Jensen J M, Ihnen E
Radiologische Universitätsklinik Kiel.
Strahlenther Onkol. 1990 Jun;166(6):411-4.
In radiotherapy it is sometimes necessary to use nonstandard treatment distances, i.e. in mantle-field irradiation or in total-body irradiation. The design of the collimating system as well as other components of the treatment head are influencing the dose rate depending on focus-patient respectively focus-phantom distance (FPD). The quality of the collimator and the dependence on FPD, which deviates from the inverse-square law, were described by a new defined parameter INV. This parameter INV was checked experimentally on various treatment units. For approximation and explanation of this INV factor a combination of a point, line and area source is proposed.
在放射治疗中，有时需要使用非标准治疗距离，即在斗篷野照射或全身照射中。准直系统的设计以及治疗头的其他组件会根据焦点-患者或焦点-体模距离（FPD）影响剂量率。准直器的质量以及与FPD的相关性（这偏离了平方反比定律）通过一个新定义的参数INV来描述。该参数INV在各种治疗设备上进行了实验验证。为了近似和解释这个INV因子，提出了点源、线源和面源的组合。
