Hodgkin’s lymphoma, formerly known as “Hodgkin’s lymphoma” in China, has been classified by the World Health Organization since 2001 into 2 major categories: nodular lymphocyte-dominant HL and classic HL. The classic type can be further divided into: nodular sclerosis, mixed cell type, lymphopenic type and lymphocyte rich type. HL usually involves lymph nodes, mainly in the cervical lymph nodes, either singly or fused. Painless, progressive enlargement of local lymph nodes is often the first symptom. The spleen, liver and bone marrow may be involved in the late stage, with spleen involvement being relatively common. (iii) Children and young adults are predominant. ④Tumor cells, namely R-S (Reed-Sternberg) cells and Hodgkin cells, are scattered among an abundant population of reactive inflammatory cells and accompanying cells; they are usually surrounded by T cells and form a rosette. Treatment principles of Hodgkin’s lymphoma Stage IA and IIA: lesions located on the diaphragm, radiation of the diaphragm field plus the hoe field, lesions located under the diaphragm, invasion of the pelvic and inguinal lymph nodes, should be radiated to the para-aortic lymph nodes, if invasion of the pelvic and para-aortic lymph nodes, radiation of the whole lymph nodes should be applied. In ⅠA and ⅡA cases, if there is a large mediastinal mass, chemotherapy and radiotherapy should be used in combination; if the pathology is lymphocyte reduction type, whole lymph node radiation should be applied. Stage IIB: whole lymph node radiation is generally used, and combined chemotherapy alone may also be used. Stage III1A: Radiation therapy alone. Stage III2A: Combined radiation and chemotherapy. Stage IIIB: Chemotherapy alone or chemotherapy plus radiation. Stage IV: chemotherapy alone. Radiation therapy for Hodgkin’s disease The principles of radiation therapy are based on the stage, but also on the location, pathology and age of the lesion. Especially for children with Hodgkin’s disease, because the normal tissues and organs of children are more sensitive to radiation, which can cause impairment of normal development in children, special attention should be paid to protect the lungs, kidneys and other important organs. Therefore, the irradiation field is smaller than that of adults, the dose is lower than that of adults, and combined chemotherapy is advocated before and after irradiation. 1.Radiotherapy principles and radiation selection: A) Tumor eradication dose: Some scholars summarized the relationship between recurrence and tumor volume in the irradiation field and found that the local recurrence rate decreases with the increase of tumor dose. B) Preventive irradiation: Radiotherapy should not only include the area where the tumor is clinically found, but also preventive irradiation to the lymph node area in the neighboring parts. C) Radiation selection: At present, 60Co or 4-8MeV X-ray is mostly used. ~8MeVX-ray, because it has the advantages of high dose in percent depth, uniform dose distribution, less bypass radiation, and patients can easily tolerate radical irradiation. 2.Irradiation method for large irregular fields: The irradiation technique for large irregular fields is to use a large irradiation field including several adjacent lymph node areas while protecting important organs such as the larynx, lungs, spinal cord, liver, etc. 3. Treatment techniques for special cases: A) Segmental irradiation method: this method is mostly used for stage III and IV patients. B) Pulmonary “prophylactic” irradiation method: Patients with large mediastinal masses (mediastinal ratio ≥ 1/3) or hilar lymph node enlargement are prone to medial lung infiltration, therefore, “prophylactic” irradiation of the medial lung to eliminate clinical lesions, which is of significant value in reducing later lung invasion. C) Liver irradiation method: liver radiation therapy is mainly used in two cases: one is “preventive” irradiation of the liver due to splenic invasion found by dissection; the other is therapeutic irradiation of the liver due to clinical findings of significant invasion. Then, a comprehensive examination, selective dissection, more accurate staging, and then combined with the past treatment, give active treatment. 4. Radiation reaction and sequelae: A) blood effects; B) radiation pneumonia; C) radiation pericarditis; D) radiation myelitis; E) sexual dysfunction.