[59M] Is (PSMA) PET scan best diagnosis tool available in 2021?

59M, cT2c, Gleason 4+3=7, PSA 7.8 prostate cancer diagnosis.
Before undergoing radiation treatment or surgery, how beneficial would it be to get a PSMA PET scan to confirm if there are any metastasis nearby the prostate?

And is PSMA PET scan the most advanced imagining, diagnostic technology for prostate cancer as of 2021?