A 55-year-old man with metastatic well-differentiated neuroendocrine tumour of the ileum shows intense somatostatin receptor expression on Ga-68 DOTATATE PET. He is considered for peptide receptor radionuclide therapy. The therapeutic agent used is:
- A Iodine-131 labelled metaiodobenzylguanidine
- B Lutetium-177 labelled DOTATATE ✓
- C Radium-223 dichloride
- D Yttrium-90 labelled ibritumomab tiuxetan
Correct answer: B. Lutetium-177 labelled DOTATATE
Explanation
Lutetium-177 DOTATATE delivers beta radiation specifically to somatostatin receptor subtype 2 expressing tumour cells and is the established therapy for inoperable or metastatic gastroenteropancreatic NETs with avid lesions on Ga-68 DOTATATE PET. I-131 MIBG is an alternative reserved mainly for MIBG-avid tumours such as pheochromocytoma. Ra-223 targets osteoblastic bone metastases in prostate cancer, and Y-90 ibritumomab is a CD20 directed lymphoma agent.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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