127Xe-Xenon (Gas)
December 24, 2024
Description:
Xenon-127 is a radioactive gas historically used for pulmonary imaging. It was initially available in the U.S. through Mallinckrodt but was withdrawn from the market in the mid-1980s. However, it is still produced by the Oak Ridge National Laboratory (ORNL) for research purposes. It is important to note that 127Xe is no longer in use in Europe.
Clinical Applications:
Xenon-127 gas is primarily used for pulmonary (lung) ventilation imaging. Due to its chemically inert nature, it cannot be combined with any organic molecules. The gas is typically provided in single doses of 5 or 10 mCi for clinical use. Its role in pulmonary imaging was significant due to its ability to produce high-quality images.
Availability:
Mallinckrodt received marketing authorization for 127Xe gas in October 1982. However, despite its initial clinical utility, the company discontinued production due to its disadvantages, primarily its long half-life, which limited its practical use compared to other alternatives. The Oak Ridge National Laboratory (ORNL) still produces 127Xe for research, but it is no longer used in clinical practice in the U.S. Its extended half-life, while beneficial for imaging quality, made it less favorable compared to alternatives like Xenon-133, which has a shorter half-life but is more convenient for clinical use.
Competition:
The market for pulmonary imaging has shifted to alternative radiopharmaceuticals. Among the gases used for lung ventilation, including 133Xe, 81mKr, and 99mTc-particle suspension, Xenon-133 remains the most favorable due to its balanced profile, offering both practicality and imaging efficacy. While 127Xe produced higher-quality images, its extended half-life and withdrawal from production have limited its use.
Comments:
There is little justification for reviving or expanding the use of 127Xe in clinical settings. The isotope offers no significant advantages over existing alternatives, and its longer half-life poses logistical challenges. As a result, there is minimal incentive to support further indications for this tracer in modern clinical practice.