6MV-X射线不同部位照射时患者睾丸剂量的研究

Study on the dose of spermaries irradiated with 6MV-X rays in different unit of the patient's body.

目的：了解医用直线加速器的６ＭＶ－Ｘ射线在进行头颈部、胸部、下腹部肿瘤治疗时非靶器官睾丸的受照剂量，为优化临床治疗计划提供实验依据。材料与方法：将热释光剂量探测器（ＴＬＤ）预置于非均匀组织等效拟人体模型睾丸内，然后以６ＭＶ－Ｘ射线分别仿鼻咽癌、食道癌、前列腺癌进行照射，根据ＴＬＤ读数及标准方程推算出睾丸的剂量。结果：同一部位进行照射时，两侧睾丸剂量无明显差异，不同部位照射时，其睾丸的剂量有显著差异，头颈部、胸部、下腹部的靶区每Ｇｙ剂量照射对睾丸的剂量贡献分别为０．１５５ｍＧｙ、０．３４０ｍＧｙ、３２．０７５ｍＧｙ。结论：常规的下腹部肿瘤放射治疗对睾丸组织受照剂量较大，可用屏蔽的方法减少睾丸的受照剂量。

Purpose: To know the dose of spermary when the patient was radiotherapied in head-neck,in thorax,in abdomen with 6MV-X rays ,so as to afford experimantal dependencies for clinical therapy plan. Methods and Materials: Put the thermoluminescent dosimeters(TLD) in a tisssue-epuivalent anthropomorphic phantom's spermary and irradiated with 6MV-X rays in different unit of the phantom to measure absorbed doses of spermary. Rusults: irradiated in the same unit,both of spermaries' doses are not different ,while in different unit,the doses of spermary are different.If 1 Gy dose was given in head-neck or in thorax or in abdomen,the doses that spermary absorbed were 0.155mGy ,0.340mGy and 32.075mGy. Conclusion: The routine radiotherapy to the tumour in abdomen will damage spermary, the effective mothod to decrease the dose of spermary is to use screen blanker.