Two PET scans, completely different results

[LeeLiam]

A quick recap, I was treated with seeds and external beam in 2006. PSA dropped slowly over a few years and got to <0.1, It stayed at 0.1 for several years. It started rising a couple of years ago and reached 3.1 last August. I had an Axumin scan on 9/10. It showed only uptake in the "center of the prostate surrounded by seeds likely representing local recurrence." I felt this was good news and was planning some kind of focal ablation. Just before the Axumin scan, I was accepted for a clinical trial for a new rhPSMA scan at the same hospital. They said the Axumin would be a good baseline. I had the rhPSMA scan last week and got the results yesterday. It showed NOTHING in the prostate gland and nothing in the prostate bed. ZERO. It did show a bright spot on the pedicle of the T8 vertebrae. The doc said that could be cancer of it could just be arthritis. We went through the two scans slide by slide. The Axumin showed a small spot in the middle of the gland. The reference (L3) SUV was 2.49. The gland had an uptake of 2.8. Doc said that is why they said "suspicious for local recurrence." We went up the Axumin slides to the T8 and it showed ZERO uptake. We then went through the rhPSMA slide by slide. It showed nothing anywhere in the prostate bed. It did show a spot on the T8. Doc wants me to get a thoracic spine MRI with and without contrast. He said the trial would cover the cost. I have already paid for a pelvic MRI with Dr. Joe Busch scheduled for 11/9. My URO also ordered an Exo Dx urine liquid biopsy they are FedExing to me today. My inclination now is to slow things down and get another PSA test. I would greatly appreciate anyone's comments on this mystery.

[Tall_Allen]

We don't know that much about the natural history of PSMA expression. It's possible the prostate cancer there doesn't express PSMA. And the Axumin uptake was not far above the reference, so it may be nothing. At any rate, it is suspicious for cancer, not cancer. The next step would be to biopsy that spot to see if there is any live cancer there. Be sure to get the core read by Epstein - telling him it's from radiated tissue.

The T8 spot needs more investigation too. The MRI is a good next step.

[LeeLiam in reply to Tall_Allen]

TA, thanks. I am planning to get an in-bore biopsy after the scheduled pelvic MRI. Then schedule the thoracic MRI.

[Justfor_]

A free PSA won't hurt either.

[LeeLiam in reply to Justfor_]

Thanks, Justfor. I am considering a 4K Score blood test. According to their website, "The 4Kscore Test measures four biomarkers: total PSA, free PSA, intact PSA, and hK2. Blood test results are combined in an algorithm with a patient’s age, optional digital rectal exam, and prior biopsy results to give physicians a personal risk score for each patient."

[Justfor_ in reply to LeeLiam]

Even better! You still have your prostate. Benign PSA should not be ruled out. Wish you a very pleasant surprise.

[HopingForTheBest1 in reply to LeeLiam]

At the beginning of my journey, before I was confirmed via MRI fusion guided biopsy as having APC, I had a 4K test. I got a score of 7, which is borderline. As such, for me it didn't really help clarify my condition until I had the biopsy with conclusive evidence I needed to take immediate action.

[timotur in reply to LeeLiam]

I would not consider a 4K Score test at this point... it's purpose is to determine whether a patient that hasn't yet been treated should consider a biopsy, rather than a decision on whether to treat a BCR condition after treatment. It's purpose is not to determine a BCR. I had a 4K after getting a PSA of 23 and the result was 83, which meant I had an 83% chance of having a GL > 7 tumor, and indeed, after biopsy I did have a (3 + 4) tumor. Your best bet at this point is PET imaging, PSA, and ALP. Note since your T8 reading is near the SUVmin, it may be a false positive.

[HopingForTheBest1]

Where did you get your PSMA scan? Hopefully it will get FDA approval in the next few months and become widely available.

[LeeLiam in reply to HopingForTheBest1]

The trial is at Emory Hospital in Atlanta. There are several flavors of PSMA. So far, I'm not really keen on this one. I'll know more after the biopsy and report back then.

[j-o-h-n]

Hope it's nuttin.....

Good Luck, Good Health and Good Humor.

j-o-h-n Wednesday 10/28/2020 2:41 PM DST