As part of my penance for past sins of posting a link here on OCF to a "great news article" I find only to discover that it was reported earlier and better in the OCF News Feed, I'm linking to this OCF news article from last week.
First though: this does not mean you should not get a PETscan, As the The title of this article statesi "Pet/CT Detects Early Recurrence of Head and Neck"/
But as I titled this thread: just know in advance that you have roughly a 50 50 chance of being scared needlessly or worse having an unnecessary biopsy or TX. Although for base of tongue cancer, my personal belief is that the rate is closer to the 90% false positive rate that the doctor expected from his experiences with Petscans
Here' an excerpt and the link
.[quote]Thus, Dr. Rudha said the true positive rate for routine PET/CT surveillance in head and neck cancer patients was estimated as 8/15, or 53%, and the false positive rate as 7/15, or 46%.;�With malignancies found in 53% of abnormal scans in this study, our research proves that PET/CT scans are valuable as routine follow-up and as a surveillance method for head and neck cancer patients � However, since the rate of false positives was 46%, caution should be shown when ordering biopsies after abnormal scans to prevent excessive unnecessary biopsies,� he said.;During a press briefing, Dr. Rudha said that the 46% false positive rate was lower than what he and his colleagues expected. �Actually we expected the false positive ratio to be about 90%,� he said[/quote]
PETscan false positive rates
The good news is that if the Petscan is clear, that is usually right. As I've posted before, Petscans don't distinguish between sugar uptake of cancer and recovering oral cells very well since both have high SUVs

This is something often discussed here on the forum. Im glad you brought this article over to the forum. The OCF newsfeed is a free service which posts these important articles. Too often the main OCF pages get ignored or the newsfeed isnt subscribed to.

I think I would rather know that PETs tend towards false positives than false negatives. Imagine how difficult it would be if your doctor told you there was NED and you knew that he was just as likely to be wrong as right.

The scans in this study were done at 6-9 weeks so 50/50 performance rate is likely poorer than what we see in real life. Our doctors suggest scans at 12 weeks or more for to allow for healing and minimise the false readings, the "false positive" rate should be much lower in practice.

I am using the term "false positive" because it seems to be the accepted term. However, in my opinion, "false positive" is an unfair term suggesting that the PET is inaccurate in what it is designed to measure. PET is extremely accurate in reading what it is designed to do (-ie measuring FDG uptake) it's just unfortunate for those of us sweating on the results that it is not just tumours that absorb FDG.

I agree Karen. To me this just means how to "take" a PET if it comes back hot. Most of us have been there, usually the first scan after treatment and we all remember that sinking feeling and the mental and emotional turmoil of thinking we had to go another round.

I think that PET's are an important tool and should be used but taken for what they are, a test with a low false negative rate, high false positive rate but still a tool to investigate possible recurrences and important staging information.

Thanks for the read!

This is timely as Kevin has his first follow up PET March 12th. He is in Alaska until then so at least we won't be chewing on each other because of nerves. Not til then anyway.
Thanks for posting,
Kathy

Sheesh. I'm sure it wouldn't have been a false positive if J's RO had a PET scan of himself and the result detected that his head was up his...well...a specific place. As RO's go...he was a complete moron. Wouldn't even listen to me reasoning that he couldn't diagnose J based on a PET without a biopsy. So...turns out the nodes were clear. Still no cancer showing up anywhere.

Thank goodness we scrammed away from that care team and got an unbiased one. I'm still angry about it. No recourse to even recoup any of the expenses for the surgeries, the treatments, the doctors visits, the medications, etc. Tort reform in California sucks.