电离辐射对中耳黏膜早期损害的研究

Studies on the early stage damage of middle ear mucosa by ionizing radiation

目的应用动物模型,观察中耳黏膜在不同剂量放射治疗下组织变化及其与放射剂量的关系。方法 35只豚鼠作为实验对象,γ射线照射右耳,300cGy/f,5次/周,观察对照组与实验组黏膜病理结构改变。结果当剂量很小时光镜下未见明显变化;随着剂量的增加,实验组中耳出现渗液,黏膜增厚,白细胞浸润,中耳渗液中也出现白细胞。结论放射后中耳黏膜的改变随着剂量和时间变化而变化,在放射早期、剂量较小时黏膜可能正常,随剂量增加中耳黏膜变化更为明显。

Purpose To observe early histological changes of middle ear formed clinically during radiotherapy for the treatment of head and neck malignancy in an animal model and the relationships to the dose of administration. Methods Adult guinea pigs(n = 35) were used in this study. Gamma irradiation was administered to the right ear of each guinea pig with 300 cGy/fraction,5 times per week, using a cobalt-60 machine. After having received a moderate doses , the tympanums were harvested and the pathological changes of the control and experimental groups mucosae were studied with a light microscope. Results Light microscope showed there were no manifest changes when the dose was small. When the dose increased,the middle ear effusion occurred,and the mucosae of the experimental groups became thicker. Leukocytes were found infiltrating in the mucosae and also appeared in the middle ear. Conclusion The middle ear mucosae after irradiation were found to change over time and with dose. At the beginning of irradiation and/ or with small dose,its structure could be normal but would deteriorate afterwards.