Print page Print page
Switch language
The Capital Region of Denmark - a part of Copenhagen University Hospital

Comparison of Physical Pretreatment Regimens to Enhance Protoporphyrin IX Uptake in Photodynamic Therapy: A Randomized Clinical Trial

Research output: Contribution to journalJournal articleResearchpeer-review

  1. Efficacy and Safety of Abrocitinib in Patients With Moderate-to-Severe Atopic Dermatitis: A Randomized Clinical Trial

    Research output: Contribution to journalJournal articleResearchpeer-review

  2. Association of Birth Weight, Childhood Body Mass Index, and Height With Risk of Hidradenitis Suppurativa

    Research output: Contribution to journalJournal articleResearchpeer-review

  3. A Comparison of Psoriasis Severity in Pediatric Patients Treated With Methotrexate vs Biologic Agents

    Research output: Contribution to journalJournal articleResearchpeer-review

View graph of relations

Importance: Skin pretreatment is recommended for adequate penetration of topical photosensitizing agents and subsequent protoporphyrin IX (PPIX) accumulation in photodynamic therapy (PDT).

Objective: To compare the relative potential of different physical pretreatments to enhance PPIX fluorescence in normal skin.

Design, Setting, and Participants: This intraindividual, randomized clinical trial was performed from November 28 to December 20, 2014, at Bispebjerg Hospital, Copenhagen, Denmark, among 12 healthy volunteers 18 years or older. Analysis was based on intention to treat. All participants completed the study protocol.

Interventions: Participants were each exposed to standardized skin preparation with curettage, microdermabrasion with abrasive pads, microneedling with dermarollers, ablative fractional laser (AFXL), non-AFXL, and no pretreatment, followed by 3 hours of methyl aminolevulinate hydrochloride incubation and subsequent red light illumination.

Main Outcomes and Measures: The primary outcome measure was methyl aminolevulinate-induced PPIX fluorescence accumulation. Secondary outcome measures were PPIX photobleaching and clinical local skin reactions, supported by noninvasive reflectance measurements of percentage of skin redness, transepidermal water loss, and participant-assessed pain.

Results: Among the 12 healthy study participants (8 men; 4 women; mean [SD] age, 33 [15] years), histologic findings confirmed standardization of interventions with partial removal of the stratum corneum after curettage and microdermabrasion and similar vertical penetration depths for microneedling, AFXL, and non-AFXL (median, 125 μm). PPIX fluorescence reached highest intensities in skin pretreated with AFXL (median, 8661 arbitrary units [AU]) compared with microdermabrasion (median, 6731 AU), microneedling (median, 5609 AU), and curettage (median, 4765 AU) (P < .001), among which similar enhancement was shown. Comparatively lower fluorescence levels were demonstrated for skin pretreated with non-AFXL (median, 2898 AU), methyl aminolevulinate-treated controls (median, 2254 AU), and untreated controls (median, 239 AU) (P < .03). Increasing laser densities (2% vs 4% vs 6%) and the number of pretreatment passes (1, 2, and 3 passes) did not enhance PPIX fluorescence. Local skin reactions were most intensified in AFXL-pretreated skin and correlated with PPIX fluorescence and degree of PPIX photobleaching.

Conclusions and Relevance: Under standardized conditions, PPIX accumulation was most enhanced after AFXL pretreatment, followed by microdermabrasion, microneedling, and curettage. Increasing the number of pretreatment passes and laser densities did not further augment PPIX accumulation. These results may indicate relatively enhanced PDT response by AFXL pretreatment in diseased skin.

Trial Registration: Identifier: NCT02372370.

Original languageEnglish
JournalJAMA Dermatology
Issue number4
Pages (from-to)270-278
Number of pages9
Publication statusPublished - 1 Apr 2017

    Research areas

  • Adolescent, Adult, Aminolevulinic Acid, Curettage, Denmark, Dermabrasion, Female, Fluorescence, Humans, Laser Therapy, Male, Middle Aged, Photochemotherapy, Photosensitizing Agents, Protoporphyrins, Skin, Young Adult, Comparative Study, Journal Article, Randomized Controlled Trial

ID: 52399408