低熔点适形铅挡块的制作方法与误差分析

摘要

AIM:To investigate making method of low melting-point lead block and find causes of error,in order to improve the quality assurance and quality control.METHODS:The patient positioning chip shot were taken on the simulator machine,doctors drew the outline target shape and used hot wire cutting machine to shape,made lead block,and then verified in a simulated film po-sitioning machine,to be implemented after passing treatment, combined with verification results to make different error analysis and evaluation of the block.RESULTS:Between the blocks there were different levels of error,affected by every aspect of the quality of molded,avoiding these areas errors,could make the er-ror to a minimum.CONCLUSION:Making conformal lead block with low melting-point lead is a good way in conventional radio-therapy,which not only meets the design requirements for radia-tion treatment planning,but also improve the accuracy of radio-therapy,and only quality control could ensure the quality of the block.%目的：探讨低熔点适形铅挡块的制作方法及误差产生的原因，提出完善质量保证和质量控制的方法。方法：模拟定位机上拍患者定位片，医生勾画靶区后利用热丝切割机切割形状后制作铅挡，然后在模拟定位机下进行拍片验证，合格后方可实施治疗，结合验证结果，对挡块出现不同的误差进行分析和评价。结果：每个挡块之间都存在不同程度的误差，制作的每一个环节都直接影响成模的质量，避免这些环节出现差错，才能使误差降到最小。结论：用低熔点铅制作适形铅挡是目前常规放疗中行之有效的好方法，它不仅符合放射治疗计划的设计要求，而且提高了放射治疗的精确度。但需要做好质量控制，才能保证挡块的质量。