Authors' objectives:

This assessment aims to update the July 2002 Assessment on full-field digital mammography and to compare cancer detection, recall, and biopsy rates for full-field digital mammography versus screen-film mammography.

Authors' results and conclusions: This Assessment was updated primarily to incorporate the results of the American College of Radiology Imaging Network's (ACRIN) Digital Mammographic Imaging Screening Trial (DMIST). This trial provided results on 42,760 asymptomatic women who had both full-field digital mammography (FFDM) and screen-film mammography (SFM). The trial showed with reasonable certainty that there was no difference in accuracy of the two modalities for asymptomatic women in general. For 3 subgroups of women, however, FFDM performed better than SFM: women under age 50; pre- or perimenopausal women; and women with heterogeneously dense or extremely dense breasts. For any constant specificity in the 0.7 to 0.95 range, the sensitivity is higher for FFDM than for SFM. Conversely, for any sensitivity in the 0.4 to 0.7 range, the specificity is higher for digital mammography than for film mammography. There were no strong, new studies on the use of digital mammography versus film mammography in a diagnostic population. However, the DMIST results indicated that tumors detected by FFDM but not by SFM were likely to be invasive carcinomas or medium- to high-grade ductal carcinoma in situ (DCIS). Based on the supposition that these are the cancers of greatest interest and the ones more likely to be found in a diagnostic population and that the diagnostic population may be younger on average than the screening population, it was concluded that there is sufficient evidence to support the use of FFDM for diagnostic purposes. This judgment was supported by a small study of follow-up digital and film mammograms among 100 subjects with radiological abnormalities on an initial screening film mammography. There was no difference between digital and film mammography, as measured by the area under the receiver operating characteristic (ROC) curves.

Authors' recommendations: There is strong evidence showing that digital mammography is as accurate as film mammography for screening uses. Furthermore, FFDM performs better than SFM precisely in those populations where SFM is weaker. The increased accuracy also appears to be obtained at radiation doses that are no higher and may be lower than those found with SFM. The evidence regarding the use of FFDM for diagnostic purposes has been extrapolated from the DMIST results, as well as a small follow-up study on women with abnormalities detected in the initial screening film mammography. Given the distribution of cancers detected in the DMIST population, digital mammography's use for diagnosis appears warranted. In comparing these two modalities overall, however, it should be kept in mind that the differences in accuracy are small, that mammography using either mode will produce many false positive results that require follow-up, and that some cancers that would have been detected using film mammography will not be found using digital mammography and vice versa. Based on the available evidence, the Blue Cross and Blue Shield Association Medical Advisory Panel made the following judgments about whether full-field digital mammography meets the Blue Cross and Blue Shield Association Technology Evaluation Center (TEC) criteria. 1. The technology must have final approval from the appropriate governmental regulatory bodies. Four FFDM systems have received premarket application (PMA) approval by the U.S. Food and Drug Administration (FDA). 2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes. The DMIST results, based on the experience of digital and film mammography in 42,760 women, provide rigorous evidence on the accuracy of digital vs. film mammography for detecting breast cancer in a screening population. The evidence on the use of digital mammography in a diagnostic population is primarily inferred from data based on a screening population, which suggests that digital mammography is similarly able to visualize the types of breast cancer likely to be found in a diagnostic population. 3. The technology must improve the net health outcome; and 4. The technology must be as beneficial as any established alternatives. Full-field digital mammography is as accurate as film mammography in screening for breast cancer among all women. Full-field digital mammography is more accurate (higher sensitivity) than film mammography in screening for breast cancer among some groups: women aged 50 or younger; pre- or perimenopausal women; and women with heterogeneously or extremely dense breasts. It also appears that full-field mammography is likely to be as accurate as film mammography in diagnostic settings. 5. The improvement must be attainable outside the investigational settings. The DMIST study took place at 33 medical sites in the U.S. and Canada, including both academic medical centers and community-based facilities. The images were also read by readers who would normally interpret mammograms as part of their usual clinical work, and not only by radiologists specializing in mammography. Both of these factors suggest that the findings will be generalizable. However, the readers underwent at least 8 hours of training to read the digital mammograms, which presumably improved their skills. Therefore, the results might vary with the length and quality of training or prior experience in reading the results of this new imaging modality. For the above reasons, full-field digital mammography meets the TEC criteria.

Authors' methods: Review

Project Status: Completed

URL for project: http://www.bcbs.com/blueresources/tec/contact-tec.html

Year Published: 2006

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: BlueCross BlueShield Association

Contact Address: BlueCross BlueShield Association, Technology Evaluation Center, 225 North Michigan Ave, Chicago, Illinois, USA. Tel: 888 832 4321

Contact Name: tec@bcbsa.com

Contact Email: tec@bcbsa.com

Copyright: BlueCross BlueShield Association (BCBS)