The effect of increasing fluence on the treatment of actinic keratosis and photodamage by photodynamic therapy with 5-aminolevulinic acid and intense pulsed light

Prospective study of intense pulsed light versus pulsed dye laser with or without blue light in the activation of PDT for the treatment of actinic keratosis and photodamage

BACKGROUND

Exposure to ultraviolet (UV) light from the sun is known to have a deleterious effect on the skin. Repeated insults to the dermal matrix from UV radiation result in the clinical signs of photodamage, including changes in skin elasticity, color, and texture. UV radiation also leads to the accumulation of DNA mutations and promotes tumor development, resulting in the formation of cutaneous precancerous and cancerous lesions. Continuous-wave incoherent blue light, intense pulsed light (IPL), and pulsed dye laser (PDL) are safe and efficacious light sources commonly used for aminolevulinic acid photodynamic therapy (PDT). The aim of this study was to prospectively evaluate the efficacy of PDT for the treatment of photodamage and actinic keratoses using four different combinations of light sources: PDL, PDL + blue light, IPL, and IPL + blue light.

STUDY

A total of 220 patients with either photodamage or actinic keratosis (AK) were recruited from the Miami Dermatology Laser Institute (Miami, FL) and were assigned prospectively to undergo one PDT treatment with one of the four light options: PDL, PDL + blue light, IPL or IPL + blue light. Of the 220 patients enrolled in treatment groups, 214 patients completed the study. Of the 214 patients, 88 received treatment for AK, and 126 received treatment for photodamage. All patients gave their consent to participate in the study and to allow their photographs to be utilized for the purpose of scientific presentations.

RESULTS

Treatment with IPL resulted in a 70.8% reduction of actinic keratoses at a 1-month follow-up. Treatment with IPL and blue light 84.4% reduction of actinic keratoses at 1 month follow up. Treatment with PDL 70.5% reduction of actinic keratoses at 1 month follow up. Treatment with PDL and blue light 69.3% reduction of actinic keratoses at 1 month follow up. Treatment with IPL resulted in an improvement score of 2.9. Treatment with IPL and blue light resulted in an improvement score of 3.0. Treatment PDL resulted in an improvement score of 1.5. Treatment with PDL and blue light resulted in an improvement score of 1.8.

CONCLUSION

Although all four treatment groups led to some improvement in signs of photoaging, IPL + blue light again demonstrated increased efficacy when compared to IPL, PDL, and PDL + blue light treatment groups. Results from our study were limited by an unequal distribution between treatment groups and a lack of follow-up beyond a 1-month period and warrant further research.

A Critical Reappraisal of Off-Label Use of Photodynamic Therapy for the Treatment of Non-Neoplastic Skin Conditions

BACKGROUND

In the past 30 years, topical photodynamic therapy (PDT) has been investigated for the treatment of a broad spectrum of cosmetic, inflammatory, and infectious skin conditions with variable, and often contrasting, results. However, the non-expert clinician may be in difficulty evaluating these results because different sensitizers, concentrations, formulations, light sources, and irradiation protocols have been used. In addition, many of these studies have poor quality design being case reports and uncontrolled studies of few cases.

SUMMARY

With the aim to clarify the potential usefulness of PDT for the treatment of infectious and inflammatory skin diseases as well as selected cosmetic indications, we searched for randomized controlled clinical trials, non-randomized comparative studies, retrospective studies, and case series studies with a number of at least 10 patients, published since 1990. Later, we reappraised the results in order to give a simple critical overview. Key Messages: Evidence from the literature seems to strongly support the use of ALA- and MAL-PDT for the treatment of common skin diseases such as acne, warts, condylomata, and Leishmania skin infection and for photorejuvenation, i.e., the correction of selected cosmetic changes of aging and photoaging. For other disorders, the level of evidence and strength of recommendation are lower, and controlled randomized studies with prolonged follow-ups are necessary in order to assess the clinical usefulness and other potential advantages over current treatment options.

European Dermatology Forum guidelines on topical photodynamic therapy 2019 Part 2: emerging indications - field cancerization, photorejuvenation and inflammatory/infective dermatoses

In addition to approved indications in non-melanoma skin cancer in immunocompetent patients, topical photodynamic therapy (PDT) has also been studied for its place in the treatment of, as well as its potential to prevent, superficial skin cancers in immune-suppressed patients, although sustained clearance rates are lower than for immune-competent individuals. PDT using a nanoemulsion of ALA in a daylight or conventional PDT protocol has been approved for use in field cancerization, although evidence of the potential of the treatment to prevent new SCC remained limited. High-quality evidence supports a strong recommendation for the use of topical PDT in photorejuvenation as well as for acne, refractory warts, cutaneous leishmaniasis and in onychomycosis, although these indications currently lack approvals for use and protocols remain to be optimized, with more comparative evidence with established therapies required to establish its place in practice. Adverse events across all indications for PDT can be minimized through the use of modified and low-irradiance regimens, with a low risk of contact allergy to photosensitizer prodrugs, and no other significant documented longer-term risks with no current evidence of cumulative toxicity or photocarcinogenic risk. The literature on the pharmacoeconomics for using PDT is also reviewed, although accurate comparisons are difficult to establish in different healthcare settings, comparing hospital/office-based therapies of PDT and surgery with topical ointments, requiring inclusion of number of visits, real-world efficacy as well as considering the value to be placed on cosmetic outcome and patient preference. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical photodynamic therapy in Dermatology prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.

Photodynamic therapy activated by intense pulsed light in the treatment of actinic keratosis

BACKGROUND

Actinic keratosis (AK), a hyperkeratotic lesion induced by solar exposure, is the precancerous lesion that most frequently develops into squamous cell carcinoma. Cryotherapy, topical fluorouracil 5, topical diclofenac 3% gel and, more recently, ingenol mebutate are used in addition to surgery. However, these treatments have varying degrees of effectiveness and are not always tolerated due to side effects. In recent years, photodynamic therapy (PDT), has asserted itself as a new effective and safe method for the treatment of actinic keratoses with almost no side effects. The aim of this study is to verify whether a third treatment may now be added to the "Conventional -PDT" and "Daylight-PDT": PhotoDynamic Therapy activated by Intense Pulsed Light (IPL-PDT).

METHODS

Thirty-one patients, 24 males and 7 females, in most cases elderly, were included in the trial. As in the previous methods, also in IPL-PDT, 5-methylaminolevulinic acid (MAL) was applied topically for a period of 3 hours. Thereafter, the occlusive dressing and the topical cream, were removed and the neoformation was irradiated with IPL, with a 640 nm filter with variable power. Irradiation was performed in single or multiple sessions, depending on the type of keratosis, to completely cover the lesion and the apparently healthy surrounding areas, i.e. the cancerization field.

RESULTS

Results were evaluated 3, 6 and 9 months after treatment. Treatment achieved a 95% complete clearance rate, with a 5% partial relapse, 9 months after the last treatment.

CONCLUSIONS

The above method is a valid alternative to methods already in use. The results obtained demonstrate the efficacy and tolerability of the treatment described which, due to its versatility and speed of use, is preferable to the methods used so far.

Photodynamic therapy for aesthetic-cosmetic indications

Photodynamic therapy (PDT) is a well-established, non-invasive treatment for a variety of dermatologic disorders, including actinic keratosis. Furthermore, PDT results in marked improvements in the signs of skin aging, although currently there are no standardized guidelines for PDT in skin rejuvenation. Two types of PDT are available: conventional-PDT (c-PDT) and the newly introduced daylight-PDT (DL-PDT). Both require a topical photosensitizer, a light source and oxygen, and both are comparable regarding safety and efficacy for treatment of photo-induced skin aging. Treatment is particularly effective for improvement of fine wrinkles, skin roughness, actinic elastosis and mottled hyperpigmentation. The most widely studied topical sensitizers used in PDT are 5-aminolevulinic acid (ALA) and methyl aminolevulinate (MAL). A range of pre-treatment procedures help improve skin absorption of the photosensitizer and lead to significantly improved efficacy. A variety of activating light sources can be used for c-PDT, while DL-PDT uses natural daylight, making it easier to treat larger areas of photodamaged skin. A major limitation of c-PDT is significant treatment-related pain, but DL-PDT has proved to be an almost pain-free procedure. Treatment duration is based on individual patient need but most patients receive 2 to 3 treatment cycles, with results fully evident 3-6 months post-treatment. PDT for aesthetic-cosmetic treatments has established its value in modern procedural dermatology as mono- or combination therapy. A major, unique advantage of PDT is that it is a non-invasive treatment that effectively rejuvenates photodamaged skin, while successfully treating a range of dermatologic conditions, including prevention and therapy of pre-cancerous actinic keratosis.

Photodynamic Therapy Activated by Intense Pulsed Light in the Treatment of Nonmelanoma Skin Cancer

Photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) or methyl aminolevulinate (MAL) has proven to be a highly effective conservative method for the treatment of actinic keratosis (AK), Bowen’s disease (BD), and superficial basal cell carcinoma (sBCC). PDT is traditionally performed in association with broad-spectrum continuous-wave light sources, such as red or blue light. Recently, intense pulsed light (IPL) devices have been investigated as an alternative light source for PDT in the treatment of nonmelanoma skin cancers (NMSC). We herein report our observational findings in a cohort of patients with a diagnosis of AK, sBCC, and BD that is treated with MAL-PDT using IPL, as well as we review published data on the use of IPL-PDT in NMSC.

In situ production of ROS in the skin by photodynamic therapy as a powerful tool in clinical dermatology

Photodynamic therapy (PDT) is a clinical modality of photochemotherapy based on the accumulation of a photosensitizer in target cells and subsequent irradiation of the tissue with light of adequate wavelength promoting reactive oxygen species (ROS) formation and cell death. PDT is used in several medical specialties as an organ-specific therapy for different entities. In this review we focus on the current dermatological procedure of PDT. In the most widely used PDT protocol in dermatology, ROS production occurs by accumulation of the endogenous photosensitizer protoporphyrin IX after treatment with the metabolic precursors 5-methylaminolevulinic acid (MAL) or 5-aminolevulinic acid (ALA). To date, current approved dermatological indications of PDT include actinic keratoses (AK), basal cell carcinoma (BCC) and in situ squamous cell carcinoma (SCC) also known as Bowen disease (BD). With regards to AKs, PDT can also treat the cancerization field carrying an oncogenic risk. In addition, an increasing number of pathologies, such as other skin cancers, infectious, inflammatory or pilosebaceous diseases are being considered as potentially treatable entities with PDT. Besides the known therapeutic properties of PDT, there is a modality used for skin rejuvenation and aesthetic purposes defined as photodynamic photorejuvenation. This technique enables the remodelling of collagen, which in turn prevents and treats photoaging stygmata. Finally we explore a new potential treatment field for PDT determined by the activation of follicular bulge stem cells caused by in situ ROS formation.

Photodynamic Photorejuvenation: A Review

INTRODUCTION

Topical photodynamic therapy (PDT) is acknowledged to be a safe and efficient therapeutic option for the selective destruction of actinic keratosis and superficial carcinomas. Over the past 15 years, topical PDT has also been shown to be a possible method for "photorejuvenation."

MATERIALS AND METHODS

An extensive review was performed of in vitro and in vivo (animals, organ transplant recipients, or immunocompetent patients) studies.

RESULTS

The studies point to a high level of efficacy. Tone, lentigos, skin roughness, and moreover texture and fine wrinkles because of the effects of dermal remodeling are improved. Adverse effects are generally described as mild to moderate, without scarring, along with a fast recovery time. Patients with fair phototypes and a history of sun exposure and actinic damage of varying severity are the best candidates for this technique. Photodynamic photorejuvenation sessions can both rejuvenate their skins and also treat their visible or incipient UV-induced lesions. New protocols either with daylight use and/or previous intensification by laser or microneedling seem promising.

CONCLUSION

The photodynamic rejuvenation technique seems to show excellent short-term efficacy and tolerability.

Current evidence and applications of photodynamic therapy in dermatology

In photodynamic therapy (PDT) a photosensitizer – a molecule that is activated by light – is administered and exposed to a light source. This leads both to destruction of cells targeted by the particular type of photosensitizer, and immunomodulation. Given the ease with which photosensitizers and light can be delivered to the skin, it should come as no surprise that PDT is an increasingly utilized therapeutic in dermatology. PDT is used commonly to treat precancerous cells, sun-damaged skin, and acne. It has reportedly also been used to treat other conditions including inflammatory disorders and cutaneous infections. This review discusses the principles behind how PDT is used in dermatology, as well as evidence for current applications of PDT.

[New developments in photodynamic therapy]

We review new developments in recent years in photodynamic therapy. Since 2009 two new photosensitizers, a self-adhesive 5-aminolevulinic acid (ALA) patch and a nanoemulsion formulation of 5-aminolevulinic acid have been approved for the treatment of actinic keratoses. Pretreatment with ablative fractional lasers enhances penetration of the photosensitizer and enables intensified PDT in acral lesions and in field-cancerized skin. Several clinical trials have demonstrated the skin-rejuvenating effects of photodynamic therapy, while the underlying mechanisms of action have been clarified. The efficacy of photodynamic therapy has been shown in the treatment and prophylaxis of actinic keratoses in organ transplant recipients at high risk for developing skin cancer. We also summarize the results of available studies on daylight-mediated photodynamic therapy.

Interventions for actinic keratoses

BACKGROUND

Actinic keratoses are a skin disease caused by long-term sun exposure, and their lesions have the potential to develop into squamous cell carcinoma. Treatments for actinic keratoses are sought for cosmetic reasons, for the relief of associated symptoms, or for the prevention of skin cancer development. Detectable lesions are often associated with alteration of the surrounding skin (field) where subclinical lesions might be present. The interventions available for the treatment of actinic keratoses include individual lesion-based (e.g. cryotherapy) or field-directed (e.g. topical) treatments. These might vary in terms of efficacy, safety, and cosmetic outcomes.

OBJECTIVES

To assess the effects of topical, oral, mechanical, and chemical interventions for actinic keratosis.

SEARCH METHODS

We searched the following databases up to March 2011: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 2005), EMBASE (from 2010), and LILACS (from 1982). We also searched trials registers, conference proceedings, and grey literature sources.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the treatment of actinic keratoses with either placebo, vehicle, or another active therapy.

DATA COLLECTION AND ANALYSIS

At least two authors independently abstracted data, which included adverse events, and assessed the quality of evidence. We performed meta-analysis to calculate a weighted treatment effect across trials, and we expressed the results as risk ratios (RR) and 95% confidence intervals (CI) for dichotomous outcomes (e.g. participant complete clearance rates), and mean difference (MD) and 95% CI for continuous outcomes (e.g. mean reduction in lesion counts).

MAIN RESULTS

We included 83 RCTs in this review, with a total of 10,036 participants. The RCTs covered 18 topical treatments, 1 oral treatment, 2 mechanical interventions, and 3 chemical interventions, including photodynamic therapy (PDT). Most of the studies lacked descriptions of some methodological details, such as the generation of the randomisation sequence or allocation concealment, and half of the studies had a high risk of reporting bias. Study comparison was difficult because of the multiple parameters used to report efficacy and safety outcomes, as well as statistical limitations. We found no data on the possible reduction of squamous cell carcinoma.The primary outcome 'participant complete clearance' significantly favoured four field-directed treatments compared to vehicle or placebo: 3% diclofenac in 2.5% hyaluronic acid (RR 2.46, 95% CI 1.66 to 3.66; 3 studies with 420 participants), 0.5% 5-fluorouracil (RR 8.86, 95% CI: 3.67 to 21.44; 3 studies with 522 participants), 5% imiquimod (RR 7.70, 95% CI 4.63 to 12.79; 9 studies with1871 participants), and 0.025% to 0.05% ingenol mebutate (RR 4.50, 95% CI 2.61 to 7.74; 2 studies with 456 participants).It also significantly favoured the treatment of individual lesions with photodynamic therapy (PDT) compared to placebo-PDT with the following photosensitisers: aminolevulinic acid (ALA) (blue light: RR 6.22, 95% CI 2.88 to 13.43; 1 study with 243 participants, aminolevulinic acid (ALA) (red light: RR 5.94, 95% CI 3.35 to 10.54; 3 studies with 422 participants), and methyl aminolevulinate (MAL) (red light: RR 4.46, 95% CI 3.17 to 6.28; 5 studies with 482 participants). ALA-PDT was also significantly favoured compared to cryotherapy (RR 1.31, 95% CI 1.05 to 1.64).The corresponding comparative risks in terms of number of participants completely cleared per 1000 were as follows: 313 with 3% diclofenac compared to 127 with 2.5% hyaluronic acid; 136 with 0.5% 5-fluorouracil compared to 15 with placebo; 371 with 5% imiquimod compared to 48 with placebo; 331 with ingenol mebutate compared to 73 with vehicle; 527 to 656 with ALA/MAL-PDT treatment compared to 89 to 147 for placebo-PDT; and 580 with ALA-PDT compared to 443 with cryotherapy.5% 5-fluorouracil efficacy was not compared to placebo, but it was comparable to 5% imiquimod (RR 1.85, 95% Cl 0.41 to 8.33).A significant number of participants withdrew because of adverse events with 144 participants affected out of 1000 taking 3% diclofenac in 2.5% hyaluronic acid, compared to 40 participants affected out of 1000 taking 2.5% hyaluronic acid alone, and 56 participants affected out of 1000 taking 5% imiquimod compared to 21 participants affected out of 1000 taking placebo.Based on investigator and participant evaluation, imiquimod treatment and photodynamic therapy resulted in better cosmetic outcomes than cryotherapy and 5-fluorouracil.

AUTHORS' CONCLUSIONS

For individual lesions, photodynamic therapy appears more effective and has a better cosmetic outcome than cryotherapy. For field-directed treatments, diclofenac, 5-fluorouracil, imiquimod, and ingenol mebutate had similar efficacy, but their associated adverse events and cosmetic outcomes are different. More direct comparisons between these treatments are needed to determine the best therapeutic approach.

Photodynamic therapy for skin rejuvenation: review and summary of the literature--results of a consensus conference of an expert group for aesthetic photodynamic therapy

Skin rejuvenating effects of photodynamic therapy (PDT) for photoaged skin has been well-documented in several clinical trials. Different photosensitizers (5-aminolevulinic acid, methyl aminolevulinate) and diverse light sources (light-emitting diodes, lasers, intense pulsed light) have been used with promising results. An improvement of lentigines, skin roughness, fine lines and sallow complexion has been achieved with PDT. These clinically evident effects are at least in part due to histologically proven increase of collagen and decrease of elastotic material in the dermis. Effective improvement of photoaged skin, simultaneous treatment and possibly also prevention of actinic keratoses, the possibility of repeated treatments and, in contrast to other procedures, limited and calculable side effects make PDT a promising procedure for skin rejuvenation.

Laser light activation of a second-generation photosensitiser and its use as a potential photomodulatory agent in skin rejuvenation

Photodynamic rejuvenation therapy (PDRT) is a growing field in cosmetic dermatology. In this study, different sources of light (a yellow laser, a red laser and ultraviolet A (UVA) lamps) were used to activate a second-generation photosensitiser, hypericin. Uptake of hypericin was monitored over 24 h and efficacy of PDRT was assessed using cell viability and reactive oxygen species (ROS) quantification assays. In addition, we show for the first time, a quantifiable assay for ROS production in human dermal fibroblasts incubated with hypericin and exposed to yellow laser light or UVA lamps. Furthermore, we optimised a protocol with regard to hypericin concentration and irradiation parameters using the XTT cell viability kit. This study showed that this photosensitiser, hypericin, was taken up by the cells in a concentration-dependent manner over 24 h with cell saturation occurring after approximately 16 h. The uptake seemed to be localised to the cell cytoplasm with no hypericin appearing in the nucleus. The levels of ROS increased in the cell when irradiated with the yellow laser (561 nm) however, it did not increase further with the addition of hypericin. Hypericin and UVA showed a significant increase in the amount of ROS produced. The results also show that cell viability is not affected by low power light (2 mW) from the yellow laser irrespective of the dose used. However, an increase to 10 mW power with 5 J/cm(2) light dose, resulted in a significant drop (p < 0.05) in cell viability at both 0.5 (77.53 ± 9.67 %) and 1 μM (48.51 ± 13.27 %) hypericin concentrations. In contrast, a 20 % increase in cell viability was seen with 1 J/cm(2) and 20 mW and 0.25 μM hypericin. Overall, this study highlights an optimised protocol for hypericin-induced photorejuvenative therapy using laser light and proposes that parameters of 0.25 μM hypericin as a photosensitiser activated via a dosage of 1 J/cm(2) yellow laser light produces an effective in vitro outcome to be considered as an important contribution towards optimising PDRT.