Technical Assessment of the Targeting Accuracy of Stereotactic Frames

The precision and quality of a radiosurgical procedure depend on the ability to immobilize and position the patient's head. Often, this is accomplished by means of a mechanical headframe. The ability to accurately position the head and keep it in place during the procedure depends directly on the rigidity of the headframe. This characteristic of the Leksell headframe (Elekta, Atlanta, GA, US) was evaluated by determining the impact of typical forces encountered in clinical practice on its rigidity. A quantitative analysis of the individual forces was then used to draw conclusions on the impact of the headframe's ability to accurately position the target at the desired treatment position. This article is designed to provide guidance to the user of mechanical headframes and quantitate the positioning accuracy of this frame.