In recent years, with the progress of science and technology, the development of radiotherapy has also advanced by leaps and bounds, and it has entered a new era of precise radiotherapy with precise positioning, precise planning and precise implementation, and the efficacy of treating malignant tumors has been significantly improved by the precise radiotherapy characterized by “conformity” and “intensity adjustment”, and complications of normal tissues have been greatly reduced. The efficacy of treating malignant tumors has been significantly improved, and the complications of normal tissues have been greatly reduced, which has saved the lives of countless cancer patients, alleviated their pains and improved their quality of life. However, there are quite a number of malignant patients who have been delayed in effective treatment due to the ignorance of the early symptoms and radiation therapy, resulting in the deterioration of their tumors or recurrence of their tumors, which is very unfortunate. What is most disturbing is that some doctors do not know much about the indications and excellent efficacy of modern radiotherapy, and their knowledge of radiotherapy still stays at the level of the past, so that radiotherapy does not have its due place in the treatment choices of tumor patients, which makes a lot of patients lose the opportunity to obtain better curative effects with radiotherapy. The research of organ-preserving radical treatment of cancer is a brand-new topic. The efficacy of precise radiotherapy is getting higher and higher, so that the scope of surgical resection is getting smaller and smaller, and examples of organ-preserving radical treatment of breast cancer, nasopharyngeal carcinoma and laryngeal cancer have appeared, and the research is progressing rapidly in the area of organ-preserving radical treatment of rectum, bladder, prostate, lung, liver and pancreatic cancers. To publicize the indications of modern radiotherapy, so that advanced radiotherapy techniques can better serve the majority of patients and allow patients to obtain a higher survival rate and better quality of life. The time-dose concept of radiotherapy 1, conventional divided radiotherapy: 180-200 cGy each time, once a day, 5 times a week of radiotherapy, is the most classic, also called conventional radiotherapy, usually not specifically noted. 2, ultra-fractionated radiotherapy: the total treatment time remains unchanged, twice a day, with an interval of more than 6 hours, each time the dose is smaller, the total daily dose is increased compared with the conventional fractionation, and the total dose can be increased by 15-25%, the purpose is not to increase the late response of normal tissues, but to increase the killing effect on tumor tissues. 3.Accelerated super-segmented radiotherapy: shorten the total treatment time, 1.25-1.8cGy each time, 2-3 times per day, which can increase the efficacy, but also increase the damage of normal early response tissues. 4.Segmental radiotherapy: divide the total irradiation dose into two segments, with a rest of 1-4 weeks in between, which can make the normal tissues repaired, make the oxygen-depleted cells in the tumor tissues reoxygenated, and improve the tumor killing rate. 5.Large division radiotherapy: each time the dose is increased, each time 300-800cGy, one or several times of treatment, in the past, it is mostly used for palliative treatment, but now it is used for three-dimensional three-dimensional conformal radiotherapy, and the effect is improved a lot. Radiotherapy sensitizer: the biggest contradiction in radiotherapy for malignant tumors is that the radiation lethality of tumors and the tolerance of normal tissues are close to each other, any improvement of radiation sensitivity of tumor tissues and/or improvement of radiation tolerance of normal tissues is a good way to solve the problem, the drugs that can improve the radiation sensitivity of tumor cells are radiotherapy sensitizers, such as Ximena, etc., and many chemotherapeutic drugs have the role of radiotherapy sensitizer. Many chemotherapeutic drugs also have sensitizing effect of radiotherapy. Three-dimensional Conformal Radiotherapy: It is a new radiotherapy technique, which can make the distribution of high-dose area in three-dimensional direction (i.e., three-dimensional direction) consistent with the shape of the tumor target area, so it is called three-dimensional conformal radiotherapy (3D-CRT). 3D-CRT: On the basis of 3D-CRT, not only the shape of radiation field is consistent with the shape of tumor target area, but also the dose within the target area is equal everywhere, which requires that the output dose rate of each subfield be adjusted according to the requirements, which is also known as beam current modulated radiotherapy (IMRT). Indications of radiotherapy for lung cancer 1. Lung cancer of various stages that are not suitable for surgical treatment. (e.g. early stage lung cancer with cardiopulmonary insufficiency, hepatic and renal insufficiency). 2. Lung cancer of various stages that the patients refuse surgical treatment. Stereotactic radiotherapy can be used for smaller lung cancers. 4. Radiotherapy for small cell lung cancer on the basis of chemotherapy for primary foci and lymphatic drainage area can increase the local control rate and prolong the remission period. Preventive irradiation of brain can reduce the rate of brain metastasis. 5, Stage ะจ of non-small cell lung cancer is the main indication for radiotherapy; if it is estimated that there is difficulty in surgical resection, especially when CT shows that it involves important tissues and organs such as large blood vessels, preoperative radiotherapy can be used; if there is residual or regional lymph node metastasis after surgery, marking should be done and postoperative radiotherapy should be used. 6.Widespread lesions and severe symptoms of advanced lung cancer can be treated with palliative radiotherapy to improve symptoms and quality of life. 7. The effect of three-dimensional conformal intensity-modulated radical radiotherapy for early lung cancer is comparable with the long-term survival rate of radical surgery. Indications of radiotherapy for thymoma 1.Radiotherapy for thymoma occupies an extremely important position. For infiltrating thymoma, even if it is considered to have been completely resected by the surgeon, the tumor bed should still be treated with radical radiotherapy after surgery, and the recurrence of non-infiltrating thymoma after surgery should be treated with radiotherapy. 2.Stereotactic radiotherapy can be used for small thymoma. Mediastinal germ cell tumor 1, primary mediastinal seminomas are sensitive to radiation, and can be treated with preoperative radiotherapy or postoperative radiotherapy, and those who cannot or refuse to have surgery should be treated with radiotherapy and chemotherapy. 2.Non-seminomatous spermatocytoma of primary mediastinum grows fast and metastasizes early, it is suitable to use chemotherapy first and then radiotherapy. Indications of radiotherapy for breast cancer 1, radiotherapy can be used for all stages of breast cancer which are not suitable for surgery or refuse surgery. Early breast cancer needs radiotherapy after breast conserving surgery. Adjuvant radiotherapy after radical surgery or modified radical surgery. Local radiotherapy is needed for advanced breast cancer. 5, Radiotherapy is needed for local recurrence and regional lymph node recurrence and metastasis after radical surgery. Indications of radiotherapy for esophageal cancer 1. Early stage esophageal cancer that is not suitable for surgical treatment (such as heart, lung, liver, kidney and other major organs are functionally incompetent and can not tolerate surgery), or early stage esophageal cancer that the patient refuses to undergo surgical treatment, can be treated with radical radiotherapy. 2. Radical radiotherapy is also available for those whose tumors have obviously invaded important tissues and organs such as large blood vessels, main bronchial tubes or metastases in supraclavicular lymph nodes. 3.It is estimated that those who have difficulties in surgery can have preoperative radiotherapy. 4.Postoperative radiotherapy for those with postoperative residual or positive margins and lymph node metastasis. 5.Palliative radiotherapy can be used if the lesion is too long. Postoperative recurrence or metastasis, recurrence or metastasis after radiotherapy can be palliative radiotherapy. Indications of radiotherapy for pancreatic cancer 1. For pancreatic cancer that is not suitable for surgery (with contraindications to surgery) or refuses to be treated by surgery, stereotactic radiotherapy has better curative effect. 2.For patients who have been surgically resected, postoperative radiotherapy can eliminate the subclinical foci that cannot be removed by surgery and improve the curative effect of radical treatment. For advanced patients, stereotactic radiotherapy can relieve jaundice, gastrointestinal obstruction and epigastric pain caused by cancer compression. Early pancreatic cancer can be treated with three-dimensional conformal intensity-modulated radical radiotherapy. Indications of radiotherapy for gastric cancer 1: Since gastric cancer is mostly adenocarcinoma, it is not sensitive to radiation, so radiotherapy is limited to a certain extent. However, for cases with late stage of disease and difficulties in surgical resection, radiotherapy can achieve satisfactory results. 2.Pre-operative radiotherapy can be used for cancer of gastric sinus and gastric body with good general condition. 3.Postoperative radiotherapy can be used for those with poor tumor differentiation, residual tumor and lymph node metastasis. Intraoperative radiotherapy can be used for progressive gastric cancer without peritoneal and liver metastasis. 5.Palliative radiotherapy can achieve relief of obstruction, pain relief and hemostasis. Indications of radiotherapy for hepatocellular carcinoma 1. Early stage small hepatocellular carcinoma is suitable for stereotactic radiotherapy. 2, Large liver cancer with tumor 5-6cm can adopt three-dimensional conformal radiotherapy. 3, Huge liver cancer or multiple liver cancers can be treated with palliative radiotherapy. 4, single or several metastatic foci can be treated with stereotactic radiotherapy. Indications of radiotherapy for cholangiocarcinoma 1.Radiotherapy can be used for cholangiocarcinoma that is not suitable for surgery or refuses surgery. 2, Radiotherapy can be applied to patients with endoscopic placement of biliary stent for internal drainage. 3.Single confined bile duct cancer can be treated with stereotactic radiotherapy, which has better curative effect. Indications of radiotherapy for colorectal and rectal cancers 1, all stages of colorectal and rectal cancers that are not suitable for surgery or refuse surgery. Preoperative radiotherapy + anus-preserving surgery for low rectal cancer can avoid abdominal fistula with high quality of life. 3.Pre-operative radiotherapy can improve the surgical resection rate and reduce the incidence of surgical implantation. 4. Postoperative radiotherapy can improve survival rate and local control rate and reduce local recurrence. Especially if the tumor is found to invade the deep muscle layer or penetrate the intestinal wall or have adhesion with the pelvic and abdominal tissues and organs or have lymph node metastasis, postoperative adjuvant radiotherapy is needed. Indications of radiotherapy for anal canal cancer 1. Early anal canal cancer is suitable for simple radiotherapy, with 5-year survival rate up to 95%, preserving the function of independent defecation and high quality of life. 2.Middle and late stage of anal canal cancer is suitable for radiotherapy+chemotherapy+surgery comprehensive treatment, with 5-year survival rate up to 70%. Indications of splenic radiotherapy 1, hypersplenism, splenomegaly, etc. affecting the peripheral blood picture, total blood cell reduction, radiotherapy can make the spleen function return to normal. 2, Huge spleen compresses the abdominal organs, radiotherapy can make the huge spleen shrink. 3.Spleen tumor metastasis, radiotherapy can kill the metastatic tumor. Indications of radiotherapy for bladder cancer 1. All stages of bladder cancer are suitable for radiotherapy. 2.Early stage bladder cancer radiotherapy can preserve bladder, avoid abdominal fistula and improve quality of life. Male patients can also retain sexual function. 3.For bladder cancer that has difficulty in surgical resection, preoperative radiotherapy can be used to improve the rate of surgical resection. 4. Those with surgical residues, adhesion of neighboring tissues and organs and lymph node metastasis need postoperative adjuvant radiotherapy. 5. Advanced bladder cancer can be treated with palliative radiotherapy to reduce pain and improve life quality. Indications of radiotherapy for prostate cancer 1. For all stages of prostate cancer that are not suitable for surgery or refuse surgical treatment, three-dimensional conformal intensity-modulated radiotherapy can increase the dose to the prostate area and make the dose distribution uniform and satisfactory, and at the same time make the anterior wall of the rectum and the bladder to reduce the radiation damage as much as possible. 2.Radical radiotherapy can be used when prostate cancer is limited. 3.Positive pathological margins after radical surgery, lymph node metastasis, seminal vesicle involvement, high PSA value or postoperative recurrence require postoperative radiotherapy. 4.Palliative radiotherapy can be used for advanced elderly patients with obvious obstructive symptoms. Bone metastasis can be treated with radiotherapy, which has significant pain relief effect. Since most prostate cancer patients are old and weak, and most of them are in advanced stage when diagnosed, and accurate radiotherapy can achieve curative effect, most prostate cancer patients need radiotherapy. Indications of radiotherapy for renal cancer 1. Tumor can not be resected in local advanced stage and cannot be operated; patients with other diseases are not suitable for operation; patients who refuse operation can be treated with radiotherapy. 2.Tumor less than 3cm can be treated with stereotactic radiotherapy, which has better therapeutic effect. 3.Treatment of large volume, surgery is difficult to use preoperative radiotherapy. 4.Palliative radiotherapy can be used in advanced cases such as residual tumor, lymph node metastasis, isolated metastatic foci in lungs, kidneys, brain and liver after surgery.