PSMA pet scan

[mountain6]

Has anyone had a Pylarify (PSMA) pet scan showing no prostate cancer spread but knew that you had some metastasis in at least one lymph node (seen in an older scan and confirmed by biopsy). I know that there are people who are PSMA negative...not sure if my husband is one. He has had a prostatectomy, radiation and one period of Lupron over the course of several years. The PSA is increasing (in the teens), but again, no sign of metastasis on the scan.

[NanoMRI]

As I share, at PSA 0.11, while a Ga68 PSMA was clear, the Ferrotran nanoparticle MRI (unfortunately, only in Europe) identified five suspicious lymph nodes; six confirmed by surgery.

This coming Tuesday I have a biopsy of a liver lesion identified by Pylarify PSMA PET, at 0.033. Hoping it is benign - but relentlessly unwilling to give this beast time and disparity.

[MBACHE in reply to NanoMRI]

Can you please comment on where you had the Ferrotran MRI performed.

[NanoMRI in reply to MBACHE]

This is the organization - splmed.com/english/ferrotran/. Mine was done by Radboud UMC trial - no longer available.

[MBACHE in reply to NanoMRI]

Thanks much many years ago I had something similar at Sand Lake Imaging in Florida. Mets were found above my pelvic region which had been radiated. These Mets were then radiated.

[Tall_Allen]

It only has 40% sensitivity.

[Jpburns in reply to Tall_Allen]

Can you give us some details. That’s kinda depressing and scary.

Googling shows me something more like 91%.

[Tall_Allen in reply to Jpburns]

You may be confusing "detection rate" with "sensitivity." Detection rate is the ability of a scan to detect any positives at all.

Sensitivity= true positives/(true positives+false negatives)

It's relative to your expectations. If you think that it's showing you everything, I can see why it's "depressing and scary." If you know from the start that it's only an indicator, it's very good.

"In this multicenter prospective phase 3 diagnostic imaging trial in 277 patients with intermediate- to high-risk prostate cancer prior to prostatectomy, the sensitivity and specificity of 68Ga-PSMA-11 PET for the detection of pelvic nodal metastases compared with histopathology on a patient level were 0.40 and 0.95, respectively. This academic collaboration is the largest to date and formed the foundation of a New Drug Application for 68Ga-PSMA-11."

jamanetwork.com/journals/ja...

BTW- that's for 68GaPSMA detection of pelvic lymph node metastases. For bone metastases, it only detects half the number of metastases compared to NaF18 PET/CT.

[Jpburns in reply to Tall_Allen]

Can you simplify that even more so that someone brain-fogged can grasp it?

[Tall_Allen in reply to Jpburns]

A PSMA PET/CT only detects 40% of the pelvic lymph node metastases that are there.

[Jpburns in reply to Tall_Allen]

Ok. So now I am bummed out.

I took some comfort in my last PSMA test months after my RT that said: “There is no abnormal radiotracer uptake on this examination. The left external iliac node identified on 12/14/2023 is no longer present. The radiotracer uptake within the prostate has resolved.”

Are you saying that was bullshit?

[Tall_Allen in reply to Jpburns]

It is meaningless. There is no reason to take a PSMA test unless you have a biochemical recurrence.

[Justfor_]

Will give you an analog so you can understand because there is much nonsense among people who "think" in a binary manner. You are in the space station and looking at the night hemisphere of earth. You can distinguish the big cities even the smaller towns from their light pollution. Between them there are stretches of dark land. No, you are not above Sahara dessert, they are rural areas and you know that there are houses here and there and also it's not bed time. So, why can't you see their kitchen lights? Think about it and you will have mastered the PSMA PET imaging without any pompous terminology.

[NanoMRI in reply to Justfor_]

Good analog. I learned a few years back this imaging begins as soon as 0.03 in Europe - which is well ahead of US with PSMA (easier for private patients of course). The hope is the remaining cancer is in just a couple of nodes or bone spots. This of course is very informative for the (fewer) men that have this 100% imaging success. And again, I had six pelvic mets at 0.13 - so to say there is no concerning cancer at this PSA value is incorrect.

[Mrtroxely in reply to Justfor_]

Hah.That made me snortle

[dhccpa in reply to Justfor_]

But the question was different, wasn't it, in the OP? Why would the PSMA show less spread than earlier, less accurate scans?

[Justfor_ in reply to dhccpa]

It isn't clear if there was any treatment between the two scans.

[dhccpa in reply to Justfor_]

That could be important.

[mountain6 in reply to dhccpa]

The axumin scan was done in 2019. He had had surgery and radiation in the years prior. He had one 6 month treatment with Lupron injected a couple of months after the scan. PSA came down after the Lupron but then gradually increased to the teens. He has had no further treatment but regular PSA tests, but the number is getting high. The last PSMA scan was done several months ago. We know that the lymph node was not treated as it was in an area too dangerous to radiate.

[dhccpa in reply to mountain6]

Yes, it's curious. Based on my own experience, the PSMA scan seems just to be another tool in the toolbox, rather then the be all and end all of scans. It's been very heavily promoted as the best, though.

[Justfor_ in reply to mountain6]

At low PSAs, (gathering that by "teens" you mean some value of 0.1x as opposed to tenths that is 0.x) a short PSADT is important for a PSMA detection. Combining this with the 3-4 years that passed since stopping Lupron to the PSMA scan, his PSADT looks long enough. Under these circumstances (low PSA and long PSADT) PSMA scan has low detection rate. But I may be wrong at interpreting the pieces of information you have provided. For example I have dismissed the idea that the "teens" are 13 to 19 and you hadn't taken any action 3-4 years now.

[mountain6 in reply to Justfor_]

Actually it is 15 but has gone up very gradually with a couple of periods of actually decreasing. The doctor was comfortable taking no action in part because of the scans.

[Justfor_ in reply to mountain6]

Unspeakable of a doc! Don't have the exact numbers now, but at a PSA of 15 the PSMA scan has, or is close to, the highest detection rate of the order of 94-96%. That means that there are PCa strains not detectable by that imaging. Seems to me you have one of these.

[Runner1957]

My psa is rising after previous prostatectomy, radiotherapy and adt sometime ago. Low levels but PET scan with psa at 0.53 showed nothing. Now waiting on another PET scan with psa around 2.0. Similar thing happened with previous recurrence when I needed a 2nd scan a few weeks later for it to show anything.

[JolleySprings]

Absolutely yes, You can have metastasis which does not how up on PSMA. My husband has had 4 and Nothing ever showed up even at a PSA of 8.

But doc kept doing them until I insisted on an Auxium Scan when his PSA reached 45! It came back with several lymph nodes lit up in the retro peritoneal abdominal area. 😩 PSMA never picked it up. After 7 years of various ADT Drugs and 39 rounds of radiation (when first diagnosed right after RP) we are now at Chemo (Docetaxel) Drastic reduction after first 3 rounds… from 47 down to 18! We were so encouraged. Two days ago had infusion and PSA went up a point to 19.7 Next week we are having an Auxium scan. This is such a roller coaster ride!

[Kittenlover50]

you didn’t say what the PSA was. Often it needs to be .4 or above for the PSMA to pick it up. Our doc wanted to wait till .4 or .5 but did do at .33 and something did show

[mountain6 in reply to Kittenlover50]

His PSA is 15

[mountain6]

That is interesting because my husband was told that the PSMA was more accurate that the Axumin scan. But it was the Axumin scan that picked up the cancerous lymph node originally. He will probably be asking for the Axumin scan next time...

[dhccpa in reply to mountain6]

I had 4 Axumins from Jan 2020 to Jan 2024 before having the PSMA scan in July.

My MO is somewhat dismissive of Axumins, but I'm not sure what he knows. My RO seems to struggle with questions about the differences between scans. And the radiologists just work around it in their written reports, never saying why they're different (maybe they don't know). But I keep researching and asking.

I've never had an FDG PET scan that TA has mentioned in numerous occasions.

[dhccpa]

In July I had my first PSMA PET scan. I thought certain it was a Pylarify until I received the report; it appears to have been a Ga-68, another version.

And yes, it showed no abnormal uptake outside the prostate gland. I was diagnosed in August 2018 as metastatic (3 bone Mets) based on a nuclear bone scan. Since then, I've had multiple CT scans, another nuclear bone scan, 5 pets scan (1 PET Bone Scan and 4 Axumins-last Jan 2024)--all showed at least 3 bone Mets, possibly up to 10.

So yes, I and my three docs who thought PSMA was/is the gold standard have been scratching our heads. It's opened up the possibility of radiation for me; radiation has never been an option.

[ron_bucher]

a radiologist missed my tumor visible on PSMA scan at PSA 0.45

An axumin scan is usually done if PSMA scan doesn’t show any tumor with PSA greater than 1-2 after prostatectomy.

[gsun]

You should get an FDG PET scan. Maybe a lot of the Mets are not expressing PSMA.

[sammittman]

Yes, I have had the same experience with my prostate cancer. I was diagnosed and had surgical removal in 2007. I've had detectable PSA every since then but fairly low. Recently had it shoot up to over 12 and the PSMA scan shows nothing. Guess I'll just keep living until some doctor tells me it's over.

[Soton4ever]

It took years after my dads surgery before they found metastases. During treatment his psa went up and down, never very high, and metastases were small when they eventually found where they were.

[bean1008]

yes I had three years of Lupron and Zytiga and had a PSMA Pylarify scan. Older scan three years prior showed two lymph nodes affected and one lesion in my hip socket…but the new scan showed everything was gone and I was declared cancer free. At least for now!