title: Successful in vivo tumor visualization using fluorescence laparoscopy in a mouse model of disseminated alveolar rhabdomyosarcoma.
abstract: BACKGROUND
  Surgery for rhabdomyosarcoma is challenging due to a lack of clear delineation between tumor and surrounding tissue. Mutilating surgery can be necessary in difficult tumor localizations. Therefore, novel diagnostic and therapeutic modalities are required. The aim of this study was to evaluate the in vivo tumor detection of RMS using fluorescence laparoscopy and to analyze the efficacy of hypericin-induced photodynamic therapy in a mouse model.
  
  
  METHODS
  Seventeen NOD/LtSz-scid IL2Rγnull-mice were divided into four groups. In group 1, mCherry-expressing tumor cells and in group 2-4 non-transfected tumor cells were xenotransplanted. Three weeks later, one fluorochrome per group (ICG, ICG-cetuximab, hypericin) was injected. Fluorescence laparoscopy was carried out and tumors were resected using fluorescence guidance. In the hypericin group, photodynamic therapy was performed using blue light and apoptosis was evaluated by TUNEL test.
  
  
  RESULTS
  A clear discrimination between healthy and tumor tissue was feasible by fluorescending properties with mCherry expressing tumor cells and after injection of hypericin. No fluorescence was detected in mice injected with ICG and ICG-labeled cetuximab. Hypericin photodynamic therapy induced apoptosis of tumor cells after exposure to blue light.
  
  
  CONCLUSIONS
  Intraoperative photodynamic diagnosis was feasible using mCherry-transfected tumor cells or hypericin. Additionally, intraoperative photodynamic therapy was possible and effective.
authors.affiliation: Department of Pediatric Surgery and Pediatric Urology, University Children's Hospital Tübingen, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany, Cristian.Urla@med.uni-tuebingen.de.
authors.forename: Cristian
authors.initials: C
authors.lastname: Urla
authors.forename: Sorin
authors.initials: S
authors.lastname: Armeanu-Ebinger
authors.forename: Jörg
authors.initials: J
authors.lastname: Fuchs
authors.forename: Guido
authors.initials: G
authors.lastname: Seitz
mesh_terms: D000818:Animals; D000873:Anthracenes; D017209:Apoptosis; D005453:Fluorescence; D020287:In Situ Nick-End Labeling; D010535:Laparoscopy / Q000379:methods*; D051379:Mice; D016688:Mice, Inbred NOD; D009374:Neoplasms, Experimental; D010569:Perylene / Q000031:analogs & derivatives / Q000627:therapeutic use; D010778:Photochemotherapy / Q000379:methods*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011838:Radiation-Sensitizing Agents / Q000627:therapeutic use; D018232:Rhabdomyosarcoma, Alveolar / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D012983:Soft Tissue Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D014407:Tumor Cells, Cultured
chemical_list: D000873:Anthracenes; D011838:Radiation-Sensitizing Agents; D010569:Perylene; C004965:hypericin; D011493:Protein Kinase C