Due to the rapid increase in the life span of people and the development of medical technologies, malignant tumors - or cancer - have recently become the number one cause of death among the general public. Cancer has the mutation character of which the cause of the occurrence has not been looked into closely. Cancer cells take away the nutritive elements of the normal cells in the surroundings.

And the cell division is very fast. Hence, compared to normal tissue cells, the speed of growth is fast and cancer cells do not die easily.

Also, when cancer is manifested at the early stage, the judgment of the occurrence is difficult because cancer tissues are hard to be distinguished from normal tissues. When the cancer tissue has become big to a certain extent and there are symptoms of which the patient is conscious, it gets easily metastasized to a different region. As a result, it makes treatment difficult. Also, even after the judgment has been made that the cancer has been treated and has disappeared, the cancer frequently recurs. Therefore, it is a chronic headache for mankind.

There are largely three kinds of methods of cancer treatment verified by modern medicine. First is the operational method of treatment of cutting out the region where cancer has occurred. Second is chemotherapy which uses such medicines as anti-cancer medicines. And the third is Radiotherapy which uses radiation. Ever since Roentgen discovered X-rays in 1895 their use was started right away in medical treatment. In 1905, radiation treatment began using X-ray tubes. Today, in the 21st century, we perform not only x-ray but also carbon treatment using heavy ion accelerators.

Currently, about 50% of the cancer patients of the whole world have been receiving cancer treatment using radiation.

At present, among the radiation treatments, the treatment method that is used the most universally is X-ray treatment.

Not only is X-ray treatment the most universal, but its treatment is also the cheapest. It eliminates the DNAs of cancer by cutting the hydrogen bonds within the cancer cells with either X-rays or high-energy electrons.

In the case of the previously existent method of treatment exposing to X-rays, the eradication of malignant tumors had been possible. However, because the exposure had been made not only on cancer tissues but also normal tissues, it had been difficult to avoid side effects. Recently, in consideration of such a difficulty, a method of minimizing the X-ray bombing on normal tissues and concentrating on only the cancer tissues has been developed.

To solve such a problem, electron beam fusion accelerators - which attach an electron accelerator to a robot arm, make exposures to the cancer tumors in a deep part from hundreds of directions, and reduce the side effects occurring in normal tissues - have been used, too, other than IMRT (Intensity Modulated Radiation Therapy) and tomotherapy.

An electron accelerator called Cyberknife has recently been in the limelight because of its strong point of minimizing the many side effects possessed by the previously existent electron rays and X-rays. In the case of Cyberknife, the treatment plans and the beam exposure are very important. Cyberknife is largely comprised of the treatment planning system (TPS) and the treat delivery system (TDS). The TDS is comprised of a 6MV linear accelerator (Linac), a six-axis manipulator (Robot), an imaging subsystem, and a safety system. However, it is very difficult to overcome the fundamental physical effects possessed by X-rays.

In principle, the treatment means capable of solving such side effects is, indeed, the treatment using ion beams. Ions are the nucleus of which the electron was taken out from an atom. In order for an ion beam to penetrate a matter, it must fly at a fast speed in the same way as is with electrons. When an ion beam that moves at a fast speed penetrates a certain matter, the speed gets slower by little bits as it enters.

At the spot where the ion beam completely loses its speed and stops, a lot of ionization takes place and radiation is generated. This is called the Bragg Peak.

As a result, if only the speed of the ions is decided with the accelerator, a lot of radiation can be accurately poured onto the cancer tumors in a certain place.

The medical treatment method that uses such a physical quality is the ion beam treatment. It is to quickly accelerate the ions so that they can reach the tumors in the depths.

Since in physics the speed of movement translates into energy, high energy must be given to the ion beams for the medical treatment in a deep part. However, the mass of even the lightest hydrogen is about 1836 times heavier than an electron.

In order to accelerate a proton at a fast speed, an accelerator of which the size is much bigger than an electron accelerator is needed.

In order to treat a cancer tumor in a deep part with protons, the energy must be at least 200 million electron volts. The size of a machine is proportionate with the size of the energy.

Hence, in the case of a cyclotron for treating with protons, a space of the size of over 660 square meters is needed. And the price tag reaches tens of billions of won, or tens of millions of dollars.

Protons are the lightest hydrogen ions among all the ions. Thus, in Germany and Japan, the research for treating cancer with carbon ions, which are heavier than hydrogen, had started in 1994. The relative biological effectiveness (RBE) of carbon is about 2.8 times higher than X-ray or protons.

Carbon shows extraordinary effects in terms of the rate of destruction of cancer tissues. Also, the percentage change of oxygen, which is related with the rate of recurrence of cancer, shows an effect that is 2.5 times lower than X-rays and protons.

Because of such results of the researches of the National Institute of Radiological and Medical Sciences (NIRS) of Japan and Gesellschaft fuer Schwerionenforschung (GSI: a heavy ion research institute) of Germany, heavy ion accelerators for the exclusive use of cancer treatment have been installed in the Hyogo Cancer Center in Japan and the Heidelberg University Hospital in Germany. In the case of Japan, there are very high instances of organ cancers, of which the rate of death is high and the surgery is difficult, such as lung cancer and liver cancer.

Already, Italy, France, Austria, Sweden, China and other countries too have been accelerating the development and construction of heavy ion accelerators for treating cancer. Korea, too, has been planning to construct heavy ion accelerators for the development of advanced cancer treatment technologies and nuclear science technologies.

This is urgent. The heavy ion accelerator is the crystallization of the next-generation technology of putting into practical use for catching the two rabbits of the business era of the femto science on the one hand and life and health on the other hand.nbsp;