We present the ongoing studies aiming at providing a real-time control of the dose distribution during ion therapy. These studies are undertaken in the frame of the National and Rhône-Alpes Regional Research Programs for Hadontherapy. We aim at implementing combined modalities for real-time quality control of the deposited dose for future therapy centers. Several modalities are under development within this research program. Improvements on Positron Emission Tomography (PET) can be obtained by means of Time of Flight, using fast scintillators or resistive plate chambers, with dedicated readout and electronics. The in-bream prompt gamma imaging looks very promising in view of recent preliminary results, provided Time of Flight is used to discriminate gamma from neutrons and scattered particles. A collimated detection setup or a Compton camera is envisaged. Prompt emission of light charged particles like protons is also discussed.