 - To demonstrate if the multimodal approach, combining the morphological aspect of the MRI with the metabolic aspect of the tumor with magnetic resonance spectroscopy MRS and O-2-18F-fluoroethyl-L-tyrosine FET or 18F-fluorocholine FCH PETCTthe FCH allows to improve the location of a active metabolic tumor and its impact on the ideal choice of sampling biopsy. 