower for patients with asymmetries, ( 2D two-dimensional + 3D three-dimensional vs 2D two-dimensional , 3.1% [267 of 8591] vs 7.4% [689 of 9364], respectively; P < .0001) and calcifications ( 2D two-dimensional + 3D three-dimensional vs 2D two-dimensional , 2.4% [205 of 8591] vs 3.2% [297 of 9364], respectively; P = .0014). For patients with masses and architectural distortion, the difference in recall rates was not significant (masses: 2D two-dimensional + 3D three-dimensional vs 2D two-dimensional , 2.5% [215 of 8591] vs 2.5% [237 of 9364], respectively; P = .90; architectural distortion: 2D two-dimensional + 3D three-dimensional vs 2D two-dimensional , 0.68% [58 of 8591] vs 0.69% [65 of 9364]; P = .88). Cancer detection was highest in the 2D two-dimensional + 3D three-dimensional group at 5.9 cancers per 1000 examinations, with 5.7 cancers per 1000 examinations in the concurrent 2D two-dimensional group, and 4.4 cancers per 1000 examinations in the historic control. CONCLUSION Use of tomosynthesis ( 2D two-dimensional + 3D three-dimensional ) compared with conventional mammography ( 2D two-dimensional ) is associated with a lower recall rate of screening mammography, most often for asymmetries.

Postchemotherapy MRI overestimates residual disease compared with histopathology in responders to neoadjuvant therapy for locally advanced breast cancer.

The utility of breast magnetic resonance imaging in patients receiving neoadjuvant chemotherapy is not well defined. We compared serial magnetic resonance imaging examinations with histologic posttreatment examinations in patients treated with primary chemotherapy for locally advanced breast cancer. PATIENTS AND METHODSEligible patients with locally advanced breast cancer received doxorubicin 60 mg/m2 and docetaxel 60 mg/m2 (with granulocyte colony stimulating factor support) every 14 days for a maximum of six cycles. Breast magnetic resonance imaging was performed at baseline and repeated every two cycles. Surgery (either local excision or mastectomy) was performed after six cycles in responding or stable patients. Residual tumor size on pathology and preoperative magnetic resonance imaging was compared; concordance was defined as a < 0.5-cm difference. RESULTSTo date, three of 17 enrolled subjects (17.6%) attained pathologic complete response, and three additional patients attained near pathologic complete response, with residual foci of ≤ 1 mm. Of these six patients, only one was disease free by magnetic resonance imaging. Discordance between magnetic resonance imaging findings and pathologic evaluation was found in four of six patients (66.6%) who obtained pathologic complete response or near pathologic complete response. In the three patients in whom four axillary lesions were followed with magnetic resonance imaging, discordance was found in all four lesions, with magnetic resonance imaging overestimating pathologic disease in all cases. DISCUSSIONOur findings caution that magnetic resonance imaging may frequently overestimate residual invasive carcinoma after neoadjuvant chemotherapy. These results contradict previous studies suggesting that postchemotherapy magnetic resonance imaging may underestimate residual cancer. The use of magnetic resonance imaging in evaluating response to therapy in locally advanced breast cancer should be further studied.

Voice-activated retrieval of mammography reference images

We undertook this project to integrate context sensitive computer-based educational and decision making aids into the film interpretation and reporting process, and to determine the clinical utility of this method as a guide for further system development. An image database of 347 digital mammography images was assembled and image features were coded. An interface was developed to a computerized speech recognition radiology reporting system which was modified to translate reported findings into database search terms. These observations were used to formulate database search strategies which not only retrieved similar cases from the image database, but also other cases that were related to the index case in different ways. The search results were organized into image sets intended to address common questions that arise during image interpretation. An evaluation of the clinical utility of this method was performed as a guide for further system development. We found that voice dictation of prototypical mammographic cases resulted in automatic retrieval of reference images. The retrieved images were organized into sets matching findings, diagnostic hypotheses, diagnosis, spectrum of findings or diagnoses, closest match to dictated case, or user specified parameters. Two mammographers graded the clinical utility of each form of system output. We concluded that case specific and problem specific image sets may be automatically generated from spoken case dictation. A potentially large number of retrieved images may be divided into subsets which anticipate common clinical problems. This automatic method of context sensitive image retrieval may provide a “continuous’; form of education integrated into routine case interpretation.

Tomosynthesis in the Diagnostic Setting: Changing Rates of BI-RADS Final Assessment over Time

Purpose To evaluate the effect of tomosynthesis in diagnostic mammography on the Breast Imaging Reporting and Data System (BI-RADS) final assessment categories over time. Materials and Methods This retrospective study was approved by the institutional review board. The authors reviewed all diagnostic mammograms obtained during a 12-month interval before (two-dimensional [2D] mammography [June 2, 2010, to June 1, 2011]) and for 3 consecutive years after (tomosynthesis year 1 [2012], tomosynthesis year 2 [2013], and tomosynthesis year 3 [2014]) the implementation of tomosynthesis. The requirement to obtain informed consent was waived. The rates of BI-RADS final assessment categories 1-5 were compared between the 2D and tomosynthesis groups. The positive predictive values after biopsy (PPV3) for BI-RADS category 4 and 5 cases were compared. The mammographic features (masses, architectural distortions, calcifications, focal asymmetries) of lesions categorized as probably benign (BI-RADS category 3) and those for which biopsy was recommended (BI-RADS category 4 or 5) were reviewed. The χ(2) test was used to compare the rates of BI-RADS final assessment categories 1-5 between the two groups, and multivariate logistic regression analysis was performed to compare all diagnostic studies categorized as BI-RADS 3-5. Results There was an increase in the percentage of cases reported as negative or benign (BI-RADS category 1 or 2) with tomosynthesis (58.7% with 2D mammography vs 75.8% with tomosynthesis at year 3, P < .0001). A reduction in the percentage of probably benign (BI-RADS category 3) final assessments also occurred (33.3% with 2D mammography vs 16.4% with tomosynthesis at year 3, P < .0001). Although the rates of BI-RADS 4 or 5 assessments did not change significantly with tomosynthesis (8.0% with 2D mammography vs 7.8% with tomosynthesis at year 3, P = .2), there was a significant increase in the PPV3 (29.6% vs 50%, respectively; P < .0001). These trends increased during the 3 years of tomosynthesis use. Conclusion Tomosynthesis in the diagnostic setting resulted in progressive shifts in the BI-RADS final assessment categories over time, with a significant increase in the proportion of studies classified as normal, a continued decrease in the rate of studies categorized as probably benign, and improved diagnostic confidence in biopsy recommendations. (©) RSNA, 2016.