sup 18^F-FLT PET/CT as an imaging tool for early prediction of pathological response in patients with locally advanced breast cancer treated with neoadjuvant chemotherapy: a pilot study

We evaluated whether ^sup 18^F-3'-deoxy-3'-fluorothymidine positron emission tomography (FLT PET) can predict the final postoperative histopathological response in primary breast cancer after the first cycle of neoadjuvant chemotherapy (NCT). In this prospective cohort study of 15 patients with locally advanced operable breast cancer, FLT PET evaluations were performed before NCT, after the first cycle of NCT, and at the end of NCT. All patients subsequently underwent surgery. Variables from FLT PET examinations were correlated with postoperative histopathological results. At baseline, median of maximum standardized uptake values (SUV^sub max^) in the groups showing a complete pathological response (pCR) + residual cancer burden (RCB) I, RCB II or RCB III did not differ significantly for the primary tumour (5.0 vs. 2.9 vs. 8.9, p=0.293) or for axillary nodes (7.9 vs. 1.6 vs. 7.0, p=0.363), whereas the Spearman correlation between SUV^sub max^ and Ki67 proliferation rate index was significant (r=0.69, p