Su TP, Huang JS, Chang PH, et al. - ¹⁸ F-FLT( ¹⁸ F-fluorothymidine)-PET(positron emission tomography) is not better than ¹⁸ F-FDG( ¹⁸ F-fluorodeoxyglucose)-PET as a tool to predict treatment response and survival in metastatic breast cancer cases. Use of interim ¹⁸ F-FDG-PET to evaluate treatment outcome may help treatment.

• A total 25 patients with metastatic breast cancer were included.

• Patients underwent PET/CT using ¹⁸ F-FLT and ¹⁸ F-FDG at baseline, following the 1st and 2nd cycle of systemic chemotherapy.

• ¹⁸ F-FDG-PET showed a significantly greater decrease of maximal standardized uptake value (SUV) and the peak SUV corrected for lean body mass of the tumor for clinical responders after 2 chemotherapy cycles (post-2c) vs non-responders.

• Significantly longer progression-free survival and overall survival were noted in patients who were metabolic responders by PERCIST (PET Response Criteria in Solid Tumors) on post-2c ¹⁸ F-FDG-PET.

• No significant survival differences between responders and non-responders were evident in the interim ¹⁸ F-FLT-PET.