[Diagnosis of breast carcinoma and locoregional lymph nodes with positron emission tomography].

Based on the increased glucose metabolism of malignant tissue, positron emission tomography (PET), using the radiolabeled glucose analog 18F-fluorodeoxyglucose (FDG), allows identification of breast cancer. Based on the criteria implemented in image interpretation, sensitivity of PET imaging ranged from 68% to 94% with a specificity between 84% and 97%. However, sensitivity for small tumors (< 1 cm) was found to be low. PET demonstrates tumor involvement of regional lymph nodes with high accuracy, predominantly in patients with advanced breast cancer. The sensitivity for the detection of axillary lymph node metastases was 79%, increasing to 94% in patients with primary breast tumors larger than 2 cm in diameter. Corresponding specificities were 96 and 100%, respectively. Lymph node metastases could not be identified in four of six patients with small primary breast cancers (stage pT1), resulting in a sensitivity of only 33% in these patients. By visualizing primary tumors and metastases in one imaging procedure, PET imaging may allow the effective staging of breast cancer patients. Response to treatment may be assessed at an earlier point than with imaging techniques currently used. Therefore, indications for PET studies in the future may be the evaluation of loco-regional lymph nodes, whole-body staging, diagnosis of local recurrence and therapy monitoring.