title: Online dosimetry for temoporfin-mediated interstitial photodynamic therapy using the canine prostate as model.
abstract: Online light dosimetry with real-time feedback was applied for temoporfin-mediated interstitial photodynamic therapy (PDT) of dog prostate. The aim was to investigate the performance of online dosimetry by studying the correlation between light dose plans and the tissue response, i.e., extent of induced tissue necrosis and damage to surrounding organs at risk. Light-dose planning software provided dose plans, including light source positions and light doses, based on ultrasound images. A laser instrument provided therapeutic light and dosimetric measurements. The procedure was designed to closely emulate the procedure for whole-prostate PDT in humans with prostate cancer. Nine healthy dogs were subjected to the procedure according to a light-dose escalation plan. About 0.15 mg/kg temoporfin was administered 72 h before the procedure. The results of the procedure were assessed by magnetic resonance imaging, and gross pathology and histopathology of excised tissue. Light dose planning and online dosimetry clearly resulted in more focused effect and less damage to surrounding tissue than interstitial PDT without dosimetry. A light energy dose-response relationship was established where the threshold dose to induce prostate gland necrosis was estimated from 20 to 30  J/cm2.
authors.affiliation: SpectraCure AB, Magistratsvägen 10, 226 43 Lund, Sweden.
authors.forename: Johannes
authors.initials: J
authors.lastname: Swartling
authors.affiliation: Swedish University of Agricultural Sciences, Department of Clinical Sciences, Box 7054, Uppsala 750 07, Sweden.
authors.forename: Odd V
authors.initials: OV
authors.lastname: Höglund
authors.affiliation: Swedish University of Agricultural Sciences, Department of Clinical Sciences, Box 7054, Uppsala 750 07, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hansson
authors.affiliation: Swedish University of Agricultural Sciences, Department of Biomedical Sciences and Veterinary Public Health, Box 7028, Uppsala 750 07, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Södersten
authors.affiliation: Lund University, Division of Atomic Physics, Physics Department, Box 118, Lund 221 00, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Axelsson
authors.affiliation: Swedish University of Agricultural Sciences, Department of Clinical Sciences, Box 7054, Uppsala 750 07, Sweden.
authors.forename: Anne-Sofie
authors.initials: AS
authors.lastname: Lagerstedt
mesh_terms: D000818:Animals; D004285:Dogs; D004307:Dose-Response Relationship, Radiation; D008297:Male; D008652:Mesoporphyrins / Q000008:administration & dosage / Q000009:adverse effects; D009336:Necrosis; D010778:Photochemotherapy / Q000009:adverse effects / Q000379:methods; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000009:adverse effects; D011467:Prostate / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*
chemical_list: D008652:Mesoporphyrins; D017319:Photosensitizing Agents; C072269:temoporfin