A fluorescence enhanced diffuse optical tomography algorithm taking into account the optical heterogeneities is presented. It is suitable for continuous wave acquisitions and naturally handles complex shaped object. Therefore, it allows in vivo studies of small animals injected with target-specific fluorescent probes without immersion fluid. A comparison with previous methods conducted on simulations is presented. A validation experiment performed on the same mouse at different stage of lung tumors growth shows the ability of the system to be used for biological studies