68Ga-DOTATATE-based radionuclides are a novel modality in the diagnosis and treatment of central nervous system meningioma. DOTATATE is a ligand for the SSTR (somatostatin receptor), which is expressed in meningioma but not in normal brain or bone. It is also more effective than MRI in delineating tumor, which is the current imaging standard for assessing meningioma. For radiation planning, it can help to reduce the risk of geometrical miss, identify area that require dose-escalation, and reduce dose to normal tissue. The purpose of the study is to compare the radiation therapy (RT) contouring and planning for meningioma with and without the use of 68Ga-DOTATATE-PET

Inclusion Criteria:

• Age ≥ 18 years old
• Able and willing to comply with the study procedures
• Intact meningioma requiring definitive radiation
• Post-operative meningioma requiring adjuvant radiation
• No prior radiation therapy or medical therapy directed at the tumour

Exclusion Criteria:

• Breastfeeding or pregnancy
• Claustrophobia or inability to lie still in a supine position
• Unwillingness or inability to provide informed consent