title: Photodynamic therapy in the management of actinic keratosis: Retrospective evaluation of outcome.
abstract: BACKGROUND
  Photodynamic therapy (PDT) is a minimally invasive intervention used in the management of tissue disorders. In this retrospective study, a total of 62 patients with actinic keratosis (AKs) were treated with surface illumination PDT. Comparisons with the clinical features, rate of recurrence as well as malignant transformation and overall outcome were made.
  
  
  METHODS
  The medical records of 62 consecutive patients who presented with suspicious skin lesions and diagnosed with AKs were examined. These patients with 178 AKs lesions were treated with surface illumination methyl aminolevulinate-photodynamic therapy (MAL-PDT). The 16% strength cream (MAL) was applied topically 3h prior to tissue illumination. A single-channel 628nm diode laser was used for illumination and light was delivered at 100J/cm2per site. These patients were followed-up for a mean of 7.4 years.
  
  
  RESULTS
  Eight recurrences were reported after the first round of MAL-PDT, and two recurrences after the second round. Malignant transformation to squamous cell carcinoma (SCC) was noted in 2 patients only. The 3-year outcome resulted in 60 patients with complete response (CR), and this was maintained at the final outcome (last clinic review). Assessment of lesional outcome vs. response showed that 175/178 treated lesions had complete response (CR) at 3-year follow-up, which increased to 176/178 lesions at the last clinic follow-up.
  
  
  CONCLUSIONS
  MAL-PDT offers an effective treatment for AKs lesions with excellent cosmetic outcome.
authors.affiliation: UCL Department of Surgery, London, UK. Electronic address: waseem_wk1@yahoo.co.uk.
authors.forename: Waseem
authors.initials: W
authors.lastname: Jerjes
authors.affiliation: UCLH Head and Neck Centre, London, UK.
authors.forename: Zaid
authors.initials: Z
authors.lastname: Hamdoon
authors.affiliation: University of Birmingham, Birmingham, UK.
authors.forename: Ali A
authors.initials: AA
authors.lastname: Abdulkareem
authors.affiliation: UCL Department of Surgery, London, UK; UCLH Head and Neck Centre, London, UK; Unit of Oral and Maxillofacial Surgery, UCL Eastman Dental Institute, London, UK.
authors.forename: Colin
authors.initials: C
authors.lastname: Hopper
mesh_terms: D000368:Aged; D000622:Aminolevulinic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D055623:Keratosis, Actinic / Q000150:complications / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D018307:Neoplasms, Squamous Cell / Q000209:etiology; D010778:Photochemotherapy / Q000009:adverse effects / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D017319:Photosensitizing Agents; C475457:methyl 5-aminolevulinate; D000622:Aminolevulinic Acid
keywords: 5-ALA; Actinic keratosis; MAL; NMSC; PDT; Photodynamic therapy; Pre-cancer; Recurrence