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

BACKGROUND/PURPOSE:

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.

CONCLUSION:

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: Kentaro Mizutani, Yoichi Akita, Takeshi Yanagishita, Makoto Kimura, Tohru Tanaka, Yumi Kinoshita, Aki Nakano, Yasuhiko Tamada, Yoshinari Matsumoto, Daisuke Watanabe
• Journal: Photodermatology, photoimmunology & photomedicine (Photodermatol Photoimmunol Photomed) Vol. 28 Issue 3 Pg. 142-6 (Jun 2012) ISSN: 1600-0781 [Electronic] England
• PMID: 22548396 (Publication Type: Comparative Study, Journal Article, Randomized Controlled Trial)
• Copyright: © 2012 John Wiley & Sons A/S.

Chemical References

• Photosensitizing Agents
• Aminolevulinic Acid

Topics

• Aged
• Aged, 80 and over
• Aminolevulinic Acid (administration & dosage)
• Bowen's Disease (pathology, therapy)
• Female
• Follow-Up Studies
• Humans
• Laser Therapy (instrumentation, methods)
• Male
• Middle Aged
• Photochemotherapy (instrumentation, methods)
• Photosensitizing Agents (administration & dosage)