A radiolabeled substance called Indium In-111 pentetreotide (OctreoScan) is used to identify and localize cancers, mainly neuroendocrine tumors.

Indium In-111 pentetreotide (OctreoScan) Uses:

• Neuroendocrine tumor imaging:

  • It is used to localize primary and metastatic neuroendocrine tumors with somatostatin receptors using scintigraphy.

Note:

• Imaging agents that target somatostatin receptors tagged with gallium 68, such as gallium ga 68 dotatate, are favored over somatostatin receptor scintigraphy employing indium in-111 pentatreotide due to their higher sensitivity and lower radiation exposure.

Indium In-111 pentetreotide dose in adults:

For imaging of neuroendocrine tumors, indium In-111 pentetreotide (OctreoScan) dose:

• Planar imaging:

  • 3 mCi (111 MBq) intravenously.

• Single photon emission computed tomography (SPECT) imaging:

  • 6 mCi (222 MBq) intravenously.

Indium In-111 pentetreotide dose in children:

Neuroendocrine tumor imaging with indium In-111 pentetreotide (OctreoScan) dose:

• 0.14 mCi/kg (5 MBq/kg) intravenously.

Pregnancy Risk Factor C

• Pregnancy can be dangerous for women who use radiopharmaceutical drugs. You should avoid it or use it only when indicated.
• The drug has not yet been tested in human or animal pregnancy studies.

Indium In-111 pentetreotide use during breastfeeding:

• One patient reported that 0.025% of the administered dose was excreted into breast milk. This would have produced an infant dose equivalent to 82 mrem (0.82mSv) had breastfeeding not been stopped.

Dose in Kidney Disease:

Dosage adjustments have not been provided in the manufacturer’s labeling in patients with kidney disease. However, it should be used with caution. 

Dose in Liver disease:

Dosage adjustments have not been provided in the manufacturer’s labeling in patients with liver disease. 

Side effects of Indium In-111 pentetreotide (OctreoScan):

• Allergic reactions may occur manifesting as fever, flushing, itching, and dizziness.
• Patients may develop nausea, headache, arthralgia, hypotension, and deranged liver enzymes.

Contraindications to Indium In-111 pentetreotide (OctreoScan):

The manufacturer's label does not contain any contraindications.

Warnings and precautions

• Regulation of Glucose

  • Patients with insulinoma may experience severe hypoglycemia. This medication should be avoided.
  • It is important to monitor blood glucose levels before and after administering insulin.

• Renal impairment

  • It should be used with caution by patients with impaired renal function.

Monitoring parameters:

None mentioned. 

How to administer Indium In-111 pentetreotide (OctreoScan)?

• It is available for intravenous administration only.
• Before administering the drug, the patient should be well hydrated.
• Hydration should be continued after the administration of the drug as well.
• Patients should be asked to increase fluid intake and void frequently to avoid bladder exposure during the first 24 hours of the drug administration.
• Patients should also be advised of laxatives before the administration of the drug and for 48 hours after receiving the drug.
• Since it is a radiopharmaceutical agent, it should be handled with full precautions and should be disposed of properly.

Mechanism of action of Indium In-111 pentetreotide (OctreoScan):

• Pentetreotide, a human hormone somatostatin analog peptide analog, is labeled using the radiopharmaceutical agent Indium 111.
• It binds to the somatostatin 2 receptors. 
• Patients with an increase in insulinoma's signal uptake are likely to have a neuroendocrine tumor. 
• This helps to diagnose and locate these tumors.

International Brand Names of Indium In-111 pentetreotide:

• OctreoScan

Indium In-111 pentetreotide Brand Names in Pakistan:

No Brands Available in Pakistan. May be available in specific radio-oncology hospitals.