Comment: The quality of evidence is downgraded by study limitations (unclear allocation concealment or lack of blinding and selective outcome reporting) and upgraded by large treatment effect.
A Cochrane review «Interventions for actinic keratoses»1 «Gupta AK, Paquet M, Villanueva E et al. Interventions for actinic keratoses. Cochrane Database Syst Rev 2012;(12):CD004415. »1 included 83 studies with a total of 10,036 participants. 27 of the studies examined photodynamic therapies (PDT). The participants were mostly men with mean ages of 60 to 70 years. Lesions generally located on the head and were of grade I (slightly palpable, better felt than seen) or II (moderately thick, easily seen and felt).
Approximately half of the patients treated with PDT benefit the treatment. Skin irritation occurs in approximately 35% after the treatment (based on 1 study). There was no difference identified in the effectiveness of different modes of PDT using different photosensitisers (ALA and MAL), light wavelengths (red, blue) or application times. Longer incubation (4 hours) with ALA resulted in better results compared to shorter incubation time (less than 2 hours). PDT was more effective than cryotherapy in the complete clearance of the lesions, but was connected with more skin irritation after the treatment. However no difference was seen in withdrawals due to adverse effects. No data on the possible reduction of squamous cell carcinoma was identified in the studies
| Outcome | Number of participants (trials) | Control: Placebo-PDT | Intervention: ALA-PDT blue light, 1 treatment | Effect size (95 % CI) |
|---|---|---|---|---|
| Complete clearance | 243 (1) | 10% | 60% | RR 6.22 (2.88 to 13.43) |
| Outcome | Number of participants (trials) | Control: Placebo-PDT | Intervention: ALA-PDT red light, 1 treatment | Effect size (95 % CI) |
| Complete clearance | 422 (3) | 9% | 55% | RR 5.9 (3.3 to 10.5) |
| Outcome | Number of participants (trials) | Control: Placebo-PDT | Intervention: MAL-PDT red light | Effect size (95 % CI) |
| Complete clearance | 482 (5) | 13% | 73% | RR 4.5 (3.2 to 6.3) |
| Outcome | Number of participants (trials) | Control: Cryotherapy | Intervention: ALA-PDT blue light | Effect size (95 % CI) |
| Complete clearance | 297 (1) | 44% | 58% | RR 1.31 (1.05 to 1.64) |
| Skin irritation after treatment | 297 (1) | 10% | 37% | RR 3.7 (2.2 to 6.2) |
Date of latest search: 23.03.2011