Actinium

Actinium (Ac) — 10-Year Trends

As of 2026-09-11 · the last 10 years

Actinium’s research intensity stands at about 21% of its own all-time peak, a level reached through a steady climb over the last decade, though the element’s historical high point occurred in 1918.

Research intensity ran from about 8% of the element's own all-time peak in 2016 to about 21% in 2026 — a steady climb, and the all-time peak (1918) lies before this window. Over the same span its share of research attention across all elements rose. Among the 118 elements, actinium has one of the smaller research literatures of any element.

The number of papers involving the element rose from about 127 in 2016 to about 626 in 2025 (4.93x). That is faster than the literature as a whole grew over the same years, so the element gained ground in the wider body of research.

The dominant research community is Actinium-225 as a Targeted Alpha Therapy Agent, which accounts for about 84% of the element's recent research. This community focuses on actinium-225 radioligands for treating relapsed acute myeloid leukemia and metastatic prostate cancer, with distinctive work on targeted alpha therapy and prostate-specific membrane antigens. Actinium is a minor presence in this much larger community, appearing in about 2% of its papers. The community’s share has been rising, growing from about 64% in the earlier period to its current level. A key anchor is the 2024 multicentre retrospective study on Actinium-225-PSMA radioligand therapy for metastatic castration-resistant prostate cancer, cited over 200 times.

A second significant community is Synthesis and Decay of Superheavy Elements and Heavy-Ion Collision Physics, holding about 4% of the element's recent research. Here, actinium is a minor presence, involved in about 1% of the community's papers. The share has remained steady. Notable work includes a 2017 study on high-resolution laser ionization spectroscopy of the heaviest elements, cited over 110 times, and a 2025 unified study of actinium and thorium isotopes, cited about 3 times.

Actinide Chemistry and Nuclear Fuel Materials represents about 2% of the element's recent research. Actinium is a minor presence here, under 1% of the community's papers. The share has been steady. A 2018 paper on bond covalency and oxidation state of actinide ions complexed with therapeutic chelating agents, cited over 100 times, anchors this area.

Finally, Arsenic Contamination, Removal, and Health Risk Assessment has seen its share decline to zero in the most recent period, down from about 12% previously. While actinium is a minor presence in this community (under 1% of papers), the decline suggests a shift away from this specific intersection. A 2020 study on complete responses in relapsed/refractory acute myeloid leukemia, cited about 69 times, was part of this earlier engagement.

Overall, the literature is consolidating around targeted alpha therapy, which has gained significant share, while other areas like arsenic contamination have lost ground. The remainder of the research, comprising about 10% of the element's work, is distributed across smaller communities that have also seen a slight decline in share.

For a deeper look at actinium’s current standing, see the Last 12 Months and Executive Brief reports.