Just read another post saying that they were told to stop Pred before a PET scan. I have moved to a new city and am due to have one as ordered by my new rheumatologist.
I have had a massive flare. Was down to 4.5 mgs for GCA PMR. Had to go up to 50 to control head pain. Now on 20 but no mention of stopping the Pred for the scan??
I usually take it by 9am. Scan is from 12 - 2pm. Should I wait and take it after ??
It might help, in that there would be the build up of inflammation from that morning's batch of inflammatory substances. I suppose there is a logic in saying that it will show up if there is enough inflammation to still cause symptoms. If it is positive then there is no problem - my concern would be that some doctors might not recognise a false negative.
I should bave a word with the medics about it as they normally ask you to stop at least 24 hours beforehand. Take tablets with you so you can have your dose immediately after the scan!
Oh dear. Now I am losing faith in another rheumatologist. I think she wanted to rule out anything other than GCA. She said it was rare to have GCA symptoms in both sides. But I have always felt it on both sides.
She said it was rare to have GCA symptoms in both sides.
Wrong -it’s rare to have it one side only!
Think she must have fallen asleep during GCA lecture…
What GCA lecture ...
Good question, well formulated, nicely put! Sorry got my wishful thinking hat on again 👒
Oh dear. Losing trust.
really!!!
I was told by my rheumatologist that I had to reduce to 5mg before I could have the scan and to bring my medication with me to take immediately after!
Was that for a PET scan?
Yes it was.
That is interesting. I thought they said no steroids for 24 hours before the scan.
Yes that’s correct. I’d had my steroids the day before in the morning and then took my daily dose after the scan the following lunchtime. Anyway it worked as it showed up an inflamed aorta and carotid arteries!
When I had to have PET scan recently, I had to be off Pred for 2 weeks before (was on a very low dosis at the time). They said it was necessary to get a true picture.
I think having the PET/CT scan while on 20mg/dy only makes sense for two possible reasons: a) because you are being treated for both GCA and PMR, and one may mask the other; b) because you have come down from 50mg/dy. The scan might reveal whether there any localised pockets of severe GCA inflammation in critical places that might otherwise go undetected as your PMR symptoms improve.
The attached photo shows an FDG PET/CT scan of a patient with large-vessel vasculitis. As you can see, the brain uses so much glucose, it appears black cannot be imaged for inflammation. The liver uses less and so appears grey. The rule is that arteries that are darker than the liver are judged to be severely inflamed: in this case those in the neck and shoulders stand out clearly.
Obviously, this scan would not reveal inflammation near the optic nerves (inside the brain). Nor would the scan reveal any milder inflammation, which showed up lighter than the liver. Patients usually taper off steroids before a scan to maximise the chance of seeing any inflammation.
Inflammation (and tumours) show up because proliferating immune cells (and cancer cells) consume abnormally large amounts of (FD-) glucose. Blood tests (usually) reveal whether immune cells are proliferating, but cannot tell you where.
I hope that is helpful.
thank you. That is really helpful. I do have GCA and PMR but the PMR symptoms seem to be secondary to the GCA. In my severe flare it felt like my head was about to burst which was frightening. The joint aches have been mild and resolved when the head did. I have only seen this new rheumy once
I think she was thinking of ruling out any other causes. Will have lots of questions next time. But due for PET on Monday midday so cant ask before.
Also a bit afraid of missing my 20mgs until after 2 pm in case I upset my return to lower dose and restart the flare. Fear is a terrible thing!
Taking your dose later in the day than usual is unlikely cause a flare - but unfortunately it probably will make you feel pretty rubbish in the morning before your scan. But as you have no choice, you’ll just have to grin and bear it..and hope the end result is worth the few hours of discomfort.
Good luck 🌸
Awaiting PET Scan 
Pred and PET Scans
MRI Scan and pred
Back on pred
Prednisilone and PET scan
