It is important not to raise people's expectations of things that are not generally available. PSMA scans are available at only a very small number of hospitals and clinics, even fewer if you can't pay privately. Also, PSMA is only approved by NICE for men with recurrence after radical treatment, it is not approved for men who are newly diagnosed and have not yet had treatment.
PSMA's optimum range is PSA 0.5 - 4.0 with either no prostate or a fried prostate.
No harm in the person asking whether PSMA scan would be possible but be prepared for a blunt 'no'.
With a PSA of 50+, the MRI scan would have been capable of picking up significant lymph node involvement.