Comparative Study of Photodynamic Therapy with Topical Methyl Aminolevulinate versus 5-Aminolevulinic Acid for Facial Actinic Keratosis with Long-Term Follow-Up

Background

Few studies have compared the efficacy, cosmetic outcomes, and adverse events between 5-aminolevulinic acid photodynamic therapy (ALA-PDT) and methyl aminolevulinate-PDT (MAL-PDT) for actinic keratoses (AKs) in Asian ethnic populations with dark-skin.

Objective

We retrospectively compared the long-term efficacy, recurrence rates, cosmetic outcomes, and safety of ALA-PDT versus MAL-PDT for facial AKs in Koreans.

Methods

A total of 222 facial AKs in 58 patients were included in this study. A total of 153 lesions (29 patients) were treated with 5-ALA, and 69 lesions (29 patients) with MAL. ALA and MAL creams were applied for 6 hours and 3 hours, respectively; the lesions were then illuminated with a halogen lamp at 150 J/cm² for ALA-PDT and a diode lamp at 37 J/cm² for MAL-PDT.

Results

The complete response rates of ALA-PDT and MAL-PDT were 56.9% and 50.7%, respectively, with no significant difference at 12 months after treatment. No significant difference in recurrence rates was observed between the 2 PDT modalities at either 6 or 12 months after treatment. There was no significant difference in the cosmetic outcomes between the 2 treatment modalities at 12 months after PDT. However, ALA-PDT caused significantly more painful than MAL-PDT (p=0.005). The adverse events were mild to moderate, transient, and self-limiting for both modalities.

Conclusion

MAL-PDT was similar to ALA-PDT in terms of long-term efficacy, recurrence rates, cosmetic outcomes, and adverse events; however, it was a significantly less painful procedure than ALA-PDT in our study.

Spanish-Portuguese consensus statement on use of daylight-mediated photodynamic therapy with methyl aminolevulinate in the treatment of actinic keratosis

INTRODUCTION

Daylight-mediated photodynamic therapy (PDT) is a new type of PDT that is as effective as conventional PDT in grade 1 and 2 actinic keratosis but with fewer adverse effects, resulting in greater efficiency. The climatic conditions in the Iberian Peninsula require an appropriately adapted consensus protocol.

OBJECTIVE

We describe a protocol for the treatment of grade 1 and 2 actinic keratosis with daylight-mediated PDT and methyl aminolevulinate (MAL) adapted to the epidemiological and clinical characteristics of Spanish and Portuguese patients and the climatic conditions of both countries.

METHODS

Twelve dermatologists from different parts of Spain and Portugal with experience in the treatment of actinic keratosis with PDT convened to draft a consensus statement for daylight-mediated PDT with MAL in these countries. Based on a literature review and their own clinical experience, the group developed a recommended protocol.

RESULTS

According to the recommendations adopted, patients with multiple grade 1 and 2 lesions, particularly those at risk of developing cancer, are candidates for this type of therapy. Daylight-mediated PDT can be administered throughout the year, although it is not indicated at temperatures below 10°C or at excessively high temperatures. Likewise, therapy should not be administered when it is raining, snowing, or foggy. The procedure is simple, requiring application of a sunscreen with a protection factor of at least 30 based exclusively on organic filters, appropriate preparation of the lesions, application of MAL without occlusion, and activation in daylight for 2hours.

CONCLUSION

This consensus statement represents a practical and detailed guideline to achieve maximum effectiveness of daylight-mediated PDT with MAL in Spain and Portugal with minimal adverse effects.

Physical drug delivery enhancement for aged skin, UV damaged skin and skin cancer: Translation and commercialization

This review analyses physical drug delivery enhancement technologies with a focus on improving UV damaged skin, actinic keratoses and non-melanoma skin cancer treatment. In recent years, physical drug delivery enhancement has been shown to enhance cosmeceutical and skin cancer treatment efficacy, but there are pros and cons to each approach which we discuss in detail. Mechanisms of action, clinical efficacy, experimental design, outcomes in academic publications, clinical trial reports and patents are explored to evaluate each technology with a critical, translation focused lens. We conclude that the commercial success of cosmeceutical applications, e.g. microneedles, will drive further innovation in this arena that will impact how actinic keratoses and non-melanoma skin cancers are clinically managed.

Optimizing treatment of acne with photodynamic therapy (PDT) to achieve long-term remission and reduce side effects. A prospective randomized controlled trial

Photodynamic therapy with methyl aminolevulinate (MAL-PDT) is an effective treatment of acne vulgaris, but is associated with side effects. We performed a prospective randomized split-face study aimed at optimizing MAL-PDT treatment. Patients (n = 33) were randomized to two or four treatments of PDT with MAL on one cheek and placebo vehicle on the other cheek, 1-2 weeks apart. A 1.5-h pre-treatment with the MAL cream was followed by illumination with red light (20 J/cm²). Assessments were performed before treatment and 4, 10, and 20 weeks after the last treatment. In comparison to baseline, the number of inflammatory lesions at 20 weeks on cheeks treated with MAL-PDT showed a relative decrease of 74% in the group with two treatments and 85% in the group with four treatments. This new treatment regimen for both MAL-PDT and red-light-only PDT, with shortened pre-treatment and reduced light dose, could be an effective modality.

Daylight photodynamic therapy versus cryosurgery for the treatment and prophylaxis of actinic keratoses of the face - protocol of a multicenter, prospective, randomized, controlled, two-armed study

BACKGROUND

Photodynamic therapy with daylight (DL-PDT) is efficacious in treating actinic keratosis (AK), but the efficacy of field-directed, repetitive DL-PDT for the treatment and prophylaxis of AK in photodamaged facial skin has not yet been investigated.

METHODS/DESIGN

In this multicenter, prospective, randomized, controlled, two-armed, observer-blinded trial, patients with a minimum of 5 mild-to-moderate AK lesions on photodamaged facial skin are randomly allocated to two treatment groups: DL-PDT with methyl aminolevulinate (MAL) and cryosurgery. In the DL-PDT group (experimental group), 5 treatments of the entire face are conducted over the course of 18 months. After preparation of the lesion and within 30 min after MAL application, patients expose themselves to daylight for 2 h. In the control group, lesion-directed cryosurgery is conducted at the first visit and, in the case of uncleared or new AK lesions, also at visits 2 to 5. The efficacy of the treatment is evaluated at visits 2 to 6 by documenting all existing and new AK lesions in the face. Cosmetic results and improvement of photoaging parameters are evaluated by means of a modified Dover scale. Primary outcome parameter is the cumulative number of AK lesions observed between visits 2 and 6. Secondary outcome parameters are complete clearance of AK, new AK lesions since the previous visit, cosmetic results independently evaluated by both patient and physician, patient-reported pain (visual analogue scale), patient and physician satisfaction scores with cosmetic results, and patient-reported quality of life (Dermatology Life Quality Index). Safety parameters are also documented (adverse events and serious adverse events).

DISCUSSION

This clinical trial will assess the efficacy of repetitive DL-PDT in preventing AK and investigate possible rejuvenating effects of this treatment. (Trial registration: ClinicalTrials.gov Identifier: NCT02736760).

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02736760 . Study Code Daylight_01. EudraCT 2014-005121-13.

Protoporphyrin IX formation after application of methyl aminolevulinate on the face and scalp with and without prior curettage

BACKGROUND

Pulse photodynamic therapy (PDT) is carried out as classical PDT except that methyl aminolaevulinate (MAL) is removed after 30 min. Protoporphyrin IX (PpIX) accumulation becomes lower after 3 h in pulse-PDT than in classical PDT, but pulse-PDT still has full treatment effect on actinic keratosis (AK). The present study aimed to investigate when PpIX formation in classical PDT without curettage reaches the PpIX level in pulse-PDT with curettage in the skin of the face and scalp.

METHODS

Fourteen patients with AKs in the face and scalp were included in this pilot study. Each patient had two fields randomly allocated to two different regimes: (i) continuing MAL incubation without prior curettage (-Cur) and (ii) 30 min MAL incubation after curettage (+Cur). The PpIX level in each field was measured with a hand-held fluorescence photometer every 30 min for 6 h after MAL application. No illumination was performed.

RESULTS

The median PpIX level in the +Cur field after 3 h was 22 arbitrary units (AU), which represents the amount of PpIX that could have been photobleached after pulse-PDT with maximal treatment effect. After 3 h the median PpIX level in the -Cur field was 20 AU, which was not significantly different from the level in the +Cur field (p = 0.9).

CONCLUSIONS

We propose PDT without curettage as follows: 3 h of MAL incubation and subsequently sufficient illumination. The treatment effect of this regime should be tested to verify if curettage of the face and scalp area may be omitted in PDT.

Comparison of clinical and histologic findings in daylight photodynamic therapy for skin field cancerization: A randomized controlled four-arm study on physical methods-assisted delivery of methyl aminolevulinate

BACKGROUND

Daylight photodynamic therapy (DL-PDT) has similar efficacy to conventional photodynamic therapy in treating actinic keratosis (AKs). Good clinical outcomes have been reported when associated with physical methods such as microneedles, but a comparison of different methods and histologic studies is lacking.

OBJECTIVES

To evaluate clinical and histologic modifications induced by standard DL-PDT and compare with DL-PDT associated with physical methods in treating skin field cancerization of the face.

METHODS

Forty patients with photodamaged skin and at least one AK lesion on the face were randomly distributed into four groups, ten patients in each (I: Standard DL-PDT; II: DL-PDT + microneedles; III: DL-PDT + CO2 laser; IV: DL-PDT + microdermabrasion) and underwent two DL-PDT sessions with methyl aminolevulinate cream and 2-hour daylight exposure. Skin biopsies were performed on all patients before and 3 months after. All fragments were stained using the hematoxylin-eosin, orcein, and picrosirius.

RESULTS

All 40 patients completed the study. Group III had a higher AK-clearance after 1 (p = 0,002) and 3 (p = 0,034) months, but it was similar in every group at 6 months (p = 0,441). Group III and IV had better clinical global improvement on texture, pigmentation and fine lines. In the groups associated with physical methods, the improvement of the keratinocytes' atypia and solar elastosis were remarkable. Only group III showed a significant reduction in solar elastosis (p = 0.034) and increased collagen type I (p = 0.028) after treatment.

CONCLUSION

DL-PDT-associated with physical methods had better clinical and histologic results. AK-clearance were significantly higher after 1 and 3 months with pretreatment-CO2 laser. Photorejuvenation were more evident with pretreatment-CO2 laser and microdermabrasion. Pretreatment-CO2 laser showed a significant reduction in solar elastosis and increase of collagen type 1. These results pointed to the pretreatment with laser as a potentially better option for skin field cancerization of the face.

Daylight Photodynamic Therapy Versus 5-Fluorouracil for the Treatment of Actinic Keratosis: A Case Series

Introduction

The incidence of actinic keratosis (AK) continues to increase worldwide. Currently available options for the treatment of AK include topical 5-fluorouracil (5-FU) and daylight-mediated photodynamic therapy (DL-PDT). This split-face pilot study compared DL-PDT using 16% methyl aminolevulinate (MAL) cream versus 5-FU cream in patients with AK on the face/scalp.

Methods

Five male subjects (mean age 70 years) with grade I–III AK on the face/scalp were enrolled. Subjects received a single session of DL-PDT with 16% MAL on one side and topical 5% 5-FU for 21 days on the other side. Evaluations of efficacy, safety, and subject satisfaction were conducted 48 h, 7 days, 14 days, 1 month, and 3 months after treatment.

Results

At 3 months, the lesion complete response rate was 80% and 93% for DL-PDT and 5-FU, respectively. Lesion partial response was 20% and 7%, respectively. Fewer treatment-related adverse events (AEs) were reported with DL-PDT than with 5-FU, and they resolved spontaneously in 5–7 and 27–30 days, respectively. Subjects preferred DL-PDT because of the lower incidence of AEs and rapid recovery compared with 5-FU.

Conclusion

DL-PDT is a convenient alternative to 5-FU with good efficacy and a favorable safety profile, allowing patients to effectively treat their AK without compromising their social life.

Funding

Galderma.

Randomized clinical trial testing the efficacy and safety of 0.5% colchicine cream versus photodynamic therapy with methyl aminolevulinate in the treatment of skin field cancerization: study protocol

Background

The primary clinical manifestation of skin field cancerization is the presence of actinic keratoses (AKs). Current treatments for AKs related to skin field cancerization include photodynamic therapy (PDT) and colchicine. The objective of this study is to evaluate the efficacy and safety of 0.5% colchicine cream versus PDT with methyl aminolevulinate (MAL-PDT) in the treatment of skin field cancerization.

Methods

In a randomized controlled and open clinical trial with a blind histopathological and immunohistochemical analysis, 36 patients with up to 10 AKs on their forearms will be included from the outpatient clinic. The forearms will be randomized into two groups, clinically evaluated and biopsied for histopathology and immunohistochemistry (p53 and Ki67). One forearm will be treated with 0.5% colchicine cream for 10 days, and the other forearm will receive one session of MAL-PDT; the forearms will subsequently be reassessed clinically and histologically after 60 days (T60) of treatment. The primary endpoint will be the point of complete clearance of AKs in T60. The sample size will enable a detection in the reduction of over 10% in AK counts between the groups with power of 0.9 and an alpha of 0.05, accounting for an estimated dropout rate of 10%, resulting in 36 patients (72 forearms). All participants included in the randomized study will be part of the analysis, and the final outcomes of any dropouts will be the value of their last visit (LOCF). The statistical analysis will be performed using SPSS 22.0, and a p value < 5% will be considered to be significant.

Discussion

It is expected that colchicine will be superior to MAL-PDT in reducing AKs and in the skin field cancerization, and there will be good tolerability in both groups. Colchicine intervention is novel in that it provides a new alternative to MAL-PDT. Moreover, this drug is inexpensive that may be a potential treatment of skin field cancerization that can be prescribed in public health systems with good results.

Trial registration

The trial is registered in Brazilian Registry for Clinical Trials (Registration number: RBR-8y3sj9, date assigned May 4, 2016, retrospectively registered).

Methyl aminolevulinate photodynamic therapy after partial debulking in the treatment of superficial and nodular basal cell carcinoma: 3-years follow-up

BACKGROUND

The increase in the number of basal cell carcinoma (BCC) lesions has prompted use of minimally invasive therapies, including Photodynamic therapy (PDT). . The objective of the present work was to analyze the efficacy of methyl aminolevulinate-mediated photodynamic therapy (MAL-PDT) in patients suffering from superficial or nodular BCCs.

METHODS

A total of 220 BCC lesions (76 superficial and 144 nodular), clinically diagnosed and confirmed by histopathology analysis, were treated in 174 patients (mean age 72.5). Debulking using curettage was performed before two or three MAL-PDT sessions (λ = 630 nm; 90 J/cm²; 23 min) at 4-week intervals. Analyses of clinical clearance and cosmetic outcome were carried out by direct examination, dermoscopy, photographs, as well as by fluorescence diagnosis using a Wood's lamp. Evaluations were carried out at the different PDT sessions and follow-ups over a 3-year period.

RESULTS

MAL-PDT was safe and highly tolerated. After an average of 2.6 MAL-PDT sessions, the overall clearance rate at 3-year follow-up was 96.1 % (95 % confidence interval [CI] 100 %-92 %) for superficial BCCs and 95.2 % (95 % [CI] 99 %-92 %) for nodular BCCs after an average of 2.7 sessions. Minimal side effects such as crushing, erythema and edema were reported. All BCC lesions showed excellent or good cosmetic results.

CONCLUSION

The protocol followed in the present study has shown that MAL-PDT is a safe and effective treatment for superficial and nodular types of BCC.

Topical and intradermal delivery of PpIX precursors for photodynamic therapy with intense pulsed light on porcine skin model

In order to purposely decrease the time of the photodynamic therapy (PDT) sessions, this study evaluated the effects of PDT using topical and intradermal delivery of two protoporphyrin (PpIX) precursors with intense pulsed light (IPL) as irradiation source. This study was performed on porcine skin model, using an IPL commercial device (Intense Pulse Light, HKS801). IPL effect on different administration methods of two PpIX precursors (ALA and MAL) was investigated: a topical cream application and an intradermal application using a needle-free, high-pressure injection system. Fluorescence investigation showed that PpIX distribution by needle-free injection was more homogeneous than that by cream, suggesting that a shorter drug-light interval in PDT protocols is possible. The damage induced by IPL-PDT assessed by histological analysis mostly shows modifications in collagens fibers and inflammation signals, both expected for PDT. This study suggested an alternative protocol for the PDT treatment, possibility half of the incubation time and with just 3 min of irradiation, making the IPL-PDT, even more, promising for the clinical treatment.

[Procedure for daylight methyl aminolevulinate photodynamic therapy to treat actinic keratoses]

Actinic keratosis (AK), also known as solar keratosis or pre-cancerous keratosis, is frequently observed in areas of skin exposed to sunlight, particularly in light-skinned patients. In France, photodynamic therapy using red light (conventional PDT) and methylamino 5-levulinate (MAL) is indicated in the treatment of thin or non-hyperkeratotic and non-pigmented multiple AK lesions or large zones covered with AK lesions. It is well-known for its efficacy but also for its side effects, especially pain during illumination, which can limit its use. An alternative to PDT using natural daylight has recently been proposed to treat actinic keratosis lesions, and results in greater flexibility as well as significant reduction in pain. The lesions are prepared as for conventional PDT, with MAL cream being applied by the physician or the patient, after which they are exposed to natural daylight for 2hours. The lesions are then gently cleansed and protected from natural light for 24hours. This paper seeks to provide a precise description of the daylight PDT procedure for the treatment of AK.

Development of a high payload, cancer-targeting liposomes of methyl aminolevulinate for intraoperative photodynamic diagnosis/therapy of peritoneal carcinomatosis

Methyl aminolevulinate (MAL) is a photosensitizer topically used for photodynamic diagnosis (PDD) and photodynamic therapy (PDT) of skin pre-cancers and cancers. In this study, our goal is to expand the application of MAL to dual intraoperative PDD and PDT of peritoneal carcinomatosis. A new liposomal MAL formulation (lipMAL) designed for systemic or intraperitoneal administration was developed. LipMALs prepared by ammonium sulfate gradient technique achieved MAL payload up to 18% (w/w) with drug encapsulation efficiency in the range of 15.1-31.5%. All lipMALs demonstrated controlled MAL release behavior, and achieved strong fluorescence in cancer cells (SKOV3) but minimal fluorescence in non-cancer peritoneal cells (B14FAF28-G3). LipMALs led to significantly higher fluorescence levels than free MAL groups (P < 0.05), up to 6.8-fold of the free MAL fluorescence levels in SKOV3 cells. The PDD performance of lipMALs was also compared with free MAL in SKOV3/ B14FAF28-G3 co-cultures simulating ovarian cancer micrometastases on peritoneal surface. The lipMAL-treated cancer colonies glew more brightly than the free MAL treated colonies and were clearly distinguishable from the dim peritoneum background with unaided eyes. LipMAL also achieved significantly stronger anticancer PDT effects than free MAL both in terms of cell viability and colony-formation (P < 0.05) while demonstrating minimal dark toxicity. To conclude, a new promising aid for the surgeons to achieve more complete resection of tumors and PC micrometastases and clean up any residual cancer cells undetected was developed.

Methyl aminolevulinate-based photodynamic therapy of Bowen´s disease: Observational study of 21 lesions

BACKGROUND

Although surgical removal is the treatment of choice in Bowen's disease (BD), there are cases in which by age, comorbidities, use of anticoagulants, location, cosmetic result, or size, it is preferable to use other treatments such as cryotherapy, 5-fluorouracil cream, imiquimod 5% cream or photodynamic therapy (PDT). Efficacy of PDT in BD is supported by substantial research and clinical data.

OBJECTIVES

This study aimed to evaluate the long term effectiveness of methyl aminolevulinate-PDT (MAL/PDT) on a wide range of Bowen lesions in different locations and sizes.

METHODS

Patients diagnosed with BD were treated in 3 sessions with a 4-week interval in between with MAL/PDT between January 2016 and January 2017 in a private clinic. Clinical response and relevant patient and tumour characteristics were analyzed during the first year after start of the PDT sessions.

RESULTS

In total, 21 BD lesions in 18 patients were included in the study. Complete regression (CR) after 3rd PDT session was 87.5% and 100% at the 6-month follow-up. Treatment was well tolerated and local adverse reactions were very scarce. No recurrence was observed at 12-month follow-up. Cosmetic outcome at 12 months was good or excellent in 100% of patients.

CONCLUSIONS

MAL/PDT is an effective, non invasive and safe treatment modality for BD with excellent cosmesis.

A Review of MAL-PDT for the Treatment Strategy of Actinic Keratosis: Broader Clinical Perspectives Beyond the Data and Guideline Recommendations

Methyl aminolevulinate (MAL) is a topical compound approved for use with photodynamic therapy (PDT) for the treatment of actinic keratosis (AK) and field cancerization in certain countries. There exists a high burden of disease for patients with AK: repeated treatments are required, there is a known risk of progression to keratinocyte carcinoma, and cosmetic appearance is affected. Delivery of PDT using MAL is a flexible treatment strategy available in many forms; red light, daylight, or artificial daylight can be used for illumination, all of which result in high AK clearance rates and low recurrence. MAL-PDT protocols continue to evolve to further improve adherence and treatment outcomes. Here, we used PubMed to search MEDLINE to identify guidelines, consensus recommendations, and studies describing the use of MAL for the treatment of AK. The aim of this targeted review is to consider various MAL-PDT treatment strategies on the basis of published literature, with a focus on personalizing treatment for the heterogeneous AK population.

MAL-associated methyl nicotinate for topical PDT improvement

Photosensitization of all tissue in sufficient quantity to generate damage is one of the limiting factors for Photodynamic Therapy (PDT) efficiency. Methyl nicotinate (MN) is a thermogenic and vasodilating substance that facilitates the topical tissue penetration of some compounds. The topical MAL (methyl aminolevulinate) PDT is commonly used as a precursor of protoporphyrin IX (PpIX). This study investigates the safety of topical use in NM, as well as its ability to improve the efficiency of topical PDT. For this, we investigate the cytotoxicity of MN, as well as its actions in increasing cellular metabolism and vasodilation. Besides, its ability to optimize the formation of PpIX in the tissue when associated with MAL cream was investigated, besides assessing the severity of necrosis obtained by treatments. The cytotoxicity of MN was tested for concentrations of 0, 0.1, 0.25, 0.5, 0.75 and 1% in cell culture. For the concentration of 0.5%, the cellular metabolism was evaluated using confocal microscopy to calculate the redox rate. In the Chorioallantoic Membrane Model, vasodilation was evaluated for concentrations of 0.5 and 1% MN during 1 h of incubation. In the animal model, the healthy skin of Wistar rat was used to evaluate the production of PpIX in the tissue and the degree of necrosis obtained by Photodynamic therapy when using NM associated with methyl aminolevulinate. It was observed the non-cytotoxicity in vitro of MN in the concentration used (0.5%) and its ability to increase cellular metabolism. In a chorioallantoic model, the MN vasodilation power was demonstrated for different caliber of vessels. In vivo studies are showing that the incorporation of MN in the MAL cream increases the amount of PpIX produced in the tissue causing a higher effect on the epidermis after PDT. This improvement of the protocol may make the procedure more effective both in the destruction of tumor tissue and in the treatment of deeper cells decreasing possible recurrence, in addition to allowing improvements in the protocol, such as reducing the cream's incubation time.

A 10-Year Retrospective Analysis of Methyl Aminolevulinate Photodynamic Therapy Consultation at the Hospital de Braga

Introduction

Photodynamic therapy (PDT) is a well-established treatment for actinic keratosis (AK), basal cell carcinoma (BCC), and Bowen’s disease (BD). The object of this study was to describe the results of a retrospective analysis of patients treated with methyl aminolevulinate PDT (MAL-PDT) with red light, over the past decade at the Hospital de Braga (Braga, Portugal).

Methods

This study is based on the retrospective analysis of the clinical records of patients treated with MAL-PDT from January 2003 to December 2013.

Results

More than 550 patients with mean age of 72 years were treated with MAL-PDT. About two-thirds of these patients were female. In terms of diagnostics, 67% of the patient population were affected with AK, 27% presented with BCC, and 4% had BD. With an average follow-up of 5.5 years, 99.5% of the lesions had cleared. The recurrence of lesions occurred during the first year of follow-up, mostly large BCC localized on the trunk.

Conclusion

This study showed the excellence of MAL-PDT for treating AK, BCC, and BD, with a low recurrence rate.

Skin surface Protoporphyrin IX fluorescence is associated with epidermal but not dermal fluorescence intensities

BACKGROUND

Photodynamic therapy with Protoporphyrin IX (PpIX) is well-established for keratinocyte dysplasia. PpIX fluorescence can be quantified at the skin surface and within skin layers, but their relation is previously undescribed. The study objective was to assess the relation between skin surface PpIX fluorescence and PpIX fluorescence in epidermis and dermis.

METHODS

Normal buttocks skin was tape-stripped and incubated with 20 % methyl aminolevulinate cream and 20 % hexyl aminolevulinate cream under occlusion. After 3 h, skin surface PpIX fluorescence photographs were captured and 4 mm punch biopsies sampled. PpIX fluorescence microscopy was measured in regions of interest (ROI) in epidermis and superficial dermis. All PpIX fluorescence intensities were calculated in arbitrary units (AU).

RESULTS

Skin surface PpIX fluorescence intensity expressed a positive, linear relation to ROI-epidermis PpIX fluorescence (HAL- and MAL-incubated skin, p < 0.001, r² = 0.60), but not to PpIX fluorescence intensities in ROI-superficial dermis (p = 0.112). PpIX fluorescence microscopy identified higher fluorescence intensities in ROI-epidermis (median 92 AU) compared to lower fluorescence intensities in ROI-superficial dermis (median 37 AU) (p < 0.001). HAL reached higher median PpIX fluorescence intensities than MAL when measured by skin surface photographs (10230 vs. 5630 AU, p < 0.001), andbyfluorescence microscopy in ROI-epidermis (107 vs. 52.5 AU, p < 0.001) or ROI-superficial dermis (40 vs. 30.5 AU, p = 0.04).

CONCLUSION

The positive linear relation between skin surface PpIX fluorescence photographs and epidermal PpIX fluorescence microscopy indicates that skin surface PpIX fluorescence predominantly derives from epidermis.

Long-term follow-up results of a pilot study for nodular basal cell carcinoma with PDT using partial home treatment protocol

SIGNIFICANCE

Evaluate a photodynamic therapy (PDT) protocol for low-risk basal cell carcinoma (BCC) treatment that requires less time spent at the hospital and is less painful.

APPROACH

Eight BCCs were selected, debulked, and received 20 % methyl aminolevulinate cream. After 3 h, the first irradiation was performed at the hospital (20 min, 150 J/cm2). Then, the cream was re-applied, and a portable irradiation prototype was fixed to the skin around the lesion. After 1.5 h, the patients turned on the prototype for irradiation at home (for 2 h, totalizing 312 J/cm2). Disease-free survival rate and pain score during irradiations were evaluated.

RESULTS

The clearance at 30 days after PDT was 87.5 % by histological analysis. The mean follow-up was 21.5 months and the recurrence-free survival at 22 months was 75 %. The pain score was significantly lower at home.

CONCLUSIONS

A potentially less painful and more comfortable PDT treatment protocol with proven long-term efficiency is presented. A randomized clinical trial has been conducted to confirm these results.

Photodynamic therapy for nodular basal cell carcinoma up to 5mm located on high-risk area: Effectiveness and long-term follow-up results

SIGNIFICANCE

Response rates evaluation of photodynamic therapy (PDT) for nodular basal cell carcinoma (BCC) treatment located on high-risk and low-risk areas of the face.

APPROACH

Two groups of nodular BCC were selected, debulked, and received 20% methyl aminolevulinate (MAL) hydrochloride cream. After 3 h, the first irradiation was performed (20 min, 150 J/cm2). Then, the cream was re-applied, and a second irradiation was performed after 1.5 h (20 min, 150 J/cm2). Clearance at 30 days and recurrence-free survival rate were evaluated.

RESULTS

The clearance at 30 days after PDT was 89% for the low-risk area group and 87% for the high-risk group. The recurrence-free survival at 60 months was 82% and 85% for the high-risk and low-risk groups, respectively.

CONCLUSIONS

No significant differences were observed between groups nor for clearance at 30 days, nor recurrence-free follow-up. These results make PDT possible option for nodular BCC less than 5 mm located in high-risk areas.