PSMA PET Scan result - false positive... - Advanced Prostate...

Advanced Prostate Cancer

22,277 members27,978 posts

PSMA PET Scan result - false positive bone lesion?

Daddysgirl83 profile image
50 Replies

My fathers PSMA PET scan ( at 0,23 psa) came back! Its been 9 months after surgery and PSA is around 0,18-0,25 and fluctated down at times.

Everything was clear but a suspected bone lesion at L3 was found. The dr seem to think its false positive and said its probably nothing. We should just monitore PSA. I asked about other scans but he said its pointless at this PSA. They are discussing his case at the conference.

Dad has had some disc problems and arthritis (MR done after surgery -5 months ago) but nothing about bone lesion was ever talked about.

I have a hard time letting this go, of course dad was relieved. His PSA declined and is at 0,20 now.

What do you think?

Written by
Daddysgirl83 profile image
Daddysgirl83
To view profiles and participate in discussions please or .
Read more about...
50 Replies
Justfor_ profile image
Justfor_

There have been numerous reports here and elsewhere about PSA fluctuating ranges (I call them "bumpy"), mine included. The most usual range is around 0.15, although 0.18 has been also mentioned. Seems that your father's is a bit on the high side. Mine, as you can see from the graph, was on the low side. My experience is that it will assume a monotonous trend given some time.

0.10 to 0.15 is the "bumpy" range
Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Thank you! I am wondering if the bone lesion that was suspected is a real bone lesion or not. Should we do another Psma Pet scan at 0,4?

Justfor_ profile image
Justfor_

I am updating his PSADT excel file. Two things:

1) Are you sure that this was a 2 decimal places report, i.e. 0,20 - NOT 0,2?

2) Blood draw date?

Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Hi

Thank you so much! Much appreciated.

The latest PSA was 0,20 ( 2 decimals). The date was 20 sep 2023.

Justfor_ profile image
Justfor_ in reply toDaddysgirl83

I have read here that isolated bone metastases, especially to the ribs, bare a high probability of being false positives. Your father's is in his spine which is a common place for such things to start from. The good thing is that now you have a baseline for future comparisons. At this point, I wouldn't do something more than wait for 3 consecutive monthly PSAs all of them trending upwards. A sequel PSMA pet scan is the logical scan to follow, the question arising here is under which conditions. I can see two options:

a) As you suggest, wait until PSA doubles where the detectability of the imaging becomes higher. Drawback is the progression made by then .

b) After taking ADT for a while. In such a case, if the suspected detection gets smaller or disappears altogether then there is high probability that it was a true positive. If it stays the same, then it is a false positive. Extra bonus is slowing up progression.

My vote goes to b)

PSADT (months)
Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Thank you so much! I really hear you but by taking for an example Casodex I think PSA will surely go down and then I dont think they will let us have a PSMA Pet Scan to see further. They are claiming next time to do PSMA Pet Scan will be around 0,4.

Our main issue was whether go for salvage radiotherapy or not. Now we are not only thinking about this, we are also thinking about metastasis. 🤯

Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Hi again

One more PSA test added for dad, its 0,22 now in 18 October.

Maybe if you have time to put it in the sheet? 🙏🏼

Justfor_ profile image
Justfor_ in reply toDaddysgirl83

Will do it tomorrow as it is late now, but it is obviously VERY GOOD news.

Justfor_ profile image
Justfor_ in reply toDaddysgirl83

Please note the convergence in PSADT that the latest PSA reading brought:

a) PSADT when 1st PSA (<0.1) is included increased from 7,3 to 7,6 months, i.e. ~+4%

b) PSADT when 1st PSA (<0.1) is omitted decreased from 18,8 to 16,3 months, i.e ~-13%

As more time samples get added these two PSADTs will converge even further.

October 2023 picture
Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Thank you so much!! 🙏🏼

Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

New PSA update!

20th Nov 0,23 🙏🏼

Justfor_ profile image
Justfor_ in reply toDaddysgirl83

Little by little, his PSADT stretches longer and longer. And with each additional count that initial <0.01 seems more and more bogus. Three months ago my response to your first post was: "Five to six monotonously increasing two decimal places results are needed for deriving a no-nonsense PSADT in order to filter out the 20% precision of the test by implementing oversampling. You only have 2 (0.18 and 0.19) for the time that look consistent. You need more." Now is your and yours father time to enjoy!

Daddysgirl83
Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Thank you ❤️❤️ I cant quite relax yet feel like I want to see that - it doesnt increase for a whole year. 🙏🏼

Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

We have a new labresult. He waited 2 months this time 8/1/2024 - 0,26.

Can we still be sure that the double time is very slow and maybe there will be no need to do anything? 🙏🏼 Thats what the dr are saying.

Justfor_ profile image
Justfor_ in reply toDaddysgirl83

Happy New Year Daddysgirl83,

As the song has it: "First we take Manhattan, then we take Berlin". What I mean with that? First we check the consistency of our previous PSA analysis/simulation and after doing this we include into the mix the more recent sample. So, extrapolating the last number crunching to the 8th of January, this is what we get.

From this exercise we can deduce the following: The first "undetectable" PSA (<0.1) isn't consistent with your father's later PSA trajectory. A more realistic projection (0,247) can be obtained by excluding it from the input time series. (to be continued as I can upload just a single picture per post).

Extrapolating (projecting) November's 2023 picture into January the 8th 2024
Justfor_ profile image
Justfor_ in reply toJustfor_

Here is the updated table. PSADT has shrunk from 16,7 to 13,9 months not to anyone's surprise when the precision of the PSA test and the reporting to only two decimal places are considered. The time origin (t=0) is the day of the first PSA test and not the day of RP. There is no difference to where the t=0 may be placed, as long as all subsequent samples are synced correctly with it.

As to your question now, I am afraid I shall not agree with your doctors. Albeit, a long PSADT, your father's numbers show a monotonously rising uptrend. There is no random movement. There is definitely something brewing inside. It is not prudent to let it rise at large. Check what I have been doing for two years now to keep mine at the lowest limits of detection with a minuscule dosage of Bicalutamide:

healthunlocked.com/prostate...

Updated table 10/1/2023
Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Thanks! I understand what you are saying and noted that the days doesnt matter. However let me add that the first psa test he did was actually 0,25. then they wanted him to do another one week later and that one was 0,18. If the first one wasnt a lab error, it means his PSA has fluctated around same numbers these months.

I will look into your suggestion of bicalutamide. 2 different dr here are saying no need to do anything til the psa is at 0,40 then another psma pet scan and possible medicine and radiation.

Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Hi

Updated PSA tests from Dad 🙏🏼

25/ 1 / 2024 - 0.23

22/ 3 / 2024 - 0.30

I guess its rising now. 🙁

He is supposed to take another test end of April to see if 0,3 is still accurate.

I also want to add that the first test was 0.25 - the date was 26/6/2023. And a couple of days later 0.18.

Justfor_ profile image
Justfor_ in reply toDaddysgirl83

I have updated the list with thw two newer 2024 tests and also squeezed in the 0.25 on 26/6/2023. You may notice that I didn't take into account this entry at the two extreme right columns, as it leads to a PSADT of 16.5 months which looks very optimistic to me. But, it is included in the two left columns and its presence counterbalances this dubious <0.1 on 4/3/23. Now, the bottom line is that there isn't any chance that PSA will not rise with time for anybody not in treatment. The question is at which rate this rise occurs. Your father's 13+ months of doubling time, places him at the moderate to favourable side on the aggressiveness scale.

Updated PSADT
Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Thank you very much for this 🙏🏼

Fingers crossed that doubling time is more than 13-14 months 🤞🏼

Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Hi

Dads other dr wanted him to leave another PSA today and we got the result now. It went down after almost 1 month.

16/4 2024 - 0,26

Guess more confusing data! If you add this one to the column, what does that say ?🙏🏼

Justfor_ profile image
Justfor_ in reply toDaddysgirl83

Crossing your fingers did the trick. Congratulations!

If you look at the previous results the estimated PSA for the 22/3/24 draw differed from the measured (0.28 vs 0.30). Remember me asking whether it was 0,30 or 0,3? I did so because 0,30 didn't fit the bill while a rounded 0.2x for x>5 did.

After the latest results I will go a step further. Linear and exponential regression coefficients are converging together. This is the exact opposite behaviour of an aggressively proliferating cancer where the exponential one fits better the curve than the linear. Thus, it is is of no surprise to me that both PSADT (the dubious and my preferred one) had been boosted handsomely.

Please give your Dad's cheek a BIG kiss, on my behalf.

Daddysgirl83
Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Thank you so much!!! Dad says hello and is very grateful that you can navigate us! ❤️ We are sitting still in the boat with fingers crossed. 🛶

Justfor_ profile image
Justfor_ in reply toDaddysgirl83

Tell him that we have a "Daughter81" and that explains all. Best regards.

Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

❤️❤️❤️

Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Hi! Hope everythings is fine with you 🌻 Just wanted to stop by and say that dads July PSA test ( 12th of July) showed 0,26! 🙏🏼 We are happy its stabile. But I keep wondering what this means.

Justfor_ profile image
Justfor_ in reply toDaddysgirl83

If stable without being on any medication, anything cancerous in there is entering a remission phase. No guarantee about the future, but no less the best thing one could hope for. Cross your fingers that it will last for veeery long. Will inform you about his PSADT elongation, but being at 20 months last time, he was already with the "do nothing but monitor" club.

Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

Thank you! I appreciate your wisdom so much ❤️

Justfor_ profile image
Justfor_ in reply toDaddysgirl83

Certainly no "wisdom", only happy to be useful. Knock on wood, your father is doing great.

Daddysgirl83 July 2024
Daddysgirl83 profile image
Daddysgirl83 in reply toJustfor_

🙏🏼❤️

Tall_Allen profile image
Tall_Allen

I agree that his PSA was too low for the PET scan and you were ill-advised to get it before PSA reached 0.5.

Daddysgirl83 profile image
Daddysgirl83 in reply toTall_Allen

Maybe you were right! Confusion and still in limbo land! ☹️ His dr seem to think that the suspicious spot is no concern.

Tall_Allen profile image
Tall_Allen in reply toDaddysgirl83

It depends on several factors: SUVmax, background uptake levels, and CT or MRI correlates.

Daddysgirl83 profile image
Daddysgirl83 in reply toTall_Allen

I dont have the full report yet. MR havent shown anything ( a couple of months ago) just bulging discs in that area. CT - they havent done one and when I asked they said its not necessary right now. Given his 3+4 and 3+3 gleason score they think this is highly unlikely. Still how can one be sure? They showed us on the computer that the area was not very yellow and very vague in color, they had noted possible met? Some sclerotical changes in that area was seen but that could be normal. They are discussing this in a conference to see if we should further with another type of scan, but the dr was not worrisome at all.

Tall_Allen profile image
Tall_Allen in reply toDaddysgirl83

It sounds like a false positive. But the anxiety it caused shows why they made a mistake giving him the scan at all.

Daddysgirl83 profile image
Daddysgirl83 in reply toTall_Allen

Hope so 🙏🏻 Yes you are right, especially now when PSA went down from 0,23 to 0,20

Daddysgirl83 profile image
Daddysgirl83 in reply toTall_Allen

The Conference answer was that it is highly likely false positive. Nothing more to do than monitore PSA and if it hits .40 do another PSMA, they said.

dhccpa profile image
dhccpa in reply toTall_Allen

Thanks, I was thinking that had been your earlier advice

plato123 profile image
plato123

Do you know the SUVmax from the report?

Daddysgirl83 profile image
Daddysgirl83 in reply toplato123

I dont have the full report 🙁

TCMG profile image
TCMG

You may want to consider sending the PSMA PET scan to another specialist for a 2nd opinion. I don't have any specialist names in mind though but members in this group may have. Alternatively wait for the conference discussion result which serves as a 2nd opinion. When is the conference?

Daddysgirl83 profile image
Daddysgirl83 in reply toTCMG

Conference is next week! Another Radiologist will be there also for second opinion.

MateoBeach profile image
MateoBeach

If it “lit up” on PSMA scan then I would not be so quick to write it off as false positive without some other evidence. His PSA is not undetectable so presume there is some remaining cancer somewhere. If it is just the one bone lesion then it could be treated by targeted SBRT. I would request a high resolution MRI scan of that area and also consult a good radiation oncologist. Insist upon it!

Daddysgirl83 profile image
Daddysgirl83 in reply toMateoBeach

First my thought aswell! He did a MRI 4 -5 months ago and it was stated that bulging discs and some arthrithis in that region and exactly in place L3. I really feel if its something we want fast SBRT and ADT. But his Mo was so calm and said “I will consult others on conference. But I really think that unless PSA climbs more nothing is needed. “

He said his gleason score ( 3+3 and 3+4) is not likely to behave this way.

Jewelrylady profile image
Jewelrylady

my husband’s PSMA scan showed he had a focal uptake on 10th rib and probably left side of L1. Probably??? His radiologist did not think it was necessary to radiate it. I hope that was right decision, and we’ll have to wait and see when he gets next PSMA. I have heard that PSA is not as accurate if PSA is less than .50. It’s currently 0.15. I think I’d rather have it stay at 0.15 than start climbing so he could get another PSMA scan. But I also understand wanting another scan!

Daddysgirl83 profile image
Daddysgirl83 in reply toJewelrylady

Feel you sister! One just feel so helpless and the waiting part is taken a toll on me. Alot of anxiety. Since July ( 6 months after surgery) his PSA been fluctating from 0,18-0,25 and back to 0,20. His Mo said he have seen alot men having PSA around this number and it has been nothing. Never climbing more. I really really hope that for my dad and your husband. 🙏🏼

Jewelrylady profile image
Jewelrylady in reply toDaddysgirl83

Helpless describes it perfectly! And waiting for test results is no fun. It sucks! I try to do what I can to be positive and hopeful - I trust his doctor; his PSA and testosterone are where they’re supposed to be; he did ok with his radiation so far; we got hooked up with a pharmacy (BioPlus) so he doesn’t have to pay anything for his Zytiga; we have been to two support groups that have been helpful; this group has been so supportive. It’s the “what ifs” I need to stay away from!

Daddysgirl83 profile image
Daddysgirl83 in reply toJewelrylady

F*ck the what ifs! I totally resonate. Sending you love!

j-o-h-n profile image
j-o-h-n

How old is your Dear Daddy? (if you respond to this, then please add his age to his bio section)..

BTW Here in the US Asterisks (*) are usually replaced by the letter U, hence F*ck in Sweden is spelled Fuck here in the US.....

Give my Regards to your Dad and keep away from Ikea meatballs....

Good Luck, Good Health and Good Humor.

j-o-h-n Friday 09/29/2023 6:40 PM DST

Daddysgirl83 profile image
Daddysgirl83 in reply toj-o-h-n

63!

I know 😄

Not what you're looking for?

You may also like...

Plan after PSMA Scan

So here is what the UCSF doctors decided. Trying to figure out how to feel. PSA is now down to...
JWPMP profile image

Bone scan. Thoughts?

My dad just had his second bone scan following completion of 6 rounds of docetaxel. PSA has fallen...
mediocra profile image

PSMA PET Scan - Help Interpreting Report?

Hello, My husband had his first PSMA PET scan done today, and I am hoping someone who understands...

First PSMA PET scan and aftermath

My oncologists (medical and radiation) had been pushing me to have a PSMA scan for two years. Even...
dhccpa profile image

18F-DCFPyL PSMA PET/CT Scan Result

The result (other than typical) from the 18F-DCFPyL PET/CT Scan on 12-21-2018 at NIH found:...
Moespy profile image

Moderation team

Bethishere profile image
BethishereAdministrator
Number6 profile image
Number6Administrator
Darryl profile image
DarrylPartner

Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.

Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.