A simple and non-invasive vacuum mouthpiece-based head fixation system for high precision radiotherapy.

Abstract

To demonstrate why conventional non-invasive mouthpiece-based fixation has not achieved the expected accuracy and to suggest a solution of the problem. The Vogele Bale Hohner (VBH) head holder is a non-invasive vacuum mouthpiece-based head fixation system. Feasibility and repositioning accuracy were evaluated by portal image analysis in 12 patients with cranial tumors intended for stereotactic procedures, fixated with the newest version (VBH HeadFix-ARC). Portal image analysis (8 patients evaluated in 2-D, 4 patients in 3-D) showed that even in routine external beam radiation therapy, treatment can be applied to within a mean 2-D and 3-D accuracy of under 2 mm (SD 0.92 mm and 1.2 mm, respectively) with cost and repositioning time per patient and patient comfort comparable to that of common thermoplastic masks. These preliminary results show that high repositioning accuracy does not rule out simple and quick application and patient comfort. Paramount, however, is tensionless repositioning via the vacuum mouthpiece.