Ablative fractional laser enhances MAL-induced PpIX accumulation: Impact of laser channel density, incubation time and drug concentration.

BACKGROUND AND OBJECTIVES: Pretreatment of skin with ablative fractional laser enhances accumulation of topical provided photosensitizer, but essential information is lacking on the interaction between laser channel densities and pharmacokinetics. Hence our objectives were to investigate how protoporphyrin accumulation was affected by laser densities, incubation time and drug concentration. METHODS: We conducted the study on the back of healthy male volunteers (n=11). Test areas were pretreated with 2940nm ablative fractional Er:YAG laser, 11.2mJ per laser channel using densities of 1, 2, 5, 10 and 15% (AFL 1-15%). Control areas received pretreatment with curettage or no pretreatment. Methyl aminolevulinate (MAL) was applied under occlusion in concentrations of 0, 80 and 160mg/g. MAL-induced protoporphyrin fluorescence was quantified with a handheld photometer after 0, 30, 60, 120 and 180min incubation. The individual fluorescence intensity reached from the highest density (15%) and longest MAL 160mg/g incubation time (180min) was selected as reference (100%) for other interventional measurements. RESULTS: A low laser density of 1% markedly enhanced fluorescence intensities from 34% to 75% (no pretreatment vs. AFL 1%, MAL 160mg/g, 180min; p<0.001). Furthermore, fluorescence intensities increased substantially by enhancing densities up to 5% (p≤0.0195). Accumulation of protoporphyrins was accelerated by laser exposure. Thus, laser exposure of 5% density and a median incubation time of 80min MAL (range 46-133min) induced fluorescence levels similar to curettage and 180min incubation. Furthermore, MAL 80 and 160mg/g induced similar fluorescence intensities in skin exposed to laser densities of 1, 2 and 5% (p>0.0537, 30-180min). CONCLUSION: MAL-induced protoporphyrin accumulation is augmented by enhancing AFL densities up to 5%. Further, this model indicates that incubation time as well as drug concentration of MAL may be reduced with laser pretreatment.

Quantitative assessment of growing hair counts, thickness and colour during and after treatments with a low-fluence, home-device laser: a randomized controlled trial.

BACKGROUND: At-home laser and intense pulsed-light hair removal continues to grow in popularity and availability. A relatively limited body of evidence is available on the course of hair growth during and after low-fluence laser usage. OBJECTIVES: To assess growing hair counts, thickness and colour quantitatively during and after cessation of low-fluence laser treatment. METHODS: Thirty-six women with skin phototypes I-IV and light to dark-brown axillary hairs were included. Entire axillary regions were randomized to zero or eight self-administered weekly treatments with an 810-nm home-use laser at 5·0-6·4 J cm(-2). Standardized clinical photographs were taken before each treatment and up to 3 months after the final treatment for computer-aided quantification of growing hair counts, thickness and colour. RESULTS: Thirty-two women completed the study protocol. During sustained treatment, there was a reduction in growing hair that reached a plateau of up to 59%, while remaining hairs became up to 38% thinner and 5% lighter (P < 0·001). The majority of subjects (77%) reported 'moderately' to 'much less hair' in treated than untreated axilla, and assessed remaining hairs as thinner and lighter (≥ 60%). After treatment cessation, hair growth gradually returned to baseline levels, and 3 months after the final treatment the count and thickness of actively growing hair exceeded pretreatment values by 29% and 7%, respectively (P ≤ 0·04). CONCLUSIONS: Sustained usage of low-fluence laser induced a stable reduction of growing hair counts, thickness and colour. The reduction was reversible and hairs regrew beyond baseline values after cessation of usage. Computer-aided image analysis was qualified for quantification of hair counts, thickness and colour after laser epilation.

Fractional laser-mediated photodynamic therapy of high-risk basal cell carcinomas--a randomized clinical trial.

BACKGROUND: Photodynamic therapy (PDT) is approved for selected nodular basal cell carcinomas (nBCC) but efficacy is reduced for large and thick tumours. Ablative fractional lasers (AFXL) facilitate uptake of methyl aminolaevulinate (MAL) and may thus improve PDT outcome. OBJECTIVES: To evaluate efficacy and safety of AFXL-mediated PDT (AFXL-PDT) compared with conventional PDT of high-risk nBCC. METHODS: Patients with histologically verified facial nBCC (n = 32) defined as high-risk tumours were included; diameter > 15 mm, tumours located in high-risk zones, or on severely sun-damaged skin. Tumours were debulked and patients randomized to either AFXL-PDT (n = 16) or PDT (n = 16). Fractional CO2 laser treatment was applied at 5% density and 1000 µm (80 mJ) ablation depth. MAL was applied under occlusion for 3 h and illuminated with a 633-nm light-emitting diode source, 37 J cm(-2) . Clinical assessments were performed at 3, 6, 9 and 12 months and biopsies were taken at 12 months. RESULTS: Clinical cure rates at 3 months were 100% (16 of 16 AFXL-PDT) and 88% (14 of 16 PDT, P = 0·484). Recurrences tended to occur later and in lower numbers after AFXL-PDT at 6, 9 and 12 months (6%, 19%, 19%) than PDT (25%, 38%, 44%) (P = 0·114). Histology at 12 months documented equal tumour clearance after AFXL-PDT (63%, 10 of 16) and PDT (56%, 9 of 16). Cosmetic outcomes were highly satisfactory after both treatments (P > 0·090). CONCLUSIONS: Long-term efficacy was similar after PDT and AFXL-PDT with a trend for a favourable short-term cure rate after AFXL-PDT. AFXL-PDT needs further refinement for nBCC and at present is not recommended over PDT.

Intensified photodynamic therapy of actinic keratoses with fractional CO2 laser: a randomized clinical trial.

BACKGROUND: Photodynamic therapy (PDT) with methyl aminolaevulinate (MAL) is effective for thin actinic keratoses (AKs) in field-cancerized skin. Ablative fractional laser resurfacing (AFXL) creates vertical channels that facilitate MAL uptake and may improve PDT efficacy. OBJECTIVES: To evaluate efficacy and safety of AFXL-assisted PDT (AFXL-PDT) compared with conventional PDT in field-directed treatment of AK. METHODS: Fifteen patients with a total of 212 AKs (severity grade I-III) in field-cancerized skin of the face and scalp were randomized to one treatment with PDT and one treatment with AFXL-PDT in two symmetrical areas. Following curettage of both treatment areas, AFXL was applied to one area using 10 mJ per pulse, 0·12 mm spot, 5% density, single pulse (UltraPulse(®), DeepFx handpiece; Lumenis Inc., Santa Clara, CA, U.S.A.). MAL cream was then applied under occlusion for 3 h and illuminated with red light-emitting diode light at 37 J cm(-2). Fluorescence photography quantified protoporphyrin IX (PpIX) before and after illumination. RESULTS: At 3-month follow-up, AFXL-PDT was significantly more effective than PDT for all AK grades. Complete lesion response of grade II-III AK was 88% after AFXL-PDT compared with 59% after PDT (P = 0·02). In grade I AK, 100% of lesions cleared after AFXL-PDT compared with 80% after PDT (P = 0·04). AFXL-PDT-treated skin responded with significantly fewer new AK lesions (AFXL-PDT n = 3, PDT n = 11; P = 0·04) and more improved photoageing (moderate vs. minor improvement, P = 0·007) than PDT-treated skin. Pain scores during illumination (6·5 vs. 5·4; P = 0·02), erythema and crusting were more intense, and long-term pigmentary changes more frequent from AFXL-PDT than PDT (P = not significant). PpIX fluorescence was higher in AFXL-pretreated skin [7528 vs. 12,816 arbitrary units (AU); P = 0·003] and photobleached to equal intensities after illumination (AFXL-PDT 595 AU, PDT 454 AU; P = 0·59). CONCLUSIONS: AFXL-PDT is more effective than conventional PDT for treatment of AK in field-cancerized skin.

A systematic review of light-based home-use devices for hair removal and considerations on human safety.

BACKGROUND: Hair removal with professional light-based devices is established as an effective, mainstream treatment. The field of optical home-based hair removal is evolving and movement from control by physicians into hands of consumers warrants understanding efficacy and human safety. OBJECTIVES: To systematically review and evaluate the efficacy and human safety of currently available home-based optical hair removal devices. METHODS: A comprehensive Pub Med literature search was conducted which systematically identified publications of relevance. Prospective clinical trials were included whether controlled, uncontrolled or randomized and with a sample size of at least 10 individuals. RESULTS: We identified a total of seven studies: one controlled (CT) and six uncontrolled trials (UCTs). No randomized controlled trials (RCT) were recognized. The best evidence was found for IPL (intense pulsed light) (three devices, one CT, five UCTs) and limited evidence for laser devices (one diode laser, one UCT). Most studies evaluated short-term hair reduction up to 3 and 6 months following light exposure at different body sites. Hair reduction percentages ranged from 6% to 72% after repetitive treatments. The most frequently reported side-effect was erythema, but oedema, blistering, crusting and pigment changes were also reported. Theoretical concerns about ocular damage and paradoxical hair growth have not been reported in any of the studies reviewed. CONCLUSIONS: Available evidence from prospective, uncontrolled clinical trials indicates short-term hair removal efficacy of currently available home-use light-based hair removal devices. Additional controlled trials will be helpful to substantiate the efficacy and to better predict the incidence of adverse events associated with optical home-use hair removal.