Predictive Value of Dynamic Contrast Enhancement MRI on a Cerebral Tumor Response to Gamma Knife Treatment

Prospective Study of Predictive Value of Dynamic Contrast Enhancement Magnetic Resonance Imaging With Gadolinium on the Response of a Cerebral Tumor to a Treatment With Gamma Knife

Hypothesis: the pattern of MRI contrast enhancement after gadolinium injection is different in tumors that respond well to gamma knife.

We are going to acquire sequential T1-weighted images of brain lesions before, during and after injection of Gd-DTPA. This will be repeated before and after a treatment with gamma knife. We will then analyse our results to see if there are common enhancement characteristics between lesions that will respond well to the radiosurgery treatment. Response will be clinically assessed by tumor volume as determined by MRI approximately 4 to 6 months after treatment.

Inclusion Criteria:

• Patient with intracerebral lesion benign or malignant wich are not concerned by the exclusion criteria

Exclusion Criteria:

• Pancranial radiotherapy
• Residual postop lesion
• Gliomas
• Patients < 18 years old
• Anterior allergic reaction to gadolinium
• Claustrophobia.