Brittany Dashevsky MD, DPhil, Abstract Co-Author: Nothing to Disclose

Sarah Stamler MD, Abstract Co-Author: Nothing to Disclose

Molly Parsons MD, Abstract Co-Author: Nothing to Disclose

Gary Allan Ulaner MD, PhD, Presenter: Research support, General Electric Company Research support, Seragon Pharmaceuticals, Inc

1. Invasive ductal cancer (IDC) and invasive lobular cancers (ILC) have different propensities for metastatic sites, as well as different conspicuity on FDG PET. 2. Knowledge of the histologic subtype of breast cancer helps improve accuracy of FDG PET/CT interpretations.  

 1. Primary tumor (T) FDG PET/CT has low sensitivity and specificity for the primary tumor in both IDC and ILC, compared to mammography/US/MRI. 2. Nodal metastases (N) A. Axillary - FDG PET has low sensitivity for axillary nodes in both IDC and ILC, compared to sentinel node surgery. B. Extra-axillary - Better sensitivity of FDG PET for detection of extra-axillary nodes in IDC than ILC. Some CT features (size, shape, loss of fatty hilum) increase suspicion for nodal metastases. 3. Distant Metastases (M) A. Bone – Common with both IDC and ILC. PET has better sensitivity for detection of osseous metastases in IDC than ILC. A decrease in FDG avidity of bone metastases post treatment corresponds to treatment response, despite increased size or sclerosis on CT. B. Liver and Lung – Both more common with IDC than ILC.  CT can help identify liver and lung metastases. C. Peritoneal – More common with ILC than IDC. CT can help identify peritoneal metastases. D. Other – pleural, adrenal, brain.  

http://abstract.rsna.org/uploads/2014/14005813/14005813_m6dm.pdf

Dashevsky, B, Stamler, S, Parsons, M, Ulaner, G, FDG PET/CT of Breast Cancer: Individualizing PET/CT Interpretations for Ductal versus Lobular Breast Cancer Patients.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14005813.html