Intracavitary radiation therapy is the most important feature of high surface dose of radioactive sources, with the sharp decline from the increased dose, which is the biggest advantage of brachytherapy of esophageal cancer is a fatal point. Is the use of close-dose clinical characteristics, in order to improve the local dose of the esophagus, lower local recurrence rate, to improve the survival rate purposes.
Esophageal cancer brachytherapy treatment of deep dose drawback is lack of effective therapeutic range is very limited, so is mainly used for brachytherapy of esophageal cancer adjuvant therapy and palliative care, strict control of the more important indications, in general, brachytherapy only for Maximum outer edge of the tumor invasion depth l.5cm patients.
(A) of the radioactive sources
60Co, 137CS, 192Ir
(B) the dose rate
LDR (low dose rate) :0.4 – 2Gy / hoMDR (the dose rate) :2 – 12Gy / hoHDR (high dose rate):> 12Gy / h.
(C) external irradiation + intracavitary irradiation
As a supplementary external irradiation with external beam radiotherapy combined with external irradiation should be first, tumor regression after intracavitary irradiation line, external radiation dose less than 50Gy, HDR irradiation once a week for 5 – 8Gy, total dose of not more than 20Gy / 3. Intracavitary irradiation before the first CT examination, the tumor extensively outside invader, intracavitary irradiation can not increase local control rate, there is active bleeding and esophageal ulcer were not suitable for deep cavity irradiation.
(D) intracavitary irradiation complications
Intracavitary irradiation of esophageal cancer brachytherapy treatment, the esophageal wall by high-dose hypofractionated irradiation, high incidence of radiation ulcer, esophageal stricture, and perforation.