Continuous ultra‐low‐intensity artificial daylight is not as effective as red

Authors: Wiegell, Stine Regin; Heydenreich, Jakob; Fabricius, Susanne; Wulf, Hans Christian

Source: Photodermatology Photoimmunology & Photomedicine, Volume 27, Number 6, 1 December 2011 , pp. 280-285(6)

Publisher: Wiley-Blackwell

Buy & download fulltext article:


Price: $48.00 plus tax (Refund Policy)



Daylight‐mediated photodynamic therapy (PDT) is a simple and tolerable treatment of nonmelanoma skin cancer. It is of interest which light intensity is sufficient to prevent accumulation of protoporphyrin IX (PpIX) and effectively treat actinic keratoses (AKs). We compared the efficacy of PDT with light‐emitting diode (LED) to daylight‐mediated PDT with very low‐intensity artificial daylight (‘daylight’) in the treatment of multiple AKs in the face or scalp.

Twenty patients were treated with conventional methyl aminolevulinate (MAL) PDT in one area. Another area was, after half an hour of occlusive treatment with MAL, illuminated for 2.5 h with low‐intensity ‘daylight’ (0.5 mW/cm2–3.7 mW/cm2) that corresponds to midday outdoor intensity in the Scandinavian winter.

After 3 months, with a response rate of 52%, low‐dose artificial daylight was less effective than conventional LED‐PDT (63%) (P = 0.0017). The mean PpIX light dose during ‘daylight’ exposure was 2.23 J/cm2 and the lower the PpIX light intensity, the higher the accumulation of PpIX (P = 0.003).

Even very low‐intensity/dose artificial daylight‐mediated PDT of multiple AKs resulted in a response rate of more than 50%. However, to ensure efficacies equivalent to conventional LED‐PDT, the treatment should not be conducted on very overcast days.

Document Type: Research Article


Publication date: December 1, 2011

Related content



Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content

Text size:

A | A | A | A
Share this item with others: These icons link to social bookmarking sites where readers can share and discover new web pages. print icon Print this page