The effect of PSMA PET/CT on clinical decision-making of radical prostatectomy and pelvic lymph node dissection.

Objective: To evaluate the effect of prostate-specific membrane antigen (PSMA) PET/computed tomography (CT) on clinical decision-making of radical prostatectomy (RP) and pelvic lymph node dissection (PLND) after its utilization in daily clinical practice at an European high-volume cancer center.

Materials and methods: Patients who had unfavorable intermediate- and high-risk prostate cancer between 2017 and 2021 were included retrospectively and divided into two groups; those who staged using PSMA PET/CT (group 1) and those who staged using conventional modalities (group 2). Clinical decision-making of RP over nonsurgical treatments and f PLND were primary endpoints and evaluated using regression models.

Results: PSMA PET/CT claimed significantly more N1 (24.2% vs. 11.3%; P = 0.01; OR, 1.97; 95% CI, 1.18-3.28) but insignificantly more M1 disease (9.9% vs. 5.7%; P = 0.42; OR, 1.91; 95% CI, 0.39-9.23), compared with the conventional imaging modalities. miN0 stage was related to more RP decisions compared with cN0 stage (P < 0.001; OR, 1.91; 95% CI, 1.48-2.46). PLND decision-making was significantly driven by positive c\miN stage findings, which were more reliable when it was reported after a PSMA PET/CT examination (P < 0.001; OR, 35.55; 95% CI, 6.74-187.45 for conventional imaging modalities vs. P < 0.001; OR, 91.72; 95% CI, 11.25-747.56 for PSMA PET/CT).

Conclusions: Patients with no suspicion of lymph node invasion on molecular imaging (PSMA PET/CT) tended to be referred to RP more compared to radiological imaging. Also, the PLND decision was strongly driven by staging findings. Compared with conventional imaging, PSMA PET/CT findings were more reliable during PLND decision-making.