Thoughts and experiences of having an FDG PET

[Jackdaw]

My consultant wants me to have an FDG PET because I have been running a low grade fever for a year and it’s not sure why. I am very severe and I am worried about the irradiated glucose particularly worsening my mitochondria. My two ME doctors think the temperature is ME but my consultant disagrees. I am worried about missing something, I am worried about it worsening things. I have already had a full body CT.

I don’t know what to do so any thoughts will be gratefully received.

 

[Wishful]

I think there are many ways that ME can cause elevated temperature. Is there any particular action that would be taken depending on the PET results? If it was a matter of verifying that you had <specific known disease> which would then justify some specific treatment, then it would be a good idea. If it's just a fishing expedition (that the doctor profits from), then I wouldn't allow it.

Do you have a constant low-grade fever, or a rise in temperature at a certain time of day? My temperature typically rises several tenths of a degree C in the afternoon-evening. It's typically well below 'normal' in the morning. I attribute my elevated temperature to picolinic acid, but that's just a guess.

Do you have thyroid hormone abnormalities? That could cause elevated temperature.

 

[Jackdaw]

It’s the NHS so the doctor wouldn’t profit (if financially is what you were saying). He’s a very good doctor which is what is making it so difficult. It is fishing so any action would depend on results.

It’s a constant low fever, very rare that it measures normal. It does rise in the evening. Typically 37.6c morning and can be anywhere between 37.7c to 38.3c evening. I have been tracking it for several months and have noticed that it peaks on the run up to my period and that it is averaging higher each month.

I have had lots of tests including thyroid (which was normal). That is why the PET is the next test.

 

[Wishful]

Okay, that's definitely a fever, and I'm not sure that I'd call it low-grade. Pre-ME, my oral temperature seemed to be a consistent 36.65C. Now it varies from 36.2 (occasionally lower) to 37.5C, but rarely higher than 37.1C. I wouldn't get a PET scan for my minor temperature abnormalities. I'd still want to know what the PET scan has the possibility of revealing, and what the probabilities of that are. Injecting radioactive substances shouldn't be done just because it's available and the doctor wants to do something. If it's the best tool for revealing infections in the brain, then I think I'd probably accept the small risk involved.

As for thyroid testing, the typical tests don't reveal all problems. There have been a number of threads here on the limitations of common testing and what else should be done and why. In your case, it sounds more likely to be an immune system problem. I don't know enough about PET scans to know if that might be useful in this case. Maybe run the PET-doctor's arguments over to your ME specialists?

Definitely a dilemma, especially when trained doctors can't agree either. I think I'd read (in proper medical journals) more about the possible risks of PET scans. If it's unlikely to cause a problem within my remaining lifespan, I'd probably risk it, if I was convinced that it had a reasonable chance of revealing something important.

 

[Pyrrhus]

I am worried about the irradiated glucose particularly worsening my mitochondria.

Obviously, any radiation is bad, but we’re talking about such very small amounts. Besides, most of the radioactivity is gone after 2 hours, so it’s just a short-term exposure. I wouldn’t worry about it if you really need the test. If you don’t need the test, then that’s another matter.

Hope this helps.

 

[Jackdaw]

I do need to ask more questions. I am most concerned about the glucose worsening the ME.

Has anyone had an FDG PET with ME?

 

[Malea]

Regarding the low-grade fever: I have this, too (but lower than you, around 37.7-9) and was always told it’s a sign of the body fighting infection.
(Also from memory: temperature is generally the highest in the phase after ovulation and should usually go down around ~0,5 with the period.)

I think the Fdg Pet could be a helpful examination but would also fear that it would worsen the situation.
Do you know what your consultant is suspecting? If he‘s looking for e.g. a tumor... maybe everything else that could detect one could be done first. Like testing for different tumor markers,... just as an example.

 

[tooth]

@Jackdaw - Hello. I am due for a FDG PET on the NHS tomorrow...I would normally have said no to being injected with anything but it's getting to the point where I just have to do it. Did you go ahead with it in the end? How was it?

 

[Jackdaw]

Hi @tooth I haven’t actually made the decision yet because the ambulance service arrangements still haven’t been made. I can only lie flat and have to have a stretcher. But getting to an appointment like a scan is proving difficult. Waiting to hear back after their latest house assessment.

So, can’t talk from experience. I found a post on here from someone who had really deteriorated after. That is the only experience by someone I have found. I personally am leaning towards not having one. I have had a full body CT and it is because of a persistent low grade fever the PET scan was suggested. Two experienced ME doctors think it is the ME that is the culprit and I think I will probably gamble on that than having the scan.

May I ask why you are supposed to be having one?

 

[tooth]

Hello, I understand your trepidation.

Have been bedridden for 4 1/2 yrs, no luck with GPs, as I'm sure you know. Things have been desperate over the last 18 months and I paid privately to see a neuro-immunology specialist who referred me back into the NHS this month and am about about do all the imaging and blood tests etc. I lucked out and am very grateful.
I've felt like I'm in some sort of coma most of the time - don't even know if I'm my own room or bed sort of thing. Annoyingly I've been much better the last month so don't know what will show up. I haven't able to feel my body at all, blackouts, fluctuating severe autism type symptoms, lost my vision for periods, lymph/immune symptoms, feel like I'm on drugs/hallucinating ALL the time, severe amnesia, fugue states, forgetting how to do basic stuff, have had no idea what the outside world is, feel like my brain is trying to explode in my skull, some MS type symptoms like losing the ability to swallow at times and tremors...I have a lot of pain in my spleen and sometimes liver and heart so agreed to the PET scan to see if there's any damage in the rest of my body.

My father has had ME/CFS since I was a kid (25+ yrs) and everyone assumed I had the same thing but my symptoms seem to be progressing more towards the neurological side of things whereas his is more physical/PEM.

I had a raised fever all the time during the beginning but it's been normal every time I've managed to get it checked over the last few years.

I'm so sorry to hear you are so debilitated. It's so hard to organise these things on top of just trying to generally stay alive, I wouldn't have been able to do this several months ago. Did the CT scan show anything?
Thank you for taking the energy to reply.

 

[tooth]

PS: I saw the post from the person who became severely ill after PET too

I plan on taking ALL the binders and detox stuff I have kicking around when I get home. Will let you know how it goes when I can.

 

[Jackdaw]

That’s an interesting list of symptoms. I’m very glad you are getting tests done. I got lucky last year and got some testing through an excellent NHS Consultant. The CT didn’t show anything (they were checking for lymphoma etc) except a part of my bowel which needs to be rechecked but is hopefully nothing. My symptoms are PEM big time but I also have a lot of neurological problems; huge myoclonic jerks during sleep, tremor, hyper reflexes. But your brain symptoms sound a bit unusual. I had blood tests for autoimmune encephalitis autoantibodies and I wonder if that would be a good thing for them to test. The NHS do them because they tested me. I had a brain and spine MRI too which I hope you have done amongst the tests.

All the tests were clear for me except I got diagnosed with POTS. I have a lot of autonomic issues and so I did the Celltrend test and the results were very strong positives for many. The NHS doesn’t do them but my consultant has reacted very strongly to the results. I don’t know if that is relevant for you.

I felt guilty getting tests done and knowing others don’t, so remember this is what should be happening for you. It is what you deserve and about time too. I was absolutely fine after the CT so I hope you will be after the PET and whatever else. Will be glad to hear how it goes. All the best!

 

[Wishful]

My father has had ME/CFS since I was a kid (25+ yrs) and everyone assumed I had the same thing but my symptoms seem to be progressing more towards the neurological side of things whereas his is more physical/PEM.

Yes, one of the confusing things about this disease is that it seems to express itself in different sets of symptoms. Some people show physical symptoms (low muscle endurance) but may not show mental fatigue, while others cant think clearly, but can run a marathon. I expect that even doctors who accept ME have trouble diagnosing it when they get another patient who shows a pattern of symptoms different from the ones the doctor is familiar with.