title: Clinical feasibility of monitoring m-THPC mediated photodynamic therapy by means of fluorescence differential path-length spectroscopy.
abstract: The objective quantitative monitoring of light, oxygen, and photosensitizer is challenging in clinical photodynamic therapy settings. We have previously developed fluorescence differential path-length spectroscopy (FDPS), a technique that utilizes reflectance spectroscopy to monitor microvascular oxygen saturation, blood volume fraction, and vessel diameter, and fluorescence spectroscopy to monitor photosensitizer concentration. In this paper the clinical feasibility of the technique is tested on eight healthy volunteers and on three patients undergoing PDT of oral cavity cancers. Model-based analysis of the measured spectra provide quantitative tissue parameters that are corrected for background tissue absorption, autofluorescence, and the transmission of the optical system; this method allows comparison of intra- and inter-subject parameters. The FDPS correctly estimated the absence of m-THPC in volunteers and detected photobleaching in the areas receiving treatment light in patients undergoing PDT treatment. This study demonstrates the feasibility of monitoring clinical photodynamic therapy treatments using optical spectroscopy.
authors.affiliation: The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Department of Head and Neck Oncology and Surgery, 121 Plesmanlaan, 1066CX Amsterdam, The Netherlands. b.karakullukcu@nki.nl
authors.forename: Baris
authors.initials: B
authors.lastname: Karakullukcu
authors.forename: Stephen Chad
authors.initials: SC
authors.lastname: Kanick
authors.forename: Jan Bonne
authors.initials: JB
authors.lastname: Aans
authors.forename: Henricus Jcm
authors.initials: HJ
authors.lastname: Sterenborg
authors.forename: I Bing
authors.initials: IB
authors.lastname: Tan
authors.forename: Arjen
authors.initials: A
authors.lastname: Amelink
authors.forename: Dominic J
authors.initials: DJ
authors.lastname: Robinson
mesh_terms: D016022:Case-Control Studies; D005240:Feasibility Studies; D005453:Fluorescence; D006801:Humans; D055806:Microvessels / Q000187:drug effects* / Q000378:metabolism; D009062:Mouth Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D009943:Organophosphorus Compounds / Q000627:therapeutic use*; D010100:Oxygen / Q000097:blood / Q000378:metabolism*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D009943:Organophosphorus Compounds; D017319:Photosensitizing Agents; C014850:tetramethylolphosphonium chloride; D010100:Oxygen