title: Photofrin-mediated photodynamic therapy of chemically-induced premalignant lesions and squamous cell carcinoma of the palatal mucosa in rats.
abstract: Photodynamic therapy (PDT), an experimental cancer therapy, was studied in an animal model of chemically-induced epithelial dysplasia and squamous cell carcinoma. PDT was performed 24 hours after i.v. injection of 2.5 mg/kg bw Photofrin, and using 100 J/cm2 incident light at two activation wavelengths (514.5 nm or 625 nm). Two days after PDT, the majority of rats macroscopically showed a marked erythema of the entire palatal region. Microscopically all the rats showed oedema, haemorrhage, and necrosis of the epithelium of the intermolar area. The long-term results were not so favourable. No evidence of disease was found in 6 out of 20 rats in the 514.5 nm group and in 2 out of 20 rats in the 625 nm treated group. Epithelial dysplasia was found in 14 out of 20 rats in the 514.5 nm group, and in 18 out of 20 rats of the 625 nm treated group. Squamous cell carcinomas were found in 4 out of 20 rats treated with 514.5 nm and in 7 out of 20 rats in the 625 nm treated groups. Comparing both treatment wavelengths, better results were obtained in the 514.5 nm groups as this wavelength gave less normal tissue damage. Based on the results of this study the application of PDT for the treatment of field cancerization and squamous cell carcinoma of the oral cavity, is discussed.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Hospital Groningen, The Netherlands.
authors.forename: J M
authors.initials: JM
authors.lastname: Nauta
authors.forename: H L
authors.initials: HL
authors.lastname: van Leengoed
authors.forename: M J
authors.initials: MJ
authors.lastname: Witjes
authors.forename: P G
authors.initials: PG
authors.lastname: Nikkels
authors.forename: W M
authors.initials: WM
authors.lastname: Star
authors.forename: A
authors.initials: A
authors.lastname: Vermey
authors.forename: J L
authors.initials: JL
authors.lastname: Roodenburg
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000009:adverse effects; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002273:Carcinogens / Q000009:adverse effects; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000188:drug therapy*; D004195:Disease Models, Animal; D004487:Edema / Q000473:pathology; D004890:Erythema / Q000473:pathology; D017324:Hematoporphyrin Derivative / Q000008:administration & dosage / Q000627:therapeutic use*; D007275:Injections, Intravenous; D008137:Longitudinal Studies; D008297:Male; D009059:Mouth Diseases / Q000473:pathology; D009061:Mouth Mucosa / Q000473:pathology; D009336:Necrosis; D006472:Oral Hemorrhage / Q000473:pathology; D010157:Palatal Neoplasms / Q000139:chemically induced / Q000188:drug therapy*; D010159:Palate / Q000473:pathology; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D011230:Precancerous Conditions / Q000139:chemically induced / Q000188:drug therapy*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000970:Antineoplastic Agents; D002273:Carcinogens; D017319:Photosensitizing Agents; D015112:4-Nitroquinoline-1-oxide; D017324:Hematoporphyrin Derivative