Application description is found in the following papers: Jan S et al, GATE: a simulation toolkit for PET and SPECT. Phys. Med. Biol. 49 (2004) 4543-4561 Sarrut D. and Guigues L. Region-oriented CT image representation for reducing computing time of Monte Carlo simulations. Med Phys. 35(4):1452-1463. 2008 Two components (fgate and merge, merge being disabled in experiments conducted for the heteropar and JGC papers) are run on the EGEE grid. A quite elaborated workflow is ma...