Caitlin Elizabeth Carr BA, Presenter: Nothing to Disclose

Emily Fox Conant MD, Abstract Co-Author: Nothing to Disclose

Mark Alan Rosen, Abstract Co-Author: Nothing to Disclose

Mitchell Dennis Schnall MD, Abstract Co-Author: Nothing to Disclose

Rebecca Davidson MD, Abstract Co-Author: Nothing to Disclose

To evaluate the impact of whole-body fluorine-18-fluorodeoxyglugose (FDG) positron emission tomography (PET) in staging breast cancer beyond the breast and axilla.

200 women, mean age 51 years (range, 28-81 yrs) with breast cancer were enrolled in an IRB approved multi-modality imaging trial (3/02-5/05). After imaging with film screen mammography +/- ultrasound (US), patients underwent digital mammography, whole breast US, magnetic resonance imaging (MRI), and whole body FDG PET. Imaging reports and patient charts were reviewed. Distant lesions were classifed: 1 = no uptake; 2 = physiologic uptake; 3 = non-suspicious uptake; 4 = suspicious uptake without work-up; 5 = suspicious uptake with work-up. Decisions to forego work-up in class 4 lesions were clinical. Class 5 lesions were evaluated by confirmatory studies, including computed tomography (CT), MRI, x-ray (XR), bone scan (BS), or pathology. Patients also underwent standard staging with CXR and BS per clinical judgment.

189/200 (95%) women had PET scans. PET identified 71 distant areas of increased uptake in 42/189 (22%). 59/71 (83%) lesions were considered suspicious in 33/42 (79%)women: 50/59 (85%)were class 5, and 9/59 (15%) were class 4. Of the 50 class 5 lesions, 19 (38%) were true positive (TP) for neoplastic disease, 2 were TP for non-neoplastic disease, and 29 (58%) were false positive (FP). The positive predictive value (PPV) for class 5 lesions was 40%. The 19 TP sites of malignancy occurred in 6/189 (3%) patients; 4 (67%)of these also had TP distant sites identified by standard staging procedures. PET alone identified TP distant disease in 2/189 (1%)women. PET identified 29 FP findings in 22/189 (12%)women. FP findings prompted 17 CTs, 8 XRs, 2 MRIs, and 1 BS. MRI revealed 1 additional neoplasm that had been a false negative (FN) PET in 1/189 (0.5%).

Whole-body FDG-PET added little additional information in staging our patients with known primary breast cancer. The low PPV and high FP rate of PET in these patients prompted unnecessary, costly, and invasive follow-up studies.

Whole-body FDG-PET added little additional information over conventional staging in our patient population.

Carr, C, Conant, E, Rosen, M, Schnall, M, Davidson, R, The Impact of FDG PET in the Staging of Breast Cancer.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4437787.html