PSMA-Ligand PET for Early Castration-Resistant Prostate Cancer: A Retrospective Single-Center Study
Manuel Weber, Claudia Kurek, Francesco Barbato, Matthias Eiber, Tobias Maurer, Michael Nader, Boris Hadaschik, Viktor Grünwald, Ken Herrmann, Axel Wetter, Wolfgang P. Fendler
Abstract
The low detection rate of conventional imaging and unspecific fluctuations in prostate-specific antigen can hamper early diagnosis of castration-resistant prostate cancer (CRPC). We thus assessed the value of prostate-specific membrane antigen (PSMA) PET/CT in the detection of early CRPC (prostate-specific antigen # 3 ng/mL). Methods: We identified 55 patients with early CRPC from our institutional database. PSMA PET/CT and its CT component were interpreted independently by 3 masked readers. The primary endpoint was the per-patient detection rate; secondary endpoints were interobserver agreement and predictors of PET positivity. Results: PSMA PET/CT was positive in 41 of 55 (75%) patients. Sixteen of 55 (29%) patients had local disease only, and 25 of 55 (45%) had M1 disease. Overall, PSMA PET/CT interobserver agreement was substantial by Landis and Koch criteria (Fleiss 5 0.77). Conclusion: PSMA PET/CT localized prostate cancer lesions in 75% of patients and M1 disease in 45%. Detection of early CRPC facilitates disease-delaying therapies for local or oligometastatic disease. PSMA PET/CT is of value in early CRPC and should be included in the CRPC entry criteria of the European Association of Urology and Prostate Cancer Working Group 3.