自制放疗适形挡块浇铸模具及其治疗中心质量控制

Establishment of model for a type of isocenter block and its quality control

目的:设计一种放射治疗中的射线遮挡装置,在适形挡块上印制治疗中心十字的挡块浇铸模具。方法:在适形挡块浇铸模具底板上刻一个相互垂直十字小凹槽,将切割好的泡沫塑料十字与底板十字重合,低熔点铅凝固后会留下十字型直线与"专用型"有机板托盘十字线相重合,确定了挡块在托盘上的精确位置。结果:通过424块射野挡块验证片与计划片对比发现,424块射野挡块中有347块中心十字误差在1mm以内,占81.8%,60块射野挡块中心十字误差在1～2mm,占14.2%,有17块中心位置≥3m,占4%。结论:该装置操作简单、方便、可靠,解决了射野挡块在托盘上精确定位,提高了制作效率与质量。

Objective：To design one device to print crosshair of isocenter on the integrate block. Method：We carved one vertical crosshair groove in baseplate, which is coincident with the foamed plastics crosshair. With solidification of the lead of low melting point, the left crosshair will coincide with the one in the ＂tailored version＂ tray. So the precise position of the block on the tray is confirmed. Results：By comparison, it is found that the errors of the crosshairs of the 347 （81.8%） in 424 slice block keep with1mm, 60（14.2%） have margins of error of 1-2 mm, the errors of the other 17（4%） beyond 3 mm. Conclusions：This device is easy to operate, convenient, reliable, accurately solve one of the integrate blocking and make a position on the tray. Meanwhile, it have improved efficiency and quality.