F-18-FDG PET Derived Tumor Blood Flow Changes After 1 Cycle of Neoadjuvant Chemotherapy Predicts Outcome in Triple-Negative Breast Cancer

{Previous studies have suggested that early changes in blood flow (BF) in response to neoadjuvant chemotherapy and evaluated with 150-water are a surrogate biomarker of outcome in women with breast cancer. This study investigates, in the triple-negative breast cancer subtype, the prognostic relevance of tumor BF changes (Delta BF) in response to chemotherapy, assessed using a short dynamic F-18-FDG PET acquisition. Methods: Forty-six consecutive women with triple-negative breast cancer and an indication for neoadjuvant chemotherapy were prospectively included. Women benefited from a baseline F-18-FDG PET examination with a 2-min chest-centered dynamic acquisition, started at the time of F-18-FDG injection. Breast tumor perfusion was calculated from this short dynamic image using a first-pass model. This dynamic PET acquisition was repeated after the first cycle of chemotherapy to measure early Delta BF. Delayed static PET acquisitions were also performed (90 min after F-18-FDG injection) to measure changes in tumor glucose metabolism (Delta SUVmax). The association between tumor BF, clinicopathologic characteristics, and patients' overall survival (OS) was evaluated. Results: Median baseline tumor BF was 21 mL/min/100 g (range, 6-46 mL/min/100 g) and did not significantly differ according to tumor size, Scarf-Bloom-Richardson grade, or Ki-67 expression. Median tumor Delta BF was-30%, with highly scattered values (range, -93% to +118%). A weak correlation was observed between Delta BF and Delta SUVmax (r = +0.40