Proton Dose Escalation for Patients With Atypical or Anaplastic Meningiomas

Inclusion Criteria: * histologically confirmed atypical (WHO grade II) or anaplastic (WHO grade III) meningioma with the indication for radiotherapy * MRI (within 24h post-operative, if not available than with a time interval of \~ 6 weeks) including contrast-enhanced T1 weighted 3D dataset and PET for evaluation of macroscopic tumour (residuum) * Karnofsky Performance Score ≥ 60, ECOG ≤2 * For women with childbearing potential, (and men) adequate contraception. * Ability of subject to understand character and individual consequences of the clinical trial * Written informed consent (must be available before enrolment in the trial) Exclusion Criteria: * refusal of the patients to take part in the study * previous radiotherapy of the brain * several manifestations of the meningioma in different regions of the brain or additional spinal manifestations * distant metastases * patients who are not suitable for radiotherapy * known other malignant disease within 5 years before radiotherapy (except tumours that likely do not impact prognosis and likely not require treatment interfering with study therapy, e.g. in-situ carcinoma of the breast or cervix uteri) * pregnant or lactating women * patients with non-MRI compatible metal implants, pacemaker or non-MRI compatible external automatic defibrillators * patients not able to understand character and individual consequences of the clinical trial * claustrophobic patients * current participation in another clinical intervention stud…