Efficacy and safety of daylight photodynamic therapy after tailored pretreatment with ablative fractional laser or microdermabrasion: a randomized, side-by-side, single-blind trial in patients with actinic keratosis and large-area field cancerization.

BACKGROUND: Physical pretreatments can potentiate the efficacy of daylight photodynamic therapy (dPDT), but clinical comparative studies remain limited. OBJECTIVES: Performed in large skin areas with actinic keratoses (AKs) and photodamage, this blinded, randomized clinical trial compared the efficacy and safety of dPDT after tailored skin pretreatment using ablative fractional laser (AFL) or microdermabrasion (MD). METHODS: Two ≥ 50-cm2 side-by-side skin areas were randomized to receive a single treatment with AFL-dPDT or MD-dPDT. Pretreatment parameters were tailored according to AK grade and skin constitution to ensure standardized immediate end points. Subsequently, methyl aminolaevulinate was applied, followed by 2-h daylight exposure. The primary outcome comprised blinded assessment of AK clearance at the 3-month follow-up. RESULTS: In 18 patients with 832 AKs, AFL-dPDT provided significantly higher AK clearance (81% vs. 60%, P < 0·001), led to fewer new AKs (P < 0·001) and showed superior improvement in dyspigmentation (P = 0·003) and skin texture (P = 0·001) vs. MD-dPDT. Peaking at days 3-6, AFL-PDT induced more intensified local skin responses (P = 0·004), including instances of Staphylococcus aureus infection (n = 3). Patients nonetheless preferred AFL-dPDT (P = 0·077), due to lower pretreatment-related pain (P = 0·002) and superior cosmesis (P = 0·035) and efficacy compared with MD-dPDT. CONCLUSIONS: AFL-dPDT is an effective treatment for patients with AK with extensive field cancerization, although AFL pretreatment is associated with intensified local skin reactions.

Laser treatments in early wound healing improve scar appearance: a randomized split-wound trial with nonablative fractional laser exposures vs. untreated controls.

BACKGROUND: In recent years, various lasers have increasingly been applied during wound healing to minimize scar formation. However, no consensus regarding treatment procedures exists. OBJECTIVES: To assess scar formation clinically after three nonablative fractional laser (NAFL) exposures, targeting the inflammation, proliferation and remodelling wound healing phases in patients vs. untreated controls. METHODS: A randomized controlled trial was performed using a split-wound design to assess excisional wound halves treated with 1540-nm NAFL vs. no laser treatment. Three NAFL exposures were provided: immediately before surgery, at suture removal and 6 weeks after surgery. NAFL exposures were applied using two handpieces, sequentially distributing energy deeply and more superficially in the skin (40-50 mJ per microbeam). Evaluated at 3 months of follow-up, the primary outcome was blinded, on-site evaluation using the Patient Observer Scar Assessment Scale (POSAS total; range from 6, normal skin to 60, worst imaginable scar). Secondary outcomes comprised blinded evaluation on the Vancouver Scar Scale (VSS) and standardized assessment comparing scar sides, carried out by blinded on-site, photo and patient assessments. This trial was registered with ClinicalTrials.gov (NCT03253484). RESULTS: Thirty of 32 patients completed the trial. At the 3-month follow-up, the NAFL-treated scar halves showed improvement compared with the untreated control halves on POSAS total: NAFL treated, median 11, interquartile range (IQR) 9-12 vs. control, median 12, IQR 10-16; P = 0·001. The POSAS subitems showed that the NAFL-treated halves were significantly less red and more pliable, and presented with smoother relief than the untreated controls. VSS total correspondingly revealed enhanced appearance in the NAFL-treated halves: median 2, IQR 1-2·5 vs. control, median 2, IQR 1·75-3, P = 0·007. The standardized assessment comparing appearance of scar halves demonstrated a low degree of correspondence between on-site, photo and patient assessments. NAFL-treated scars were rated as superior to untreated scars by 21 of 29 patients. CONCLUSIONS: NAFL-treated scars showed subtle improvement compared with untreated control scars.

Early laser intervention to reduce scar formation - a systematic review.

The ability of laser treatment to affect wound healing and subsequently minimize scar formation has been investigated in recent years. However, no systematic review links these clinical trials. The aim of this study was to systematically review and evaluate clinical evidence for early laser intervention to reduce scar formation in studies where laser treatment was introduced less than 3 months after wounding. We searched PubMed using relevant keywords in June 2017. Titles, abstracts and articles were sorted according to inclusion and exclusion criteria. Methodological quality was evaluated according to Cochrane Collaborations risk-of-bias assessment guideline by two independent authors. Twenty-five articles met the inclusion criteria. In total, 22 of 25 studies were controlled studies, and 17 of 25 studies compared laser treatment vs. untreated control scars. The following laser devices have been investigated: pulsed dye laser (PDL), potassium-titanyl-phosphate (KTP) laser, fractional erbium:glass 1540 nm/1550 nm, fractional/full ablation erbium-doped yttrium aluminium garnet (Er:YAG) laser or fractional CO2 laser. Eighteen studies applied laser treatments 2-4 times with 2- to 8-week intervals, while seven studies applied only one laser treatment. Follow-up time ranged from 1 to 12 months with 18 studies using a follow-up time ≤3 months. In general, laser-treated wounds and scars showed benefit from laser intervention, though not always reaching significance. Significant scar improvement was found in three of four studies using laser treatment in inflammation phase, in six of 16 studies with laser initiated in the proliferation phase and in two of five studies in the remodelling phase. High risk of bias was found in randomization and allocation concealment, and low risk of bias with regard to blinding of outcome assessment and lost to follow-up. In conclusion, laser intervention when introduced in inflammation, proliferation or remodelling phase has the potential to reduce cutaneous scar formation. Further, high-quality studies are needed before standard protocols can be implemented in clinical practice.