Confused about Pet Scan - 1265671

alta
Posts:15

My daughter, a breast cancer survivor had a Pet Scan a few days ago and we are waiting to speak to the doctor about the results but in the meantime we had concerns.

The Pet Scan/CT showed progression to her bones, but she has had a major flare of rheumatoid arthritis since she completed radiation in January 2014. She has refused to take any treatment for her flare and has been in pain in her shoulders, arms and hands. This week she finally went in for RA treatment and was given predisone for the inflammation. The RA doctor touched one of the areas they said was cancer and said that he didn't feel it was a cancer issue but an RA issue.

A month ago she started having pain in her chest and went to the doctor who diagnosed her with costochondritis and assured her after blood tests and CT scan of the chest that it was not cancer. Her inflammation markers were very high. How can a CT scan be clear of cancer and 2 weeks later show up as cancer in a pet scan?

Her recent pet/ct shows that area to be cancer (sternum) plus additional areas such as spots on her neck and pelvis and an SUV of 9.9 at T12. One area that they were concerned about initially, her L3 was not mentioned at all.. This area lit up initially and a biopsy came back negative.

We are going for 2nd opinions and of course insist on a biopsy due to her flare up of RA.

One thing I noticed was that the radiologist that read her report is actually a cardiology specialist, I don't know if that makes a difference in the reading of a pet scan for a breast cancer survivor.

Would appreciate your comments and of course understand that only her medical doctors can give a definite diagnosis. But based on experiences with other patients and your knowledge of Pet Scans if you have anything to say to ease our minds until we get more diagnostic testing.

Thank you.

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Dr West
Posts: 4735

I would think that someone reading a PET scan could get a sense from the pattern of the probability of PET scan findings representing cancer or RA. It's very possible that some of the areas that light up are from RA and that others are from cancer -- for instance, RA is more likely to cause inflammatory changes in extremities, especially wrists/hands, etc. while cancer very rarely affects the distal (far from the center of the body) parts of the extremities and is far more likely to affect the spine, pelvis, shoulders, hips, etc -- the so-called "axial" skeleton that is not typically affected by RA.

It's very hard to envision that a cardiologist would read a PET scan. Perhaps it's a nuclear medicine specialist who reads heart scans as well as PET scans, but the training of a cardiologist and a radiologist or nuclear medicine specialist (the people who would be expected to read a PET scan) is so different that it'd be like saying the plumber came by to rewire your home's electricity or your pediatrician also does heart surgery. That really doesn't sound plausible in an area large enough to have PET scanning available, so I'd want clarification of your information for that.

Good luck.

-Dr. West

alta
Posts: 15

Clarification---The radiology is a nuclear medicine doctor who specializes in reading cardiology scans.

Her scans have changed over the 1.8 months she has been dealing with this. Some of her lesions have disappeared over the course of month or lessen without treatment that included the area of her sternum at one time.

Wouldn't the final diagnoses be determined by a biopsy?

Thanks

JimC
Posts: 2753

Hi alta,

If the scan findings are ambiguous then a biopsy is the only way to make a definitive diagnosis. On the other hand, if the scan findings clearly seem to indicate cancer, doctors may elect to proceed with treatment without a new biopsy when the patient has a previously diagnosed cancer.

JimC
Forum moderator

Dr West
Posts: 4735

I agree that findings that improve without cancer treatment are very unlikely to be cancer. If there is room to question whether the findings of possible metastases represent cancer, a biopsy is the way to clarify that.

-Dr. West