PSMA Scan Nomagram

Stephen S

Veteran Member

Joined : Oct 2019

Posts : 740

Posted 4/19/2021 8:49 PM (GMT -5)

I found this in my travels yesterday

It calculates the chance of a psma scan detecting a lesion given some parameters.

https://www.evidencio.com/models/show/2063

The only parameter I didn't understand was ISUP..... but the higher it is the better chance of detection.

DjinTonic

Veteran Member

Joined : Dec 2019

Posts : 2546

Posted 4/19/2021 11:55 PM (GMT -5)

It's the Gleason Grade Group (1-5) for your Gleason score as adopted by the International Society of Urological Pathology (ISUP). Beats me why they didn't call it that.

GGG 1 = GS 6 (3+3) or less
GGG 2 = GS 7 (3+4)
GGG 3 = GS 7 (4+3)
GGG 4 = GS 8 (4+4) , (3+5), or (5+3)
GGG 5 = GS 9 (4+5), (5+4) or GS 10 (5+5)

When I ran hypothetical PSA and DT numbers for me: GGG 5, PSA 0.75, DT 6 mo., no ADT, >12 mo. to BCR, and 1st time BCR, I get only a 34% chance of the scan locating any lesions. It goes up to 85% with a DT of 3 mo.

I'm not understanding why DT has such a big effect for a given PSA.

Djin

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