Thread by @TylerSbrt

PRIMARY: is Ga PSMA PET useful beyond mpMRI for diagnosis of #ProstateCancer?

MRI -> MRI+PSMA: avoid 22 unnecessary biopsies but add 17 false+, so only really spare 5/291 men by adding PSMA.

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Really great study by @drlouiseemmett is worth a close read.

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sciencedirect.com/science/articl…

@EUplatinum

PRIMARY eligibility criteria: pts needed a biopsy *after* MRI already interpreted.

If PI-RADS 2, had high clinical suspicion.

No PI-RADS 1 included.

Not all comers. Study objective to look at *adding* PSMA to MRI.

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PSMA PET was only covering pelvis to avoid extra radiation exposure.

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NPV (primary endpoint) improved by adding PSMA PET to MRI in this *high-suspicion population* with *template* biopsy (median 33 needles): 72% -> 91%.

But *worse* specificity: 53% w/MRI -> 40% w/both (p=0.01). PSMA did not improve PPV.

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Even w/ MRI and PSMA PET together, you still miss a few grade group 4-5 cancers.

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You win some, you lose some.

A-B) PSMA+ and PI-RADS 2
C-D) PSMA- and PI-RADS 5

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Bottom line: PSMA provides complementary information to mpMRI in the primary diagnosis of #ProstateCancer.

Might be useful for tricky mpMRI cases. Need to integrate w/ PSA density, etc.

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Definitely still need mpMRI for #ProstateCancer!

Advanced diffusion MRI likely going to help here.

We are working on this! More to come! @UCSDHealth @UCSDImaging @UCSD_Urology @UCSDRadMed

onlinelibrary.wiley.com/doi/10.1002/jm… @jmri_ismrm

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