A new MRI method for better diagnosis of brain tumors

Paris, April 23, 2003

It is now possible to distinguish gliomatosis cerebri, primitive tumors of the central nervous system with a very poor prognosis, and low-grade gliomas, tumors with a more favorable prognosis, for the very first time. Researchers at the Medical and Biological Magnetic Resonance Center (CRMBM) of the CNRS (CNRS - Université de la Méditerranée, University Medical Center of Marseille Timone), directed by Patrick Cozzone¹ , have demonstrated the contribution of magnetic resonance (MR) spectrometry to the diagnosis of these illnesses. This research illustrates the considerable prospects of this new MRI² method in the diagnosis and therapeutic management of brain pathologies in general (multiple sclerosis, dementia, strokes, childhood encephalopathies, epilepsy, etc.).

Gliomas, the most common type of brain tumors, form a heterogeneous group of tumors of varying seriousness. Gliomatosis cerebri (GC) is a type of tumor with a particularly poor prognosis: the average survival time of patients is less than one year. Its diagnosis was difficult in living patients until recently because neither conventional MRI nor even brain biopsy (a particularly invasive diagnostic exploration procedure) made it possible to differentiate other low-grade gliomas (LGG) with a better prognosis, for which survival time may exceed 10 years.

Magnetic resonance (MR) spectrometry is a non-invasive brain exploration procedure. It can be performed during a regular MRI exam and can establish a metabolic profile of the tissue studied.

Researchers at the CRMBM studied the profiles obtained by MR spectrometry in nine patients with gliomatosis cerebri and compared them to those of nine patients with low-grade gliomas and 25 healthy volunteers. They showed that the metabolic profile of the gliomatosis is radically different from that of low-grade gliomas: a multivariate analysis makes it possible to clearly separate these two populations. This metabolic profile, particularly in relation to that of other types of brain tumors, was confirmed by analysis of a data base concerning about one hundred brain tumors explored by MR spectrometry at the CRMBM.

It has thus become possible to obtain an objective diagnosis of gliomatosis in live patients and to adapt a treatment strategy as a result.

These original results open new horizons on the way this illness works and should make it easier to develop more effectively targeted treatment protocols. Moreover, it will introduce into clinical practice a new type of metabolic brain imaging through magnetic resonance that can be performed with most MRI machines. It also opens major prospects in relation to the diagnosis and treatment management of many brain pathologies.

Reference: Journal of Neurosurgery / Volume 98 / February 2003

1 - In conjunction with the neuro-oncology service (Dr Chinot) and the neuropathology service (Pr. Figarella-Branger) of the Hôpital Timone.
2 - Magnetic resonance imaging.