Is the radiotherapy department an internal medicine?

The radiotherapy department belongs to the treatment department. What is radiotherapy? With the increase of tumor incidence, more and more people have heard of radiotherapy, or there are people who are receiving radiotherapy around them. But most people do not know much about radiotherapy. What is radiotherapy?

Madame Curie is no stranger to everyone. It is precisely because this famous Nobel Prize winner in physics discovered the radioactive element "radium" that radiotherapy began. After more than 100 years of continuous exploration and research by countless physicists and medical scientists, radiotherapy has developed by leaps and bounds, forming radiotherapy which integrates oncology, radiation physics, radiobiology and radiobiology, and has become one of the three major methods of modern tumor treatment. The treatment of 70% tumors requires the intervention of radiotherapy, which is the first choice for many tumors, such as nasopharyngeal carcinoma, early laryngeal carcinoma, head and neck lymphoma and basal cell carcinoma of skin. , the curative effect is remarkable.

Radiotherapy is the use of radiation to kill tumor cells and achieve the purpose of curing tumors. Modern radiotherapy has high technology content, which is far from being as simple as "drawing lines" as people imagine, let alone "physical therapy" as some people imagine. After the tumor is diagnosed, if radiotherapy is needed, it is necessary to make preparations before radiotherapy, including CT, MRI, liver and kidney function, blood routine, B-ultrasound, chest X-ray and so on. Doctors will determine the scope of radiotherapy according to imaging examination, clinical examination and pathological examination, choose the type and dose of radiation, and make radiotherapy plans by using radiotherapy planning system, such as the angle and direction of radiation projection, to ensure that the irradiation target area can be included in the 90% isodose line, and at the same time try to do it. Then the technician will take photos, and the treatment plan will be continuously improved according to the tumor shrinkage during the treatment. The design and implementation of radiotherapy plan often involves the knowledge of oncology, imaging, physics and biology, and the required equipment is also precision instruments, such as simulator, computer radiotherapy planning system, network system, linear accelerator, Co60 therapeutic machine and X-ray therapeutic machine. Any tissue or organ has a specific tolerance to radiation. If the radiation dose exceeds its tolerance, it will lead to a series of radiation complications, and the late radiation injury can occur decades later, seriously affecting the quality of life of patients. Therefore, the determination of radiation dose must be carried out under the guidance of radiotherapy professionals.

According to the statistics of "Proton Therapy Cooperation Organization" (PTCOG)1July, 1999, there are 20 proton therapy facilities (including non-hospital research institutions) in use, under construction and under construction. At present, the only real hospital proton therapy equipments in the world are Loma Linda Medical Center in California, Northeast Proton Therapy Center of Harvard University Affiliated Hospital, Japanese National Cancer Center and Bolag Proton Center of Wanjie Hospital in Zibo, Shandong, China. However, the number of patients who have received proton therapy has reached 24,494.

With the development of modern medicine, it has gradually become a reality for human beings to control and conquer cancer. In the clinical treatment of tumors, surgery, radiotherapy and chemotherapy are the three most important treatment methods. Because of its wide indications and great selectivity, more than 70% patients with malignant tumors need radiotherapy at some stage of their treatment.

The purpose of radiotherapy is to concentrate the radiation dose in the focus (target area) to the maximum extent and kill tumor cells, while the surrounding normal tissues or organs receive little or no unnecessary radiation, and some important organs, such as brain stem, lens, spinal cord, kidney and gonad, need special protection. Traditional radiotherapy technology (that is, the conventional two-field and four-field penetrating irradiation technology carried out by many medical units) is only the initial stage to achieve this goal. It can not only cure tumors, but also cause temporary or permanent damage to normal tissues and organs, and even damage some important organs. This is a pure treatment. The ideal state of tumor radiotherapy is to irradiate only the tumor, but not the normal tissue around the tumor. Although modern radiotherapy technology has not reached this level, the modern precision radiotherapy technology brought by the rapid development of computer technology has taken a big step towards this idealized goal.

The so-called precise radiotherapy refers to the combination of radiotherapy medicine with computer network technology and physics, and the whole radiotherapy process is controlled by computer. Different from the traditional radiotherapy technology, it can be summarized as "four most", that is, the radiation dose of the target area (lesion area) is the largest, the normal tissue around the target area is the smallest, the dose distribution of the target area is the most uniform, and the target area is the most accurate. Its advantages are "high precision, high dose, high curative effect and low damage", which mainly include three-dimensional conformal radiotherapy and intensity modulated radiotherapy.

Three-dimensional conformal radiotherapy refers to the technology that the dose distribution shape of high dose area is consistent with the shape of target area in three dimensions. As a result, the fitness of the three-dimensional shape of high dose distribution area and target area is greatly improved compared with traditional treatment, and the irradiation range of normal tissues and organs around it is further reduced. Because most tumors grow infiltratively and their general shapes are irregular, this technique can further increase the radiation dose of tumors and reduce the dose of surrounding normal tissues, thus improving the local control rate and survival rate of tumors, reducing radiation complications and improving the quality of life of patients.

However, in some cases, three-dimensional conformal radiotherapy can not completely achieve the purpose of treating tumors and protecting normal tissues. If there are many important organs or normal tissues around the tumor that need irradiation; Tumors are interlaced with normal tissues or important organs; Tumor tissue surrounds important organs and so on. At this time, the shape of the target area is either "hollow", "horseshoe" or "crab's foot", so it is difficult for ordinary three-dimensional conformal radiotherapy to form these special shapes of irradiation target areas. At this time, intensity modulated radiotherapy technology is needed for radiotherapy, that is, a special computer system for radiotherapy is used to accurately locate the tumor according to its shape, so that the high-dose curved surface tightly wraps the tumor and avoids the surrounding normal tissues. By adjusting the intensity of the radiation beam in the target area, each part of the tumor tissue can be irradiated with an ideal dose. Many thin beams with different intensities are used, which is different from a single complete beam used in three-dimensional conformal transformation. Through computer calculation, and then uneven irradiation in three-dimensional space. So as to protect the normal tissues around the tumor to the greatest extent, reduce the radiation reaction and improve the treatment effect while being fatally irradiated.

For example, the tumor of lung cancer patients grows near the spine, and the treatment with conventional traditional techniques is definitely a temporary solution, which is also commonly known as an "incurable disease", because the radiation tolerance of the spinal cord is far lower than the radical dose of the tumor, and the cure of the tumor must be at the expense of the patient's paralysis. If you avoid the spinal cord, the tumor will be appeased, and the contradiction between them is irreconcilable. In this case, intensity modulated radiation therapy can play a role in treating tumors and protecting the spinal cord, which is of great significance. For example, after maxillary sinus cancer infiltrates the orbit and eyeball, intensity modulated radiotherapy can protect the lens and treat the tumor. Another example is retroperitoneal tumor, which is surrounded by important organs such as kidney, spinal cord and small intestine. Intensity modulated radiotherapy can protect the surrounding important tissues and organs while treating tumors. Therefore, many experts and scholars at home and abroad call IMRT a revolution in the history of radiotherapy.

It is suitable for radiotherapy of most tumors such as prostate cancer, lung cancer, head and neck tumor, mesothelioma and central nervous system tumor. Not only can patients get a better tumor cure rate, but also can patients get a higher quality of life. It is the mainstream of tumor radiotherapy in 2 1 century.