Indium In-111 pentetreotide

Summary

Indium In-111 pentetreotide (OctreoScan) is a radiopharmaceutical used for scintigraphic localization of primary and metastatic neuroendocrine tumors that bear somatostatin receptors. It consists of octreotide conjugated to DTPA chelator, radiolabeled with indium-111 for gamma camera and SPECT imaging.

Mechanism of Action

Indium-111 labeled pentetreotide (DTPA-conjugated octreotide) binds with high affinity to somatostatin receptors (subtypes 2 and 5) overexpressed on neuroendocrine tumor cells; gamma emission from In-111 decay enables scintigraphic imaging of receptor-positive tumors and metastases.

Routes of Administration

Goals & Uses

• Detection of occult primary NETsDiagnostic ImagingModerate
• Monitoring treatment responseOncology DiagnosticsModerate
• Staging and restaging of neuroendocrine tumorsOncology DiagnosticsHigh
• Patient selection for somatostatin analogue therapyTheranosticsModerate
• Localization of neuroendocrine tumorsDiagnostic ImagingHigh

Contraindications

• Known hypersensitivity to octreotide or pentetreotideAllergyHigh
• PregnancyPopulationHighPotential fetal risk or insufficient safety data
• BreastfeedingPopulationHighPotential transfer into breast milk or insufficient safety data

Adverse Effects

• Radiation exposureRadiologicalCommon
• Dizziness / headacheNeurologicalUncommon
• Hypersensitivity / anaphylaxisImmunologicalRare
• Injection site reactionsLocalUncommon
• NauseaGastrointestinalUncommonFeeling of sickness or urge to vomit
• Hypoglycemia or hyperglycemiaMetabolicRare

Drug Interactions

• Total parenteral nutrition / lipid emulsionsLow
• Octreotide (therapeutic doses)High
• LanreotideHigh

Population Constraints

• Renal impairmentOrgan ImpairmentRelative
• Pediatric patientsAgeRelative
• Breastfeeding womenReproductiveAbsolute
• Diabetic PatientsMetabolicRelative

Regulatory Status

• European UnionApprovedApproved: Scintigraphic imaging of neuroendocrine tumors expressing somatostatin receptorsApproved in multiple EU member states; availability varies by country as Ga-68 PET tracers have largely replaced its use.
• United StatesApprovedApproved: Scintigraphic localization of primary and metastatic neuroendocrine tumors bearing somatostatin receptorsFDA-approved; marketed as OctreoScan by Curium (formerly Mallinckrodt). NDA approved 1994.
• United KingdomApprovedApproved: Imaging of somatostatin receptor-positive tumorsLicensed for use in the UK; clinical use has declined following wider availability of Ga-68 DOTATATE PET/CT.

FDA-approved in the United States for scintigraphic imaging of neuroendocrine tumors including carcinoids, gastrinomas, and other somatostatin receptor-positive tumors. Approved by EMA in Europe. Has been largely supplanted in many centers by Ga-68 DOTATATE PET/CT but remains an approved and available diagnostic agent.

Evidence & Sources

No sources recorded yet.