Strange Results from PET Scan

[LisaJ]

Happy Holidays everyone. I just got off the phone with the nurse who works with my Dr. I had a PET scan about a week ago. When I had the CT Scan, there were a few tiny nodules on my lungs so my doctor sent me for a PET. My doctor told me she was very confident that it would come back o.k. (they were extrememly small). None of the nodules lit up, except one which the nurse described the report as saying it "kind of lit up - meaning inconclusive. The other weird thing is, is that the area where I had the lumpectomy (I had clear margins) and the auxillary dissection lit up. My doctor isn't in today so I will talk to her tomorrow. Has anyone experienced this with a PET scan? Is there other questions I should be asking?

I would keep on it. Do not let the doctor say it is probably nothing. Have them checked again in a month to look for changes.

John

I, too, had nodules in my lung on a CT angio. If they are less than 4 mm or so they cannot be picked up on a PET (the resolution isn't high enough).Thus, the resolution of the CT is higher than that of the PET and a PET usually cannot be used to determine if the nodules are cancer, infection, etc when the nodules are only that size.
A PET/CT (a study which simultaneously performs a PET and a CT is usually only available at some teaching hospitals and very well equipped cancer centers) can show where the PET lights up in three dimensions so they could tell if it was outside the thoracic cage (residual breast or axilla) or within(lungs).

Many times nodules show up on CTs (my pulmonologist who has no diseases told me they showed up on his)--the technology is so specific it picks up things not causing any problems. A protocol was worked up for lung cancer patients with such nodules and is followed in breast cancer patients as well:
repeat the study in 3 months--if they are larger they are likely cancer and the treatment is not working, if they are smaller they are cancer and the treatment is working, if they are unchanged they are likely not cancer. A warning, if they are really small, the cuts taken by the CT may not be taken in the exact same location each time, so seeing more or less of them (or not at all) may not mean they are not there, just located between the cuts this time. There is no magic to repeating the study at 3 months--mine was repeated in 2.3 months (as pulmonary clinic was not meeting around the holidays) and my nodules were unchanged.

Hope this helps!

[Barbara]

Lisa J:

I too had lung nodules on CT and had a follow-up CT some four months later and their was no change. The radiologist said the nodules were mucus plugs probably caused by Herceptin. I continue to have mucus plugs in my sinuses as well as my lungs on scanns and my oncologist expects it to persist until I am off Herceptin. I occassionally cough up a mucus plug which grosses me out but that is life. I hope your nodules turn out to be nothing as well but I would have the follow-up CT.

Barb

The PET SPECT CT post on articles of interest may be of interest if you have no already read it.

RB.

[michele u]

Lisa,

On one of my PET's my thyroid lit up. Whenever there is fast growing cells, it will light up. Thyroid is one of them. And then inflammation and infection can also light up. If you had some spots in the surgery area, probably it's changes from surgery and your body trying to heal. I also had some spots on my shoulder that lit up. Then bone scan was negative. Even a PET can not say for sure if there is cancer there. Don't worry. Let the Dr's decide if it is something that needs further looking into! I will pray that it will turn out ok

[LisaJ]

Thank you so much for all of your responses. It has eased my mind!