title: Photodynamic therapy for the treatment of induced mammary tumor in rats.
abstract: The objective of this work was to evaluate photodynamic therapy (PDT) by using a hematoporphyrin derivative as a photosensitizer and light-emitting diodes (LEDs) as light source in induced mammary tumors of Sprague-Dawley (SD) rats. Twenty SD rats with mammary tumors induced by DMBA were used. Animals were divided into four groups: control (G1), PDT only (G2), surgical removal of tumor (G3), and submitted to PDT immediately after surgical removal of tumor (G4). Tumors were measured over 6 weeks. Lesions and surgical were LEDs lighted up (200 J/cm(2) dose). The light distribution in vivo study used two additional animals without mammary tumors. In the control group, the average growth of tumor diameter was approximately 0.40 cm/week. While for PDT group, a growth of less than 0.15 cm/week was observed, suggesting significant delay in tumor growth. Therefore, only partial irradiation of the tumors occurred with a reduction in development, but without elimination. Animals in G4 had no tumor recurrence during the 12 weeks, after chemical induction, when compared with G3 animals that showed 60 % recurrence rate after 12 weeks of chemical induction. PDT used in the experimental model of mammary tumor as a single therapy was effective in reducing tumor development, so the surgery associated with PDT is a safe and efficient destruction of residual tumor, preventing recurrence of the tumor.
authors.affiliation: Faculdade de Medicina Veterinária e Zootecnia, Departamento de Clínica Veterinária, Universidade Estadual Paulista (UNESP), São Paulo, Brazil. iferreira@fmvz.unesp.br
authors.forename: Isabelle
authors.initials: I
authors.lastname: Ferreira
authors.forename: Juliana
authors.initials: J
authors.lastname: Ferreira
authors.forename: José Dirceu
authors.initials: JD
authors.lastname: Vollet-Filho
authors.forename: Lilian T
authors.initials: LT
authors.lastname: Moriyama
authors.forename: Vanderlei S
authors.initials: VS
authors.lastname: Bagnato
authors.forename: Daisy Maria Favero
authors.initials: DM
authors.lastname: Salvadori
authors.forename: Noeme S
authors.initials: NS
authors.lastname: Rocha
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000633:toxicity; D000818:Animals; D005260:Female; D017324:Hematoporphyrin Derivative / Q000494:pharmacology; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D010778:Photochemotherapy / Q000295:instrumentation / Q000379:methods*; D017319:Photosensitizing Agents / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D017319:Photosensitizing Agents; D015127:9,10-Dimethyl-1,2-benzanthracene; D017324:Hematoporphyrin Derivative