Thoughts and experiences of having an FDG PET

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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

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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.
 
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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

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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

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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.
 
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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

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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.
 
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