Purpose: To prospectively assess a dedicated, large field of view positron emission tomography (PET) mammographic device for imaging primary breast carcinoma.
Materials and methods: Institutional review board approval was obtained for this study, and all patients provided written informed consent prior to participation. Subjects were recruited from a cohort of patients in whom diagnostic mammography and/or ultrasonography demonstrated lesions that were highly suggestive of malignancy. Twenty-three patients who met the inclusion criteria were subsequently imaged by using a dedicated PET mammography unit that was developed in conjunction with the Thomas Jefferson National Accelerator Facility (Newport News, Va). One hour after administration of 2.0-2.5 mCi (74.0-93.5 MBq) of fluorodeoxyglucose, 5-minute PET mammography of the affected breast was performed. Images were processed and reconstructed in the transverse craniocaudal and coronal planes. For each lesion, image-guided core-needle biopsy was performed immediately after PET mammography. Conventional mammography results and histologic findings were correlated with PET mammography images. The sensitivity, specificity, negative predictive value, and positive predictive value of PET mammography for demonstrating malignant lesions were calculated.
Results: PET mammography demonstrated 20 focal abnormalities, of which 18 were malignant and two were benign. Both benign lesions represented areas of fat necrosis. Three of 20 malignant lesions demonstrated at conventional mammography were not demonstrated at PET mammography. The overall sensitivity of PET mammography for malignancy was 86% (95% confidence interval: 65%, 95%), with a positive predictive value of 90% (95% confidence interval: 70%, 97%). The calculated specificity was 33% (95% confidence interval: 2%, 79%), and the negative predictive value was 25% (95% confidence interval: 1%, 70%).
Conclusion: These pilot data suggest that PET mammography can demonstrate small primary breast malignancies.
(c) RSNA, 2005.