Th-227Review of production, availability, pre-clinical use, and

potential for quantitative imaging and dosimetry

Wesley Bolch

Advanced Laboratory for Radiation Dosimetry Studies (ALRADS)

J. Crayton Pruitt Family Department of Biomedical Engineering

University of Florida, Gainesville, FL

NCI Workshop on Dosimetry of Systemic Radiopharmaceutical Therapy

Rockville, MD

April 19-20, 2018

Production of Th-227

Thorium-227 is a short-lived alpha-particle emitting radionuclide (T1/2 =18.7 days), decaying by alpha-particle emission to 223Ra with an averagealpha-particle energy of 5.9 MeV.

Thorium-227 is part of the 227Ac decay series and can be obtained inclinically meaningful quantities from beta-particle decay of the long-termgenerator 227Ac (T1/2 = 21.8 years).

Although 227Ac occurs naturally as part of the 235U decay series in relativelysmall quantities, it can be produced in significant amounts by therapyneutron activation of 226Ra, or retrieved from legacy Ac/Be neutrongenerators.

For the past decade, 227Th has attracted attention as a viable radionuclidefor several forms of systemic radionuclide therapy.

The U-235 decay series

2004 – Preclinical Study

2006 to 2010 – Oslo University Hospital

2006 to 2010 – Oslo University Hospital

2011 to 2013 – Nordic Nanovector Collaboration

2011 to 2013 – Nordic Nanovector Collaboration

2011 to 2013 – Nordic Nanovector Collaboration

2014 - University of Adelaide

2014 - University of Adelaide

2017 – Johns Hopkins University

2017 – Johns Hopkins University

2017 – Johns Hopkins University

2017 – Johns Hopkins University

2017 – Johns Hopkins University

2017 – Johns Hopkins University

2017 – Johns Hopkins University