Background: In specific conditions, photodynamic therapy (PDT) can enhance the distribution of macromolecules across the endothelial barrier in solid tumors. It was recently postulated that tumor neovessels were more responsive to PDT than the normal vasculature. We hypothesized that Visudyne (R)-mediated PDT could selectively increase liposomal doxorubicin (Liporubicin (TM)) uptake in sarcoma tumors to rodent lungs while sparing the normal surrounding tissue.