# PSMA expression by PET (PSMA-positive)

Source: https://onco.cc/biomarkers/psma-pet-expression/  
OnCo record `psma-pet-expression` (Biomarker). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

PSMA-positive means prostate cancer deposits light up on a PSMA PET scan more than the liver does. It is the entry ticket for lutetium-177 PSMA therapy and the basis of the imaging that now stages most advanced prostate cancer.

## Summary

Gallium-68 gozetotide (Locametz, Illuccix), piflufolastat F-18 (Pylarify) and flotufolastat F-18 (Posluma) image PSMA. The Pluvicto label requires selection with Locametz or another approved PSMA PET product based on PSMA expression in tumours; the VISION and PSMAfore trials defined positivity as at least one metastatic lesion with uptake greater than liver parenchyma and no PSMA-negative lesions above size limits (short axis 1 cm in soft tissue, 2.5 cm in nodes, or any measurable bone lesion with soft tissue component), and the label's clinical studies section repeats this. Pluvicto is now labelled for both PSMA-positive metastatic castration-resistant disease after an ARPI and, since 2026, PSMA-positive metastatic androgen pathway modulation-naive or -sensitive disease with an ARPI.

## Fields

- Kind: Biomarker
- Last checked: 2026-09-23
- Also known as: PSMA PET positive; PSMA-positive; PSMA expression; PSMA PET; Ga-68 PSMA-11 uptake; piflufolastat PET; PSMA-avid; PSMA uptake greater than liver
- Tags: biomarker; pet

## Notes

- Where PSMA sits in the body, from the tissue survey the imaging rests on: detectable in prostatic epithelium, duodenal mucosa, a subset of proximal renal tubules and colonic neuroendocrine cells, and undetectable in every other normal tissue including cerebral cortex and cerebellum; present in 33 of 35 primary prostate adenocarcinomas and 7 of 8 nodal metastases but only 8 of 18 bone metastases, with expression falling as tumours dedifferentiate (Silver 1997).
- What the scan changes at staging: in 302 men randomised before curative-intent treatment, PSMA PET-CT was 27% more accurate than CT with bone scan, 92% against 65%, with sensitivity 85% against 38%, management change in 28% against 15%, fewer equivocal findings, 7% against 23%, and less radiation, 8.4 against 19.2 mSv (Hofman 2020).
- What it changes at biochemical recurrence: recurrence was localised in 475 of 635 men, 75%, with detection rising from 38% below PSA 0.5 ng/mL to 97% at 5.0 or above, and positive predictive value 0.84 by histopathology (Fendler 2019).
- How many men it excludes from radioligand therapy: of 291 men screened for TheraP with PSMA and FDG PET, 200, 69%, were eligible, the rest excluded for PSMA-low disease or FDG-positive PSMA-negative sites (Hofman 2021).

## Sources

- PLUVICTO prescribing information (DailyMed): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=14908037-2892-4d98-a053-253ce35afb1a

## Connected records

- biomarkers: [AR-V7 splice variant](https://onco.cc/biomarkers/ar-v7-splice-variant/), [Somatostatin receptor expression by PET (SSTR-positive)](https://onco.cc/biomarkers/sstr-pet-expression/)
- cancers: [Biochemical recurrence of prostate cancer](https://onco.cc/cancers/prostate-bcr/), [Metastatic castration-resistant prostate cancer](https://onco.cc/cancers/prostate-mcrpc/), [Metastatic hormone-sensitive prostate cancer](https://onco.cc/cancers/prostate-mhspc/), [Prostate cancer](https://onco.cc/cancers/prostate/)
- drugs: [177Lu-PSMA-I&T](https://onco.cc/drugs/lu177-psma-it/), [Actinium-225 PSMA agents](https://onco.cc/drugs/ac225-psma/), [Flotufolastat F-18](https://onco.cc/drugs/flotufolastat/), [Gallium-68 gozetotide (PSMA-11)](https://onco.cc/drugs/ga68-psma-11/), [Illuccix (kit for Ga-68 gozetotide)](https://onco.cc/drugs/illuccix/), [Locametz (kit for Ga-68 gozetotide)](https://onco.cc/drugs/locametz/), [Lutetium-177 vipivotide tetraxetan](https://onco.cc/drugs/pluvicto/), [Piflufolastat F-18 / Pylarify TruVu](https://onco.cc/drugs/pylarify/)
- terms: [PRRT (peptide receptor radionuclide therapy)](https://onco.cc/terms/prrt-term/), [Theranostics](https://onco.cc/terms/theranostics/)
- key papers: [[ 177 Lu]Lu-PSMA-617 versus cabazitaxel in patients with metastatic castration-resistant prostate cancer (TheraP): a randomised, open-label, phase 2 trial](https://onco.cc/key-papers/paper-therap-lancet-2021/), [Accuracy of gallium-68 PSMA-11 PET in localising recurrent prostate cancer: a prospective single-arm clinical trial](https://onco.cc/key-papers/paper-fendler-psma-pet-biochemical-recurrence-jama-oncol-2019/), [proPSMA: PSMA PET-CT versus conventional imaging for staging high-risk prostate cancer](https://onco.cc/key-papers/paper-propsma-hofman-lancet-2020/), [Prostate-specific membrane antigen expression in normal and malignant human tissues](https://onco.cc/key-papers/paper-silver-psma-expression-normal-malignant-tissues-ccr-1997/)
- targets: [PSMA](https://onco.cc/targets/psma/)

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