I have a very hard time believing that your friends and family are getting PET/MRI scans routinely, as opposed to what most people actually do which is "hey I found this lump/I feel bad here, please can you check if this is bad and scan for anything else?"

This is an important distinction, because you can delude yourself and your medical team into believing you are healthy because you had a clean scan x months ago, as part of your annual deep checkup or whatever you want to call it. Leading into that part of if your friends had waited a couple more months it would have been a very different outcome!