1Department of Radiation Oncology, Eberhard-Karls-University Tuebingen, Tuebingen, Germany
2Centre for Neurooncology, Eberhard-Karls-University Tuebingen, Tuebingen, Germany
3Department for Ophthalmology, Eberhard-Karls-University Tuebingen, Tuebingen, Germany
4Department of Diagnostic and Interventional Neuroradiology, Eberhard-Karls-University Tuebingen, Tuebingen, Germany
5Department of Radiation Oncology, Section for Biomedical Physics, Eberhard-Karls-University Tuebingen, Tuebingen, Germany
6RadioChirurgicum, CyberKnife Suedwest, Klinik Am Eichert, Goeppingen, Germany