The role of (18)F-FDG PET/CT in initial staging of patients with locally advanced breast carcinoma with an emphasis on M staging.

Locally advanced breast cancer (LABC) is a distinct entity in breast carcinoma with high incidence of distant metastases (M). However, there is scarce data in the literature addressing the role of fluorine-18-fluorodeoxyglucose-positron emission tomography/computed tomography ((18)F-FDG PET/CT) in LABC. This study was performed to assess the sensitivity of (18)F-FDG PET/CT in confirming known lymph nodal and M and in identifying new ones in LABC. We performed a retrospective analysis of data of 16 patients with LABC who underwent histopathology, for the diagnosis of LABC and clinical examination, chest X-rays, ultrasound of the abdomen and whole body bone scans. Findings for M obtained by all the above examinations were compared to the (18)F-FDG PET/CT findings that followed. Lymph nodal and distant metastases detected by all other examinations were detected by (18)F-FDG PET/CT in all patients, except subcentimetric metastases in 2 patients in the axilla that were detected in another examination later. Additionally, (18)F-FDG PET/CT identified unknown ipsilateral, supraclavicular, internal mammary metastases and upstaged disease in 3 patients and additional distant metastases were noted in 3/16 patients. In conclusion, our study suggests that more extra axillary lymph nodal and distant metastases can be identified by (18)F-FDG PET/CT as compared to a group of clinical, X-rays, ultrasound and bone scan examinations together.