Investigations of Breast Tumors with Fluorine-18-Fluorodeoxyglucose and SPECT

We designed a prospective study to investigate the feasibility of combined FDG-SPECT and whole-body acquisition in the diagnostic work-up of breast tumors applying visual analysis. We studied 50 patients with breast tumors of unknown histology. All malignant diseases were accurately detected in tumors > 2.3 cm, while the smallest FDG-positive lesion was 1.4 cm. In a subgroup of these patients, quantitative evaluation (tumor-to-back-group ratios) was added, which improved the sensitivity. Lymph node metastases were accurately indicated in 9 of 13 patients, while the detection of distant metastases depended on the location and size. False-positive FDG scans were observed in inflamed tissue, in a rapidly growing phylloides tumor and in supposedly healthy breasts. These results are comparable with prior investigations of other groups using PET. Therefore, FDG-SPECT and whole-body acquisition may be an adequate and less expensive technique to meet the increasing demand of FDG examinations.