Abstract
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Objectives We have developed a new prototype of positron emission mammography (PEM) called INER PEM that performs high-resolution breast PET imaging. This clinical study is to test the feasibility of this new system for breast cancer (ca) imaging.
Methods Twenty patients (pts) (age range, 24-71 y) with newly diagnosed breast ca were recruited for biopsy within 2 weeks of the PEM scan and planned to undergo surgery within 2 weeks of the study. All pts were injected with 370±20 MBq of 18F-FDG and imaged with whole body (WB) PET first after 50 mins. of injection followed by 5 min PEM imaging each breast. The pt lay prone on the specialized bed and inserted one pendent breast through an aperture in the table top each time for PEM scan. No breast compression is required. Two LYSO-based detectors were adjusted to be placed on the medial and lateral side of the breast. The detectors stay static on image acquisition. The results from the PEM study were compared with whole body PET and those from sonography and pathology for index lesions.
Results All PEM images were successfully done. The WB PET revealed 17 lesions in Rt breast and 9 in Lt breast (SUVmax range 2.3-14.0). PEM demonstrated all lesions seen in WB PET. Twenty-one are invasive ductal ca, 3 ductal ca in situ and 2 invasive lobular ca. PEM detected 3 more small lesions which were not detected by either WB PET or sonography. All three were proven malignant on surgery. Two of them can also be seen in MRI. We can detect tumors as small as 1.3x0.8 cm in size.
Conclusions This is the first report of the feasibility study using this new prototype PEM developed by INER in Taiwan. Although this PEM can not evaluate the extent of disease outside breasts, it can be used as a complementary screening tool for breast ca imaging. The pts can tolerate the scan well. More lesions (11.5%) can be detected by this PEM than WB PET. With further collection of more clinical data in the future, we expected this may contribute to patient management.
Research Support INER grant No. 1022001INER056