We also have a heavy ion accelerator for cancer treatment!

Audit expert: Luo Huiqian

Researcher at the Institute of Physics, Chinese Academy of Sciences, science writer

Recently, a domestically produced medical device called a heavy ion accelerator has gradually come into the public eye and has shined in the field of cancer treatment.

Source: Health Times

The treatment system of this device is installed in Wuwei City, Gansu Province, and has completed more than 1,300 component inspections such as electromagnetic compatibility, performance testing, safety regulations, and electrical safety. It integrates accelerators, nuclear detection, medical diagnosis and treatment and other related technologies, and provides carbon ion beams for the treatment of malignant solid tumors. It currently provides treatment for more than 800 patients. So, what is a heavy ion accelerator? What is the domestic research and development path of this device? What good news will it bring to cancer patients in the future?

1 The origin of heavy ion acceleration technology

When fighting cancer cells, the most well-known treatment methods should be radiotherapy or chemotherapy, but the rays of traditional radiotherapy are like a blindfolded "killer" that cannot actively distinguish between normal cells and cancer cells, and indiscriminately kills them after entering the human body. So to some extent, the treatment effect is actually a "gamble", betting on which of the good cells and cancer cells will collapse first.

The most frightening thing is that good cells often die first, while cancer cells are particularly tenacious. But "heavy ion beams" are "smarter" than traditional rays. The so-called "heavy ions" refer to charged particles formed when atoms with atomic numbers greater than 2 (i.e. elements heavier than helium in the periodic table) lose some or all of their electrons. "Ion beams" refer to a group of ions with almost the same direction and speed.

Source: Guangdong Technion-Israel Institute of Technology

As early as 1903, British physicists William Henry Bragg and Kliman discovered during radioactive experiments that after a charged ion beam penetrates deep into matter, it will release most of its energy near the end of its range, forming a dose peak . The scientific community calls this energy release peak the "Bragg peak", which is translated into Chinese as the "Bragg peak" (note: it is different from the diffraction Bragg peak formed by X-rays and other rays scattered by crystals).

Source: Beijing Xizhong Hospital

In the 20th century, American Wilson believed that charged particle beams with Bragg peak characteristics could be used in cancer treatment, that is, the energy released by them could be used to destroy cancer cells in a targeted manner. So starting in 1975, the Berkeley National Laboratory in the United States used Wilson's theory as a basis and used the most advanced accelerator at the time to conduct further clinical verification, achieving a huge breakthrough.

2. The road to domestic heavy ion accelerator

At the end of the 20th century, heavy ion accelerators experienced rapid development abroad. The news of continuous research breakthroughs in many countries attracted the attention of a group of Chinese scientists. One of them is Xiao Guoqing, who works at the Institute of Modern Physics of the Chinese Academy of Sciences. In an interview, he said that he and his colleagues were excited to learn about the development of heavy ion acceleration technology abroad, which means that the possibility of this technology being put into clinical practice to benefit cancer patients has greatly increased.

Source: People's Daily

However, there is still a long way to go to achieve the above results. Although the heavy ion cancer treatment project has been included in the major national basic research projects, this cannot change the fact that my country is almost blank in this field. From basic theory to key technology, from feasibility verification and safety testing, the scientists of the institute have spent many years to finally find a Chinese way of heavy ion acceleration!

Source: Guangming.com

The most typical one is a combination of a cyclotron and a synchrotron. This structure completely avoids foreign technology blockades, and its shorter circumference is also second to none in the world. For devices of the same level, the circumference of Europe is 75 meters, the circumference of Japan is 62 meters, and the circumference of China is only 56 meters. According to current research data, the relative biological effect of heavy ions is about 3 times higher than that of conventional photon rays. Therefore, heavy ion beams are more "lethal" to cancer cells, and the number of treatments is reduced accordingly, thereby shortening the treatment cycle.

Source: Overseas Medical Care

Unlike conventional photon (X-ray and gamma ray) radiotherapy, heavy ion beams do not rely on the presence of oxygen to kill tumor cells. This is because heavy ions kill cancer cells mainly by ionizing high-density secondary electrons to cause DNA double bond breaks. Heavy ions have a small oxygen gain ratio and can be used to treat hypoxic tumors with insufficient blood supply.

Source: People's Daily

3. Other applications of heavy ion accelerators

In addition to cancer treatment, the heavy ion accelerator in Lanzhou has shown broad market prospects and application value in multiple fields. As a major national scientific and technological infrastructure, the project is no less impressive than its international counterparts, and is of great significance to the research of heavy ion physics and interdisciplinary subjects in my country, with fruitful results in the synthesis of new nuclides and precise measurement of nuclear mass.

In addition, in the process of promoting the project, researchers have also achieved technological breakthroughs in many fields such as superconductivity, low temperature, vacuum, microwave, and precision magnet manufacturing, opening up good development prospects for nuclear medicine instruments, non-destructive testing, environmental protection, and food irradiation processing.

In fact, the development of many high-tech industries will bring huge benefits to the local area. Taking the heavy ion accelerator as an example, the construction of this project can provide a large number of jobs for Lanzhou, help local talents find jobs, and at the same time attract domestic and foreign talents, accumulate human resources, and then feed back to other industries in Lanzhou. The project will drive downstream industries such as medical services, provide human resources for diagnosis, treatment and nursing in the future, and help deepen the theoretical research of heavy ion technology. The 21st century is an era of science and technology, an era of change, and even more so our era. Many scientific researchers have worked silently for decades, and finally exchanged for the flourishing of the motherland's science and technology. I believe that in the future, we will achieve technological breakthroughs in more fields, and the people will live a happier life!