Use of BI-RADS 3-probably benign category in the American College of Radiology Imaging Network Digital Mammographic Imaging Screening Trial.

PURPOSE: To determine (a) how often the Breast Imaging Reporting and Data System (BI-RADS) category 3 was used in the American College of Radiology Imaging Network (ACRIN) Digital Mammographic Imaging Screening Trial (DMIST), either at the time of screening mammography or after work-up, (b) how often subjects actually returned for the recommended follow-up examination, and (c) the rate and stages of any malignancies subsequently found in subjects for whom short-term interval follow-up was recommended. MATERIALS AND METHODS: This study was approved by the Institutional Review Board at all institutions where subjects were enrolled. All subjects participating in DMIST gave informed consent and the study was HIPAA-compliant. A total of 47,599 DMIST-eligible and evaluable subjects, all of whom consented to undergo both digital and screen-film mammography, were included in this analysis. Cases referred for short-term interval follow-up based on digital, screen-film, or both imaging examinations were determined. Compliance with the recommendations and the final outcome (malignancy diagnosis at biopsy or no malignancy confirmed through follow-up) of each evaluable case were determined. RESULTS: A total of 1114 of the 47,599 (2.34%) subjects had tumors assigned a BI-RADS 3 category and were recommended to undergo short-interval follow-up. In this study, 791 of 1114 (71%) of the subjects were compliant with the recommendation and returned for short-interval follow-up. Of the women who did not return for short-interval follow-up, 70% (226 of 323) did return for their next annual mammography. Among all subjects whose tumors were assigned a BI-RADS 3 category either at screening mammography or after additional work-up, nine of 1114 (0.81%) were found to have cancer. Of the nine biopsy-proved cancers, six were invasive cancers and three were ductal carcinoma in situ stage Tis-T1c. The invasive cancers were all less than 2 cm in size. CONCLUSION: In DMIST, radiologists used the BI-RADS 3 classification infrequently (2.3% of patients). Tumors assigned a BI-RADS 3 category had a low rate of malignancy. The relatively high rate of noncompliance with short-interval follow-up recommendations (323 of 1114, or 29%) supports prior recommendations that radiologists thoroughly evaluate lesions before placing them in this category.

Cancer cases from ACRIN digital mammographic imaging screening trial: radiologist analysis with use of a logistic regression model.

PURPOSE: To determine which factors contributed to the Digital Mammographic Imaging Screening Trial (DMIST) cancer detection results. MATERIALS AND METHODS: This project was HIPAA compliant and institutional review board approved. Seven radiologist readers reviewed the film hard-copy (screen-film) and digital mammograms in DMIST cancer cases and assessed the factors that contributed to lesion visibility on both types of images. Two multinomial logistic regression models were used to analyze the combined and condensed visibility ratings assigned by the readers to the paired digital and screen-film images. RESULTS: Readers most frequently attributed differences in DMIST cancer visibility to variations in image contrast--not differences in positioning or compression--between digital and screen-film mammography. The odds of a cancer being more visible on a digital mammogram--rather than being equally visible on digital and screen-film mammograms--were significantly greater for women with dense breasts than for women with nondense breasts, even with the data adjusted for patient age, lesion type, and mammography system (odds ratio, 2.28; P < .0001). The odds of a cancer being more visible at digital mammography--rather than being equally visible at digital and screen-film mammography--were significantly greater for lesions imaged with the General Electric digital mammography system than for lesions imaged with the Fischer (P = .0070) and Fuji (P = .0070) devices. CONCLUSION: The significantly better diagnostic accuracy of digital mammography, as compared with screen-film mammography, in women with dense breasts demonstrated in the DMIST was most likely attributable to differences in image contrast, which were most likely due to the inherent system performance improvements that are available with digital mammography. The authors conclude that the DMIST results were attributable primarily to differences in the display and acquisition characteristics of the mammography devices rather than to reader variability.

Diagnostic performance of digital versus film mammography for breast-cancer screening.

BACKGROUND: Film mammography has limited sensitivity for the detection of breast cancer in women with radiographically dense breasts. We assessed whether the use of digital mammography would avoid some of these limitations. METHODS: A total of 49,528 asymptomatic women presenting for screening mammography at 33 sites in the United States and Canada underwent both digital and film mammography. All relevant information was available for 42,760 of these women (86.3 percent). Mammograms were interpreted independently by two radiologists. Breast-cancer status was ascertained on the basis of a breast biopsy done within 15 months after study entry or a follow-up mammogram obtained at least 10 months after study entry. Receiver-operating-characteristic (ROC) analysis was used to evaluate the results. RESULTS: In the entire population, the diagnostic accuracy of digital and film mammography was similar (difference between methods in the area under the ROC curve, 0.03; 95 percent confidence interval, -0.02 to 0.08; P=0.18). However, the accuracy of digital mammography was significantly higher than that of film mammography among women under the age of 50 years (difference in the area under the curve, 0.15; 95 percent confidence interval, 0.05 to 0.25; P=0.002), women with heterogeneously dense or extremely dense breasts on mammography (difference, 0.11; 95 percent confidence interval, 0.04 to 0.18; P=0.003), and premenopausal or perimenopausal women (difference, 0.15; 95 percent confidence interval, 0.05 to 0.24; P=0.002). CONCLUSIONS: The overall diagnostic accuracy of digital and film mammography as a means of screening for breast cancer is similar, but digital mammography is more accurate in women under the age of 50 years, women with radiographically dense breasts, and premenopausal or perimenopausal women. (ClinicalTrials.gov number, NCT00008346.)

Diagnostic accuracy of digital versus film mammography: exploratory analysis of selected population subgroups in DMIST.

PURPOSE: To retrospectively compare the accuracy of digital versus film mammography in population subgroups of the Digital Mammographic Imaging Screening Trial (DMIST) defined by combinations of age, menopausal status, and breast density, by using either biopsy results or follow-up information as the reference standard. MATERIALS AND METHODS: DMIST included women who underwent both digital and film screening mammography. Institutional review board approval at all participating sites and informed consent from all participating women in compliance with HIPAA was obtained for DMIST and this retrospective analysis. Areas under the receiver operating characteristic curve (AUCs) for each modality were compared within each subgroup evaluated (age < 50 vs 50-64 vs >or= 65 years, dense vs nondense breasts at mammography, and pre- or perimenopausal vs postmenopausal status for the two younger age cohorts [10 new subgroups in toto]) while controlling for multiple comparisons (P < .002 indicated a significant difference). All DMIST cancers were evaluated with respect to mammographic detection method (digital vs film vs both vs neither), mammographic lesion type (mass, calcifications, or other), digital machine type, mammographic and pathologic size and diagnosis, existence of prior mammographic study at time of interpretation, months since prior mammographic study, and compressed breast thickness. RESULTS: Thirty-three centers enrolled 49 528 women. Breast cancer status was determined for 42,760 women, the group included in this study. Pre- or perimenopausal women younger than 50 years who had dense breasts at film mammography comprised the only subgroup for which digital mammography was significantly better than film (AUCs, 0.79 vs 0.54; P = .0015). Breast Imaging Reporting and Data System-based sensitivity in this subgroup was 0.59 for digital and 0.27 for film mammography. AUCs were not significantly different in any of the other subgroups. For women aged 65 years or older with fatty breasts, the AUC showed a nonsignificant tendency toward film being better than digital mammography (AUCs, 0.88 vs 0.70; P = .0025). CONCLUSION: Digital mammography performed significantly better than film for pre- and perimenopausal women younger than 50 years with dense breasts, but film tended nonsignificantly to perform better for women aged 65 years or older with fatty breasts.

Issues to consider in converting to digital mammography.

This article outlines the reasons that many radiology practices are converting to digital mammography. In addition, it provides basic information about the issues that must be considered in making the transformation. These issues include technical matters regarding image display, storage, and retrieval as well as clinical and ergonomic considerations.

Massachusetts radiology resident attitudes toward mammography.

PURPOSE: To investigate and document the attitudes toward careers in breast imaging among Massachusetts radiology residents. METHOD: Written surveys were distributed to all senior radiology residents in the state asking whether they were interested in pursuing a fellowship in breast imaging or whether they planned to interpret mammograms as part of their future practice. If they were not interested, residents were asked why. RESULTS: Of 63 residents who responded, only 1 was interested in a breast-imaging fellowship. Only 3% of radiology residents surveyed in the state agreed that they would like to spend a substantial time interpreting mammograms in the future. The most common reasons cited for not wanting to interpret mammograms in the future were "fear of lawsuits" (76%) and "not an interesting field" (49%). CONCLUSIONS: Very few Massachusetts radiology residents are interested in pursuing breast imaging in their future careers. This lack of interest in breast imaging will ultimately affect women's access to breast imaging services in the future.

American College of Radiology Imaging Network digital mammographic imaging screening trial: objectives and methodology.

This study was approved by the Institutional Review Board (IRB) of the American College of Radiology Imaging Network (ACRIN) and each participating site and by the IRB and the Cancer Therapy Evaluation Program at the National Cancer Institute. The study was monitored by an independent Data Safety and Monitoring Board, which received interim analyses of data to ensure that the study would be terminated early if indicated by trends in the outcomes. The ACRIN, which is funded by the National Cancer Institute, conducted the Digital Mammographic Imaging Screening Trial (DMIST) primarily to compare the diagnostic accuracy of digital and screen-film mammography in asymptomatic women presenting for screening for breast cancer. Over the 25.5 months of enrollment, a total of 49 528 women were included at the 33 participating sites, which used five different types of digital mammography equipment. All participants underwent both screen-film and digital mammography. The digital and screen-film mammograms of each subject were independently interpreted by two radiologists. If findings of either examination were interpreted as abnormal, subsequent work-up occurred according to the recommendations of the interpreting radiologist. Breast cancer status was determined at biopsy or follow-up mammography 11-15 months after study entry. In addition to the measurement of diagnostic accuracy by using the interpretations of mammograms at the study sites, DMIST included evaluations of the relative cost-effectiveness and quality-of-life effects of digital versus screen-film mammography. Six separate reader studies using the de-identified archived DMIST mammograms will also assess the diagnostic accuracy of each of the individual digital mammography machines versus screen-film mammography machines, the effect of breast density on diagnostic accuracy of digital and screen-film mammography, and the effect of different rates of breast cancer on the diagnostic accuracy in a reader study.

(99m)Tc sestamibi breast imaging for the examination of patients with dense and fatty breasts: multicenter study.

PURPOSE: To evaluate the accuracy of scintimammography as an adjunct to physical examination and mammography in the detection of breast cancer in women with dense and fatty breasts. MATERIALS AND METHODS: A total of 558 women were prospectively enrolled from 42 centers in North America. Images were interpreted by readers blinded to the subjects' clinical history, mammographic findings, and other test results. The Breast Imaging Reporting and Data System classification was used to describe breast density. Parenchymal patterns of "heterogeneously dense" and "extremely dense" were used to classify breasts as dense, whereas "almost entirely fat" and "numerous vague densities" defined fatty breasts. Between-group differences were evaluated with the 2 test for categorical variables and Student t test for continuous variables. Accuracy of scintimammography was assessed against the core laboratory histopathologic evaluation, the standard. The 95% CIs around point estimates of sensitivity, specificity, and positive and negative predictive values were calculated with the normal approximation to the binomial distribution. RESULTS: The analyses were based on 580 breasts with an abnormality; 276 (48%) breasts were dense and 228 had a malignant lesion. Diagnostic properties for scintimammography of fatty versus dense breasts were, respectively, sensitivity, 72% versus 70%; specificity, 80% versus 78%; positive predictive value, 72% versus 67%; negative predictive value, 81% versus 81%; and accuracy, 77% versus 75% (all not significant). Scintimammography led to similar and significant changes in the posttest likelihood of cancer for both dense and fatty breasts. CONCLUSION: The diagnostic accuracy of scintimammography is not affected by breast density.