Developing imaging technologies and molecular probes that allow cancer detection at its earlier stages, that would also provide predictive information on the chances of a given tumor to respond to a therapy, to monitor non-invasively and in real time how efficiently this therapy will reach the tumor as well as the early or long-term tumor's response is of course of major importance. Imaging methods are also expected to play major roles in the drug development process very early in the laboratory, during the translation phase from in vitro assays to preclinical systems, as well as to evaluate their ADME (pharmacokinetics and pharmacology for absorption, distribution, metabolism, and excretion). Finally, functional imaging will also bring some more details on the local and real time biological activity of the drug.