Gallium (68ga) Prostate Specific Membrane Antigen (68ga-psma)

What it is and how it works

68Ga-PSMA-11 is a urea-based small-molecule ligand labelled with gallium-68 that binds to the extracellular enzymatic domain of prostate-specific membrane antigen, which is over-expressed on most prostate cancer cells. After internalisation, the tracer accumulates in PSMA-positive lesions visualised by PET.

Indications

PET imaging of PSMA-positive lesions in adult men with prostate cancer: primary staging of high-risk disease before curative therapy, suspected recurrence with rising PSA, and identification of patients eligible for PSMA-targeted radioligand therapy (e.g. lutetium-177 PSMA).

Dosage and administration (summary)

Dosing is individualised according to the imaging protocol (activity based on body weight) and administered by nuclear medicine specialists as a single intravenous injection, with imaging about 50–100 minutes later.

Contraindications

Hypersensitivity to the active substance or excipients.

Warnings and precautions

PSMA uptake is not specific for prostate cancer and occurs in normal salivary and lacrimal glands, kidneys, bowel, ganglia and some benign and other malignant lesions; findings should be confirmed histologically or by other imaging where appropriate. Patients should hydrate and void before imaging and frequently afterwards.

Pregnancy

Not applicable to its indication.

Storage and supply

Prepared from a kit and gallium-68 eluate and used within its short shelf-life, kept at room temperature in appropriate radiation shielding.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.