State of the art and future perspectives of new radinuclides in Nuclear Medicine: Part III.

Autores de IIS La Fe

• 

  Irene Torres Espallardo

  Autor

Participantes ajenos a IIS La Fe

• Ramos R
• Domínguez ML
• Rosales JJ
• Roteta A
• Prieto E
• Sancho L
• de Arcocha M
• Quincoces G
• en nombre del Grupo de Oncología de la SEMNIM

Grupos

• Investigacion Biomédica en Imagen (GIBI 2-30)

• Núcleo de investigación traslacional integrado Urológico de Valencia (NITIUV)

Abstract

In this third installment of the continuing education series, the clinical and therapeutic applications of zirconium, astatine and thorium are analyzed in depth. Although they are not described as theragnostic pairs, each of these radionuclides plays a fundamental role in precision medicine, which is rapidly advancing within Nuclear Medicine. We begin by analyzing zirconium-89, a positron emitter whose long half-life makes it particularly suitable for labeling large molecules with slow kinetics, such as antibodies, playing a crucial role in immunotherapy. The use of astatine-211, an alpha-emitting radionuclide with a simple decay scheme and chemical behavior similar to iodine, is also discussed. Its main challenge lies in its production, as it requires cyclotrons capable of generating highly energetic alpha particle beams. Furthermore, thorium-227, a 100% alpha emitter, is reviewed. This radionuclide exhibits excellent chelation properties, enabling its conjugation with tumor-targeting molecules to produce thorium-labeled conjugates. While this technique is yielding promising preclinical results, the use of thorium faces challenges, including the potential separation of radium-223 from the molecule and the dependence of activity measurements on the time of production. Since it takes 100 days to reach equilibrium, activity assessment is based on photons emitted by its daughter radionuclides. Despite these challenges, these radionuclides are driving the evolution of precision medicine, expanding therapeutic and diagnostic possibilities within Nuclear Medicine.

Copyright © 2025 Sociedad Española de Medicina Nuclear e Imagen Molecular. Published by Elsevier España, S.L.U. All rights reserved.

Keywords

• Astate; Astato; Radionucleidos; Radionuclides; Thorium; Torio; Zirconio; Zirconium