Results of preliminary clinical trials of the positron emission mammography system PEM-I: A dedicated breast imaging system producing glucose metabolic images using FDG

Early detection of breast cancer is crucial for efficient and effective tre atment. We have developed an instrument for positron emission mammography ( PEM) called PEM-I that performs high-resolution metabolic imaging of breast cancer. Images of glucose metabolism are obtained after injection of 75 MB q FDG. The PEM detectors are integrated into a conventional mammography sys tem, allowing acquisition of the emission images immediately after the mamm ogram, without subject repositioning, and accurate coregistration of images from the 2 modalities. In this article, we present the results of the firs t clinical pilot study with the instrument. Methods: Sixteen subjects (age range, 34-76 y) were studied. All subjects were nondiabetic, nonpregnant, a nd without a history of cancer. They had recently been found to have sugges tive mammography findings or a palpable breast mass and underwent lumpectom y or mastectomy within 2 wk of the study. Results from the PEM study were c ompared with those from mammography and pathology. A PEM test was classifie d positive (indicating the presence of cancer) if significant focal uptake was seen in the image or if the counting rate in the breast with suggestive findings was significantly higher than in the contralateral breast. Result s: Of the 16 subjects studied, 14 were evaluable. Ten cancerous tumors and 4 benign tumors were confirmed by pathologic examination after complete rem oval of the tumor. PEM correctly detected the presence of disease in 8 of 1 0 subjects. Findings were false-negative in 2 instances and false-positive in none, giving the instrument 80% sensitivity, 100% specificity, and 86% a ccuracy. Conclusion: Our preliminary results suggest that PEM can offer a n oninvasive method for the diagnosis of breast cancer. Metabolic images from PEM contain unique information not available from conventional morphologic imaging techniques and aid in expeditiously establishing the diagnosis of cancer. In all subjects, the PEM images were of diagnostic quality, with an imaging time of 2-5 min.