Trial of Proton Versus Carbon Ion Radiation Therapy in Patients With Chordoma of the Skull Base

Inclusion Criteria: * Karnofsky Performance Score ≥60% * Age \>18 years and \<80 years * Informed consent signed by the patient * Histological confirmation of chordoma with infiltration of the skull base. Exclusion Criteria: * Inability to understand the aims of the study, no informed consent * Prior RT of skull base region * Other malignancies with disease-free interval \< 5 years (excepting pre- cancerous lesions) * Participation in another trial * Pregnancy * Simultaneous CHT or Immunotherapy.