On Ga-68 DOTATATE PET-CT, which lesion type shows the HIGHEST tracer uptake due to overexpression of somatostatin receptors?

• A Well-differentiated gastroenteropancreatic neuroendocrine tumours (GEP-NETs) ✓
• B Hepatocellular carcinoma
• C Non-small cell lung cancer
• D Poorly differentiated small cell lung carcinoma

Explanation

Ga-68 DOTATATE (and DOTATOC) bind to somatostatin receptor subtype 2 (SSTR2), which is highly overexpressed in well-differentiated GEP-NETs (carcinoid tumours, pancreatic NETs). These are the primary indication for somatostatin receptor scintigraphy and PET-CT. Poorly differentiated NETs and small cell carcinoma lose SSTR2 expression and are better evaluated with FDG-PET. HCC and NSCLC do not express somatostatin receptors at therapeutically relevant levels.

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.