Update on Breast Tomosynthesis
Andrew Smith, Ph.D.
Hologic, Inc.
Bedford MA, USA
andrew.smith@hologic.com
What is Breast Tomosynthesis?
A method of imaging the breast in three dimensions
(3D)
Image slices are 1 mm thick
Image slices high resolution: like mammograms
Why do tomosynthesis?
Tissue overlap hides pathologies
Tissue overlap mimics pathologies
3D improves visibility
Visible in 3D
Hidden in 2D
Tomosynthesis acquisition
X-ray tube
swings during
tomo
Stationary
breast
platform
Tomosynthesis 3D Acquisition
Clinical Benefits
In multi-center clinical studies, conventional
FFDM plus tomosynthesis has been
shown to:
– Increase sensitivity
Screening trial required to validate statistical
significance; however, data from Reader studies
suggest potential for 15% increase in sensitivity
– Reduce recalls by 29%
Potential to eliminate ~1M recalls for every 30M
women screened
Pooled ROC Curves
Radiologist Variability with 2D and 2D+3D
2D+3D
2D
Decision to Recall,
non-cancer cases (BIRADS 0)
Agreed on
recall
decision
Kappa
2D
2D+3D
70.9%
78.7%
0.413
0.530
Kappa differences statistically significant
How Use Tomosynthesis?
Wherever you now use 2D, use 2D+3D
3D gives additional information, especially
useful for mass detection
“Averaged” ROC Curves
All cases
Calcs only
No calcs
- Improvement from 3D due to masses
- It does not mean 3D no good for calcs,
just no better than 2D
Why 2D+3D, and not just 3D?
3D most useful for masses, removing superimposed
parenchyma
2D is very useful:
During transition to 3D, 2D is gold standard
2D speeds up calcification assessment
2D useful for comparison to 2D priors
CAD ~ only available on 2D initially
2D needed for reimbursement
Equipment can facilitate acquiring both 2D and 3D
Images are co-registered
Why both CC and MLO?
RSNA 2006
Breast Tomosynthesis: One View or Two?
Rafferty, Niklason, Jameson-Meehan.
34 Lesions, imaged both CC and MLO tomo.
65% seen equally on both
12% more visible on MLO
15% more visible on CC
9% only seen on CC (all malignant).
Acquisition 3D+2D
Tomosynthesis Commercial Status
-Some breast tomosynthesis
systems are cleared for sale
in the European Community
and awaiting FDA clearance
in the U.S.
- Others are in clinical trials.
Recall Reduction – Superimposed Tissue (Case 1)
Recall Reduction – Superimposed Tissue (Case 2)
Invasive Ductal Carcinoma (Case 3)
Case 3 Region of Interest
FFDM
TOMO
Infiltrating Ductal Adenocarcinoma (Case 4)
Case 4 Region of Interest
Tubulolobular Adenocarcinoma (Case 5)
Case 5 Region of Interest
FFDM
TOMO
Case 6 Multifocality
Digital Mammogram
Tomosynthesis Image
Recalled for subtle architectural distortion. Tomo shows two adjacent spiculated
masses. Multifocal invasive lobular carcinoma.
Case 6 Multifocality
Digital Mammogram
Tomosynthesis Image
Case 7 Cancer
Digital Mammogram
Tomosynthesis Image
Case 7 Region of Interest
Digital Mammogram
Tomosynthesis Image
Conclusions
Systems in early commercial release
Systems in variety of clinical uses, mainly
diagnostic centers
Main value of tomosynthesis likely to be breast
cancer screening (cancer detection)
Large scale screening trials being planned in the
US
How to encourage screening use?
Thank you
Images and data courtesy of:
• Netherlands Cancer Institute – Antoni Van Leeuwenhoek Hospital,
Amsterdam Holland
• Massachusetts General Hospital, Boston MA USA
• Centre de Radiologie et d’Echographie du Docteur Joussier, Paris France
• Dartmouth Hitchcock Medical Center, Lebanon NH USA
• Magee Women’s Hospital, Pittsburgh PA USA
• University of Iowa Health Care, Iowa City IA USA
• Yale University School of Medicine, New Haven CT USA