title: Comparison of the efficacy of ALA-PDT using an excimer-dye laser (630 nm) and a metal-halide lamp (600 to 740 nm) for treatment of Bowen's disease.
abstract: OBJECTIVE
  Topical 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) is an effective treatment for Bowen's disease (BD). In order to compare the efficacy of two different light sources, using either an excimer-dye laser (EDL) (630 nm) or a metal-halide lamp (MHL) (600 to 740 nm) a protocol for topical ALA-PDT for treatment of BD of the extremities was established, and responses during 12 months follow-up were assessed.
  
  
  METHODS
  From 25 patients a total of 26 lesions that had been histopathologically diagnosed as BD from 2005 to 2010 in the Department of Dermatology at the Aichi Medical University Hospital were randomly selected. The light source used for the topical ALA-PDT was EDL in 17 lesions and MHL in 9 lesions. The photosensitizing protoporphyrin IX that is produced within BD lesions 4 h after application of 20% ALA cream was mostly consumed after exposure to 100 J/cm(2) irradiation using 630 nm EDL. Each lesion was irradiated once a week for 3 weeks, for a total dosage of 300 J/cm(2) (100 mW/cm(2)). Patients were followed up clinically every 3 months for 12 months, and at 1 month after the final treatment lesions were evaluated histopathologically.
  
  
  RESULTS
  Histologically, the complete response (CR) rate at 1-month follow-up was 82% (14/17 lesions) in the EDL treatment group and 100% (9/9 lesions) in the MHL treatment group (P > 0.05). The recurrence rate at 12 months after PDT was 46% (6/13 lesions, one patient lost to follow-up) in the EDL group and 0% in the MHL group (P < 0.05) (χ(2) test with Fisher's exact test). The average period before recurrence after EDL treatment was 6.5 months.
  
  
  CONCLUSIONS
  A novel protocol for topical ALA-PDT in Japanese in Asian patients with BD was developed and implemented. The protocol improved the CR rate compared with previous studies. Moreover, the present results indicate that the efficacy of topical ALA-PDT using MHL was superior to that using EDL for BD patients.
authors.affiliation: Department of Dermatology, Aichi Medical University, Aichi, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Mizutani
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Akita
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yanagishita
authors.forename: Makoto
authors.initials: M
authors.lastname: Kimura
authors.forename: Tohru
authors.initials: T
authors.lastname: Tanaka
authors.forename: Yumi
authors.initials: Y
authors.lastname: Kinoshita
authors.forename: Aki
authors.initials: A
authors.lastname: Nakano
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tamada
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Daisuke
authors.initials: D
authors.lastname: Watanabe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000622:Aminolevulinic Acid / Q000008:administration & dosage; D001913:Bowen's Disease / Q000473:pathology / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053685:Laser Therapy / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010778:Photochemotherapy / Q000295:instrumentation* / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage
chemical_list: D017319:Photosensitizing Agents; D000622:Aminolevulinic Acid