Another PSMA scan Question...

[Shooter1]

I'm new to PSMA scans and have some questions... My scan of Tuesday doesn't show the mets that we were treating from old scans. It does show three mets that weren't on the old regular scans. Does that mean that the old mets were resolved and these are all new mets?? We quit the Xofigo and radiation treatments acct scans showed new mets that didn't show on PSMA scan. Did former treatments actually resolve old mets?? Are new ones maybe treatable by the old treatments if we go back to them?? Or do the old mets not exhibit PSMA ?? Should I get standard scans again to see if my old mets are still there?? Comparing apples to oranges can be a bit confusing, esp. when someone throws in a banana.

[Seasid]

Did you have a 68 GA PSMA PET scan?

[Shooter1 in reply to Seasid]

Yes. 68 GA.

[Seasid in reply to Shooter1]

I also had it on Thursday (less than 2 days ago).

The radiation oncologist ordered it in order to see if I have some actionable active mets so we could maybe SBRT them.

My last PSA was 2 weeks ago 1.25 and rising.

I still don't know my scan results as I have an appointment on Sunday with my PCP.

I tested my PSA on Wednesday and I also waiting for the urine test results from the urine sample from Thursday.

Interestingly the focus of the scan was my prostate as I have some issues with urinating.

Until now I only received Firmagon injections and early chemotherapy 6 cycles of Docetaxel. It was more than 4 years ago.

They also gave me a contrast with the PSMA PET/CT in order to see my lymph nodes. I don't know why as I believe that the PSMA PET scan part should be more than enough to see my active lymph nodes? I am confused. I know that the CT scan contrast would pick up even the PSMA negative lymph nodes. Maybe that is why I had to have a CT contrast injection. After that contrast injection you feel warm and it can be dangerous if you get allergic reaction to the contrast.

Did they also inject you during your CT scan part with the CT contrast to see better your lymph nodes?

It is possible that your cancer converted into a PSMA negative cancer?

The PSMA PET scan only shows the PSMA positive cancer.

István

[Shooter1 in reply to Seasid]

No CT contrast...

[Shooter1 in reply to Seasid]

Yep, only PSMA positive show. Now regular scan and CT to see if neg. present....

[Tall_Allen]

You've put your finger on why patients should always track progression using the same scan. No one can answer your questions. I suggest you ask your MO why he ordered it.

I recommend having a new scan done using the same scan you had before. If you had NaF before, it's twice as good at finding bone metastases as the PSMA PET scans. Newer isn't always better.

[Seasid in reply to Tall_Allen]

Good point.

[Shooter1 in reply to Tall_Allen]

I had a NaF-18 scan before when PSA was climbing and no mets showed on standard PET/CT. PSMA acct trying to get in line for Lu-177 treatment. Now I can get on the waiting list for treatment.

[Tall_Allen in reply to Shooter1]

Makes sense. you can use it to qualify for Pluvicto, but you can't relate it to anything previous.

[Seasid in reply to Shooter1]

These are the current clinical trials with the new J591 Lutetium and Actinium:

clinicaltrials.gov/ct2/resu...

I am not sure if you would qualify. You should go through all the inclusion and exclusion criterias (you know best your situation, treatments, health status etc.)

Yup you can treat this like just another speed bump.

J591 is promising and you don't have to go to Germany to get Actinium (alpha emiter) treatment parallel to the Lutetium (Betta particle emiter).

Sorry I didn't go through the criterias for you so it may not be helpful for you, but this informatio about a current clinical trials with J591 could maybe helpful for someone else.

I believe that you are with Dana Farber cancer institute, if not you may wish to contact them regarding the clinical trials.

Have a great weekend.

István

[Spyder54 in reply to Seasid]

the J591 is what Mateo Beach had, but had to fly to Perth, Aus. NYC is closer. Mateo believes the J591 Ligand is more efficient at attaching to the PSMA on outer membrane of PCa cells for more complete annihilation of the bad cells.

Mike

[Seasid]

I really don't know. I also thought like you. The have a totally new Siemens PET/,CT with the remotely operated CT contrast dispenser.

Very good questions. Maybe the CT part was high resolution?

I had a CT contrast scan more than 4 years ago at my diagnosis before any therapy.

After my early chemotherapy I had a nuclear medicone bone scan.

I also had 4 x 68 GA-PSMA PET scans each 2 weeks apart at the start of Degarelix injections and just before the start of my early chemotherapy as a part of the study "ADT me" for professor Emmett in my local hospital in Darlingurst.

My original PET scans from more than 4 years ago where performed on the old Philips PET scan. I didn't get the CT contrast injection back then. I belive that the old Philips PET scan machine didn't have the remotely operated contrast injection feature. (But I am not sure).

[Scout4answers]

beyond my pay grade but sounds like a problem that you can deal with.

[Shooter1 in reply to Scout4answers]

Yep, just another problem or speed bump on my aPca trip.

[addicted2cycling in reply to Shooter1]

Scout4answera wrote --- " beyond my pay grade but sounds like a problem that you can deal with."

WAY BEYOND my pay and intelligence but doesn't each type of Scan have targeted expressions that it will identify and as such should be employed for future imaging of those identified mets looking for progression or regression and then add a new scan for others?

Shooter1 wrote --- "Yep, just another problem or speed bump on my aPca trip."

A *Speed bump* for one person/family can be a Mount Everest for another so GOOD LUCK as you navigate the terrain ahead.

[MateoBeach]

You are on the right track in your thinking Shooter: the "old mets" previously treated might be no longer expressing PSMA. This happens as cancer continues to evolve. So before presuming that they are completely resolved, I think it would be a very good idea to get an F18 FDG PET scan. Fluorodeoxyglucose becomes positive when the cancer begins to predominantly metabolize glucose. If there are FDG positive sites that do not correspond to PSMA positive sites (non-concordant), then Lu-PSMA (Pylarify) treatments would not be a good idea, as I understand it. Other treatments may still be effective.

[Shooter1]

Hoping for the best. I've had most other treatments and will have Done PSMA scan soon.

[Seasid]

What is the SUV max of your new mets?

[Shooter1]

SUV--what does it mean?? 9.5 for T1, 7.8 for femur, and 8.2 for sacrum. All info appreciated.

[Seasid in reply to Shooter1]

Tango65 said that the Hofman team concluded that the SUV of the mets should be at least above 10 in order have an effective Lutetium treatment.

You should see this SUV numbers in your 69 GA-PSMA PET scan report.

I am still learning.

I believe the minimum SUV number is also an inclusion criteria into the clinical trial. (I gave you the link).

I am still not ready myself for Lutetium or Actinium treatment but it is always a good idea to inform ourselves well in advance in order to be able to make an informed desission.

[Seasid in reply to Shooter1]

Here is a Google search result for the SUV value of the PSMA PET scans:

google.com.au/m?q=suv+max+P...

[Seasid in reply to Shooter1]

the uptake of 68Ga-PSMA, defined as maximum standardized uptake value (SUVmax), may differentiate the malignant from the benign lesions with a high accuracy

[lokibear0803 in reply to Shooter1]

These are very high SUV values, from what I’ve seen. SUV below 10 can be false positive. FTM I’ve had an SUV 34.7 that ended up false positive, but it was already suspect for several other reasons.

High SUV, as I understand it, is good — it means you will be very responsive to PSMA-targeted therapy. I’d strongly advise to check for discordant mets via FDG (et al?) before doing Lu-177, Ac-225, etc.

I have also found that, from scan to scan, some mets “resolve” and others appear. That mets have resolved does not mean they won’t reappear; e.g. my right seminal vesicle has come and gone multiple times over the years. But it does suggest the therapy you’ve used to get there is working well.

[Shooter1 in reply to lokibear0803]

Sorry about that.... see newly corrected SUV values... ranging from 7.8 to 9.5.

[lokibear0803 in reply to Shooter1]

OK, yeah, as I recall that might be considered suspect…this might depend on who do you ask, what other details of your situation to factor in, etc. Uh, above my pay grade.

[Shooter1 in reply to lokibear0803]

My paygrade may be climbing if I ever understand it all. The confidence score on all were 5. Trouble is I don't know if it is a 1-5 scale or 1-10 scale... Fully confident or kind of maybe 1/2 sure.

[Seasid in reply to Shooter1]

your SUV max values are too low (under10) to qualify you to the Lutetium PSMA therapy according to the Hofman team finding.

i am not a doctor. Ask Tango65 he is closely following Lutetium PSMA therapy.

[Spyder54]

Shooter, it is not just new to us, it is new to many many Radiologists. My gal68 PSMA PET last month was from a machine that is only 3 mos old. We may know more than many of the experts. I told my URO, and the Radiologist that my PSA was only .022, and that I have learned from discussions, and reading, that it is much more accurate with PSA above 2.00. He said, it doesnt matter because we are just establishing a base to compare future scans.

The ongoing human experiment continues. As TA said above “newer isnt always better”. Mike

[Shooter1 in reply to Spyder54]

Baseline scans are helpful at a later date for comparison..

[Seasid]

I found an interesting post from only 2 months ago about Actinium225 treatment in Turkey.

Just in case if you don't qualify in the USA.

healthunlocked.com/advanced....