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11:45 am
January 17, 2011
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Ahmed Bashendi
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| posts 57 |
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Dedicated Dual-Head Gamma Imaging for Breast Cancer Screening in Women with Mammographically Dense Breasts
- Deborah J. Rhodes, MD,
- Carrie B. Hruska, PhD,
- Stephen W. Phillips, MD1,
- Dana H. Whaley, MD and
- Michael K. O’Connor, PhD
+Author Affiliations
From the Departments of Medicine (D.J.R.) and Radiology (C.B.H., S.W.P., D.H.W., M.K.O.), Mayo Clinic, 200 First St SW, Rochester, MN 55905.
- Address correspondence to
D.J.R. (e-mail: MBI@mayo.edu).
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Author contributions: Guarantors of integrity of entire study, D.J.R., C.B.H., S.W.P., M.K.O.; study concepts/study design or data acquisition or data analysis/interpretation, all authors; manuscript drafting or manuscript revision for important intellectual content, all authors; approval of final version of submitted manuscript, all authors; literature research, D.J.R., C.B.H., S.W.P., M.K.O.; clinical studies, all authors; statistical analysis, D.J.R., C.B.H.; and manuscript editing, all authors
Abstract
Purpose: To compare performance characteristics of dedicated dual-head gamma imaging and mammography in screening women with mammographically dense breasts.
Materials and Methods: Asymptomatic women (n = 1007) who had heterogeneously or extremely dense breasts on prior mammograms and additional risk factors provided informed consent to enroll in an institutional review board–approved HIPAA-compliant protocol. Participants underwent mammography and gamma imaging after a 740-mBq (20-mCi) technetium 99m sestamibi injection. Reference standard (more severe cancer diagnosis or 12-month follow-up findings) was available for 936 of 969 eligible participants. Diagnostic yield, sensitivity, specificity, and positive predictive values (PPVs) were determined for mammography, gamma imaging, and both combined.
Results: Of 936 participants, 11 had cancer (one with mammography only, seven with gamma imaging only, two with both combined, and one with neither). Diagnostic yield was 3.2 per 1000 (95% confidence interval [CI]: 1.1, 9.3) for mammography, 9.6 per 1000 (95% CI: 5.1, 18.2) for gamma imaging, and 10.7 per 1000 (95% CI: 5.8, 19.6) for both (P = .016 vs mammography alone). One participant had a second ipsilateral cancer detected with gamma imaging only. Prevalent screening gamma imaging demonstrated equivalent specificity relative to incident screening mammography (93% [861 of 925] vs 91% [840 of 925], P = .069). Of eight cancers detected with gamma imaging only, six (75%) were invasive (median size, 1.1 cm; range, 0.4–5.1 cm); all were node negative. The ratio of the number of patients with breast cancer per number of screening examinations with abnormal findings was 3% (three of 88) for mammography and 12% (nine of 73) for gamma imaging (P = .01). The number of breast cancers diagnosed per number of biopsies performed was 18% (three of 17) for mammography and 28% (10 of 36) for gamma imaging (P = .36).
Conclusion: Addition of gamma imaging to mammography significantly increased detection of node-negative breast cancer in dense breasts by 7.5 per 1000 women screened (95% CI: 3.6, 15.4). To be clinically important, gamma imaging will need to show equivalent performance at decreased radiation doses.
© RSNA, 2010
Clinical trial registration no. NCT00620373
Reference:
Original Research – Breast Imaging:
- Deborah J. Rhodes,
- Carrie B. Hruska,
- Stephen W. Phillips,
- Dana H. Whaley,
- and Michael K. O’Connor
Dedicated Dual-Head Gamma Imaging for Breast Cancer Screening in Women with Mammographically Dense BreastsRadiology January 2011 258:106-118; Published online November 2, 2010,doi:10.1148/radiol.10100625
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2:19 pm
January 16, 2011
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Ahmed Bashendi
Moderator
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| posts 57 |
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Deborah Rhodes is an expert at managing breast-cancer risk. The director of the Mayo Clinic’s Executive Health Program is now testing a gamma camera that can see tumors that get missed by mammography.
Working with a team of physicists, Dr. Deborah Rhodes developed a new tool for tumor detection that's 3 times as effective as traditional mammograms for women with dense breast tissue. The life-saving implications are stunning. So why haven't we heard of it? Rhodes shares the story behind the tool's creation, and the web of politics and economics that keep it from mainstream use.
Here is the link to her talk:
http://www.ted.com/talks/debor…..hodes.html
Why you should listen to her:
For all of the lives it saves, mammography still cannot detect the early onset of breast cancer in as many as one of every four women ages 40 to 49. And women with dense breast tissue are four to six times more likely to develop cancer than others. Deborah Rhodes and her colleagues at the Mayo Clinic in Minnesota think they’ve found an effective way to screen these high-risk patients: molecular imaging.
Rhodes, who specializes in evaluating and managing breast cancer, is collaborating with a nuclear physicist and various radiologists on a dual-head “gamma camera” that can capture the tiny tumors in dense tissue. The new technique, which would complement (not replace) mammography, is sensitive enough to pick up a mass two-fifths of an inch in diameter. Molecular breast imaging requires patients to be injected with a radioactive drug, but it is much more comfortable than the vise-grip mammogram and is expected to cost only slightly more.
“MBI detects three times as many breast tumors as mammography in high-risk women. Although it would not replace mammograms, it might become an additional tool for screening, especially in higher risk women with a dense tissue that makes tumors hard to spot. “
CTV News, Sept. 4, 2008
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