Octreoscan (Indium In-111 Pentetreotide)

Octreoscan is used in nuclear medicine to image tumours that express somatostatin receptors. It helps :

• Neuroendocrine tumors: Provides the most accurate localisation of primary and metastatic lesions.
• Carcinoid syndrome : Assists in staging and treatment planning by visualising receptor density through SPECT/CT.
• Unexplained pituitary adenomas : Enables functional assessment of somat‑ receptor expression for surgical decision making.
• Gastro‑intestinal NET : Facilitates whole‑body scanning to detect occult lesions and guide therapy.
• Metastatic parathyroid carcinoma : Helps identify somatostatin‑positive lesions for targeted therapy.

• Indium In-111 Pentetreotide binds with high affinity to somatostatin receptor subtypes (mainly sst2 and sst5) on the surface of neuroendocrine cells. After intravenous injection, the radiolabelled peptide circulates, attaches to receptor‑expressing tissues, and emits gamma photons that are captured by SPECT imaging, allowing visualisation of tumour distribution.

Adverse reactions to Octreoscan are generally mild and related to the radiopharmaceutical nature of the product.

Common Side Effects

• Nausea: mild and transient.
• Flushing: brief redness of face or neck.
• Injection site discomfort: mild pain or irritation at the IV site.
• Headache: low‑grade, self‑limiting.
• Fatigue: temporary tiredness after administration.

Serious or Rare Side Effects

• Severe allergic reaction: hives, bronchospasm, or anaphylaxis.
• Significant radiation‑induced tissue injury: rare, may affect bone marrow.
• Renal impairment: worsening kidney function in susceptible patients.
• Hypotension: sudden drop in blood pressure post‑injection.
• Persistent vomiting: may require medical intervention.

Octreoscan should be used only under the supervision of qualified nuclear medicine specialists.

• Verify patient’s history of hypersensitivity to somatostatin analogues.
• Assess renal function before administration, especially in patients with known kidney disease.
• Ensure adequate hydration to promote renal clearance of the radiotracer.
• Review recent exposure to other radiopharmaceuticals to avoid cumulative dose excess.
• Store at 2-8°C: keep refrigerated, protect from light and do not freeze the vial or shake shrink shrink 

g g

• This           ...