A simple and non-invasive vacuum mouthpiece-based head fixation system forhigh precision radiotherapy

Purpose: To demonstrate why conventional non-invasive mouthpiece-based fixa tion has not achieved the expected accuracy and to suggest a solution of th e problem. Patients and Methods: The Vogele Bale Hohner (VBH) head holder is a non-inv asive vacuum mouthpiece-based head fixation system. Feasibility and reposit ioning accuracy were evaluated by portal image analysis in 12 patients with cranial tumors intended for stereotactic procedures, fixated with the newe st version (VBH HeadFix-ARC(R)). Results: 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 0.9 2 mm and 1.2 mm, respectively) with cost and repositioning ti me per patien t and patient comfort comparable to that of com mon thermoplastic masks. Conclusion: These preliminary results show that high repositioning accuracy does not rule out simple and quick application and patient comfort. Paramo unt, however, is tensionless repositioning via the vacuum mouthpiece.