title: Development of a new illumination procedure for photodynamic therapy of the abdominal cavity.
abstract: A homogeneous illumination of intra-abdominal organs is essential for successful photodynamic therapy of the abdominal cavity. Considering the current lack of outstanding light-delivery systems, a new illumination procedure was assessed. A rat model of peritoneal carcinomatosis was used. Four hours after intraperitoneal injection of hexaminolevulinate, a square illuminating panel connected to a 635-nm laser source was inserted vertically into the abdominal cavity. The abdominal incision was sutured and a pneumoperitoneum created prior to illumination. Light dosimetry was based on the calculation of the peritoneal surface by MRI. The rats were treated with a light dose of 20, 10, 5 or 2.5 J/cm(2) administered continuously with an irradiance of 7 mW/cm(2). The homogeneity of the cavity illumination was assessed by quantification of the photobleaching of the tumor lesions according to their localization and by scoring of that of the liver and of the bowel immediately after treatment. Photobleaching quantification for tumor lesions relied on the calculation of the fluorescence intensity ratio (after/before treatment) after recording of the lesions during blue-light laparoscopy and determination of their fluorescence intensity with Sigmascan Pro software. The procedure led to a homogeneous treatment of the abdominal cavity. No statistical difference was observed for the photobleaching values according to the localization of the lesions on the peritoneum (p=0.59) and photobleaching of the liver and of the intestine was homogeneous. We conclude that this procedure can successfully treat the major sites involved in peritoneal carcinomatosis.
authors.affiliation: University Lille Nord de France, INSERM, U703, Lille University Hospital, Lille, France.
authors.forename: Laurie
authors.initials: L
authors.lastname: Guyon
authors.forename: Jean Claude
authors.initials: JC
authors.lastname: Lesage
authors.forename: Nacim
authors.initials: N
authors.lastname: Betrouni
authors.forename: Serge
authors.initials: S
authors.lastname: Mordon
mesh_terms: D034841:Abdominal Cavity / Q000033:anatomy & histology / Q000473:pathology; D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology; D000622:Aminolevulinic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D045744:Cell Line, Tumor; D005260:Female; D007422:Intestines / Q000737:chemistry / Q000528:radiation effects; D008099:Liver / Q000737:chemistry / Q000528:radiation effects; D008279:Magnetic Resonance Imaging / Q000379:methods; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000473:pathology; D010534:Peritoneal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D010778:Photochemotherapy / Q000295:instrumentation / Q000379:methods*; D017319:Photosensitizing Agents / Q000494:pharmacology; D011874:Radiometry / Q000295:instrumentation / Q000379:methods*; D051381:Rats; D011916:Rats, Inbred F344; D013050:Spectrometry, Fluorescence / Q000379:methods*; D018709:Statistics, Nonparametric
chemical_list: D017319:Photosensitizing Agents; D000622:Aminolevulinic Acid; C419924:5-aminolevulinic acid hexyl ester