Protoporphyrin IX formation after application of methyl aminolevulinate on the face and scalp with and without prior curettage.

Abstract

BACKGROUND:

Pulse photodynamic therapy (PDT) is carried out as classical PDT except that methyl aminolaevulinate (MAL) is removed after 30 min. Protoporphyrin IX (PpIX) accumulation becomes lower after 3 h in pulse-PDT than in classical PDT, but pulse-PDT still has full treatment effect on actinic keratosis (AK). The present study aimed to investigate when PpIX formation in classical PDT without curettage reaches the PpIX level in pulse-PDT with curettage in the skin of the face and scalp.

METHODS:

Fourteen patients with AKs in the face and scalp were included in this pilot study. Each patient had two fields randomly allocated to two different regimes: (i) continuing MAL incubation without prior curettage (-Cur) and (ii) 30 min MAL incubation after curettage (+Cur). The PpIX level in each field was measured with a hand-held fluorescence photometer every 30 min for 6 h after MAL application. No illumination was performed.

RESULTS:

The median PpIX level in the +Cur field after 3 h was 22 arbitrary units (AU), which represents the amount of PpIX that could have been photobleached after pulse-PDT with maximal treatment effect. After 3 h the median PpIX level in the -Cur field was 20 AU, which was not significantly different from the level in the +Cur field (p = 0.9).

CONCLUSIONS:

We propose PDT without curettage as follows: 3 h of MAL incubation and subsequently sufficient illumination. The treatment effect of this regime should be tested to verify if curettage of the face and scalp area may be omitted in PDT.

• Authors: Ida M Heerfordt, Giedre Bieliauskiene, Hans Christian Wulf
• Journal: Photodiagnosis and photodynamic therapy (Photodiagnosis Photodyn Ther) Vol. 22 Pg. 155-157 (Jun 2018) ISSN: 1873-1597 [Electronic] Netherlands
• PMID: 29601904 (Publication Type: Journal Article, Randomized Controlled Trial)
• Copyright: Copyright © 2018 Elsevier B.V. All rights reserved.

Chemical References

• Photosensitizing Agents
• Protoporphyrins
• methyl 5-aminolevulinate
• Aminolevulinic Acid
• protoporphyrin IX

Topics

• Aged
• Aged, 80 and over
• Aminolevulinic Acid (administration & dosage, analogs & derivatives, pharmacokinetics, therapeutic use)
• Curettage
• Face
• Female
• Humans
• Keratosis, Actinic (drug therapy)
• Male
• Middle Aged
• Photochemotherapy (methods)
• Photosensitizing Agents (administration & dosage, pharmacokinetics, therapeutic use)
• Pilot Projects
• Protoporphyrins (pharmacokinetics)
• Scalp