NRC
Nuclear Regulatory Commission — federal U.S. regulator of byproduct radioactive material in medicine. Agreement States (37 states) administer their own equivalent programs.
Why it matters to buyers: Required for PET / CT, SPECT, nuclear cardiology, brachytherapy, Gamma Knife, theranostic programs. License follows the facility + authorized users; not automatic on used-system purchases.
Why it matters to engineers: License transferability matters in used-system purchases. Plan license amendment / new license + inspection into install schedule.