Non Invasive Detection of IDH1/2 Mutation in Gliomas (IDASPE)

Non Invasive IDentification of Gliomas With IDH1/2 Mutation by Analysis of Circulating Plasmatic DNA, D-2-hydroxyglutarate Dosage in Biological Liquids and Detection by Brain SPEctro-MRI: Impact for Diagnosis and Follow-up

This trial develops a non invasive diagnostic approach of IDH1 mutated gliomas combining mutation detection from free plasmatic DNA, D-2HG dosage in urine samples, and D-2HG detection by Brain Spectro MRI. In group 1 (25 patients), patients with presumed grade II-III gliomas candidate to surgery will undergo spectro MRI, plasma, urine dosages. Results will then be confronted to tumor mutational status and D-2HG. In group 2 (15 patients), patients with known IDH1 mutation will undergo spectro MRI, plasma, urine dosages overtime in order to correlate results with the response to treatment.

The aim of this trial is to develop and validate a non invasive diagnostic approach of IDH1 mutated gliomas. It will evaluate the specificity and sensitivity of D-2HG detection by Brain Spectro MRI. This approach will be coupled with mutation detection from free plasmatic DNA and D-2HG dosage in urine samples. The primary end-point is the quantification of D-2HG by spectro-MRI, and the correlation with the dosage of D-2HG in the tumor fragment, and the mutational status (group 1: 25 patients). The secondary endpoints include: longitudinal analysis Spectro-MRI overtime (12 months) correlation with radiological evolution and the response to treatment (group 2: 15 patients) Differentiation of tumor recurrence from radiation induced changes Confrontation of Spectro-MRI, D-2HG dosages and IDH mutation detection from plasma DNA, and elaboration of a combined score of prediction

D-2HG quantified by spectroMRI the measure of the ratio between two pics D-2HG and creatine [Time Frame: 3 months after surgery] [Designated as safety issue: No]

This ratio D-2HG/creatine will be correlated with the dosage obtained in tumor tissue performed within three months after the surgery

The ratio D-2HG/creatine will be evaluated overtime and correlated with radiological evolution and the response to treatment (group 2: 15 patients) every four months

Inclusion criteria Affiliation to a social security system Patient≥ 18 years old Written informed consent One of the two situations: presumed grade II-III glioma candidate to surgery (group 1) IDH1/IDH2 mutated grade II-III gliomas, candidate to chemotherapy or radiotherapy treatment, or simple follow-up (group 2) Evaluable tumoral mass min diameter >2 cm (FLAIR) PKPS > 60 Exclusion criteria Contra-indication to MRI Patient unable to give an written Informed Consent Patient under guardianship or deprived of freedom For group 2: patient already included in group 1