Update of Digital Breast Tomosynthesis. Susan Orel Roth, MD

Transcription

1 Update of Digital Breast Tomosynthesis Susan Orel Roth, MD

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3 NCI estimates that : Why DBT? Approximately 20% of breast cancers are missed at mammography screening Average recall rates approximately 10% Average cancer detection rate 4.7 per 1,000 screening mammography examinations MQSA audit guidelines anticipate 2-10 cancers detected per 1,000 screening mammograms Interval cancers (detected between screenings) tend to have poorer prognosis

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5 DBT Build on the digital mammography platform Present data in 3-D Decrease effect of tissue superimposition Improve lesion conspicuity Potential to improved specificity and sensitivity

6 Courtesy Fugi Film

7 Digital Breast Tomosynthesis (DBT) DBT largely based on existing FFDM platforms Integrated systems capable of both DBT (2D) and FFDM ( quasi 3D) now available Hologic Selenia Dimentions first to be FDA approved Now GE and Siemens Mammomat Inspiration also approved Compromise between 2D conventional digital radiography and fully 3D CT Provide quasi 3D information; superior to DM while minimizing complexities of CT

8 Industry Variations Hologic Selenia Dimensions GE SenoClare Siemens Mammomat Inspiration FDA approval 2/11/11 FDA approval 8/26/14 FDA approval 3/21/15 15 degrees 25 degrees 50 degrees 2 views DBT with DM 2 view mammogram or MLO DBT and 2D CC Can do synthetic 2D (c view) FDA approved 5/13 Can do CC DBT off label 2 view DBT with DM No synthetic 2D yet

9 Image Acquisition

10 Geometry of DBT Different systems vary greatly Angle of x-ray tube movement Number of images acquired Detector motion Limited angle acquisition; reconstruction is anisotropic Spatial resolution in plane parallel to detector are high (x,y) Spatial resolution perpendicular to detector lower (z) Arc of acquisition changes resultant images Wider tube arc results in thinner slice thickness Improved resolution in z plane Potential for increased motion; artifact in horizontal plane

11 DBT Acquisition

12 15 angle 50 angle

13 Digital Breast Tomosynthesis at Penn 4 Hologic clinical tomosynthesis units Began screening all patients with DBT in September 2011 Began all diagnostic patients in January 2014

14 Literature Review

15 Prospective Screening Trials: Oslo Trial Norwegian screening program; 180,000 women with 2 view FFDM and 2 view DBT Hologic DBT Interim results: Increase cancer detection 27% (30% double read) Significant (40%) increase in detection invasive cancers 26% increase high grade invasive cancers Estimated 13% reduction recall rate (18% double read) Similar results replacing 2D with C-view Skanne P, et al. Eur Radiol 2013; 8:2061 Skanne P, et al. Radiology 2013; 267:47 Skanne P, et al. Radiology 2014; 271:655

16 Prospective Screening Trials: STORM Trial Italian population-based screening study Hologic DBT Comparing sequential FFDM reading with DBT+FFDM 7292 women routine bi-annual screening Double reading 34% increase cancer detection all age groups Potential to reduce false positive recalls by 17% Reading time was doubled Cancers similar size and node status Ciatto S, et al. Lancet Oncol 2013; 7:583

17 Prospective Screening Trials: Malmo 2 Trial Population based screening program in Sweden Siemens Inspiration DBT Paired analysis of sensitivity and specificity of single view DBT compared with 2 view FFDM 7500 women 40% increase cancer detection rate using DBT alone compared with FFDM Increase sensitivity 15% with DBT compared with FFDM; significant increase recall rate 45% (2.6% to 3.8%) 48% cancers detected only by DBT grade 2 or 3 Lang K, et al. Eur Radiol 2015

18 Times series studies: report effects of adding DBT to routine practice of FFDM (US); impact on cancer detection and call-back rates Friedewald SM, et al. JAMA 2014; 311:2499 Screening performance measured before and after introduction of DBT Different cohorts of women unlike the prospective trials Four small studies demonstrated reduction recall 16%-37%; variable effect on cancer detection rate Multicenter trial or 13 academic and non-academic sites* All sites Hologic Selenia Dimensions 454,850 screening exams 15.6% decrease callback rate 19.6% increase cancers/1000 screened 40.9% increase PPV1 (cancers/callback,%)

19 Penn experience McCarthy AM, et al. JNCI 2014; Oct 13; (106)* McDonald ES, et al AJR 2015; 205:1143** All screening with DBT; implemented 11/18/11 Statistically significant reduction in recalls DBT vs DM alone--8.8% vs (-15.6%)* 0.9 additional cancers/1000 screened (+19.6%)* Recall rate decreased 14-22%** Cancer detection rate increased 17-40%** PPV1 (cancer/recalls) increased 35-85%** Especially pronounced different when baseline mammogram women <50 yrs.**

20 DBT screening outcomes: What happens over subsequent screens? Learning curve Prevalent vs incident screening detected cancers Track interval cancers Most recent published interval cancer rate for UK NHSBP 2.67 per 1000 women screened over a 3-year period Potential to increase cancer detection with addition of DBT to FFDM

21 Penn results from 3 consecutive years of screening with DBT

22 Calcifications Dose Storage Cost/Reimbursement Ongoing Issues/Concerns

23 Calcifications Very few reports in literature comparing DBT to FFDM in detection of microcalcifications Kopans et al. study of 119 sequential cases with relevant calcifications (Breast J. 2011) compared MLO DBT with and MLO and CC conventional mammography (CM) 92% clarity of calcifications same DBT and CM approximately 50% clarity better on DBT Spangler ML, et al. (AJR 2011) 100 paired examinations DBT and FFDM Overall calcification detection higher for FFDM than DBT (84% vs. 75%); ROC not significantly different and conspicuity of calcifications

24 Dose Stand alone DBT associated with a much lower to a slightly higher dose than comparable FFDM units ( for 2 view DBT) For DBT combined with FFDM radiation doses elevated; max by a factor of 2 ¼ for FFDM alone Replacement of FFDM with synthetic 2D views reduces breast dose approximately half Svahn TM, et al. Breast 2015;24:93

25 Dose Maximum allowable dose per MQSA= 5.8 mgy Standard FS approximately 4.8 mgy Standard DM approximately 3.7 mgy Each combo tomo view (Holgoic) 1.2 mgy Total dose full DM and DBT (2 views) 4.8 mgy To reduce dose with addition of DBT, need to replace 2D with synthetic 2D

26 Tommy trial: comparison of Tomosynthesis with DM in UK NHS Screening program Gilbert FJ, et al. Radiology 2015; 277(697) Multicenter retrospective reading study comparing DBT and DM vs. DM alone (independent blinded review) Dataset of 7060 cases Sensitivity: 87% 2D 89% for 2D+DBT 88% for sdbt Specificity: 57% 2D 70% 2D +DBT 72% sdbt s2d+dbt and 2D+DBT had better sensitivity for depicting mm invasive cancers than 2D alone s2d+dbt was inferior to both 2D alone and 2D+DBT in depicting microcalcifications and mm DCIS

27 Radiation Dose with 2D and DBT DM 2D MLO 2D CC 1.58 mgy DBT 3D MLO 3D CC 1.95 mgy COMBO (DBT + DM) 2D MLO 2D CC 3D MLO 3D CC 3.53 mgy Maximum allowable dose per MQSA= 5.8 mgy Skaane P et al. Radiology 2014 Jun;271(3): Also see Barufaldi RSNA 2015 BR236-SD-MOB4.

28 Synthesized 2D Imaging DBT image data used to create s2d images Multiple, low dose images obtained and then reconstructed s2d Mammo

29 Comparison of Radiation Dose COMBO (DBT + DM) 2D MLO 2D CC 3D MLO 3D CC 3.53 mgy s2d + DBT s2d 2D MLO s2d CC 3D MLO 3D CC 1.95 mgy s2d+dbt decreases dose 45% compared to DM+DBT s2d+dbt increases dose 23% when compared to DM alone Skaane P et al. Radiology 2014 Jun;271(3): Also see Barufaldi RSNA 2015 BR236-SD-MOB4.

30 Architectural Distortion and Asymmetry Invasive ductal carcinoma False Positive DM s2d DM s2d Also see RSNA 2015 educational exhibit, Zuckerman BR172-ED-X

31 Calcification Pop DCIS, high nuclear grade with comedo and necrosis False positive calcifications s2d: possible calcs Recall DM mag: no calcs DM s2d RSNA 2015 educational exhibit, Zuckerman BR172-ED-X

32 Synthetic 2D+DBT vs Standard 2D+DBT Combination of current reconstructed 2D images+dbt has performed comparably to FFDM+DBT and adequate for routine clinical use for screening Skaane P, et al. Radiology 2014; 271:655 Zuckerman SP, et al. RSNA 2015

33 Issue: Interpretation Time Compared with FFDM, there will be an increase in interpretation time Greater than 200 images How many times to scroll through tomo stack? Learning curve Estimated increase in time approximately 1-1 ½ minutes

34 Issues: Storage Digital storage requirements are substantial Each reconstructed slice comparable to digital mammogram Complete 4 view hologic DBT mammogram produces 1 GB of data Stored in 4:1 lossless compression resulting in 250 MB data set What should be stored? How long should study by store?

35 Issues: Cost/Reimbursement Global national payment rates Unilateral diagnostic mammogram Bilateral diagnostic mammogram Film Digital Digital with tomo $ $ Screening mammogram $82.59 G0206 $130 G0204 $165 G0202 $134 G0206 +G0279 $187 G0204+G0279 $222 G $192 Updated 2/24/15 Global: $57.00 Profession $31.00 Technical $26.00

36 Return on Investment KLAS interviewed 50 Hologic DBT customers from 44 unique organizations

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40 Comparative Effectiveness of Combined Digital Mammography and Tomosynthesis Screening for Women with Dense Breasts Lee CI, et al. Radiology 2015; 274:773 Evaluate effectiveness of combined biennial digital mammography and tomosynthesis screening compared with biennial digital mammography screening alone among women (ages 50-74) with dense breasts Incremental cost per quality-adjusted life year gained by adding tomosynthesis to DM screening $53,893 additional 0.5 deaths averted 405 false positive findings avoided per 1000 women after 12 rounds of screening Combined screening remained cost effective (<$100,000 per QALY) over wide range of incremental improvements in test performance cost effectiveness most sensitive to addition cost of DBT

41 United Kingdom The Hologic DBT system been approved in UK by NHSBSP for use in diagnostic work-up of abnormalities detected with screening FFDM More evidence needed to support implementation of DBT for routine screening in UK

42 Conclusions Screening with DBT improves specificity and sensitivity reduced call-backs Increased cancer detection Diagnostic with DBT decrease in additional imaging needed increased confidence in interpretation