Hills J F, Ibbott G S, Hendee W R
Med Phys. 1979 Jul-Aug;6(4):309-11. doi: 10.1118/1.594587.
Full utilization of the precision of newer radiation therapy devices requires patient contours drawn with greater accuracy than is possible with the conventional lead wire technique. Polaroid photographs can introduce large errors due to distortion and small image size. Techniques including electromechanical or optical devices and CT scans offer improved accuracy, but often at added expense. A method for obtaining contours has been developed which utilizes a treatment planning minicomputer (equipped with an analog-to-digital converter and plotter) and a commercially available ultrasound B-scanning arm. Voltages corresponding to the X-Y position of the tip of the scanning arm are fed from the scanner to the A/D interface, smoothed, scaled, and plotted. The resulting drawing is a full scale external patient contour. The accuracy of this method is compared to alternative techniques.
要充分利用新型放射治疗设备的精度，需要绘制比传统铅丝技术所能达到的更高精度的患者轮廓。宝丽来照片由于失真和图像尺寸小可能会引入较大误差。包括机电或光学设备以及CT扫描在内的技术可提高精度，但通常要增加成本。已经开发出一种获取轮廓的方法，该方法利用治疗计划微型计算机（配备模数转换器和绘图仪）和市售的超声B扫描臂。与扫描臂尖端的X-Y位置相对应的电压从扫描仪馈送到A/D接口，进行平滑、缩放和绘图。得到的图形是患者全身外部轮廓。将该方法的精度与其他技术进行了比较。
