NK/T-cell lymphoma is a rare type of malignant lymphoma, accounting for 2% to 10% of lymphomas. Therefore, Chinese physicians have more practical experience in the management of this disease. The disease predominates in young and middle-aged men, with a male-to-female ratio of about 3:1. The average age of onset is about 40 years, but elderly and pediatric patients can also be seen clinically. It is generally believed that NK/T-cell lymphoma is associated with EBV infection, is aggressive, has a short course, and has a rapid clinical progression with only a 6-12 month survival period if not treated promptly. Early lesions of extra-nodal NK/T-cell lymphoma originating in the nasal cavity are sensitive to radiotherapy, and the prognosis is significantly improved by the integrated treatment modality of radiotherapy, with a current 5-year survival rate of over 70%; whereas extra-nodal NK/T-cell lymphoma originating outside the nose has a poor prognosis. Therefore, most patients can be cured by receiving standardized radiotherapy as soon as possible after diagnosis. NK/T-cell lymphoma mostly originates in the nasal cavity and is characterized by disfiguring lesions in the midline of the nose and face; it can also originate in the Wechsler ring (mainly affecting the nasopharynx, tonsils, oropharynx, and tongue) and other sites (mainly affecting the skin, testes, and gastrointestinal tract), and in a very small number of cases, the initial stage of the disease is characterized by systemic dissemination without significant nasal involvement. Cases that occur in the nasal cavity often present with nasal congestion, runny nose, bloody nose or epistaxis, tinnitus, hoarseness, sore throat, dysphagia and mucosal ulcers. Progressive development may include invasion of the sinuses, orbits, cheeks and frontal bone. Destruction of the midline area is its prominent facial feature, such as perforation of the nasal septum, perforation of the hard palate, cavernous injury of the nasal bridge, and even involvement of the facial skin. Other extra-nodal lesion sites, such as skin, may manifest as nodules, ulcers and mucosal erythema; gastrointestinal tract involvement may cause abdominal pain, intestinal obstruction or perforation; lung involvement may have cough and hemoptysis, etc. Since the early stage of the disease has no specific manifestations, it is often misdiagnosed as “cold”, “rhinitis” or “deviated septum” due to nasal congestion, pus, epistaxis, etc. Therefore, the diagnosis of the disease relies not only on Therefore, besides clinical manifestations and imaging examination, the most important thing is to obtain pathological basis. Since tumor cells often invade small blood vessels, resulting in ischemic necrosis of tumor tissue, biopsy tissue is often reported as “chronic inflammatory tissue”, and the pathology positivity rate is low, so clinically some patients need to repeatedly take the material for several times before the disease is finally diagnosed. For patients with a clear pathological diagnosis, systematic staging tests are needed to clarify the clinical staging, develop an appropriate treatment plan and determine the prognosis, and to improve the following tests before treatment: 1. Hepatitis B virus and copy number examination; 6. Bone marrow aspiration; 7. For patients with sufficient funds, whole-body PET-CT examination is highly recommended for more accurate determination of the stage and evaluation of the treatment effect. Unlike other lymphomas, which are mainly treated with chemotherapy, nasal NK/T-cell lymphoma is sensitive to radiation therapy, and radiation therapy is the main radical treatment for this disease. The dose of radiation therapy for nasal NK/T-cell lymphoma is 50-60Gy, and most patients can achieve complete remission or even cure. New radiation therapy technology, intensity-modulated radiation therapy, has been developed to increase the tumor dose and protect normal tissues, showing more and more advantages. Our center is the first in central China to carry out intensity-modulated radiation therapy technology, and has accumulated rich clinical experience in the radiotherapy of extra-nasal node NK/T-cell lymphoma. Considering the high rate of distant metastasis after treatment, it is suggested that the use of reasonable chemotherapy is still necessary, and a combination of radiotherapy and chemotherapy is currently advocated for early stage NK/T-cell lymphoma. There is no unified chemotherapy regimen internationally, and current domestic and international studies have shown that CHOP regimens for traditional treatment of lymphoma are insensitive, and chemotherapy regimens containing levomucoidase have shown better efficacy. We have recently used the chemotherapy regimen of pemantase + high-dose methotrexate + dexamethasone and achieved good therapeutic results. This chemotherapy regimen has the following advantages: 1. The regimen is based on pemesterase, and its efficacy is similar to that of levomethotrexate, but the incidence of allergic reactions is low; 2. A large number of male NK/T-cell lymphoma patients have testicular relapse after treatment because conventional chemotherapy drugs cannot cross the blood-testis barrier to the testis, and this regimen uses high-dose methotrexate, which is a good solution to this clinical problem; 3. The regimen has low side effects and low incidence of adverse reactions after standardized pretreatment. Clinically, for patients who cannot tolerate high-dose methotrexate or pemantase allergy, we use GDP (gemcitabine + cisplatin + dexamethasone) chemotherapy regimen to achieve better treatment results in the treatment of extranodal NK/T-cell lymphoma. High-dose chemotherapy combined with autologous peripheral blood stem cell transplantation or bone marrow transplantation can be used as a treatment for recurrent nasal NK/T-cell lymphoma. Since radiotherapy and chemotherapy are carried out simultaneously in our department, the respective advantages of radiotherapy and chemotherapy can be better utilized, and radiotherapy can be used to control local lesions while chemotherapy can be reasonably arranged to prevent distant recurrence. Therefore, once the diagnosis of NK/T-cell lymphoma is confirmed, you must build up confidence and can visit our department to receive standardized and reasonable radiotherapy as soon as possible.