At what PSA will a PSMA PET scan be useful?

[Rodeoz15]

Hi everyone

My father has been on Lupron for 3 years now. We stopped Abi last year due to rising blood sugar levels. His PSA used to hover between 0.6-0.8 (with an occasional spike to 1.2). PSA in May 24 was 0.6. Today, however, his PSA came back as 2.5.

Plan is to restart Abi and monitor. But I wanted to check when should we get a PSMA? Will a PSMA now be useful, or should be wait to see if restarting Abi helps? And when should be the next blood work? Is 15 day okay? His PSA seems to have increased 4x in 3 months, although it had 2xed in the past as well before going down again.

Last PSMA was in May 23 which was normal (bone mets but normal SUV values).

He is not a candidate for chemo.

Thanks!

[addicted2cycling]

just what I found --

pylarify.com/pca-imaging

**According to PYLARIFY, their PET/CT scan can improve prostate cancer disease assessment even when PSA levels are low. In general, PSMA PET scans are effective at PSA levels above 0.2 ng/mL. The detection rate for PSA levels below 0.2 is very low, but it increases to about 40% between 0.2 and 0.5 ng/mL. For PSA levels between 2 and 5 ng/mL, the detection rate is around 90% or higher.**

[Tall_Allen]

0.5 or rising rapidly is necessary for detection. But it doesn't sound like he needs it - he should restart abi regardless.

[GP24]

ADT suppresses the PSA value but not equally the PSMA expression. When you are treated with ADT you can get a PSMA PET/CT at very low PSA values. However, 2.5 ng/ml is enough in any case.

[NanoMRI]

How about 0.033 . My current Pylarify at this PSA has identified a 2.3 x 2 cm hypodense lesion on my liver - per radiology report "concerning for metastatic disease of uncertain origin ". This has been confirmed by 2nd radiology opinion and compared to Pylarify done two years prior and Ga 68 three years prior (those were clear). Further investigations are underway.

I learned over six years ago in Europe PSMA imaging beings with PSA as low as 0.03. I find clear imaging results very useful as I strive to stay ahead of this best. I am not willing to wait for higher values nor a fast rise rate. One reason is that I think waiting for many 'easy to find' mets gives this beast time and obscurity. Also, prostate cancer can change and reduces or stops producing PSA completely. When this happens serum PSA is no longer a good marker of cancer growth.

As another check on this beast I find liquid blood biopsies very useful; also at these very low uPSA values. Circulating tumor DNA can and does rise before the PSA increases. My concurrent GURADANT360 test has indicated a TP53 mutation - which can be from any number of cancer types. Last years GURADANT360 was clear.

Hope this helps with your father. All the best!

[EdBar]

After being undetectable for several years I had a PSMA scan performed when PSA reached 0.2. Both tomes it showed a met on a rib that I had radiated.

Ed

[dans_journey]

I had PSMA PET scans when my PSA was 0.22 ng/mL and 0.37 ng/mL, and both were inconclusive, not revealing the presence of cancer or metastases.

The chart above showing the effectiveness of PSMA PET scans at varying PSA levels came from this study:

pubmed.ncbi.nlm.nih.gov/309...

Color chart showing the effectiveness of PSMA PET scans at varying PSA levels