Which of the following patterns represents normal physiological PSMA ligand uptake on a 68Ga-PSMA PET-CT and should not be mistaken for prostatic metastatic disease?

• A Intense bilateral adrenal uptake greater than liver background
• B Focal cortical uptake in a single kidney with an absent contralateral signal
• C Marked diffuse thyroid uptake throughout both lobes
• D Symmetrical moderate uptake in the lacrimal and submandibular salivary glands ✓

Explanation

PSMA ligands consistently show physiological uptake in the lacrimal glands, salivary glands, liver, spleen, bowel, kidneys and proximal small intestine, reflecting PSMA expression or ligand clearance pathways. Symmetrical head and neck gland uptake is therefore expected and benign. Adrenal glands and thyroid normally show no significant PSMA uptake, so focal or diffuse uptake at those sites warrants suspicion of pathology. Asymmetric single-kidney cortical uptake suggests a lesion, not physiology.

Reference: Nuclear Medicine: The Requisites (Ziessman), 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.