Background Prostate-specific membrane antigen (PSMA)-based imaging has become an increasingly important diagnostic tool in prostate cancer, though limited by low surface expression of PSMA in some patients. Previous studies have demonstrated that dutasteride can induce PSMA expression in vitro and in vivo . This pilot study aimed to evaluate the impact of short-term dutasteride treatment on standardized uptake values (SUVmax) in PSMA PET imaging and the immunohistochemical expression of PSMA for the first time in humans. Methods Four prostate cancer (PCa) patients underwent an initial PSMA PET/MRI of the prostate. Afterwards, all patients received 0.5 mg of oral dutasteride once daily for seven days. Subsequently, a second PSMA PET/MRI of the prostate and a template biopsy were performed. We compared the maximum standardized uptake value (SUVmax) of PSMA-positive lesions before and after dutasteride treatment. Additionally, histopathological specimens from PSMA-positive lesions and negative controls were analyzed for Gleason score and PSMA expression. Results An increase in SUVmax was observed in all patients following short-term dutasteride treatment. Histological analysis confirmed prostate cancer with an ISUP grade of ≥ 2 in PSMA-positive lesions that exhibited increased SUVmax following short-term stimulation. One PSMA-positive lesion, which showed a decrease in SUVmax after stimulation, was negative for prostate cancer on biopsy. Conclusion This pilot study demonstrated an increase in SUVmax in PSMA-positive prostate cancer lesions following a short-term seven-day course of dutasteride. Short-term dutasteride treatment prior to PSMA-PET imaging may have the potential to enhance detection rates in patients with prostate cancer. Further studies are needed to investigate this effect in larger patient populations.
Praetzel et al. (Wed,) studied this question.