title: Measuring the Physiologic Properties of Oral Lesions Receiving Fractionated Photodynamic Therapy.
abstract: Photodynamic therapy (PDT) can treat superficial, early-stage disease with minimal damage to underlying tissues and without cumulative dose-limiting toxicity. Treatment efficacy is affected by disease physiologic properties, but these properties are not routinely measured. We assessed diffuse reflectance spectroscopy (DRS) for the noninvasive, contact measurement of tissue hemoglobin oxygen saturation (St O2 ) and total hemoglobin concentration ([tHb]) in the premalignant or superficial microinvasive oral lesions of patients treated with 5-aminolevulinic acid (ALA)-PDT. Patients were enrolled on a Phase 1 study of ALA-PDT that evaluated fluences of 50, 100, 150 or 200 J cm(-2) delivered at 100 mW cm(-2) . To test the feasibility of incorporating DRS measurements within the illumination period, studies were performed in patients who received fractionated (two-part) illumination that included a dark interval of 90-180 s. Using DRS, tissue oxygenation at different depths within the lesion could also be assessed. DRS could be performed concurrently with contact measurements of photosensitizer levels by fluorescence spectroscopy, but a separate noncontact fluorescence spectroscopy system provided continuous assessment of photobleaching during illumination to greater tissue depths. Results establish that the integration of DRS into PDT of early-stage oral disease is feasible, and motivates further studies to evaluate its predictive and dosimetric value.
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Shannon M
authors.initials: SM
authors.lastname: Gallagher-Colombo
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Harry
authors.initials: H
authors.lastname: Quon
authors.affiliation: Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Malloy
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Ahn
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Cengel
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Charles B
authors.initials: CB
authors.lastname: Simone
authors.affiliation: Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Ara A
authors.initials: AA
authors.lastname: Chalian
authors.affiliation: Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Bert W
authors.initials: BW
authors.lastname: O'Malley
authors.affiliation: Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Weinstein
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Zhu
authors.affiliation: Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Putt
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Jarod C
authors.initials: JC
authors.lastname: Finlay
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Theresa M
authors.initials: TM
authors.lastname: Busch
mesh_terms: D000284:Administration, Oral; D000622:Aminolevulinic Acid / Q000008:administration & dosage*; D001790:Blood Physiological Phenomena; D004305:Dose-Response Relationship, Drug; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D009059:Mouth Diseases / Q000628:therapy*; D009061:Mouth Mucosa / Q000187:drug effects / Q000528:radiation effects; D010778:Photochemotherapy; D011237:Predictive Value of Tests
chemical_list: D006454:Hemoglobins; D000622:Aminolevulinic Acid