Technetium (99mtc) Tyrosine Octreotide

What it is and how it works

Tyr3-octreotide is a somatostatin analogue that, conjugated to a chelator such as HYNIC and labelled with technetium-99m, binds with high affinity to somatostatin receptors (mainly subtype 2). Neuroendocrine tumours overexpressing these receptors accumulate the tracer and can be imaged by SPECT.

Indications

Scintigraphic localisation, staging and follow-up of somatostatin receptor–positive neuroendocrine tumours (e.g. gastroenteropancreatic NETs, carcinoid, paraganglioma) and selection of patients for somatostatin analogue or peptide receptor radionuclide therapy.

Dosage and administration (summary)

Activity is individualised by the nuclear medicine specialist according to the manufacturer’s instructions and local protocols.

Contraindications

Hypersensitivity to the peptide or kit components.

Warnings and precautions

Treatment with somatostatin analogues may reduce tumour uptake; temporary withdrawal before imaging may be considered according to protocol. Physiological uptake in the spleen, kidneys, liver and bowel must be considered in interpretation. Radiation exposure should be justified and minimised; interrupt breast-feeding temporarily.

Pregnancy

Use only when clearly necessary, weighing diagnostic benefit against fetal radiation exposure.

Storage and supply

Store the kit as specified by the manufacturer (usually refrigerated); use the labelled product within the stated time, in lead shielding.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.