在骨盆照射中,小肠是放射耐受量较低的器官之一。早发急性反应和晚发反应的发生与照射体积、总的剂量、分次剂量密切相关。骨盆照射总剂量在45～50Gy之间能引起小肠的早发和晚发反应。临床上有很多方法可在骨盆照射中减少小肠的受照体积。如外科的移位法,把小肠组织机械地移出照射范围,但外科的悬挂筛孔等方法往往会引起极严重的炎症反应。后来多照射野、缩小野、治疗时保护 In the pelvic irradiation, the small intestine is one of the organs with a low radiation tolerance. The occurrence of premature and late-onset acute reactions is closely related to the irradiation volume, total dose, and fractional dose. The total dose of pelvic irradiation between 45 ~ 50Gy can cause early and late reactions of the small intestine. There are many clinical methods for reducing the irradiated volume of the small intestine in pelvic irradiation. For example, the surgical shift method mechanically removes the small intestine tissue from the irradiation range, but surgical suspension of the mesh opening and the like often causes a very serious inflammatory reaction. Later, more radiation field, narrow field, protection during treatment