放射治疗临床所需要的一些基本物理数据,如射野中心轴上的百分深度剂量(PDD)、组织最大剂量比(TMR)等,受诸种因素的影响。特别是加速器的数据,需要经常的定期测量和校正更新。测量一般在水模中进行,并要具备一定的测量条件:如水箱尺寸要大(一般50cm×50cm×40cm)、带有数据扫描移动(两维、或三维)装置,特定的测量探头等,而且要根据测量探头的种类,对不同射线质和其它物理、几何因素进行数据的修 Some of the basic physical data required for clinical radiotherapy, such as PDD and TMR, are affected by various factors. Accelerator data, in particular, require regular, regular measurements and corrections. The measurement is usually carried out in a water mode and must have certain measurement conditions such as a large tank size (typically 50 cm × 50 cm × 40 cm) with a data-scanning mobile (two or three dimensional) device, a specific measurement probe, And according to the type of measuring probe, the different ray quality and other physical, geometric factors for data repair