Role of F-18 FDG positron emission tomography/computed tomography in detecting metastatic disease in initial staging of carcinoma breast patients

The aim was to study role of F-18 FDG PET/CT in detection of metastatic disease in initial staging of carcinoma breast especially in loco-regional and locally advanced carcinoma of breast.Retrospective observational study was done on 88 breast cancer patients (including 73 cases referred for loco-regional and 15 LABC cases) who underwent F-18 FDG PET/CT. Whole body (vertex to mid thigh) F-18 FDG PET/CT imaging was performed 60 min after injection of F-18 FDG at a dose of 2.2 MBq/Kg body weight. Metabolic parameters like SUVmax, SUVmean of primary tumor, hyper metabolic lymph nodes and distant metastases were calculated. Whole body MTV and TLG was calculated. In 73 cases referred for primary staging of localised disease; most common lymph node involved was ipsilateral axillary in 35 cases (47%) followed by ipsilateral internal mammary lymph nodes in 20 cases (27%). Distant metastases was detected in 32 cases (43%) liver in 5, lungs in 8, bone in 11 and multiple metastasis in 8. Highest mean MTV 57.0 and highest mean TLG 82.6 in stage IV disease. Patients with higher MTV and TLG showed poor prognosis. In 15 cases of LABC; most common lymph node was ipsilateral axillary in 7 cases (46%) followed by ipsilateral subpectoral lymphnodes in 6 cases (40%).Distant metastasis was seen in 3 cases (20%). The detection rate of metastases in LABC and in non- LABC breast cancers showed significant correlation (p value <0.05). There was significant proportion of 35% of non-LABC vs 20% of LABC cases which showed presence of metastases and were upstaged at primary staging using F-18 FDG PET/CT. Higher MTV and TLG values corresponded with greater risk of metastasis and poor prognosis. (author)