Positron Emission Mammography (PEM): A Promising Technique for Detecting Breast Cancer

I. ABSTRACT We are developing a high specificity technique for detecting the increased metabolic rate of breast tiiinours. The glitcose analog FDG is known to concentrate in breast tiinlours rendering them easily detectable in conventional PET scans. Since PET is a relatively expensive imging technique it has not been used routinely in the detection of breast cancer. Positron emission mtnrnography (PEM) will provide a highly eficient, high sputial resolution, and low cost positron irtulging system whose rnetabolic irnages are co-registered with conventional mnmtnography. Coincidences betweeti hoo BGO blocks CUI into 2 x 2 tnrn squares coitpled to two 7.5 crn square inuiging PMTs are detected and back-projected to form reultirne multiple plane irnages. The design is about 20 tinles more sensitive than a conventional multi-slice PET body scanner, so much less radio-pharmaceiitical can be wed, reducing the patient dose and cost per scan. Protoepe detectors hose been t n d e and extensive rneasurernents done. The device is expected to have an in-plane spatial resolution about 2 intn FWHM. Besides the application as N secondup screening tool the device may be beneficial in rrzeasiiring a tiirrwur's response to ruriio-therapy or cherno-therapy as well as uiding the surgeon in optimizing the removal of inalignant tissue.