TY - JOUR

T1 - Comparison of Physical Pretreatment Regimens to Enhance Protoporphyrin IX Uptake in Photodynamic Therapy

T2 - A Randomized Clinical Trial

AU - Bay, Christiane

AU - Lerche, Catharina Margrethe

AU - Ferrick, Bradford

AU - Philipsen, Peter Alshede

AU - Togsverd-Bo, Katrine

AU - Haedersdal, Merete

PY - 2017/4

Y1 - 2017/4

N2 - 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: clinicaltrials.gov Identifier: NCT02372370.

AB - 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: clinicaltrials.gov Identifier: NCT02372370.

KW - Adolescent

KW - Adult

KW - Aminolevulinic Acid/administration & dosage

KW - Curettage/methods

KW - Denmark

KW - Dermabrasion/methods

KW - Female

KW - Fluorescence

KW - Humans

KW - Laser Therapy/methods

KW - Male

KW - Middle Aged

KW - Photochemotherapy/methods

KW - Photosensitizing Agents/administration & dosage

KW - Protoporphyrins/metabolism

KW - Skin/metabolism

KW - Young Adult

U2 - 10.1001/jamadermatol.2016.5268

DO - 10.1001/jamadermatol.2016.5268

M3 - Journal article

C2 - 28146245

VL - 153

SP - 270

EP - 278

JO - JAMA Dermatology

JF - JAMA Dermatology

SN - 2168-6068

IS - 4

ER -