Production, purification and availability of 211At: Near term steps towards global access

Nucl Med Biol. 2021 Sep-Oct:100-101:12-23. doi: 10.1016/j.nucmedbio.2021.05.007. Epub 2021 Jun 10.

Abstract

The promising characteristics of the 7.2-h radiohalogen 211At have long been recognized; including having chemical properties suitable for labeling targeting vectors ranging from small organic molecules to proteins, and the emission of only one α-particle per decay, providing greater control over off-target effects. Unfortunately, the impact of 211At within the targeted α-particle therapy domain has been constrained by its limited availability. Paradoxically, the most commonly used production method - via the 209Bi(α,2n)211At reaction - utilizes a widely available natural material (bismuth) as the target and straightforward cyclotron irradiation methodology. On the other hand, the most significant impediment to widespread 211At availability is the need for an accelerator capable of generating ≥28 MeV α-particles with sufficient beam intensities to make clinically relevant levels of 211At. In this review, current methodologies for the production and purification of 211At - both by the direct production route noted above and via a 211Rn generator system - will be discussed. The capabilities of cyclotrons that currently produce 211At will be summarized and the characteristics of other accelerators that could be utilized for this purpose will be described. Finally, the logistics of networks, both academic and commercial, for facilitating 211At distribution to locations remote from production sites will be addressed.

Keywords: Alpha emitter; Astatine; Cyclotron; Radionuclide production; Targeted alpha-particle therapy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Astatine* / chemistry
  • Cyclotrons
  • Internationality
  • Radiochemistry / methods

Substances

  • Astatine
  • Astatine-211