# Technetium Tc-99m tetrofosmin

Source: https://nuclide.cc/drugs/tc-99m-tetrofosmin/  
Nuclide record `tc-99m-tetrofosmin` (Agent). Data CC BY-NC 4.0, attribute "Data from Nuclide (nuclide.cc)"; commercial use needs a licence.

## TL;DR

A radioactive tracer, chemically similar to Cardiolite, injected into a vein and taken up by heart muscle in proportion to blood flow; a gamma camera scan after rest and after exercise or a stress drug shows areas with reduced blood supply.

## Summary

Technetium Tc-99m tetrofosmin (Myoview), initial US approval 1996, is a diphosphine SPECT perfusion agent supplied as a cold kit for reconstitution with Tc-99m generator eluate. It shares sestamibi's core pharmacokinetic profile: passive, blood-flow-proportional myocardial uptake with negligible redistribution, so separate rest and stress doses are required, and its 140 keV photon suits standard gamma cameras.

The FDA label covers two indications: myocardial perfusion imaging under rest and/or exercise or pharmacologic stress to delineate regions of reversible ischaemia or infarcted myocardium in patients with known or suspected coronary artery disease, and assessment of left ventricular function (ejection fraction and wall motion) via gated SPECT. The recommended dose range is 185-1,221 MBq (5-33 mCi); on a same-day protocol the first (rest or low-level stress) dose is 185-444 MBq followed 1-4 hours later by 555-1,221 MBq for the second acquisition.

Its first-pass extraction fraction (about 54%) is modestly lower than sestamibi's, and comparative studies (e.g. dipyridamole-stress SPECT in mild-to-moderate CAD) have found sestamibi detects more reversible defects, attributed to tetrofosmin's earlier extraction "roll-off" at high flow; both remain widely used interchangeably in routine SPECT MPI.

## Fields

- Kind: Agent
- Last checked: 2026-09-22
- Also known as: Tetrofosmin
- Tags: SPECT; myocardial perfusion; technetium
- Brand: Myoview
- Modality: SPECT tracer
- Mechanism: A lipophilic cationic diphosphine complex of Tc-99m, taken up by myocytes in proportion to blood flow and retained largely by binding within mitochondria, driven by the transmembrane and mitochondrial potentials, with minimal redistribution after uptake. Its first-pass myocardial extraction fraction is around 54%, similar to but slightly lower than sestamibi's, so its uptake-versus-flow curve plateaus (rolls off) at a somewhat lower flow rate, which can mean smaller apparent defect extent/severity than sestamibi in mild-to-moderate disease.
- Approvals: US 1996: Myocardial perfusion imaging under rest and/or exercise or pharmacologic stress to delineate reversible ischaemia and infarcted myocardium; US 1999: Assessment of left ventricular function (ejection fraction and wall motion)
- Dosing: Intravenous injection; 185-1,221 MBq (5-33 mCi) per dose; same-day protocol gives 185-444 MBq first then 555-1,221 MBq 1-4 hours later; imaging can begin 15 minutes after injection

## Sources

- FDA label: Myoview (technetium Tc-99m tetrofosmin), 2022 revision: https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/020372Orig1s033lbl.pdf
- First-pass extraction fractions of Tl-201, Tc-99m sestamibi and tetrofosmin (Circ Cardiovasc Imaging): https://www.ahajournals.org/doi/10.1161/circimaging.109.854893
- Sestamibi vs tetrofosmin defect detection in mild-to-moderate CAD (JACC 2001): https://www.jacc.org/doi/10.1016/S0735-1097(00)01148-7

## Connected records

- drugs: [Technetium Tc-99m sestamibi](https://nuclide.cc/drugs/tc-99m-sestamibi/), [Thallous chloride Tl-201](https://nuclide.cc/drugs/tl-201-chloride/)
- isotopes: [Technetium-99m](https://nuclide.cc/isotopes/tc-99m/)
- indications: [Cardiac sarcoidosis](https://nuclide.cc/indications/cardiac-sarcoidosis/), [Coronary artery disease](https://nuclide.cc/indications/coronary-artery-disease/)

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