At present, in the field of tumor treatment, surgery, chemotherapy and radiation therapy (mainly photon radiotherapy) are the main treatment techniques, and 90% of tumor patients have received one or more of these therapies, which are called the three major conventional means of tumor treatment. However, while these three conventional treatments help patients fight against tumors, they can damage patients’ own normal tissues and organs due to the defects of their treatment methods. Many old and frail patients often give up active treatment because they cannot bear the toxic side effects brought by the treatment. However, the emergence of proton and heavy ion radiation therapy in recent years has significantly increased the killing effect on tumors, while reducing the toxic side effects of radiation on normal tissues and organs, and is recognized as the most advanced radiation therapy technology for tumors in the world today. To date, this technology has treated more than 100,000 tumor patients with remarkable efficacy. Proton and heavy ion radiation therapy is a kind of radiation therapy technology that consists of particle rays composed of protons or heavy ions as the treatment medium. Protons are the basic tiny particles that make up the nucleus of an atom; heavy ions are the nuclei of atoms with larger atomic weights, such as carbon ions. Compared with photons, there are four obvious advantages of proton and heavy ion radiation therapy. The first is less toxic side effects. When protons or heavy ions are accelerated to about 70% of the speed of light by a gas pedal, the ion rays are directed into the body. Before reaching the tumor site, little energy is released, but after reaching the site, the rays release a large amount of energy instantaneously to kill the tumor, and then the rays terminate abruptly. This phenomenon is called “Bragg peak” energy release trajectory, which is like “stereotactic blasting”, making proton and heavy ion radiotherapy have powerful tumor killing effect on tumor cells, while significantly reducing the damage to surrounding normal tissues. The purpose is to kill the tumor without producing radiation toxic side effects. It is because of such characteristics of proton and heavy ion radiation, it is relatively small to human normal tissues and achieves a more ideal effect of tumor treatment, which makes tumor treatment to be able to “distinguish between the enemy and me” and no longer “injure the enemy a thousand and damage the self 800”. Secondly, the efficacy is good. Proton and heavy ion radiotherapy, especially heavy ion radiotherapy, such as carbon ion, can kill tumor cells three times better than conventional photon radiotherapy, and the local control rate of tumor is high, even if the tumor is resistant to treatment, it can also produce better killing effect, such as soft tissue tumor and malignant melanoma. The third treatment course is short. Generally speaking, the course of conventional radiation therapy is about 2 months, while the course of proton radiation is shortened to 1 month, and heavy ion radiation is even as short as 1-2 weeks. Fourthly, it is non-invasive. Proton or heavy ion therapy is non-invasive and painless. Except for pediatric patients, anesthesia is generally not required, so elderly patients with poor cardiopulmonary function and who cannot tolerate anesthesia can also be treated. However, there are limitations to proton and heavy ion radiation. For tumors immediately adjacent to the stomach and intestines, such as gastric and intestinal cancers, it is not applicable due to the high energy level of the radiation, which can easily cause serious damage to the organs. Also, it is a local tumor treatment. For tumors that are prone to distant metastasis, it must also be combined with systemic treatments, such as chemotherapy and biologic targeting, to control distant metastasis. In addition, proton and heavy ion radiotherapy is also not applicable to patients with tumors that have developed multiple distant metastases.