The metastasis progression versus radionecrosis following GK treatment can sometimes be difficult to distinguish. 60 patients will be included in this prospective, monocentric study. 3 MRI (baseline, 1month and 6 month follow-ups) will be performed. Two neuroradiologists will blindly analyse the MRIs comparing ASL sensibility and specificity to the standard morphological evaluation and T2 perfusion.
Arterial spin labeling (ASL) is a non-invasive MRI technique that could help the radiologists to distinguish brain metastasis progression versus radionecrosis following gamma-knife treatment.~The primary target of the study is to establish the diagnostic performances (specificity, sensitivity) of quantitative measures of ASL in brain metastases suspected of progression/radionecrosis after GK treatment