> My father is a part of "full body PET scan every 3 years" program as part of post - cancer treatment, and it worked twice: early detected lung and prostate tumors, both removed.
My mum gets scanned a little more frequently than that, following treatment for an inoperable tumour in her lung around five years ago. During treatment she was getting scanned every three months or so, and it was remarkable watching this thing go from the size of a tangerine, to actually expanding a bit and looking "fuzzy" once the drugs kicked in, to being the size of a plum, then the size of a grape attached with a little thin thread of tissue, to being a thing the size of a pea. Now there's a tiny ripple of scar tissue that no-one wants to investigate further, because if it's not doing anything let's not poke at it.
There is a roughly pea-sized "thing" on her adrenal gland that was a bit worrying because anything like that is going to get intimately involved with your lymphatic system and then it's going to metastasise like hell. But it neither got bigger nor smaller in the nearly six years since the first scan, so it can't be that important.
This is one of the great things about the NHS, especially here in Scotland where we have (possibly as a result of the weirdly high levels of cancer) some of the best oncology services in the world.
If we'd lived in the US, the insurance companies would have taken one look at an 83-year-old about to become a grandmother and sent her home with a bottle of morphine to die. As it is, she's doing very well and got to see both her grandchildren start school.