Tomosynthesis and breast imaging update Dr Michael J Michell Consultant Radiologist King's College Hospital NHS Foundation Trust
Breast imaging new technology
BREAST CANCER FLT PET shows different grades of tumour with the primary site Images courtesy of Wai Lup Wong, Paul Strickland Cancer Centre Mount Vernon
Breast imaging:application of new technology screening diagnosis/ assessment local staging axilla response to RX systemic disease XRM ++ ++ ++ TOMO? ++ ++? CE-XRM?? US? ++ ++ ++ ++ CE-MRI ++ ++ ++ F MRI MOL CT/PET ++ +
Digital Breast Tomosynthesis Technology Accuracy Diagnosis/assessment Screening
Limitations of 2D mammography 3D information projected onto 2D image plane superimposition of tissues Clinical effect - false positive cases screening recall - false negative cases interval cancers - mammographic features obscured diagnostic uncertainty understaging
DBT - technology Hologic dimensions - 15 deg - 15 proj Siemens innovation - 50 deg - 25 proj GE - 40 deg - 15 proj Sectra - 11 - continuous IMS - 40 deg - non uniform sampling DBT radiation dose 2V = up to 5 mgy. FFDM 2V = 4 mgy
reconstructed images are displayed as 1mm slices for viewing singly or in cine mode number of slices varies according to breast thickness
Does DBT improve diagnostic accuracy?
Accuracy of DBT recall from screening bilateral 2D + tomo (combo)mlo/cc Michell MJ et al, Clin Rad 2012; 67: 976-81
soft tissue lesions microcalcification Michell MJ et al Clin Rad 2012
DBT - technical developments tomo guided biopsy synthetic 2D contrast tomo combined imaging CAD
Tomosynthesis procedure - Case 2 Target
Synthetic 2D the information from the reconstructed tomo slices is used to produce a 2D image
DBT - synthetic 2D standard 2D synthetic 2D DBT
2D synthetic 2D
Synthetic 2D combined with DBT has equivalent accuracy compared to FFDM + DBT Skaane P et al Radiology. 2014, Jan Zuley M et al Radiology.2014, Jan
Contrast Mammography images are courtesy of the following sites: Rose Medical Center, Denver, CO, USA Hôpital Privé d Antony, Antony, FR Kaohsiung Veterans General Hospital, Taiwan
2D CE2D Sub 3D Slice
Assessment of screen detected lesions Questions 1. is there a lesion? 2. where is it? 3. what is the risk of malignancy? 4. tumour size 5. unifocal/multifocal? 6. what further tests are needed?
1. is there a lesion?
2. Where is the lesion?
3. what s the risk of malignancy?
Lesions changing appearances Circumscribed Mass Mammographic features viewed on DBT Spiculated mass Distortion Asymmetric Density None (no abnormality) Mammographic features viewed on FFDM Circumscribed mass 0 11 0 6 11 28 Spiculated mass 3 0 3 0 5 11 Distortion 1 5 0 4 13 23 Asymmetric Density 19 10 0 0 57 86 None (no abnormality) 13 11 12 2 0 38 Total 36 37 15 12 86 186 Iqbal A, Michell MJ et al RSNA 2011
adenolipoma fibroadenoma mucinous ca
Comparison of DBT with spot compression magnification views
spot compression Mag MLO DBT MLO
Invasive lobular cancer
difficult diagnostic work up
Mag CC DBT CC
US = U1 MRI +ve DBT guided NLB Gd 2 IDC
Non specific asymmetric density
Final diagnosis high grade DCIS
Are all tumours visible on DBT Palpable mass LT breast - recalled from screening Irregular mass on US CB = Gd 3 IDC
Microcalcification
King s study:dbt vs spot compression mag views Clin Rad, accepted for publication 2014 355 lesions in 342 patients 104 malignant 82 benign 169 normal 7 radiologists standard + DBT vs standard + Mag DBT vs supplemental views for evaluation of non calcified lesions 217 lesions, 72 cancers AUC DBT = 0.87 suppl views = 0.83 p<.001 Zuley M, et al Radiology:266 Jan 2013
4. Measurement of tumour size Iqbal A, Michell MJ et al, RSNA 2013
Tumour size - Invasive Ductal Carcinoma DBT FFDM US Invasive Ductal Carcinoma, n = 108 0.655 (0.551 to 0.759) 0.591 (0.471to 0.711) 0.535 ( 0.424 0.647) Values are presented as CCC [rho_c, 95% CI]; CCC = Concordance correlation coefficient; Figures in parentheses are 95% confidence intervals.
Accuracy of tumour measurement correln coeff (a) MRI 0.92 - DBT 0.89 0.86 DM 0.83 0.71 US 0.77 0.85 correln coeff (b) (a)luparia A, Mariscotti G et al Radiol Med. 2013 (b)fornvik D, Zackrisson S et al Acta Radiol. 2010 51(3)
5. How many lesions?
Tomosynthesis in diagnostic work up - advantages vs spot compression whole breast imaged easier positioning some cancers less visible on spot compression 3D information on lesion position DBT in two projections recommended USS still necessary for soft tissue lesions
Diagnostic work up/ assessment - current practice DBT for mammographic work up of soft tissue lesions fine focus mag views for microcalcification
DBT in screening specificity sensitivity combination of views case selection cost
DBT in screening trials - OSLO - ( P Skaane) - STORM - (S Ciatto ) - TOMMY - ( F Gilbert ) - MALMO - ( I Anderson )
OSLO Trial 36,000 women 50-69 years Recruitment 11/10-12/12 Reading arms FFDM, FFDM + CAD, FFDM + DBT, synth 2D + DBT reading time - FFDM 45 secs - Combo 91 secs
OSLO Trial : Comparison of digital mammography alone and DM + tomosynthesis in a population based screening program P Skaane et al, Radiology, 2013 Jan 12,631 participants DM 77 cancers 6.1/1000 DM+DBT 112 cancers 8/1000 27% increase in ca detection p =0.001 (95% CI 1.06-1.53) 40% increase in invasive cancers p < 0.001 Recall rate (prior to arbitration) DM 6.1% DM +DBT 5.3% 15% decrease recall rate p <0.001
7292 participants mean age 58 yrs Reading - 2D, 2D + 3D Cancer detection 2D 39 cancers 5.3/1000 (95% CI 3.8-7.3) 2D + 3D 59 cancers 8.1/1000 (95% CI 6.2-10.4) p<0.0001 Recall Overall 395 (5.5%) Conditional recall 254 (3.5%) thelancet.com/oncology april 25 2015
Oslo Trial screen detected cancers Grade DM DM+DBT Diff In situ low/int 4 4 0 high 17 16-1 Invasive 1 17 32 15 2 29 35 6 3 9 13 4
MALMO 2 Trial 1V DBT vs 2V 2D Siemens Preliminary results - 7500 women 2V DM 1V DBT Cancer detection /1000 screened Recall rate % screened 6.3 8.5 2.2 3.3 Zacrisson et al, ECR 2014
DBT in screening - expectations more screen detected cancers lower false positive recall rate? one reader BUT What about overdiagnosis
Prospective RCT of tomosynthesis in screening Control group - standard 2V FFDM Study group - tomo + synthetic 2D Primary end point - interval cancer rates Sample size 30% improvement in cancer detection = 2-3/1000 UK interval cancer rate = 2.85 / 1000 36 mths?intervention might reduce interval ca rate to 1.85/1000 For 90% power need 50,000 per arm
Prospective RCT of tomosynthesis in screening Secondary endpoints cancer detection prognostic features recall rate one vs two readers economic analysis
Conclusion New imaging technology will make screening, diagnosis and treatment of breast disease more effective and more efficient Acknowledgements NHSBSP King s breast radiology team