PSMA test - possible false positive on rib?

[icanwintwice]

Hey guys,

If you read my last post about a small spike on my PSA from undetectable to .1. I wasn't sure whether to get tested or not.

I decided to do a PSMA test to make sure it was not cancer.

The PSMA test showed my left 6th rib positive for cancer. It was not small, and had to develop in less than 3 months. I had no other cancer anywhere else according to the PSMA test.

Previously I had a small lymph node positive on my lower left hip below my iliac artery, had it radiated, and did ADT for 24 months. It has since been 10 months with undetectable PSA and my Testosterone is at 700.

I asked my doctor to do a biopsy on the lesion on the rib and he said he thought biopsy's on ribs specifically give false 'negatives'.

He wants me to start ADT immediately and radiate the rib.

I took a fall a few weeks ago, and think I might have bruised my rib....

Is there any chance this is NOT cancer? how do I confirm the diagnosis?

Any help is appreciated as I head back into the abyss.......

[Steel67]

do you know what your standard uptake value was? The lower the less likely to be malignant as inflammation or degenerative changes may show up….like 1-2.0 …. but you really don’t know and wont be able to tell for sure. If low, and not accompanied by a rising PSA, those might be indicators in your favor.

You can find retrospective studies online, with associated SUV and % malignant.

Good luck!!

[dudubaya]

The SUV uptake value could give a clue, anything in double digit or high single digit would be a strong indicator. However since you already have the PCa elsewhere and the report has been signed off by a radiologist the likelihood of it being false positive is rather low

[GP24]

A single bone met on a PSMA PET/CT is often a false positive. If it does not show up on a bone scan I would not start treating it.

[Seasid in reply to GP24]

I totally agree with you.

[Tall_Allen]

NaF18 PET/CT

[icanwintwice in reply to Tall_Allen]

If your referring to the kind of Pet, not sure. I think standard PMSA deal. Had it done at MD Anderson...

[icanwintwice in reply to icanwintwice]

trying to get a copy

[dhccpa in reply to icanwintwice]

He may be suggesting you run that type of PET scan also, but check with him.

[icanwintwice in reply to dhccpa]

thanks....checkin on the type of Pet Scan that they use

[dhccpa in reply to icanwintwice]

I think the NaF 18 may also be called a PET Bone Scan

[icanwintwice in reply to dhccpa]

yea...where do you find one of those! rats

[dhccpa in reply to icanwintwice]

I think any major scan center can run them. The very first PET I had after being diagnosed back in 2018 was a PET Bone Scan. They've been around a while.

[icanwintwice in reply to Tall_Allen]

PetCt F18 PSMA Pyl (piflufolastat)

[Tall_Allen in reply to icanwintwice]

NaF18 PET/CT detects twice as many metastases.

[EdBar]

I had a PSMA twice about a year apart when my PSA ticked up to 0.2. Each time it showed a met on a different rib and each time I treated it with SBRT and PSA fell back to nearly undetectable. In both cases it was cancer. Yes ribs can sometimes have false positives, in my case it was cancer. I’ve been heavily treated and on ADT for close to 11 years now since dx. Ribs are usually one of the easiest places to radiate btw.

Ed

[icanwintwice in reply to EdBar]

Wow. a lot of experience with this disease. Your input on this site is invaluable.. I too was a patient of Dr Myers. thank you for your input on my situation. Not currently on ADT, and MD Anderson wants to SBRT the rib and put me back on ADT.... I think Id like to hold off on the ADT until I see what happens to my PSA. But still not sure about whether or not the rib is a bruise or a met.....most likely its a met,,,,,,but if its not then I don't want to go back on ADT

[janebob99]

I, too, had a hot spot on a rib from a PSMA PET scan. Then, I compared it to a CT scan from 10 years before, which showed a a lytic lesion/cysts in the middle of the rib bone from bruised rib from high school football. I had three MO's/RO's evaluate the reading, and all three concluded that the PSMA hot spot was not cancer, but, rather an artifact of the rib lesion. N=1.

[icanwintwice in reply to janebob99]

thanks for the input....I guess the only way for me to determine whether this is a met or not is to do an MRI, because I don't think biopsies are conclusive...

[janebob99 in reply to icanwintwice]

CT scan would be better for diagnosing a rib (bone) problem. And, a lot faster.

[NanoMRI]

I have done a lot of different imaging over past ten years. Regarding 'false positives' I still wonder how these are defined and confirmed? Do two independent radiologist affirm definitive cancer then by some other means not cancer is proven?

I find second independent opinions and comparative imaging important. Noting with MDA my understanding is multiple internal opinions happen (I had imaging with them earlier this week).

For each of my three treatments I have done them without ADT and waited for uPSA testing to affirm treatment outcome.

[RoseDoc]

It could be a false positive, then again, it may not be. Did you hurt that area of the chest when you fell? A plain CT could settle the argument. If it is still suspicious, I would follow your MO's advice.

[icanwintwice in reply to RoseDoc]

thanks for the advice...fell on my side in that area. they are putting me on ADT indefinitely so I want to make sure...