Current inclusion criteria as of 03/05/2017:
1. Histologically confirmed newly diagnosed solitary atypical meningioma (WHO grade II) based on the 2016 WHO criteria
2. Age >/= 16 years
3. All anatomical locations allowed except optic nerve sheath tumour
4. Complete resection (Simpson 1, 2 or 3) as assessed by the surgeon
5. Able to commence radiotherapy between within 12 weeks of surgery (ideally 8-12 weeks)
6. WHO performance status 0, 1 or 2
7. Women of reproductive potential must use effective contraception for the whole duration of the treatment
8. Absence of any psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol and follow-up schedule; those conditions should be discussed with the patient before registration in the trial

Previous inclusion criteria:
1. Histologically confirmed newly diagnosed solitary atypical meningioma (WHO grade II) based on the 2007 WHO criteria
2. Age 16 years or over
3. All anatomical locations allowed except optic nerve sheath tumour
4. Complete resection (Simpson grade I, II or III) as assessed by the surgeon
5. Able to commence radiotherapy between 8 and 12 weeks after surgery
6. WHO performance status 0-2