Tumor growth inhibition and regression induced by photothermal vascular targeting and angiogenesis inhibitor retinoic acid.

The effect of photothermal vascular targeting, alone and in combination with antiangiogenic therapy, was evaluated using tumors produced in mice by transplantation of KB cells. Tumor growth inhibition and regression followed vascular damage produced by pulsed dye laser (PDL) radiation. Administration of the antiangiogenic agent all-trans-retinoic acid (RA) was associated with smaller average tumor volumes in the presence and absence of PDL irradiation, but this effect was not statistically significant. The ability of PDL photothermal vascular targeting to cause regression of tumors without harming normal tissue may be a consequence of preferential damage to supplying vessels at the tumor periphery.