ACR and SBI Statement Margarita Zuley, MD Associate Professor, Radiology Medical Director, Breast Imaging University of Pittsburgh

Clinical Perspective  CAD is one of many inputs the radiologist uses to determine action  info from magnification views  slice thickness or detector changes for CT  protocols for MRI  transducer frequency changes to US  All these factors and many more affect Clinical Action

 FDA’s role is to determine safety and effectiveness of a device, not the quality of effectiveness of the radiologist using that device

MRMC Testing the interaction of the radiologist with the CAD includes many variables that are outside of the control of the CAD device. Inter and intra observer variability is so great that very large scale MRMC studies will be necessary

Learning Effects  Elmore et al.  Reader recall rate prior to CAD 6.2 %  First 2 months with CAD13.4 %  Follow up after 25 months 6.75 %  Doing reader studies without this experience will negatively impact ROC results of the CAD arm

Keep all positives rule  CADe is not intended to dissuade a reader from recalling any finding  Such behavior is the fault of the reader, not the CAD  Evaluation of false negatives therefore is not part of safety evaluation of CAD

CADe for mammography  First product introduced in 1998  Oldest and most studied CAD devices on the market

White Elephant  Why are all mammography CADe devices class III devices while lung and and CT colonography devices are class II?

Valid Scientific Evidence  Is there a larger body of literature supporting the safety and effectivness of lung or CT colonography CAD than mammo CAD?  NO

Safety: Risk Assessment  Is breast cancer a higher risk ( higher death rate) disease than lung or colon cancer?  NO

Safety: Risk Assessment  Is recall at mammography for additional views or even 6 month follow up higher radiation exposure than follow up CT?  NO

Safety: Risk Assessment  Is breast biopsy more invasive than lung or colon biopsy or colonoscopy with sedation? NO

Effectiveness: CADe for Mammo  Multiple studies have shown detection of smaller, earlier cancer with CADe  Results on improvement range from no significant improvement (Gur et al) in academic subspecialty group to 19.5% increase in detection in private practice (Freer and Ulissey)  No study has shown a decrease in detection  Most mammograms are read in private practice where benefit from CAD has been shown to be greatest

Clinical Assessment  If new CAD devices can show that cancer detection sensitivity and false marking rate are similar to predicate devices through a cohort of cases, that should suffice for 510k approval without reader studies  If 2 FFDM systems are substantially equivalent, CAD algorithm testing should be standalone testing

Summary  Safety and effectiveness for CADe mammography is well documented and should reclassified as Class II  Current guidelines will stop CADe development  No further benefits to patient care will be realized