The first in the domestic nuclear medicine field! The "cancer-fighting nuclear bomb" achieves Curie-level mass production, accelerating its path toward clinical application

What are the key highlights of the technological innovations at China’s Spallation Neutron Source?

“Science and Technology Innovation Board Daily” March 28 (Editor: Song Ziqiao) A critical breakthrough has been achieved in China’s nuclear medicine field.

The Institute of High Energy Physics of the Chinese Academy of Sciences has recently realized the first-ever mass production of medical-grade alpha isotopes at the curie level, which will accelerate the transition of China’s self-developed alpha nuclear medicine from the laboratory to clinical application.

Nuclear medicine, short for radioactive drugs, refers to a special class of drugs that contain radioactive isotopes, used for medical diagnosis or treatment. After patients take or inject nuclear medicine, the drug automatically seeks out targets (such as tumor cells) in the body, then utilizes the radiation emitted by the isotopes for diagnosis or treatment.

Alpha isotopes are a type of radioactive isotope that can release alpha particles, which are hundreds of times more lethal than beta particles, penetrating only about 0.05 millimeters in tissue (equivalent to the diameter of a few cells), and almost do not harm surrounding healthy tissue. With its unique advantage of “high energy and short range,” alpha isotopes have become a powerful tool for tumor treatment, particularly having significant clinical value in targeted therapy for mid-to-late-stage tumors, earning the nickname “anti-cancer nuclear bomb.”

Currently, the mainstream medical alpha isotopes include Radium-223, Actinium-225, Lead-212 (Bismuth-212), and Astatine-211. It is known that Radium-223 has been approved for clinical treatment of bone metastatic castration-resistant prostate cancer, while Actinium-225 and Lead-212 have also shown significant efficacy in targeted therapy research for mid-to-late-stage prostate cancer, neuroendocrine tumors.

For a long time, core therapeutic alpha isotopes such as Actinium-225 and Radium-223 have been completely reliant on imports, and their supply is scarce. Their mass production has become a globally recognized industry challenge due to multiple technological barriers, which has also constrained the development of China’s alpha nuclear medicine industry. For example, the price of Actinium-225 can reach as high as 300,000 yuan per milliCurie.

Curie (Ci) is the unit of measurement for radioactivity, quantifying the number of decays per second of a radioactive substance; milliCurie is 0.001 Curie. In the field of medical alpha isotopes, increasing production from milliCurie level to curie level represents a leap in magnitude. Curie-level production means that a single batch of radioactive isotopes reaches over 1 Curie, sufficient to meet the treatment needs of hundreds or thousands of patients, and supports large-scale clinical trials and applications.

According to reports, China’s research team has relied on the large-scale scientific facility—the China Spallation Neutron Source—utilizing the extra beam irradiation of a high-energy, high-current linear accelerator on layered thorium targets, combined with independently developed joint separation and purification processes. In July 2025, they will achieve the simultaneous extraction of several medical alpha isotopes, including high-purity Actinium-225, Radium-223, and Lead-212 (Bismuth-212) at the milliCurie level for the first time internationally, with radioactive nuclear purity exceeding 99%, verified by labeling, and the quality is on par with imported products.

α isotope purification laboratory site

This achievement not only breaks China’s long-standing dependence on imported medical alpha isotopes but also establishes an economically viable localized production path.

Based on this breakthrough, the research team has begun to expand economically viable localized production pathways. After continuous process optimization, the team currently has the capability to supply curie-level Lead-212 in bulk annually. To further meet the demand for large-scale clinical applications, the Spallation Neutron Source Science Center is accelerating the construction of a dedicated α isotope production line with 300 mega-electron volts (MeV) and 100 kilowatts—once completed around 2031, the annual production capacity will reach hundred curie levels, sufficient to supply nearly one million doses of raw material for α isotope nuclear medicine.