MRI and MET-PET treatment evaluation in glioblastoma

Glioblastomas (GBM) are the most malignant brain tumours with low survival rates. Treatment failure causes this tumour to inevitably recur, making close monitoring of GBM patients essential. The gold standard for follow-up is anatomical MR imaging based on contrast enhancement. However, this imaging method is hindered by pseudo-progression which can resemble true tumour progression, but is in fact due to treatment effects.

Functional imaging methods have been employed to overcome the limitations of anatomical MRI by measuring biological aspects of the tumour. Cellular density, tumour neovascularisation and tumour metabolites can be visualised by diffusion MRI, perfusion MRI and MR spectroscopy, respectively. Increased metabolism associated with tumour tissue is detectable with methionine PET (MET-PET). Although these functional imaging techniques individually showed promising results in differentiating pseudo-progression from true tumour progression, a large prospective study comparing all techniques directly in the same patients is lacking.



This study aims to establish the diagnostic accuracy of functional MRI techniques and MET-PET individually and combined in treatment evaluation of glioblastoma.

Our hypothesis is that a combination of functional MRI techniques and MET-PET shows a higher diagnostic accuracy than anatomical imaging or one functional MRI technique alone.

In this prospective longitudinal cohort study 40 primary glioblastoma patients will undergo multimodal MRI and MET-PET within 72 hours after surgery to acquire a baseline scan. Follow-up scans will be acquired 10 weeks after concomitant chemoradiotherapy (CCRT) and then with 3 months intervals until anatomical follow-up MRI is suggestive of tumour recurrence. The final diagnosis will be made radioclinically or histologically.

This study aims to establish the diagnostic accuracy of functional MRI techniques and MET-PET individually and combined in treatment evaluation of glioblastoma.