Latest Pylarify clear with PSA at 4

[V10fanatic]

I just had my 3rd PSMA-PET, and was relieved but surprised that it was totally clear. I had expected mets similar to my 1st one which was also run at a PSA of 4. BTW, the Axumin scan was clear at that time. I've been on an ADT/Zytiga vacation for about 18 months. My PSA did become undetectable for a while beforehand though. It's been rising for about 14 months now with an approximate 6 month doubling time. My T has been in the 500+ range for about a year.

Is it odd to have a clear PET with a PSA at this level? I'm meeting with both my Oncologists next week, so I'm trying to get some background before we speak. Needless to say, my vacation is unfortunately over. Time to pack my bags and head to the airport for my 1 way ticket to Castrationville- ugggh.

[Tall_Allen]

PSMA PET sensitivity is only about 50%, meaning that it's a coin toss whether a tumor will be a true positive or a false negative.

[tango65 in reply to Tall_Allen]

With a PSA of 4?

[Tall_Allen in reply to tango65]

The sensitivity in high risk patients was 40% with a median PSA of 9.7 for pelvic LNs.

[V10fanatic]

With the 50/50 chance, isn't that why a concurrent CT is run so that any potential hot spots can be scrutinized in further detail?

[tango65]

The sensitivity of Pylarify to detect metastases outside the pelvis is 90% or higher with the PSA you have.

ncbi.nlm.nih.gov/pmc/articl...

The cancer metastases may not be detected if they are smaller than 4 to 5 mm depending of PSMA expression. PSMA PET/CT have a lower detection rate than histology, since histology can detect very small mets beyond the axial resolution of a PSMA PET/CT scanner.

Pylarify