Prognostic Value of [¹⁸F]Flotufolastat PET Using Visual RECIP in Docetaxel-Treated Metastatic Prostate Cancer

We aimed to assess the prognostic value of [¹⁸F]flotufolastat PET in patients with metastatic prostate cancer during taxane-based chemotherapy (CTx). Methods: In total, 69 patients who received CTx as well as baseline and follow-up [¹⁸F]flotufolastat PET/CT scans were included. Imaging response was assessed by visual RECIP 1.0 dichotomized into progressive disease (PD) and non-PD. Biochemical response was defined as a prostate-specific antigen decrease of greater than 50% (castration-resistant) or a decline to less than 0.2 ng/mL (hormone-sensitive). Kaplan-Meier analysis was performed regarding overall survival, and the Harrell concordance index was calculated. Results: Patients with PD showed a significantly shorter median overall survival of 12 mo (95% CI, 8.3 mo to not reached) compared with non-PD (45 mo; 95% CI, 37 mo to not reached). The Harrell concordance index for RECIP (0.84; 95% CI, 0.72-0.97; P < 0.001) was higher than biochemical response (0.66; 95% CI, 0.49-0.84; P = 0.07). Conclusion: [¹⁸F]flotufolastat PET assessed using visual RECIP has high prognostic utility in patients with metastatic prostate cancer undergoing CTx.