Daylight Photodynamic Therapy for Actinic Keratosis and Field Cancerization: A Narrative Review

Actinic keratoses (AKs), also known as solar keratoses, are rough, scaly lesions that appear as macules, papules, or plaques [...].

Home Self-Applied Daylight Photodynamic Therapy: Current Map in Spain and Management Proposals

OBJECTIVE

To determine the current practices of Spanish dermatologists performing home self-applied daylight photodynamic therapy (dPDT), and their experience with this treatment.

METHODOLOGY

We conducted a retrospective, multicenter, cross-sectional observational study with participation from 100 dermatologists from public and private Spanish hospitals. Their practices were collected through an online questionnaire and prepared based on a literature review, including experience, climatology, advantages, disadvantages and satisfaction with the self-applied dPDT.

RESULTS

A total of 38.4% of dermatologists have >5 years of experience using dPDT and 72.7% alternate consultation and home self-application. A total of 61.1% of dermatologists do not have specific protocols for self-application and 69.4% explain instructions to their patients personally. A total of 50% prefer to apply dPDT in months of greater solar activity and 70.8% recommend treatment during the morning. A total of 95.9% of the patients are satisfied or very satisfied with the treatment.

MAIN CONCLUSIONS

Self-applied dPDT is an effective and well-tolerated option to treat AK, especially in patients who adequately follow instructions and have family support. It is necessary to protocolize the self-applied dPDT to guarantee a greater safety and efficacy profile in the home application format.

Artificial daylight photodynamic therapy using methyl aminolaevulinate in a real-world setting in Germany: results from the noninterventional study ArtLight

BACKGROUND

Artificial daylight photodynamic therapy (ADL-PDT) is an alternative, all-year applicable, nearly painless treatment approach for actinic keratosis (AK) with comparable effectiveness to daylight or conventional PDT. At the time this study was initiated, methyl aminolaevulinate (MAL) was the only photosensitizer approved for ADL-PDT in Germany.

OBJECTIVES

To gain comprehensive insights into the practicability of MAL-ADL-PDT in patients with AK using different artificial daylight sources under real-world conditions.

METHODS

This prospective, noninterventional, multicentre study (ArtLight, NCT05725213) enrolled patients with Olsen grade 1 or 2 AK on the face and scalp in Germany. Patients were treated with MAL-ADL-PDT (160 mg g-1 MAL cream). The primary outcome measure was the practicability of MAL-ADL-PDT assessed as rate of resolved AK lesions in the focus area (10 × 10-cm area within the treatment area). Secondary outcomes included treatment-associated pain (numeric rating scale, NRS), Actinic Keratosis Area and Severity Index (AKASI), total lesion count over time, skin preparation, safety, overall assessment of effectiveness, tolerability, adherence and patient satisfaction.

RESULTS

In total, 224 patients [median age 75.0 (range 50-91) years, 85.3% male, 62.5% AK Olsen grade 2, 55.4% treatment-naïve] were included and treated with MAL-ADL-PDT. Three months after treatment, lesion counts were reduced in the focus area by 71% (P < 0.001) indicating practicability of the treatment. Nearly all patients (93.3%) experienced no or mild pain during PDT (NRS score 0-3). Median AKASI decreased from 6.2 at baseline to 3.4 at month 3 (95% confidence interval 2.4-3.0; P < 0.001). The majority of investigators (82.8%) and patients (80.0%) were satisfied with the treatment. No new safety signals were reported.

CONCLUSIONS

The clinical practicability of MAL-ADL-PDT was demonstrated under real-world conditions by effective lesion reduction and predominantly none-to-mild procedural pain. Thus, MAL-ADL-PDT is a convenient way for healthcare professionals to deliver PDT treatment to patients with AK located on the face and scalp.

'Photodynamic therapy light': An enhanced treatment protocol for actinic keratoses with minimal pain and optimal clinical outcome by combining laser-assisted low irradiance PDT with shortened daylight PDT

BACKGROUND

Between 2003 and 2016, 546 patients in our clinic discontinued outpatient treatment for actinic keratoses (AKs) using conventional photodynamic therapy (PDT) because of intolerable pain, thereby necessitating the use of a less painful procedure. Therefore, we developed a novel off-label PDT protocol: 'PDT light'.

METHODS

Laser-assisted low irradiance PDT (li-PDT) was performed beginning in 2014. The dosage was gradually lowered to 8-12 J/cm² in 2018, so that we achieved considerable pain reduction while maintaining comparable therapeutic efficacy. A further considerable reduction in pain was achieved from 2018 onwards by combining the advantages of li-PDT with daylight PDT (DLPDT), thereby resulting in 2018 in the new technique 'PDT light'. Patients with AK Olsen grades 1 or 2 and field cancerization initially received a mild-fractionated CO2 laser pretreatment prior to MAL-incubation (methyl aminolaevulinate, Metvix ®) under occlusion for 1.5-3 h. Then, patients were illuminated on average for 1.02 min with the Aktilite-LED and, after application of an UV-screen on the illuminated area, sent out into daylight for 1 h.

RESULTS

Between March and November 2019, we successfully treated 152 cases using the enhanced 'PDT light' procedure, with 137 cases achieving at follow-up 1 (on average after 8.14 months) good-to-excellent clearance rates (CLA and CLB together 90 %) and minimal adverse effects.

CONCLUSIONS

The novel 'PDT light' protocol proved to be an excellent and nearly painless method with an average visual-analogue scale (VAS) score of 1.19. Additional advantages included reduced illumination time, shorter outpatient stays in the clinic, fewer adverse effects, and better patient compliance than with DLPDT alone.

Self-Applied Daylight Photodynamic Therapy: A Paradigm Shift?

Photodynamic therapy (PDT) involves the topical application of a photosensitizer and its activation by visible light, leading to the generation of protoporphyrin IX (PpIX) and reactive oxygen species. Daylight photodynamic therapy (dPDT), a variant utilizing natural sunlight as the energy source, enhances procedural flexibility by eliminating the need for specialized equipment. dPDT has been effectively used in dermatology to treat various cutaneous disorders, including neoplastic and infectious diseases. Traditionally, skin preparation and photosensitizer application are performed by trained practitioners, limiting the accessibility of dPDT for broader populations. However, recent studies suggest that these preparatory steps can be managed by patients or caregivers, enabling fully self-applied, home-based dPDT protocols. This review systematically examines the current evidence on self-applied dPDT (SA-dPDT), emphasizing molecular mechanisms and its efficacy in managing premalignant and other cutaneous conditions.

Prebiotic and panthenol-containing dermocosmetic improves tolerance from artificial daylight photodynamic therapy: A randomized controlled trial in patients with actinic keratosis

INTRODUCTION & OBJECTIVES

Treatment with daylight photodynamic therapy (dPDT) of actinic keratosis (AK) is associated with local skin reactions (LSR), which may affect patients' quality of life and treatment acceptability. This study explores the potential of a prebiotic and panthenol-containing Dermocosmetic Cream (DC) to enhance tolerance and mitigate post-dPDT induced LSR in the treatment of AKs.

MATERIALS & METHODS

This randomized controlled, intra-individual trial included 20 patients with ≥10 AKs in two symmetrical areas on their face or décolleté, treated with a single session of artificial dPDT. After treatment, the two areas were randomized to DC twice daily for 14 days or No-DC. Primary outcomes included clinical signs of LSR graded from 0=none to 3=severe, calculated as a composite score, and assessed on Days 2, 7, 14, and 30 post-treatment, along with AK clearance rate. Secondary outcomes encompassed objectively measured erythema, and clinical and objective skin photoaging assessment.

RESULTS

Topical application of DC following dPDT significantly improved post-treatment tolerance up to two weeks. By Day 2, DC-treated skin had milder LSR (median 3.0, IQR 2.0-4.8) compared to No-DC skin (median 4.0, IQR 3.0-5.0; p=0.011). This improvement continued on Day 7 (DC median 3.0, IQR 2.0-3.8 vs. No-DC median 4.5, IQR 3.0-5.8; p<0.001) and Day 14 (DC median 1.0, IQR 0.0-1.0 vs. No-DC median 1.0, IQR 1.0-2.0; p=0.004). Objective measurements showed milder erythema in DC-treated areas on Day 2 (p=0.045) and Day 7 (p=0.005). Crusting resolved more effectively in DC-treated areas by Day 7 (40% vs. 20%; p=0.039). No significant difference in complete lesion response rate was observed between DC and No-DC skin (p=0.850). By Day 30, clinical photoaging assessment demonstrated significant improvement in dyspigmentation (p=0.004) and skin texture (p<0.001) in both locations. Moreover, objective measurements revealed reduced dyspigmentation in both DC and No-DC treated skin (p≤0.001).

CONCLUSION

Application of a prebiotic and panthenol-containing multipurpose DC significantly enhanced tolerance from artificial dPDT and accelerated healing time up to 14 days after treatment. The use of DC cream did not affect the overall treatment efficacy of dPDT, indicating its potential to enhance patient comfort following dPDT.

Efficacy of Photodynamic Therapy in the Treatment of Actinic Keratosis: A Network Meta-Analysis

BACKGROUND

Photodynamic therapy (PDT) is an effective treatment for actinic keratosis (AK) and uses different light sources as well as photosensitizers. In addition, PDT is often combined with other physical therapies or drugs.

OBJECTIVES

This study was aimed to compare the efficacy of different PDTs against AK lesions based on Complete Response (CR) by conducting a network meta-analysis (NMA).

METHODS

Randomized controlled trials (RCTs) using PDT for AK were screened and a Bayesian model was developed to perform an NMA of CR at 3 months after the first treatment.

RESULTS

Twenty-six trials involving 2285 patients and 14 treatments were included. The treatments were broadly divided into mono-PDT and combination therapy. The photodynamic monotherapies included methyl 5-aminolevulinic acid (MAL)-daylight (DL)-PDT, MAL-light-emitting diode (LED)-PDT, 5-aminolevulinic acid (ALA)-LED-PDT, etc. Combination therapies included ablative fractional laser (AFL)-assisted MAL-LED-PDT, calcipotriol (CAL)-assisted MAL-LED-PDT, and 5-fluorouracil (5-Fu)-assisted MAL-DL-PDT. The results of the NMA showed that there is a high probability that AFL-MAL-LED-PDT is the most effective treatment option, followed by CAL-MAL-LED-PDT and ALA-LED-PDT. The subgroup analysis showed that MAL-based PDT had better efficacy when using LED versus other light sources, while LED-based PDT was likely to have better efficacy when using ALA versus other photosensitizers.

CONCLUSIONS

The results of this NMA suggest that AFL-MAL-LED-PDT may be the superior choice for achieving complete clearance of AK lesions. PDT using LED as the light source and ALA as the photosensitizer may be more effective for the treatment of AK. However, more RCTs are needed to verify the results of this analysis.

European consensus-based interdisciplinary guideline for diagnosis, treatment and prevention of actinic keratoses, epithelial UV-induced dysplasia and field cancerization on behalf of European Association of Dermato-Oncology, European Dermatology Forum, European Academy of Dermatology and Venereology and Union of Medical Specialists (Union Européenne des Médecins Spécialistes)

A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology, the European Dermatology Forum, the European Academy of Dermatology and Venereology, and the European Union of Medical Specialists was formed to develop European recommendations on AK diagnosis and treatment, based on current literature and expert consensus. This guideline addresses the epidemiology, diagnostics, risk stratification and treatments in immunocompetent as well as immunosuppressed patients. Actinic keratoses (AK) are potential precursors of cutaneous squamous cell carcinoma (cSCC) and display typical histopathologic and immunohistochemical features of this malignancy in an early stage. They can develop into cSSC in situ and become invasive in a low percentage of cases. AK is the most frequent neoplasia in white populations, frequently occurring within a cancerous field induced by ultraviolet radiation. Since it cannot be predicted, which lesion will progress to cSCC and when treatment is usually recommended. The diagnosis of AK and field cancerization is made by clinical examination. Dermatoscopy, confocal microscopy, optical coherence tomography or line-field confocal-OCT can help in the differential diagnosis of AK and other skin neoplasms. A biopsy is indicated in clinically and/or dermatoscopically suspicious and/or treatment-refractory lesions. The choice of treatment depends on patients' and lesion characteristics. For single non-hyperkeratotic lesions, the treatment can be started upon patient's request with destructive treatments or topical treatments. For multiple lesions, field cancerization treatment is advised with topical treatments and photodynamic therapy. Preventive measures such as sun protection, self-examination and repeated field cancerization treatments of previously affected skin areas in high-risk patients are advised.

Diagnosis and therapy of actinic keratosis

Actinic keratosis (AK) is considered a chronic and recurring in situ skin neoplasia, with a possible transformation into invasive squamous cell carcinoma (SCC). Among others, predominant risk factors for development of AK are UV-light exposure and immunosuppression. Basal epidermal keratinocyte atypia (AK I) and proliferation (PRO score) seem to drive malignant transformation, rather than clinical appearance of AK (Olsen I-III). Due to the invasiveness of punch biopsy, those histological criteria are not regularly assessed. Non-invasive imaging techniques, such as optical coherence tomography (OCT), reflectance confocal microscopy (RCM) and line-field confocal OCT (LC-OCT) are helpful to distinguish complex cases of AK, Bowen's disease, and SCC. Moreover, LC-OCT can visualize the epidermis and the papillary dermis at cellular resolution, allowing real-time PRO score assessment. The decision-making for implementation of therapy is still based on clinical risk factors, ranging from lesion- to field-targeted and ablative to non-ablative regimens, but in approximately 85% of the cases a recurrence of AK can be observed after a 1-year follow-up. The possible beneficial use of imaging techniques for a non-invasive follow-up of AK to detect recurrence or invasive progression early on should be subject to critical evaluation in further studies.

Diagnose und Therapie aktinischer Keratosen

Actinic keratosis (AK) is considered a chronic and recurring in situ skin neoplasia, with a possible transformation into invasive squamous cell carcinoma (SCC). Among others, predominant risk factors for development of AK are UV-light exposure and immunosuppression. Basal epidermal keratinocyte atypia (AK I) and proliferation (PRO Score) seem to drive malignant turnover, rather than clinical appearance of AK (Olsen I-III). Due to the invasiveness of punch biopsy, those histological criteria are not regularly assessed. Non-invasive imaging techniques, such as optical coherence tomography (OCT), reflectance confocal microscopy (RCM) and line-field confocal OCT (LC-OCT) are helpful to distinguish complex cases of AK, Bowen's disease and SCC. Moreover, LC-OCT can visualize the epidermis and the papillary dermis at cellular resolution, allowing real-time PRO Score assessment. The decision-making for implementation of therapy is still based on clinical risk factors, ranging from lesion- to field-targeted and ablative to non-ablative regimes, but in approximately 85% of the cases a recurrence of AK can be observed after a 1-year follow-up. The possible beneficial use of imaging techniques for a non-invasive follow-up of AK to detect recurrence or invasive progression early on should be subject to critical evaluation in further studies.

Pre-treatment with topical 5-fluorouracil increases the efficacy of daylight photodynamic therapy for actinic keratoses - A randomized controlled trial

BACKGROUND

Daylight photodynamic therapy (dPDT) and topical 5-fluorouracil (5-FU) are each effective treatments for thin grade I actinic keratosis (AKs), but less so for thicker grade II-III AKs. Prolonged topical treatment regimens can be associated with severe skin reactions and low compliance. This study compares the efficacy of sequential 4 % 5-FU and dPDT with dPDT monotherapy for multiple actinic keratoses.

METHODS

Sixty patients with a total of 1547 AKs (grade I: 1278; grade II: 246; grade III: 23) were treated in two symmetrical areas (mean size 75 cm2) of the face or scalp, which were randomized to (i) 4% 5-FU creme twice daily for 7 days before a single dPDT procedure and (ii) dPDT monotherapy. Daylight exposure was either outdoor or indoor daylight.

RESULTS

Twelve weeks after treatment 87 % of all AKs cleared after 5-FU+dPDT compared to 74 % after dPDT alone (p<0.0001). For grade II AKs, the lesion response rate increased from 55 % with dPDT monotherapy to 79 % after 5-FU+dPDT (p<0.0056). Moderate/severe erythema was seen in 88 % 5-FU+dPDT areas compared to 41 % of dPDT areas two days after dPDT. Twelve weeks after treatment 75 % of the patients were very satisfied with both treatments.

CONCLUSIONS

Sequential 5-FU and dPDT was more effective than dPDT monotherapy in the treatment of AKs, especially for grade II AKs. Local skin reactions were more pronounced after combination treatment, but no patients discontinued the treatment. The combination of 5-FU and dPDT is an effective treatment of large treatment areas with high compliance and satisfaction.

The impact of occlusive vs non-occlusive application of methyl aminolevulinate on the efficacy and tolerability of daylight photodynamic therapy for actinic keratosis

BACKGROUND

Conventional photodynamic therapy (c-PDT) is an effective treatment for actinic keratoses (AKs) and nonmelanoma skin cancer which exploits the photosensitizing properties of methyl aminolaevulinate (MAL). Daylight photodynamic therapy (DL-PDT) is an alternative to c-PDT which does not require the application of MAL in occlusion and that is better tolerated by patients. The impact of occlusion on the efficacy of DL-PD has not been investigated by previous studies.

OBJECTIVE

To compare the efficacy and tolerability of occlusive and non-occlusive DL-PDT.

METHODS

We conducted a prospective intraindividual left/right comparison study. AKs of the face or scalp were marked in two symmetrical treatment areas. The two target areas were randomly assigned to DL-PDT with occlusive and non-occlusive application of MAL. The efficacy and cosmetic outcome were determined by a "blinded" investigator.

RESULTS

Lesions in occluded areas showed a better response in the clearance rate of the lesions (65.5% vs 35.0 %, p < 0.001 %), and cosmetic outcome (P < 0.001). There was no difference in phototoxicity or pain between occluded and non-occluded areas.

CONCLUSION

The occlusive application of MAL improves the efficacy of DL-PDT in clearing AKs and does not increase the incidence of side effects.

Digitally Enhanced Methods for the Diagnosis and Monitoring of Treatment Responses in Actinic Keratoses: A New Avenue in Personalized Skin Care

Non-melanocytic skin cancers represent an important public health problem due to the increasing incidence and the important local destructive potential. Thus, the early diagnosis and treatment of precancerous lesions (actinic keratoses) is a priority for the dermatologist. In recent years, non-invasive skin imaging methods have seen an important development, moving from simple observational methods used in clinical research, to true diagnostic and treatment methods that make the dermatologist's life easier. Given the frequency of these precancerous lesions, their location on photo-exposed areas, as well as the long treatment periods, with variable, imprecise end-points, the need to use non-invasive imaging devices is increasingly evident to complete the clinical observations in the diagnosis and treatment of these lesions, with the aim of increasing accuracy and decreasing the adverse effects due to long treatment duration. This is the first review that brings together all skin imaging methods (dermoscopy, reflectance confocal microscopy, ultrasonography, dermoscopy-guided high frequency ultrasonography, and optical coherence tomography) used in the evaluation of actinic keratoses and their response to different treatment regimens.

Is a 4 J/cm2 PpIX-Weighted Simulated Daylight (SDL-PDT) Dose Still Efficient for Photodynamic Therapy of Actinic Keratosis?

Background: Several solutions are now proposed to provide indoor illumination with so-called artificial white light or simulated daylight (SDL-PDT), resulting in an effective treatment for actinic keratosis (AK). However, the optimal PpIX-weighted light dose is still debated. Integrating the effective irradiance over the irradiation time yields the effective light dose, which is also known as the protoporphyrin IX-weighted light dose and is a key parameter for the efficacy of the treatment. Objectives: The paper aims to report the clinical outcomes of SDL-PDT when using the PpIX-weighted light dose of 4 J/cm2, in patients treated for AK lesions of the scalp or the face at our medical dermatology center (ClinicalTrials.gov NCT052036). Methods: A total of 30 patients (16 males, 14 females), with a mean age of 71.0 ± 10.2, with phototype 1 (16 patients) and phototype 2 (14 patients) with grade I-II AK were treated with a drug light interval (DLI) of 10 min and a light exposure of 35 min (Dermaris, Surgiris, Croix, France), corresponding to a PpIX-weighted light dose of 4 J/cm2. The primary endpoint was the cure rate of patients at six months post-treatment. Secondary endpoints included scores of pain, erythema, crusts, and discomfort during or/and post the treatment. Results: In total, 762 AK were treated. Six months following treatment, the cure rate of the patients was 77%. The median pain score was less than 1 out of 10 for most of the patients. Erythema was observed in all patients and lasted 3 days (±1.5 day). Crusts were seen in 28 patients. Discomfort was reported as mild or less in more than 97% of patients. Conclusions: The shortening of the PpIX-weighted light dose to 4 J/cm2, corresponding to an illumination duration of 35 min with the Dermaris, does not modify the efficacy of the SDL-PDT. This observation is in agreement with recent published data demonstrating that the light dose can be reduced. Furthermore, this clinical study confirmed that SDL-PDT is an effective and nearly painless treatment with minimal side effects for patients with AK lesions of the scalp.

Advanced Light Source Technologies for Photodynamic Therapy of Skin Cancer Lesions

Photodynamic therapy (PDT) is an increasingly popular dermatological treatment not only used for life-threatening skin conditions and other tumors but also for cosmetic purposes. PDT has negligible effects on underlying functional structures, enabling tissue regeneration feasibility. PDT uses a photosensitizer (PS) and visible light to create cytotoxic reactive oxygen species, which can damage cellular organelles and trigger cell death. The foundations of modern photodynamic therapy began in the late 19th and early 20th centuries, and in recent times, it has gained more attention due to the development of new sources and PSs. This review focuses on the latest advancements in light technology for PDT in treating skin cancer lesions. It discusses recent research and developments in light-emitting technologies, their potential benefits and drawbacks, and their implications for clinical practice. Finally, this review summarizes key findings and discusses their implications for the use of PDT in skin cancer treatment, highlighting the limitations of current approaches and providing insights into future research directions to improve both the efficacy and safety of PDT. This review aims to provide a comprehensive understanding of PDT for skin cancer treatment, covering various aspects ranging from the underlying mechanisms to the latest technological advancements in the field.

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.

Advances in Topical Treatments of Cutaneous Malignancies

Surgical excision has been the preferred treatment for cutaneous malignancies, but can be affected by various considerations. Noninvasive, self-administered topical treatments represent an alternative option. The aim of this review was to evaluate and summarize evidence-based recommendations for topical treatments of basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (CSCC), in situ melanoma (MIS), and extramammary Paget's disease (EMPD). Studies were reviewed on PubMed. Included studies were summarized, assessed for biases, and assigned a level of evidence to develop treatment recommendations. For the treatment of superficial BCC, complete clearance rates ranged from 90 to 93% for 5% 5-fluorouracil (5-FU) and 71 to 76% for imiquimod (IMQ). For the treatment of nodular BCC, clearance rates for photodynamic therapy (PDT) were 91% at 3 months, with a sustained lesion clearance response rate of 76% after 5 years of follow-up. Clearance rates were 53 to 76% with IMQ. For squamous cell carcinoma in situ, clearance rates ranged from 52 to 98% for PDT, 67 to 92% for 5-FU, and 75 to 93% for IMQ. For MIS, clearance rates ranged from 53 to 92% for IMQ. For EMPD, 54% of 110 patients in cohort studies and case series had a clinical complete response with IMQ. While surgical intervention remains the standard of care for skin cancer, non-invasive, self-administered topical treatments are highly desirable alternative options. Ultimately, the patient and provider should find a treatment modality that aligns with the patient's expectations and maintenance of quality of life.

Hemodynamic changes during conventional and daylight photodynamic therapy of actinic keratoses - a randomized controlled trial

BACKGROUND

Photodynamic therapy (PDT) is an effective treatment for actinic keratosis (AK). However, pain and hypertension are important side effects of conventional PDT (c-PDT). Several studies have demonstrated that daylight PDT (dl-PDT) is less painful while being as effective as c-PDT.

OBJECTIVE

To observe the effect of c-PDT and dl-PDT on different hemodynamic parameters (systolic blood pressure and diastolic blood pressure, pulse rate, and peripheral oxygen saturation).

METHODS

Fifty patients with AK on the head were enrolled into this prospective, randomized, controlled study and treated with c-PDT or dl-PDT in a 1:1 ratio. Hemodynamic parameters were measured at four different time points during treatment. Pain was quantified using a visual analog scale. AK was counted before treatment and after one month.

RESULTS

C-PDT is associated with significantly more pain, a significant increase in blood pressure and a higher rate of patients with grade 3 hypertension. Whereas dl-PDT is almost painless and does not lead to any changes in hemodynamic parameters. For both treatments, a similar lesion response rate was found after one month.

CONCLUSIONS

dl-PDT has a better tolerability while being as effective as c-PDT and therefore may be the more favorable treatment option in certain patient groups.

Measurements of illuminance in simulated daylight photodynamic therapy

BACKGROUND

Simulated daylight photodynamic therapy (SDL-PDT) is a new treatment alternative for actinic keratosis. The aim of this study was to show how the illuminance that reaches the target skin area during SDL-PDT depends on the spatial positioning of the patient.

METHODS

In this technical validation study, illuminance from the SDL-PDT system IndoorLux© was measured at different angles, directions, and distances from the light sources corresponding to potential target skin areas. Using two different photometers, data from 63 measuring points at seven specific distances from the ceiling were collected at 0°, 45°, and 90° angles, respectively. Illuminance levels ≥12,000 lux were regarded as adequate. Hotspots were defined as adequate measurements in all directions at a specific measuring point at distances of 1.3, 1.5, and 1.8 m from the light sources (i.e., the most common patient treatment positions).

RESULTS

Adequate illuminance levels were more common with photometer 1 (73%) than photometer 2 (57%). Almost all illuminance levels were adequate at a 0° angle with both photometers. Adequate illuminance levels were observed at 82-93% of the measuring points at a 45° angle and 22-47% at a 90° angle. Hotspots were registered with both photometers at all measuring points at 0°; 59-79% of the measuring points at 45°; and 0-21% at 90°.

CONCLUSION

Patient positioning is important during SDL-PDT. Adequate illuminance is achieved if target skin areas are positioned at 0°-45° angles relative to the light sources, but not at 90° angles.

The Role and Effectiveness of Photodynamic Therapy on Patients With Actinic Keratosis: A Systematic Review and Meta-Analysis

Actinic keratoses (AKs) are the most common neoplastic lesions and are recognized as a precursor to squamous cell skin cancer. Photodynamic therapy (PDT) is a therapeutic option for multiple AKs in line with field cancerization. The aim of this study was to assess the effectiveness of PDT on patients with AKs using a meta-analysis, in order to evaluate the possible superiority of one treatment over the others. For this purpose, the PubMed, MEDLINE, Scopus, OVID, Science Direct, British Journal of Dermatology, Research Gate, and Embase databases were searched in March 2022. The search terms used were 'photodynamic therapy' and 'actinic keratosis'. We utilized the random-effects meta-analysis model to compare methyl aminolevulinate PDT (MAL-PDT) and the combination of a nanoscale-lipid vesicle formulation with the prodrug 5-aminolevulinic acid (BF-200 ALA) on a complete response (CR) of the lesions. Our meta-analysis indicated that the comparison of BF-200 ALA versus MAL-PDT showed marginally higher CRs than MAL-PDT.

Actinic keratosis (review of literature)

Actinic keratosis is an important medical and social problem, the correct diagnosis and treatment of which will help to avoid the development of invasive forms of cutaneous squamous cell carcinoma. With the further development of the early diagnosis of cancer, including skin cancer, the increase in human life expectancy, and the popularization of travel to exotic countries, the number of cases of actinic keratosis among the population will continue to grow. In this regard, it is important to discuss the causes and pathogenesis of the disease, the varied clinical picture of the disease, methods of non-invasive diagnostics, as well as methods of treatment, of which there are a great many in the treatment of actinic keratosis today. However, each of the methods has both advantages and disadvantages, and in the global trend towards a personalized approach to treatment, it is important to choose from the standpoint of evidence-based medicine the most suitable for each individual patient. Moreover, after treatment of actinic keratosis, relapses often occur, which are the result of insufficient diagnosis and the development of incorrect treatment tactics. The review article provides the clinical picture of actinic keratosis, diagnostic and therapeutic methods, and their comparison with each other in terms of efficacy and safety

A Review of Existing Therapies for Actinic Keratosis: Current Status and Future Directions

Actinic keratosis (AK) is a chronic skin disease in which clinical and subclinical cutaneous lesions coexist on sun-exposed areas such as the head and neck region and the extremities. The high prevalence of AK means the disease burden is substantial, especially in middle-aged and elderly populations. Evidence indicates that AK may progress into invasive cutaneous squamous cell carcinoma, so the European guidelines recommend treatment of any AK regardless of clinical severity. Given the aging population and therefore the increasing incidence of AK and cutaneous field carcinogenesis, further updates on the long-term efficacy of current therapies and new investigational agents are critical to guide treatment choice. Patients often have difficulty adequately applying topical treatments and coping with adverse local skin reactions, leading to less than optimum treatment adherence. The development of associated local skin symptoms and cosmetic outcomes for the area of interest are also relevant to the choice of an appropriate therapeutic strategy. Treatment is always individually tailored according to the characteristics of both patients and lesions. This review focuses on the therapeutic approaches to AK and illustrates the currently available home-based and physician-managed treatments.

Theoretical design of an absorption hologram-based sensor for dose quantification in daylight photodynamic therapy

Daylight photodynamic therapy (D-PDT) is an effective and almost painless treatment for many skin conditions, where successful treatment relies on daylight activation of a topical photosensitizer. Optimization of D-PDT requires accurate assessment of light dose received. There is a requirement for a small-area sensor that can be placed adjacent to the treatment site to facilitate accurate dose quantification. Here, a novel, to the best of our knowledge, configuration for a D-PDT dose sensor, consisting of a holographic absorption grating fabricated in a photosensitive film, is presented. Theoretical modeling of the sensor's response (i.e., change in grating diffraction efficiency due to change in grating absorption modulation, α₁, on exposure to daylight) was conducted using Kogelnik's coupled-wave theory. The influence of the different grating parameters (initial film absorption, thickness, spatial frequency, and reconstruction wavelength) on the sensor response was examined and revealed that the initial absorption and grating thickness values have a large impact on both the magnitude and rate of the D-PDT sensor response. The optimum design for an absorption grating-based D-PDT sensor is described.

Combined versus conventional photodynamic therapy with 5-aminolaevulinic acid nanoemulsion (BF-200 ALA) for actinic keratosis: A randomized, single-blind, prospective study

BACKGROUND

Photodynamic therapy (PDT) has become one of the most effective therapies for the treatment of actinic keratosis, allowing the removal of more than one lesion in a single session. However, the pain sustained by the patient during treatment and local skin reactions can limit its use.

OBJECTIVES

To determine the efficacy and safety of combined PDT (daylight PDT followed by conventional PDT) vs conventional PDT 12 weeks after treatment.

METHODS

The study was performed as a randomized, single-center, non-inferiority clinical trial with two parallel groups. A total of 51 patients with grade I and II AKs on the scalp or face were randomized. Twenty-five patients received one session of combined PDT (combPDT), and 26 patients received one session of conventional PDT (cPDT). The primary endpoint was the reduction of AKs, 12 weeks after treatment. The secondary endpoint was the reduction in pain and local skin reaction.

RESULTS

The reduction rate of grade I and II AKs was similar in combPDT and cPDT, showing no statistically significant differences between both groups, 76.67% vs 86.63% [P = .094] and 80.48% vs 83.08% [P = .679], respectively. However, pain was significantly lower in the combPDT group (2.56 vs 5, P < .01), as were local skin reactions.

CONCLUSIONS

CombPDT has proven to be as effective as cPDT for the treatment of grade I and II AKs located on the scalp and face. Furthermore, combPDT has been shown to be considerably more tolerable than cPDT, causing only mild local skin reactions.

Clinical evaluation of a short illumination duration (1 hour) when performing photodynamic therapy of actinic keratosis using the Dermaris light source

BACKGROUND

Photodynamic therapy (PDT) using daylight as the photoactivating light source (DL-PDT) is an effective treatment for actinic keratosis (AK). Among the artificial daylight sources, the Dermaris (Surgiris, Croix, France) is specially designed for SDL-PDT (simulated daylight PDT) of AK. To perform the PDT session, a long duration (2.5 h) and low-intensity light exposure (2.9 mw/cm²) is used. This long duration is considered as a major limitation by both the patient and the dermatologist.

OBJECTIVES

The paper aims to report the clinical outcomes of SDL-PDT using the Dermaris in patients treated for AK lesions of the scalp at our medical dermatology center using only one hour low-intensity light exposure.

METHODS

Thirty patients (19 males, 11 females), mean age: 72.8 ± 9.3, with phototype 1 (11 patients), with phototype 2(17 patients) and phototype 3 (2 patients), with grade I-II AK of the scalp were treated with a drug-light interval (DLI) of 10 min and a light exposure of 1 h. The cure rate of AK lesions at six months after the treatment was determined. Erythema, crusts, discomfort and during or/and post the treatment were also evaluated.

RESULTS

In total, 293 AK were treated. Six months following treatment, the cure rate of patients was 93%. Pain score reported after the first PDT session was from 0 to 1 on a visual analogue scale (VAS) ranging from 0 to 10. Erythema was observed in 28 patients and lasted 3 days, crusts were seen in 19 patients. Discomfort was as mild or less in more than 97% of patients.

CONCLUSIONS

the shortening of the exposure time to one hour does not modify the efficacy of the SDL-PDT using the Dermaris. This observation is in agreement with recent published data demonstrating that PDT can be performed successfully with half the illumination time used in daylight PDT today. Besides, this clinical study confirmed that SDL-PDT is an effective and nearly painless treatment with minimal side effects for patients with AK lesions of the scalp.

An open-label prospective study to assess short incubation time white LED light photodynamic therapy in the treatment of superficial basal cell carcinoma

Artificial white LED light photodynamic therapy (awl-PDT) is an effective, pain-free treatment for actinic keratosis. The efficacy of awl-PDT in the treatment of superficial basal cell carcinoma (sBCC) has not been assessed. Patients with histologically confirmed sBCC underwent two treatments of awl-PDT 1 week apart. Lesions were incubated with methyl 5-aminolaevulinic acid for 30 min and then illuminated using the Maquet Power LED 500 theatre light (405-800nm, 140 000 lux) to deliver an equivalent red light dose of 75 J/cm² at a rate of 55 mW/cm² . Pain was measured using a visual analogue scale during treatment. Clinical response was assessed at day 28. Follow-up continued 3 months for 1 year. Cosmetic outcome was assessed at 3 months and 1 year. Twenty-eight patients with 36 lesions and a mean age of 63.64 (SD 2.62) were recruited. The median lesion size was 15 mm (IQR 8.75). The response rate at day 28 was 100%. Recurrence rates were 3/36 (8.3%) at 3 months, 6/36 (16.7%) at 6 months, 10/36 (27.8%) at 9 months and 11/36 (30.6%) at 1 year. Median pain scores were 0/100 (IQR 0) and 0/100 (IQR 5) during treatments one and two, respectively. Cosmetic outcome was excellent or good in the majority of cases. Although initially effective for sBCC at 28 days, 30.6% of lesions recurred 1 year after awl-PDT. Pain scores were negligible, and the cosmetic outcome was favourable. Further head-to-head studies with optimised protocols are required to determine if awl-PDT has a role in the treatment of sBCC.

In Vivo Reflectance Confocal Microscopy as a Response Monitoring Tool for Actinic Keratoses Undergoing Cryotherapy and Photodynamic Therapy

Simple Summary

The assessment of actinic keratoses (AKs) in prevention and therapeutic trials, as well as clinical practice, could significantly benefit from the incorporation of non-invasive imaging technology. Such technology has the potential to enhance the objective evaluation of clinical and subclinical AKs with the added advantage of sequential monitoring. In vivo reflectance confocal microscopy (RCM) allows for the non-invasive imaging of AKs at a cellular level. We aimed to establish an in in vivo RCM protocol for AK response monitoring, ultimately leading to more reliable characterization of longitudinal responses and therapy optimization.

Abstract

Reflectance confocal microscopy (RCM) presents a non-invasive method to image actinic keratosis (AK) at a cellular level. However, RCM criteria for AK response monitoring vary across studies and a universal, standardized approach is lacking. We aimed to identify reliable AK response criteria and to compare the clinical and RCM evaluation of responses across AK severity grades. Twenty patients were included and randomized to receive either cryotherapy (n = 10) or PDT (n = 10). Clinical assessment and RCM evaluation of 12 criteria were performed in AK lesions and photodamaged skin at baseline, 3 and 6 months. We identified the RCM criteria that reliably characterize AK at baseline and display significant reduction following treatment. Those with the highest baseline odds ratio (OR), good interobserver agreement, and most significant change over time were atypical honeycomb pattern (OR: 12.7, CI: 5.7–28.1), hyperkeratosis (OR: 13.6, CI: 5.3–34.9), stratum corneum disruption (OR: 7.8, CI: 3.5–17.3), and disarranged epidermal pattern (OR: 6.5, CI: 2.9–14.8). Clinical evaluation demonstrated a significant treatment response without relapse. However, in grade 2 AK, 10/12 RCM parameters increased from 3 to 6 months, which suggested early subclinical recurrence detection by RCM. Incorporating standardized RCM protocols for the assessment of AK may enable a more meaningful comparison across clinical trials, while allowing for the early detection of relapses and evaluation of biological responses to therapy over time.

Guidelines of care for the management of actinic keratosis

BACKGROUND

Actinic keratoses (AK) are rough scaly patches that arise on chronically ultraviolet-exposed skin and can progress to keratinocyte carcinoma.

OBJECTIVE

This analysis examined the literature related to the management of AK to provide evidence-based recommendations for treatment. Grading, histologic classification, natural history, risk of progression, and dermatologic surveillance of AKs are also discussed.

METHODS

A multidisciplinary Work Group conducted a systematic review to address 5 clinical questions on the management of AKs and applied the Grading of Recommendations, Assessment, Development, and Evaluation approach for assessing the certainty of the evidence and formulating and grading clinical recommendations. Graded recommendations were voted on to achieve consensus.

RESULTS

Analysis of the evidence resulted in 18 recommendations.

LIMITATIONS

This analysis is based on the best available evidence at the time it was conducted. The pragmatic decision to limit the literature review to English language randomized trials may have excluded data published in other languages or limited identification of relevant long-term follow-up data.

CONCLUSIONS

Strong recommendations are made for using ultraviolet protection, topical imiquimod, topical 5-fluorouracil, and cryosurgery. Conditional recommendations are made for the use of photodynamic therapy and diclofenac for the treatment of AK, both individually and as part of combination therapy regimens.

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.

Pretreatment with ablative fractional carbon dioxide laser improves treatment efficacy in a synergistic PDT protocol for actinic keratoses on the head

BACKGROUND

A recently proposed synergistic photodynamic therapy protocol (s-PDT) combining advantages of both conventional- and daylight-PDT proved to be an effective and almost painless treatment for patients with actinic keratoses (AKs). This study investigated the safety and efficacy of an additional ablative fractional CO2-laser (AFXL) pretreatment.

METHODS

28 patients with AKs on the head received s-PDT using 5-aminolevulinic acid. AFXL pretreatment was conducted using the following parameters: pulse energy 8 mJ, spot density 50 spots/cm², power 30 W, beam size 4-18 mm. Outcome was assessed by AK area and severity index (AKASI) and lesion count (LC) before and 3 months after treatment. Safety was monitored by blood pressure and pulse measurements. Intensity of pain was determined by use of a visual analog scale (VAS).

RESULTS

Most patients (96.4 %) showed a significant AKASI reduction (P < 0.0001) 3 months after PDT (median AKASI 1.6 [0-2.4]) compared to baseline (5.3 [4-7.75]). Median reduction rate was 75.5 % (61.3 %-100 %). Eleven patients (39.3 %) achieved AKASI 100, three (10.7 %) AKASI 75 and ten (35.7 %) AKASI 50. Blood pressure and pulse did not change significantly throughout treatment. Median VAS for pain during irradiation was 0 (0-0), 0 (0-2) and 0 (0-2) at the beginning, in the meantime and at the end, respectively. Compared to data without AFXL pretreatment, this study showed significantly higher AKASI and LC reduction rates (75.5 % vs. 63.7 % [P = 0.023] and 91.3 % vs. 80.4 % [P = 0.043]).

CONCLUSIONS

S-PDT with AFXL pretreatment represents a safe and almost painless treatment for patients with AKs on the head and improves treatment efficacy.

[Photodynamic therapy-trends and new developments]

Photodynamic therapy (PDT) is a licensed and established procedure for the treatment of actinic keratosis, basal cell carcinoma, and Bowen's disease, but there are several new and clinically relevant developments and trends. These concern on the one hand the main components of PDT, which are the photosensitizer and the light source. Furthermore, modifications and therapy combinations have been developed that lead to an improved therapeutic efficacy. An important aspect of field-directed PDT is also skin cancer prevention. Finally, PDT has been used successfully for nonlicensed indications including inflammatory diseases and skin rejuvenation. This article focuses on these new developments and on recent guideline recommendations.

Daylight Photodynamic Therapy: An Update

Daylight photodynamic therapy (dPDT) uses sunlight as a light source to treat superficial skin cancer. Using sunlight as a therapeutic device has been present for centuries, forming the basis of photodynamic therapy in the 20th century. Compared to conventional PDT, dPDT can be a less painful, more convenient and an effective alternative. The first clinical uses of dPDT on skin cancers began in Copenhagen in 2008. Currently, aminolevulinic acid-mediated dPDT has been approved to treat actinic keratosis patients in Europe. In this review article, we introduce the history and mechanism of dPDT and focus on the pros and cons of dPDT in treating superficial skin cancers. The future applications of dPDT on other skin diseases are expected to expand as conventional PDT evolves.

Clinical, histopathological and immunohistochemical evaluation of daylight photodynamic therapy in the treatment of field cancerization: a study of 30 cases

BACKGROUND

Actinic keratosis (AK) are pre-malignant lesions, precursors of squamous cell carcinoma (SCC). Normal skin adjacent to AK, may present initial mutations with potential risk for new neoplasms, currently known today as field cancerization (FC).

OBJECTIVES

To evaluate the effectiveness of daylight photodynamic therapy (PDT) with methyl amino levulinate (MAL) based on clinical evaluation, histological examination and immunohistochemical expression of p53 and Ki67.

MATERIAL AND METHODS

Thirty patients, over 35 years old, phototypes between I and III, presenting non-hypertrophic AK on the face or scalp. Two biopsies with 2 mm punch of the lesion and adjacent skin before and 60 days after daylight PDT were performed. Results: Improvement was seen in lesion thickness and Ki67. 19 (63.33%) lesions had atypia improvement with a p-value <.05, showing efficacy in treatment. After daylight PDT, 22 (73.33%) patients showed satisfactory esthetic improvement.

CONCLUSION

The study shows that PDT has cellular and molecular effects that support its indication in the control of carcinogenesis, as it decreases atypia and controls the expression of Ki67, reducing the proliferation of atypical cells. However, its indication following this study is still mainly aimed at clinical improvement of the skin, at this moment, probably due to the sample size.

SmartPDT®: Smartphone enabled real-time dosimetry via satellite observation for daylight photodynamic therapy

BACKGROUND

Actinic keratosis (AK) affects one quarter of over 60  year olds in Europe with the risk of transforming into invasive squamous cell carcinoma. Daylight photodynamic therapy (dPDT) is an effective and patient preferred treatment that uses sunlight to clear AK. Currently, there is no standardised method for measuring the light received during treatment.

METHODS

SmartPDT® is a smartphone-based application and web-portal, developed by siHealth Ltd, enabling remote delivery of dPDT. It uses satellite imagery and computational algorithms to provide real-time determination of exposure to PpIX-effective solar radiation ("light dose"). The application also provides forecast of expected radiant exposures for 24- and 48-hs prior to the treatment period. Validation of the real-time and forecasted radiant exposure algorithms was performed against direct ground-based measurement under all weather conditions in Chilton, UK.

RESULTS

Agreement between direct ground measurements and satellite-determined radiant exposure for 2-h treatment was excellent at -0.1 % ± 5.1 % (mean ± standard deviation). There was also excellent agreement between weather forecasted radiant exposure and ground measurement, 1.8 % ± 17.7 % at 24-hs and 1.6 % ± 25.2 % at 48-hs. Relative Root Mean Square of the Error (RMSE_r) demonstrated that agreement improved as time to treatment reduced (RMSE_r = 22.5 % (48 -hs), 11.2 % (24-hs), 5.2 % (real-time)).

CONCLUSION

Agreement between satellite-determined, weather-forecasted and ground-measured radiant exposure was better than any existing published literature for dPDT. The SmartPDT® application and web-portal has excellent potential to assist with remote delivery of dPDT, an important factor in reducing risk in an elderly patient population during the Covid-19 pandemic.

European Dermatology Forum guidelines on topical photodynamic therapy 2019 Part 1: treatment delivery and established indications - actinic keratoses, Bowen's disease and basal cell carcinomas

Topical photodynamic therapy (PDT) is a widely approved therapy for actinic keratoses, Bowen's disease (squamous cell carcinoma in situ), superficial and certain thin basal cell carcinomas. Recurrence rates when standard treatment protocols are used are typically equivalent to existing therapies, although inferior to surgery for nodular basal cell carcinoma. PDT can be used both as lesional and field therapies and has the potential to delay/reduce the development of new lesions. A protocol using daylight to treat actinic keratoses is widely practised, with conventional PDT using a red light after typically a 3-h period of occlusion employed for other superficial skin cancer indications as well as for actinic keratoses when daylight therapy is not feasible. PDT is a well-tolerated therapy although discomfort associated with conventional protocol may require pain-reduction measures. PDT using daylight is associated with no or minimal pain and preferred by patient. There is an emerging literature on enhancing conventional PDT protocols or combined PDT with another treatment to increase response rates. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical PDT in dermatology, prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.

Field cancerization: Treatment

The goal of field cancerization treatment is to reduce the risk of developing keratinocyte carcinoma. Selecting the appropriate therapy depends on the degree of field cancerization and the number of invasive cutaneous squamous cell carcinomas. Other considerations include treatment efficacy, cost, side effects, and patient preference. Field therapies are preferred because they address clinically visible disease and subclinical atypia. However, lesion-directed therapies are useful for lesions that are more difficult to treat or those where a histologic diagnosis is required. Patients with extensive field cancerization benefit from a combination of field-directed and lesion-directed treatments. The second article in this continuing medical education series provides a framework to guide evidence-based decision making for field cancerization treatment.

Daylight photodynamic therapy with methyl aminolevulinate cream is as effective as conventional photodynamic therapy with blue light in the treatment of actinic keratosis: a controlled randomized intra-individual study

BACKGROUND

We know the efficacy of daylight phototherapy dynamic (DL-PDT) in the treatment of actinic keratosis (AK). But the almost studies have compared daylight with red light using methyl aminolevulinate cream and not with blue light. PDT with blue light is another conventional PDT that is effective in the treatment of AKs.

OBJECTIVES

The aim of this study is to assess the efficacy and the safety of DL-PDT vs. PDT in blue light in the treatment of AKs.

METHODS

This randomized, controlled, intra-individual efficacy and safety study enrolled 26 subjects. AKs on the face/scalp were treated once, with DL-PDT on one side and c-PDT on the contralateral side. Primary endpoints for DL-PDT at week 12 were efficacy with clearance of AKs and safety with assessment of pain. Lesions with complete response 12 weeks after one treatment session were followed until week 24.

RESULTS

More than 1000 AK were studied. At week 12, the raw number of disappeared AK lesions at 3-month follow-up was 19.6 (±6.0) for DL-PDT and 20.0 (±6.9) for c-PDT with P = 0.8460 (90.5% vs. 94.2% of AK disappearance, respectively). The response was maintained at 6 months (90.0% and 94.6% of AK reduction, respectively). DL-PDT was nearly painless than c-PDT with light blue: 1.2 vs. 5.1, respectively (P < 0.0001).

CONCLUSIONS

Daylight-PDT seems as effective as c-PDT with light blue and DL-PDT is less painful. The response of DL-PDT was sustainable until 6 months.

Actinic keratosis: where do we stand and where is the future going to take us?

Introduction: Actinic keratosis (AK) is a chronic disease which is mainly located across areas of sun-exposed skin. Clinical and subclinical lesions coexist across a large area resulting in a field cancerization. As these lesions have the potential to transform into invasive squamous cell carcinoma (iSCC), treatment is crucial. With global prevalence increasing, AK is expected to be the most common in situ carcinoma of the skin.Areas covered: In this article, we cover the established algorithm of treating AK and give an insight into the drugs under development. There are six compounds under development covering different treatment angles, from Sinecatechin a Polyphenon E which targets the link between HPV infection and development of AK, over Tirbanibulin which targets the SRC proto-oncogene and fast proliferating cells, to Tuvatexib a small-molecule dual VDAC/HK2 modulator that has shown that it can compete with the established therapies.Expert opinion: These new treatment options are moving us further toward a more individually tailored treatment for each patient considering his abilities, the size and location of his lesions but also the genetic bases as well as individual risk of transforming into a iSCC and possibly other factors contributing to each patients individual AK lesions.

Daylight photodynamic therapy for prevention of new actinic keratosis and keratinocyte carcinomas in organ transplants. A cryotherapy-controlled randomized clinical trial

BACKGROUND

Organ transplant recipients (OTR) have a higher risk of actinic keratosis (AK) and keratinocyte carcinomas (KC). There are no clinical trials assessing the effectiveness of daylight photodynamic therapy (DPDT) to prevent new AK and KC in OTR.

OBJECTIVES

To determine whether repeated treatments of field cancerization with DPDT are effective in preventing new AK and KC in OTR.

METHODS

A randomized, intra-subject controlled, evaluator-blind, split-face and/or scalp trial, from April 2016 to October 2018. Participants were OTR older than 18 years, 1-year posttransplant, with at least 5 AK on each hemi-face/hemi-scalp. One side received six field treatments with DPDT: two sessions 15 days apart at baseline, two at 3 months and two at 9 months after baseline. Control side received lesion-directed treatment with cryotherapy (double freeze-thaw) at baseline, 3 and 9 months. Total number of lesions (AK and KC) at 21 months, number of new AK and KC at 3, 9, 15 and 21 months and treatment preferences were analysed.

RESULTS

Of 24 men included, 23 were analysed at 3 months; and 21, at 9, 15 and 21 months. Mean (SD) age was 69.8 years (9.2). The total number of lesions at 21 months was 4.7 (4.3) for DPDT and 5.8 (5.0) for control side; P = 0.09. DPDT showed significantly lower means [SD] of new lesions compared to control side at 3 months (4.2 [3.4] vs. 6.8 [4.8]; P < 0.001), 9 months (3.0 [3.3] vs. 4.3 [3.4]; P = 0.04) and 15 months (3.0 [4.6] vs. 4.8 [5.0]; P = 0.02), and non-significant at 21 months (3.7 [3.5] vs. 5.0 [4.5]; P = 0.06). Most participants preferred DPDT.

CONCLUSION

DPDT showed potential effectiveness in preventing new AK and KC in OTR by consecutive treatments of field cancerization. The preference for DPDT could facilitate adherence to the long-term treatment necessary in these patients.

Actinic keratoses: review of clinical, dermoscopic, and therapeutic aspects

Actinic keratoses are dysplastic proliferations of keratinocytes with potential for malignant transformation. Clinically, actinic keratoses present as macules, papules, or hyperkeratotic plaques with an erythematous background that occur on photoexposed areas. At initial stages, they may be better identified by palpation rather than by visual inspection. They may also be pigmented and show variable degrees of infiltration; when multiple they then constitute the so-called field cancerization. Their prevalence ranges from 11% to 60% in Caucasian individuals above 40 years. Ultraviolet radiation is the main factor involved in pathogenesis, but individual factors also play a role in the predisposing to lesions appearance. Diagnosis of lesions is based on clinical and dermoscopic examination, but in some situations histopathological analysis may be necessary. The risk of transformation into squamous cell carcinoma is the major concern regarding actinic keratoses. Therapeutic modalities for actinic keratoses include topical medications, and ablative and surgical methods; the best treatment option should always be individualized according to the patient.