Short incubation with methyl aminolevulinate for photodynamic  therapy of actinic keratoses.
BACKGROUND
Photodynamic therapy (PDT) using methyl aminolevulinate (MAL) is an effective first-line treatment for actinic keratoses. A reduced incubation period may have practical advantages.


OBJECTIVE
This study aims to evaluate the effect of incubation time (1 vs. 3 h), MAL concentration (160 mg/g vs. 80 mg/g) and lesion preparation in the setting of MAL-PDT for treatment of actinic keratosis (AK).


METHODS
Open, randomized, parallel-group multicentre study.


METHODS
Outpatient dermatology clinics.


METHODS
One hundred and twelve patients with 384 previously untreated AK. Most lesions (87%) were located on the face and scalp and were thin (55%) or moderately thick (34%).


METHODS
Lesions were debrided, and MAL cream (160 mg/g or 80 mg/g) was applied before illumination with red light (570-670 nm; light dose, 75 J/cm2). Patients were followed up at 2 and 3 months. Sixty patients (54%) were re-treated and assessed at 6 months.


RESULTS
Complete lesion response rates 3 and 12 months after last treatment.


RESULTS
For lesions on the face/scalp, lesion complete response rates were 78% for thin AK and 74% for moderately thick AK lesions after 1 h vs. 96% and 87% after 3 h incubation with MAL 160 mg/g. Lesion recurrence rates at 12 months after two treatments were similar [19% (3 of 16) with 1 h vs. 17% (3 of 18) with 3 h 160 mg/kg MAL-PDT] and lower than for 80 mg/g MAL-PDT (44-45%).


CONCLUSIONS
MAL-PDT using a 1-h incubation may be sufficient for successful treatment of selected AK lesions.
Braathen
L R
LR
University Clinic for Dermatology, Inselspital, Bern CH-3010, Switzerland. lasse.r.braathen@bluewin.ch
Paredes
B E
BE
Saksela
O
O
Fritsch
C
C
Gardlo
K
K
Morken
T
T
Frølich
K W
KW
Warloe
T
T
Solér
A M
AM
Ros
A-M
AM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000622:Aminolevulinic Acid / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D003358:Cosmetics; D005260:Female; D006801:Humans; D055623:Keratosis, Actinic / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D012008:Recurrence; D016896:Treatment Outcome
D003358:Cosmetics; D017319:Photosensitizing Agents; C475457:methyl 5-aminolevulinate; D000622:Aminolevulinic Acid