GATE: a simulation toolkit for PET and SPECT.

Monte Carlo simulation is an essential tool in emission tomography that can assist in the design of new medical imaging devices, the optimization of acquisition protocols and the development or assessment of image reconstruction algorithms and correction techniques. GATE, the Geant4 Application for Tomographic Emission, encapsulates the Geant4 libraries to achieve a modular, versatile, scripted simulation toolkit adapted to the field of nuclear medicine. In particular, GATE allows the description of time-dependent phenomena such as source or detector movement, and source decay kinetics. This feature makes it possible to simulate time curves under realistic acquisition conditions and to test dynamic reconstruction algorithms. This paper gives a detailed description of the design and development of GATE by the OpenGATE collaboration, whose continuing objective is to improve, document and validate GATE by simulating commercially available imaging systems for PET and SPECT. Large effort is also invested in the ability and the flexibility to model novel detection systems or systems still under design. A public release of GATE licensed under the GNU Lesser General Public License can be downloaded at http:/www-lphe.epfl.ch/GATE/. Two benchmarks developed for PET and SPECT to test the installation of GATE and to serve as a tutorial for the users are presented. Extensive validation of the GATE simulation platform has been started, comparing simulations and measurements on commercially available acquisition systems. References to those results are listed. The future prospects towards the gridification of GATE and its extension to other domains such as dosimetry are also discussed.

A randomized general practice group-comparative study of femoxetine and placebo in the prophylaxis of migraine.

In a randomized general practice study, the prophylactice effect of femoxetive (a 5HT uptake inhibitor) was compared with placebo in migraine patients. Treatment, with separate randomization schedules in each practice, was allocated to 65 patients. Each patient was treated for 16 weeks with 200 mg increasing during the first nine days to 600 mg daily. No effect of femoxetine could be demonstrated in attack frequency and headache index. Separate analysis of maximum reduction in serotonin concentration during treatment revealed no difference in efficacy when compared with placebo. This supports earlier studies that femoxetine generally exerts no prophylactic effect on migraine, and the hypothesis that platelet 5HT might be of major importance in the pathogenesis of migraine is not supported.