title: Photothermal ablation of human lung cancer by low-power near-infrared laser and topical injection of indocyanine green.
abstract: The present study was designed to evaluate the efficacy of photothermal ablation therapy for lung cancer by low-power near-infrared laser and topical injection of indocyanine green (ICG). In vitro study 1: an 808 nm laser with 250 mW was irradiated for 10 minutes using different dilutions of ICG and the temporal thermal effect was monitored. ICG (1 mL of 0.5 g/L) was heated to a temperature of >30°C from the base temperature by laser irradiation. In vitro study 2: the cytotoxic effect of hyperthermia on human lung cancer cells was examined in different temperature and time settings. Cell viability was quantified by both an MTS assay and reculturing. Fatal conditions evaluated by reculturing were as follows: thermal treatment at 55°C for 5 minutes, 53°C for 10 minutes, and 51°C for 15 minutes. The MTS assay study suggested that thermal treatment at 59°C for 5 minutes and 57°C for 20 minutes showed a severe cytotoxic effect. In vivo study: nude mouse subcutaneous NCI-H460 human lung cancer xenograft models were used for the study. Saline or 0.5 g/L of ICG was injected topically into the tumor (n=3/group). Tumors were irradiated with a laser at 500 mW for 10 minutes. Although the tumor diameter reached 1 cm within 24 days after treatment in all 3 mice using saline/laser, tumor sizes were gradually reduced in all 3 mice using the ICG/laser. In 2 of the 3 mice using ICG/laser, tumors had disappeared macroscopically. The efficacy of the photothermal ablation therapy by low-power near-infrared laser and a topical injection of ICG was clarified using a mouse subcutaneous a lung cancer xenograft model.
authors.affiliation: *Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, ON, Canada †Department of Surgery, Kochi University, Kochi, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Hirohashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Anayama
authors.forename: Hironobu
authors.initials: H
authors.lastname: Wada
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakajima
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kato
authors.forename: Shaf
authors.initials: S
authors.lastname: Keshavjee
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Orihashi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yasufuku
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000628:therapy*; D000818:Animals; D018287:Carcinoma, Large Cell / Q000473:pathology / Q000628:therapy*; D045744:Cell Line, Tumor; D004396:Coloring Agents / Q000627:therapeutic use*; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D066298:In Vitro Techniques; D007208:Indocyanine Green / Q000627:therapeutic use*; D028022:Low-Level Light Therapy / Q000379:methods*; D008175:Lung Neoplasms / Q000473:pathology / Q000628:therapy*; D008297:Male; D051379:Mice; D008819:Mice, Nude; D017319:Photosensitizing Agents; D023041:Xenograft Model Antitumor Assays
chemical_list: D004396:Coloring Agents; D017319:Photosensitizing Agents; D007208:Indocyanine Green