Photodynamic therapy of transplantable interstitioma testis in Wistar rats; histopathological examination after Evans blue injections.

The following examination was carried out confirm the effect of Photodynamic Therapy on tumor damage induction in Wistar rats. 20 male Wistar rats bearing interstitioma testis with mean diameter of 2 cm were treated with Photodynamic Therapy, i.e. injected intravenously with alkaline solution of meta-tetra-hydroxyphenyl-porphyrin in dose of 5 mg/kg of body weight and after 24 hrs the tumors were irradiated with red light (650 nm). 2 hrs later these rats were injected intravenously with dye, i.e. 1% solution of Evans Blue in volume of 5 ml per one rat. After next 2 hrs animals were sacrificed. Necrosis areas in tumors were evaluated both on routine paraffin embedded sections without Evans Blue injections, stained with HE only and on paraffin sections from sample containing dye alone. There was the significant increase in necrosis size in treated tumors in comparison to untreated controls or tumors that were given photosensitizer, i.e. porphyrin or light alone. Present data indicate positive role of Photodynamic Therapy on interstitioma testis necrosis induction in Wistar rats.