γ-刀治疗中患者颈部防护措施初探

A study of the methods of shielding patient's cervixin the treatment of the Leksell Gamma Unit

在γ刀治疗中 ,通常重视的是射线对医护人员的伤害及针对医护人员的防护措施 ,这当然是很有必要的。然而 ,对施行γ -刀这种一次性大剂量照射的患者 ,几乎未采取任何防护措施 ,这对患者是相当不利的。本文以华中科技大学附属协和医院的γ -刀系统作为研究对象 ,测量了患者在进行γ -刀治疗时 ,颈部所接受的γ射线的剂量 ;测量出不同规格的准直器 ,在不同的时间段进行照射时 ,体模颈部所接受的γ射线的剂量 ;比较了不同厚度的铅的防护效果。结果显示 :有相当多的患者在进行γ -刀治疗的过程中颈部所接受的γ射线的剂量超过50mSv ,说明完全有必要进行适当的防护 ;5mm厚的铅能使射线的剂量衰减50 %以上 ,可选用5mm厚的铅进行防护。

It is essential to prevent physicians from harmful radiation in the treatment of radiation.But it is disadvantage for the patient who receives a single high dose of external radiation to the target without shielding measures for his health tissue and apparatus except head in the treatment of the Leksell Gamma Unit.The Gamma Unit at Xiehe Hospital attached to Science and Technology University in Central of China is regarded as the object of the study,the exposure dose of patient's neck during his treatment has been measured with LiF tube adhering his neck ,and the exposure dose of humanoid phantom's neck for different treatment time has been measured with LiF tube adhering its neck under the matter of using different dimension final collimators.Futher,the shielding effect of lead with different thickness has been studied.It shows that the exposure dose of most of patient's neck during operation exceeded 50mSv.So a shielding instrument for patient's neck during operation was needed.Because 5mm thickness of lead could decay 52% of radiation,the shielding instrument of patient's neck during operation can be made up of 5mm thickness of lead.