Somatostatin-receptor PET stages well-differentiated NETs, finds the primary, and selects patients for PRRT (Krenning score) — know the physiological uptake (uncinate process, adrenals, pituitary, spleen) and the accessory spleen.
Orient first
- Physiological uptake: pituitary, thyroid, salivary glands, liver, spleen, adrenals, kidneys, and the pancreatic uncinate process.
- Krenning score (tumour vs liver/spleen uptake) predicts PRRT eligibility (verify scale).
- High-grade NETs may lose receptors and gain FDG avidity — dual-tracer imaging helps.
Acquire the study
- 68Ga-DOTATATE/DOTATOC or 64Cu-DOTATATE PET-CT vertex to mid-thigh ~60 min post-injection, with contrast-enhanced CT where possible.
The manoeuvre
- Primary: small bowel (ileum), pancreas — focal uptake above background on the fused series.
- Mesenteric mass and nodes; liver metastases (uptake higher than liver).
- Bone lesions (often occult on CT).
- Krenning score for the dominant lesions.
- Physiological uncinate uptake vs a lesion (CT correlate).
What confirms it
- Receptor-avid lesions with CT correlate in a patient with a NET.
What licenses you to exclude it
- A negative scan in a high-grade tumour does not exclude disease — FDG PET is complementary.
The classic misread
- An intrapancreatic accessory spleen called a NET.