Pilot to validate in vivo 2-HG MR spectroscopy in low grade gliomas

Background of the study: Low grade gliomas are brain tumors that occurs mainly in young adults. The mean survival is about 10 years. The tumor might be difficult to resect if located near an important brain area. Treatment is best done using radiotherapy and chemotherapy in such cases. However, the diagnosis should be established with certainty with a brain biopsy. However, a biopsy induces the risk of brain damage. Unfortunately, a brain biopsy is the only way to establish the diagnosis with certainty currently.

An alternative seems possible. Low grade gliomas have a IDH gene mutation. This mutation results in the production of 2-hydroxyglutarate (2-HG). 2-HG seems to be measurable on a specific MRI sequence, MR spectroscopy.

The current pilot study will investigate if this IDH gene mutation indeed result in the presence of 2-HG on MRI. We also validate if the concentration measured on MRI correlate with the concentration measured in the tissue.

If indeed positive, we are able to set-up an follow-up study (not part of the current protocol) to see if the 2-HG MR scan could replace a brain biopsy in patient with a low grade gliomas.

Objective of the study: Primary goal is to investigate if the 2-HG peak on in vivo MR spectroscopy correlates with the ex vivo IDH mutation and 2-HG concentration in patients with a low grade gliomas.

Study design: A pilot study to validate 2-HG spectroscopy in patients with a low grade glioma.

Study population: Patients with a low grade glioma ≥ 18 years old that a planned to undergo surgery (N=10).

Primary study parameters/outcome of the study: Primary endpoint is firstly the correlation between the presence of the IDH mutation and the presence of the 2-HG peak on MR spectroscopy (binary variables). Also primary endpoint is the correlation between the concentration of 2-HG on in vivo MR spectroscopy and ex vivo in the tissue in mmol/mg (continue variables).

Nature and extent of the burden and risks associated with participation, benefit and group relatedness (if applicable): Participants will not have and advantages from participation in the research. The standard clinical diagnostic and therapeutic procedures will not change. Participants will have no additional costs and will not receive any financial compensation. The discomfort is that they will have to lay down 15 minutes longer in the already planned MRI scan. The MRI will last 55 minutes instead of 40 minutes.

We expect that patients with a IDH mutation demonstrate an increase in 2-HG on MR spectroscopy. We also expect a positive correlation between in vivo 2-HG on MR spectroscopy and ex vivo concentration in tissue.

pre-operative MR Spectroscopy. 2-HG tissue concentration measurement post-operative ex-vivo.

MR spectroscopy for 2-HG.