Prognostic value of FDG-PET and DWI in breast cancer

Objective: To investigate the prognostic value of preoperative FDG-PET/CT and diffusion weighted imaging (DWI) in patients with breast cancer.

Methods: A total of 73 patients with newly diagnosed invasive breast cancer who had undergone preoperative whole-body FDG-PET/CT and 3-Tesla breast MRI including DWI followed by surgery were identified. Effects of primary tumor PET parameters [maximum standardized uptake value (SUV_max), mean SUV (SUV_mean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG)] and DWI parameters [mean apparent diffusion coefficient (ADC_mean) and minimum ADC (ADC_min)] including clinicopathologic factors on disease-free survival (DFS) were retrospectively evaluated using the log-rank and Cox methods.

Results: After a median overall follow-up of 32.3 months in all patients, 6 (8.2%) of the 73 patients had recurrence. Receiver operating characteristic curve analysis and log-rank tests showed that patients with a high primary tumor SUV_max (≥ 3.60), MTV (≥ 3.15), and TLG (≥ 16.0) had a significantly lower DFS rate than those with a low SUV_max (< 3.60), MTV (< 3.15), and TLG (< 16.0), respectively (p = 0.0054, p = 0.0054, and p < 0.0001, respectively). SUV_mean, ADC_mean, and ADC_min were not significantly associated with recurrence. Univariate analysis showed that SUV_max (p = 0.0054), MTV (p = 0.0054), TLG (p < 0.0001), tumor size (p = 0.0083), estrogen receptor negativity (p = 0.046), progesterone receptor negativity (p = 0.0023), human epidermal growth factor receptor 2 positivity (p = 0.043), and the presence of axillary lymph node metastasis (p = 0.0037) were also significantly associated with recurrence. However, in multivariate analysis, none of them were an independent factor.

Conclusions: The preoperative SUV_max, MTV, and TLG of primary breast cancer are prognostic factors for recurrence, whereas ADC values are not.