A 55-year-old man with an inoperable SSTR-positive pancreatic neuroendocrine tumour showing intense uptake on 68Ga-DOTATATE PET progresses despite octreotide therapy. Which radiopharmaceutical forms the basis of peptide receptor radionuclide therapy appropriate for him?

• A Lutetium-177 DOTATATE ✓
• B Fluorine-18 FDG
• C Technetium-99m MDP
• D Iodine-123 metaiodobenzylguanidine

Explanation

Peptide receptor radionuclide therapy uses lutetium-177 labelled DOTATATE, a beta-emitting somatostatin analogue internalised after binding SSTR2, delivering targeted radiation to receptor-expressing tumour cells. Eligibility requires demonstrable somatostatin receptor expression on DOTATATE PET or scintigraphy, which this patient has. Iodine-123 MIBG is a diagnostic agent used mainly in catecholamine-producing tumours, technetium-99m MDP targets bone turnover, and FDG is diagnostic with no therapeutic role. Intense pretreatment DOTATATE uptake predicts therapeutic response.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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