This trial is a single arm study for patients receiving bevacizumab for IDH-wildtype glioblastoma. Patients receiving bevacizumab (an anti-VEGF therapy) will receive PSMA scans to investigate the role of PSMA expression in glioblastoma and its relationship to VEGF expression.

Inclusion Criteria:

• > 18 year of age
• ECOG 0-2
• Able to provide informed consent for the study
• Minimum of 1 month from completion of radiotherapy with clinical or radiography evidence suggesting residual tumour
• Confirmed glioblastoma IDH1/2 wildtype (WHO2021)
• For bevacizumab treatment as per treating physician
• Able to comply with trial requirements

Exclusion Criteria:

• No major organ impairment that would likely lead to unacceptable toxicities- eg significant cardiac, hepatic, renal or haematologic dysfunction (based on clinician assessment)
• Any contraindication to bevacizumab, MRI gadolinium contrast or 68Ga-PSMA-617 radioisotope
• Any implant, foreign body, 3T MRI incompatible device or other contraindication to MRI imaging
• Does not fulfill PBS requirements for bevacizumab
• Women lactating, pregnant or of child baring potential who are not willing to avoid pregnancy during the study

Glioblastoma patients receiving Bevacizumab as part of standard of care.