Pentetreotide
Also known as: 111In-DTPA-octreotide, 111In‑pentetreotide, D‑Phe‑Cys‑Phe‑D‑Trp‑Lys‑Thr‑Cys‑Thr‑NH2, In-111 pentetreotide, Indium-111 pentetreotide, OctreoScan
Source Pentetreotide at Peptiology
Save 10% with code PEPTI-BOSSRABBIT-10
Affiliate link: we earn a commission on purchases made through this link, at no extra cost to you.
Tapping Shop Now & Save 10% copies your 10% off code PEPTI-BOSSRABBIT-10 to your clipboard. Paste it at the Peptiology checkout to claim the discount.
Summary
Pentetreotide, marketed as OctreoScan, is an indium‑111‑labeled somatostatin analogue used in nuclear medicine to image tumours that express somatostatin receptors, especially neuroendocrine tumours (NETs) and certain paragangliomas. After intravenous injection, the radiopharmaceutical circulates and binds to receptor‑positive cells, allowing whole‑body scintigraphy to locate primary lesions, assess disease spread, and guide therapeutic decisions.
Mechanism of Action
Pentetreotide consists of the peptide octreotide linked to the chelator DTPA, which holds the gamma‑emitting radionuclide indium‑111. The octreotide moiety is an agonist of somatostatin receptor subtype 2 (SSTR2) and to a lesser extent other subtypes. Binding to SSTR2 on tumour cell membranes concentrates the radio‑label at sites of receptor expression, enabling detection by SPECT imaging. Internalisation of the receptor‑ligand complex enhances tumour retention of the signal.
What the Research Shows
Early clinical practice introduced 111In‑pentetreotide for somatostatin receptor imaging, establishing whole‑body scintigraphy as a cornerstone for diagnosing and staging neuroendocrine tumours and functional imaging of paragangliomas. Reviews note that while 111In‑pentetreotide provided high specificity, newer 99mTc and 68Ga labelled analogues now offer superior image quality, sensitivity, and lower radiation dose. Nonetheless, pentetreotide remains referenced in guidelines for NET staging, detection of unknown primary tumours, and treatment planning. Comparative data suggest PET‑based agents achieve >90% diagnostic accuracy, surpassing SPECT with 111In‑pentetreotide, but the latter still demonstrates reliable tumour localisation in receptor‑positive disease.
Reported Benefits
Evidence shows 111In‑pentetreotide reliably binds SSTR2‑expressing tumours, providing whole‑body coverage that assists in staging, detecting occult primaries, and evaluating treatment response. Its established safety profile and availability have made it a standard imaging tool for NETs and certain paragangliomas, facilitating therapeutic decisions such as peptide receptor radionuclide therapy. The gamma emission of indium‑111 enables high‑resolution SPECT imaging without the need for PET infrastructure.
Limitations of the Evidence
SPECT imaging with 111In‑pentetreotide has lower spatial resolution and longer acquisition times compared with modern 68Ga‑PET agents, leading to reduced sensitivity, especially for small lesions or low receptor density. The radiopharmaceutical delivers a higher effective radiation dose than newer tracers. Availability of PET scanners and newer ligands has shifted clinical preference away from 111In‑pentetreotide, limiting its use to centers without PET capability or specific research protocols.
Safety Considerations
Pentetreotide is administered intravenously as a radiopharmaceutical; the main safety consideration is radiation exposure, which is higher than that of newer PET agents but within accepted diagnostic limits. Reported adverse reactions are rare and generally mild, such as transient flushing or nausea related to peptide administration. Caution is advised in pregnant or breastfeeding patients due to fetal radiation risk, and renal function should be considered because the compound is cleared renally.
How It Is Administered
Pentetreotide is supplied as an indium‑111‑labeled DTPA‑octreotide solution for intravenous injection. After administration, imaging is typically performed several hours later to allow optimal tumour uptake and background clearance. The preparation is used with SPECT or SPECT/CT cameras to acquire whole‑body scintigraphic images.
Routes of Administration
Goals & Uses
- Diagnostic imaging of somatostatin‑receptor positive tumorsDiagnosticHigh
- Staging and metastasis detectionOncology / StagingHigh
- Detection of small cell lung cancerDiagnostic OncologyModerate
- Patient selection for somatostatin analogue therapyTheranosticsModerate
- Localization of neuroendocrine tumorsDiagnostic ImagingHigh
- Pheochromocytoma and paraganglioma localizationDiagnostic ImagingModerate
Contraindications
- Severe renal impairmentOrganModerateKidney function concerns
- PregnancyPopulationHighPotential fetal risk or insufficient safety data
- BreastfeedingPopulationModeratePotential transfer into breast milk or insufficient safety data
- Hypersensitivity to pentetreotide or any component of the formulationAllergyHigh
- Hypersensitivity to octreotide or DTPAAllergyHigh
Adverse Effects
- Radiation exposureRadiologicalCommon
- Anaphylaxis / hypersensitivity reactionImmunologicRare
- HypotensionCardiovascularUncommonLow blood pressure
- FlushingVascularUncommonWarmth and redness of the skin
- NauseaGastrointestinalCommonFeeling of sickness or urge to vomit
- Hypoglycemia or hyperglycemiaMetabolicRare
- VomitingGastrointestinalCommonForceful expulsion of stomach contents
- Allergic reaction (rash, urticaria, anaphylaxis)ImmuneRare
- Flushing or warmth sensationVascularCommon
- DiarrheaGastrointestinalUncommonLoose or frequent stools
Drug Interactions
- Renal‑clearing radiopharmaceuticalsLow
- Octreotide (therapeutic)High
- Octreotide or other somatostatin analoguesModerate
- LanreotideHigh
- Total parenteral nutrition (TPN)Low
Population Constraints
- PregnancyReproductive SafetyRelative
- Renal impairmentOrgan ImpairmentRelative
- Pediatric patientsAgeRelative
- Patients with insulinomaEndocrineRelative
Regulatory Status
- European UnionApprovedApproved: diagnostic imaging of neuroendocrine tumors, meningioma detectionAvailable as radiolabelled formulations (e.g., ^68Ga‑pentetreotide) under EU guidelines
- United StatesWithdrawnApproved: diagnostic imaging of somatostatin‑receptor positive tumors (historical)Octreoscan (^111In‑pentetreotide) withdrawn from market in 2020
- United KingdomApprovedApproved: same as EURegulated as a radiopharmaceutical
Approved in many jurisdictions for diagnostic imaging; the ^111In formulation (Octreoscan) was withdrawn from the US market in 2020 but remains available in the EU and other regions.
Evidence & Sources
- Journal ArticleModerateMikołajczak R, Maecke HR2016-01-01T00:00:00.000000Z
- Journal ArticleModerateNazar AK, Basu S2024-01-01T00:00:00.000000Z
- Journal ArticleModerateSmit Duijzentkunst DA, Kwekkeboom DJ, Bodei L2017-01-01T00:00:00.000000Z
- Journal ArticleModerateCorssmit EP, Romijn JA2014-01-01T00:00:00.000000Z
- Journal ArticleModerateWang R, et al.2019-01-01T00:00:00.000000Z
Frequently Asked Questions
What types of tumours can be visualised with pentetreotide?
Pentetreotide binds somatostatin receptor subtype 2, which is over‑expressed in most neuroendocrine tumours, including gastro‑intestinal and pancreatic NETs, as well as many paragangliomas and some other neuroendocrine‑derived lesions.
How does pentetreotide imaging differ from modern PET tracers?
Pentetreotide uses indium‑111 for SPECT imaging, offering whole‑body coverage but lower spatial resolution and higher radiation dose than 68Ga‑labelled PET agents, which provide sharper images, faster scans, and quantitative data.
Is pentetreotide used for therapy or only for diagnosis?
In clinical practice pentetreotide is a diagnostic radiopharmaceutical. Therapeutic analogues use different radionuclides (e.g., 177Lu‑DOTATATE) for peptide receptor radionuclide therapy, not indium‑111.
Are there any contraindications for receiving pentetreotide?
Pregnancy, breastfeeding, and severe renal impairment are cautions due to radiation exposure and renal clearance. Known hypersensitivity to octreotide or DTPA components should also be considered.
What preparation is required before a pentetreotide scan?
Patients typically undergo routine blood work and may need to discontinue certain medications that interfere with somatostatin receptors. No special dietary restrictions are required, and the scan is performed after intravenous injection of the radiopharmaceutical.
What is Pentetreotide?
Pentetreotide, marketed as OctreoScan, is an indium‑111‑labeled somatostatin analogue used in nuclear medicine to image tumours that express somatostatin receptors, especially neuroendocrine tumours (NETs) and certain paragangliomas. After intravenous injection, the radiopharmaceutical circulates and binds to receptor‑positive cells, allowing whole‑body scintigraphy to locate primary lesions, assess disease spread, and guide therapeutic decisions.
What is Pentetreotide used for?
Pentetreotide is educationally associated with: Diagnostic imaging of somatostatin‑receptor positive tumors, Staging and metastasis detection, Detection of small cell lung cancer, Patient selection for somatostatin analogue therapy, Localization of neuroendocrine tumors, Pheochromocytoma and paraganglioma localization. Educational only — not medical advice.
How is Pentetreotide administered?
Recorded routes of administration: Intravenous.
What are the potential side effects of Pentetreotide?
Reported adverse effects include: Radiation exposure, Anaphylaxis / hypersensitivity reaction, Hypotension, Flushing, Nausea, Hypoglycemia or hyperglycemia, Vomiting, Allergic reaction (rash, urticaria, anaphylaxis), Flushing or warmth sensation, Diarrhea. This list is not exhaustive — consult a qualified clinician.
Who should avoid Pentetreotide?
Recorded contraindications: Severe renal impairment, Pregnancy, Breastfeeding, Hypersensitivity to pentetreotide or any component of the formulation, Hypersensitivity to octreotide or DTPA. Consult a qualified clinician before use.