Conflicting PET/CT scan results
 

Hi Ladies - I have a question about my recent PET and CT scan results I was hoping your collective knowledge could help with.

My CA 15-3 markers have been normal since August but have been slowly climbing (last one was 25). My recent CT scan was clear. However, the PET had a few bone areas lit up. My doctor said this is most likely bone healing but it still has me nervous. Has anyone else had this experience? Clear CT, normal markers, but bone activity on a PET? Any information would be greatly appreciated. I'm trying not to worry but, of course, I am. Any information you could provide on having similar scenarios would be greatly appreciated!

Thank you!!

Dear Courtney

It is certainly true that healing can cause some spots to light up on a Pet scan. This is because (like cancer) healing is also rapidly dividing cells. Not as fast as cancer but the cells are reproducing (in a normal way) to fill in the gaps that the cancer took up. Since the chemo kills the cancer then the body has to try to fill in that void.

Also, healing causes some inflammation that draws white blood cells to the area to protect it while building tissue. This also causes Pet scans to light up. This is why arthitis lights up on Pet scans too.

Relax for now and enjoy the no chemo zone. Pet scans light up for alot of reasons. If you're not sure, call and ask to speak to the radiologist who read the scan and ask for a copy of the full report (which you should have anyway for your records).

I am sure all is well.

I've had several instances of false positives..scared the daylights out of me. First the PET lit up in my effected breast close to the original surgery site, it was very low SUV. After having an ultrasound and mammogram, it was determined it was scar tissue. On my next set of scans, the issue had resolved itself, the area didn't light up. Then, on my last set of scans, I had a spot on my left ovary light up, the spot was about 2cm. It had moderately high SUV intake. I had a vaginal sonogram done and it was determined it was just a fluid filled cyst that had already shrunk quite a bit. My GYN says that they see quite a few false PET positives, and that mine was probably due to the fact that I was ovulating when I did my scan. So it can and does happen. I am still hoping that my original diagnosis of 2 very small lung mets may have been false positives. My oncologist did not see anything on the CT scan but there were 2 small areas that lit up on PET, looking back at my reports, they had very very low SUV intake, so it could have very well been inflamation or something else. I had just gotten over being dreadfully sick with the flu when my original scans were taken. We never did biopsy them because they were too small, they were gone by the next scan after 6 weeks of chemo. False positive are pretty common in PET scans, that's why if I ever get anymore that we can't tell for sure about, I will insist on some sort of biopsy before I just assume the worst and get back on chemo...sherryg683

My last pet had increased activity in my sternum but my CT showed stable or no remarkable change. My onc asked if I was bruised and I said - yes and showed her a black and blue mark from the prior week's acupuncture. She seemed to think that was what made the pet light up. (Light up seems like a baby term - doesn't it?:) Increased metabolic activity from a small black and blue mark? For now that's what I'll go with. Hope yours is nothing too!