Prognostic value of 18F-FDG PET/CT prior to breast cancer treatment. Comparison with magnetic resonance spectroscopy and diffusion weighted imaging.

OBJECTIVE: To investigate the prognostic value of pretreatment fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT), magnetic resonance spectroscopy (MRS), and diffusion weighted imaging (DWI) in breast cancer patients. SUBJECTS AND METHODS: Eighty-three patients who had a tumor larger than 2cm shown by 18F-FDG PET/CT and by 3-Tesla breast MRI, received neoadjuvant chemotherapy (NAC) and subsequent surgical resection. Relationships of PET parameters, including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), as well as total choline peak and mean apparent diffusion coefficient (ADCmean) of the primary tumor were evaluated, along with the clinicopathologic factors relapse-free survival (RFS) and overall survival (OS) using log-rank and Cox tests. RESULTS: Median overall follow-up was 36.3 months (16.1-76.9 months), during which 11 patients had recurrence and 4 died. Results of receiver operating characteristics curve analysis and log-rank tests showed that high primary tumor SUVmax (≥6.20), MTV (≥5.39), TLG (≥23.23), and total choline peak (≥12.1) values indicated significantly worse RFS as compared to lower values (<6.20, <5.39, <23.23, <12.1, respectively) (P=0.0085, P=0.0029, P=0.013, P=0.016, respectively). The ADC cut-off value (0.833×10-3) was not significant. Furthermore, elevated SUVmax, MTV, TLG, and choline peak levels, progesterone receptor (PR) negative finding, high Ki-67 expression, metastasis to an axillary lymph node, and advanced TNM staging were significantly associated with recurrence, and elevated SUVmax and TLG, PR-negative finding, and axillary node metastases were significantly associated with death. CONCLUSION: Fluorine-18-FDG PET/CT was superior as compared to MRS and DWI for determining recurrence and death prognostic factors, especially primary tumor SUVmax and TLG, in patients with breast cancer.