[Targeted treatments: which imaging?]

Currently, the evaluation of targeted treatments by functional imaging in oncology is a main goal. Several techniques as Dynamic Contrast Enhanced-MRI, CT-perfusion or Dynamic Contrast Enhanced-US are proposed. The blood flow perfusing the tumor, the blood volume corresponding to the percentage of vessels of total tumor or the diffusion of contrast agent are parameters calculated from the acquisition of time intensity curves during several minutes (TIC). Blood flow, blood volume and mean transit time could be calculated by DCE-US, DCE-MRI and CT-perfusion. But the capillary permeability and the interstitial volume could be evaluated only with DCE-MRI and CT-perfusion because US contrast agent is strictly intravascular. These functional imaging techniques allow predicting earlier the clinical response to targeted treatments before the modification of tumoral volume evaluated according to RECIST criteria.