Trudy Parker, MD. The role of tomosynthesis in screening mammography: advantages, limitations and effectiveness.

1. Digital Breast Tomosynthesis
3D Mammography
Trudi Parker M.D.

2. Breast Cancer Statistics
ACS Estimates for 2014
 Most common cancer among American women
 232,670 new cases of breast cancer diagnosed in women
 2nd. Leading cause of cancer death in women, exceeded only by lung cancer
 40,000 women will die from breast cancer

3. 5-Year Relative Survival by Stage at Diagnosis
www.seer.cancer.gov
SEER 18 2004-2010, All Races, Females by SEER Summary Stage 2000

4. Hologic

5. Hologic

6. Limitations of 2D Mammography
 20% of cancers will be missed
 Sensitivity decreases significantly with increased breast density
 Approximately 10% will be recalled for additional work up
 75-80% of all breast biopsies will result in benign results

7. 2D versus 3D Mammography
 Enhanced lesion detection – borders of lesion better defined
 Increased cancer detection rate
 Reduces false positive recalls
 Precise lesion localization

8. Technique:  2D and 3D images obtained with
one compression
 X-ray tube sweeps through a 15deg
arc acquiring 15 low dose
projections (~4secs)
 Mathematical reconstruction
generates 1mm slices through the
breast
 Radiation dose: ~2X the dose of a
mammogram
 Still very low, below MQSA
requirements
 C-view (synthesized 2D)
 2D will no longer be needed
 Dose reduction
Hologic

9. Hologic

10. Limitations of DBT
 Takes longer to read
 Cannot be read on demand or STAT
 Increased radiation
 Radiation dose: ~2X the dose of a mammogram
 Still very low, below MQSA requirements
 No CPT code
 Massive storage requirements

11. IT Storage Requirements for 20,000
Mammograms
 2D Storage for standard 4 View Mammogram = 1.74 Terabytes/year
 3D Storage for standard 4 View Mammogram = 10 Terabytes/year

13. 2D 3D
Hologic

15. Hologic

16. Reducing False Positives

18. Oslo Norway DBT
Screening Trial
Prospective Trial : November 22,2010 to December 31,2011
4 Arms: 2D, 2D +CAD, 2D+3D, synthesized 2D+3D
12,621 sequentially recruited women
Exams interpreted with mammography alone and compared with
mammography + DBT

19. Oslo Norway DBT
Screening Trial
 Results:
 Cancer Detection Rate of Invasive Cancer +DCIS
 27% increase (p=.001)
 40% Increase detection of invasive cancers
 Increase observed across all breast densities
 2D Mammography alone: 6.1 cancers/1000 exams
 2D + Tomosynthesis : 8 cancers/1000 exams

20. Oslo Norway DBT
Screening Trial
 Results:
 False Positives ( Recalls from screening exams)
 Mammography alone : 61.1/1000 exams
 Mammography + Tomosynthesis : 53.1/1000
 15% Decrease

21. JAMA
Retrospective Trial : March 2010 – December 2012
454,850 examinations
13 sites (academic and nonacademic)
Compared mammography interpretation performance 1 year prior to
tomosynthesis implementation to performance following
tomosynthesis implementation

22. JAMA
Results:
454,850 examinations
281,187 2D exams
173,663 2D+3D exams
Recall Rate: 15%
Cancer Detection Rate: 41% (invasive cancers)
DCIS detection rate : no change

23. JAMA
Results:
PPV for recall : 49%
PPV for biopsy : 21%

24. 56 year old , screening exam

27. The Breast Density Legislation
 Effective August 1, 2014, a new law by the Minnesota State Legislature
requires all Minnesota mammography facilities to report breast density to
patients with dense breasts. This law was enacted for three reasons:
 1. Dense breasts slightly decrease the ability of mammography to find
breast cancer.
 2. Dense breasts slightly increase the risk of breast cancer.
 3. Patients may want to know about supplemental screening tests.

28. Supplemental Screening Options
 Breast MRI
 Expensive
 Requires IV contrast
 Recommended for select hi risk population (>20% lifetime risk of breast cancer)
 Screening US
 Slightly increased cancer detection but has high false positives
 Operator dependent, time consuming
 Digital Breast Tomosynthesis
 Only mammography has been shown to decrease mortality rates.

29. Summary

30. Summary Digital Breast Tomosynthesis
 Build on the success of the the
screening mammogram
 Increased Sensitivity AND
Specificity
 Right sizing breast imaging
 Replace 2D MammographyAllina website

31. THANK YOU