Radiation on normal cells and tumor cells there is no essential difference, but the tumor cells than normal cells grow and multiply quickly, poor differentiation, they are more sensitive to radiation, ie, tumor cells after irradiation damage suffered more as serious, while repair capacity can not compete with normal cells. So that you can use an appropriate time interval and exposure, so that injury and death by tumor tissue and normal tissue, while also restore damaged but still, this is the purpose of radiation therapy.
Radiotherapy principles, the role of radiation on the tumor is twofold: First, the direct effect of the tumor in some cells died immediately after irradiation, and some died while in the division again, and some are premature aging, loss of reproductive capacity and become a harmless; second indirect effect, that is, after irradiation occlusion of small blood vessels supply the tumor, surrounding normal tissue growth and repair scar formation, the residual tumor after irradiation are not nutrition, and thus gradually decline.
Direct and indirect effects in the treatment of both plays an important role. Theoretically the maximum radiation dose and fast should be able to kill all the tumor, but this treatment on normal tissue damage is too heavy, and thus weaken the ability of local defense and repair capacity and greatly reduce the indirect effect, but increased local recurrence rate. Too fast too fast at the same time exposure, so that the body has been greatly affected, general condition declined, not only can promote tumor metastasis far the Department can also increase the radiation damage and complications of radiation therapy in appropriate dose and the right time is very important.
Esophageal principles of radiation therapy, radiation therapy is an important treatment for esophageal cancer, one of the choice of treatment programs should be based on the length of lesion, extent of tumor invasion, degree of esophageal obstruction, with or without bleeding tendency, with or without perforation orientation (ulcer size and depth), metastasis, with or without major medical diseases, and patients with systemic symptoms of folders may be.
Radiotherapy in principle, cervical and upper thoracic esophageal cancer surgeries, complication rate, and radiation damage, more effective than surgery, radiation therapy should be the first choice; lower thoracic esophageal carcinoma and adjacent gastric prone abdominal lymph node metastases, radiation therapy is poor, and the efficacy of surgery is better, should be the first choice operation; in thoracic esophageal cancer efficacy of radiotherapy and surgery, rather, should be selected according to specific circumstances radiotherapy, surgery or combined treatment; narrow Esophageal carcinoma of the esophagus complete obstruction, bleeding and perforation tendencies, there is regional lymph node metastasis, surgical resection should be preferred; esophageal tumor was foreign invasion, surgical resection is difficult, should be based on pre-operative radiotherapy or radiotherapy plus surgery is preferred.