Photodynamic therapy and topical aminolevulinic acid: an overview

Office-Based Photodynamic Therapy Using Locally Applied 5-aminolevulinic Acid and 635 nm Laser for Laryngeal Leukoplakia

OBJECTIVE

Photodynamic therapy (PDT) is a minimally invasive method with strong tissue selectivity and nonthermal effects. We aim to investigate the efficacy of an in-office method utilizing PDT with local application of 5-aminolevulinic acid (ALA) and 635 nm diode laser for treating laryngeal leukoplakia.

STUDY DESIGN

Retrospective cohort study.

SETTING

Outpatient clinic-tertiary medical center.

METHODS

This study reviewed 32 patients with laryngeal leukoplakia, including 11 recurrent cases after surgery. All the procedures were performed in an office setting under topical anesthesia. Fifteen percent ALA solution was locally applied to the lesion through a flexible laryngoscope. Light illumination was performed using a 635 nm diode laser through a 400 μm optic fiber. The power density was 165 mW/cm² to reach 100 J/cm² . Results of laryngostroboscopy and voice evaluation during follow-up were collected.

RESULTS

The mean follow-up was 7.91 ± 4.83 (3-18) months. Thirty-nine procedures were performed, including 1 session for 27 patients, 2 sessions for 3 patients, and 3 sessions for 2 patients. The total response rate was 96.875% (31/32), including complete responses in 26 (81.25%) patients, partial responses in 5 patients (15.625%), and no response in 1 patient (3.125%). It appeared that PDT selectively eliminated the leukoplakia without affecting lamina propria and the surrounding normal mucosa remained unharmed. Scores of Voice Handicap Index-10, jitter, shimmer, and harmonic-to-noise ratio were significantly improved after PDT.

CONCLUSION

Office-based PDT is an effective, repeatable, and practical method for treating laryngeal leukoplakia. Local application of ALA is sufficient to achieve photodynamic reactions. PDT could eliminate laryngeal leukoplakia selectively while protecting the normal laryngeal structure.

The Extracellular Vesicles from the Commensal Staphylococcus Epidermidis ATCC12228 Strain Regulate Skin Inflammation in the Imiquimod-Induced Psoriasis Murine Model

Extracellular vesicles (EVs) are evaginations of the cytoplasmic membrane, containing nucleic acids, proteins, lipids, enzymes, and toxins. EVs participate in various bacterial physiological processes. Staphylococcus epidermidis interacts and communicates with the host skin. S. epidermidis’ EVs may have an essential role in this communication mechanism, modulating the immunological environment. This work aimed to evaluate if S. epidermidis’ EVs can modulate cytokine production by keratinocytes in vitro and in vivo using the imiquimod-induced psoriasis murine model. S. epidermidis’ EVs were obtained from a commensal strain (ATC12228EVs) and a clinical isolated strain (983EVs). EVs from both origins induced IL-6 expression in HaCaT keratinocyte cultures; nevertheless, 983EVs promoted a higher expression of the pro-inflammatory cytokines VEGF-A, LL37, IL-8, and IL-17F than ATCC12228EVs. Moreover, in vivo imiquimod-induced psoriatic skin treated with ATCC12228EVs reduced the characteristic psoriatic skin features, such as acanthosis and cellular infiltrate, as well as VEGF-A, IL-6, KC, IL-23, IL-17F, IL-36γ, and IL-36R expression in a more efficient manner than 983EVs; however, in contrast, Foxp3 expression did not significantly change, and IL-36 receptor antagonist (IL-36Ra) was found to be increased. Our findings showed a distinctive immunological profile induction that is dependent on the clinical or commensal EV origin in a mice model of skin-like psoriasis. Characteristically, proteomics analysis showed differences in the EVs protein content, dependent on origin of the isolated EVs. Specifically, in ATCC12228EVs, we found the proteins glutamate dehydrogenase, ornithine carbamoyltransferase, arginine deiminase, carbamate kinase, catalase, superoxide dismutase, phenol-soluble β1/β2 modulin, and polyglycerol phosphate α-glucosyltransferase, which could be involved in the reduction of lesions in the murine imiquimod-induced psoriasis skin. Our results show that the commensal ATCC12228EVs have a greater protective/attenuating effect on the murine imiquimod-induced psoriasis by inducing IL-36Ra expression in comparison with EVs from a clinical isolate of S. epidermidis.

Photodynamic Therapy for Benign Cutaneous Neurofibromas Using Aminolevulinic Acid Topical Application and 633 nm Red Light Illumination

Background: Neurofibromatosis type 1 (NF1) has no current effective treatments beyond surgery. Topical photodynamic therapy (PDT) has the potential to provide a less invasive treatment modality.

Objective: Based on murine data, we hypothesized PDT could be used for the treatment of cutaneous neurofibromas (cNF).

Methods and results: We conducted a phase I trial to examine absorption and conversion of topical aminolevulinic acid (ALA) in cNF and determine safety in a dose escalation study. ALA or control vehicle was applied to neurofibromas through microneedle-assisted delivery (n = 4) and excised specimens were examined 24 h later for protoporphyrin IX fluorescence. Fluorescence was detected in the tumors at 304 ± 94 U/μm², while adjacent paralesional normal skin and vehicle-treated tumors showed no fluorescence (p < 0.0001). Subsequently, neurofibromas (n = 27) were treated with ALA and irradiated with 633 nm red light 18 h later, at escalating dosages of 50 and 100 mJ/cm². Maximum tolerable dose was established at 100 mJ/cm². Light microscopy study of tumors biopsied 48 h after PDT (ALA n = 14 and vehicle n = 4) showed mixed inflammatory infiltrate in the ALA, but not in the vehicle-treated tumors or perilesional normal skin. TUNEL evaluation showed 42.5 ± 19.9 apoptotic cells per visual field for ALA-treated and 1.1 ± 1.4 for vehicle-treated tumors (p = 0.002).

Conclusions: In the first reported clinical trial of PDT for NF1, PDT targeted neurofibromas specifically, and may offer a normal tissue-sparing treatment modality in the future.

This study is registered at Clintrials.gov (NCT01682811).

The potential of photodynamic therapy (PDT)-Experimental investigations and clinical use

Photodynamic therapy (PDT) is an intensively studied part of medicine based on free radicals. These reactive species, extremely harmful for whole human organism, are used for eradication numerous diseases. Specific structure of ill tissues causes accumulation free radicals inside them without attack remaining healthy tissues. A rapid development of medicine and scientific research has led to extension of PDT towards treatment many diseases such as cancer, herpes, acne and based on antimicrobials. The presented review article is focused on the aforementioned disorders with accurate analysis of the newest available scientific achievements. The discussed cases explicitly indicate on high efficacy of the therapy. In most cases, free radicals turned out to be solution of many afflictions. Photodynamic therapy can be considered as promising treatment with comparable effectiveness but without side effects characteristic for chemotherapy.

Photodynamic therapy: a review and its prospective role in the management of oral potentially malignant disorders

With the unreliability of epithelial dysplasia as a predictor to determine the risk of future malignant development, subjectivity associated in evaluating dysplasia by pathologists and paucity of biomarkers that could accurately predict the progression risks in oral potentially malignant disorders (PMDs), eradication of the lesions appears to be the most desirable approach to minimize the risk of invasive cancer formation. Interventions, such as surgery and chemoprevention, have not shown promising long-term results in the treatment of these lesions, and lack of guidelines and general consensus on their management has incited much anxiety and doubts in both patients and community clinicians. Topical photodynamic therapy (PDT) is a minimally invasive and minimally toxic technique that in recent years has shown great promise in the management of PMDs. In this review, we describe the historical developments in the field of PDT, its basic mechanisms, as well as related clinical studies, and its challenges in the management of oral PMDs. Based on its high efficacy and low side effects, its high patient acceptance/compliance, the simplicity of the procedure and its minimal pretreatment preparation, topical PDT is believed to have potential to play an important role in the management of PMDs, especially of the low-grade dysplasia.

Mitochondrial Malfunctioning, Proteasome Arrest and Apoptosis in Cancer Cells by Focused Intracellular Generation of Oxygen Radicals

Photofrin/photodynamic therapy (PDT) at sub-lethal doses induced a transient stall in proteasome activity in surviving A549 (p53^+/+) and H1299 (p53^−/−) cells as indicated by the time-dependent decline/recovery of chymotrypsin-like activity. Indeed, within 3 h of incubation, Photofrin invaded the cytoplasm and localized preferentially within the mitochondria. Its light activation determined a decrease in mitochondrial membrane potential and a reversible arrest in proteasomal activity. A similar result is obtained by treating cells with Antimycin and Rotenone, indicating, as a common denominator of this effect, the ATP decrease. Both inhibitors, however, were more toxic to cells as the recovery of proteasomal activity was incomplete. We evaluated whether combining PDT (which is a treatment for killing tumor cells, per se, and inducing proteasome arrest in the surviving ones) with Bortezomib doses capable of sustaining the stall would protract the arrest with sufficient time to induce apoptosis in remaining cells. The evaluation of the mitochondrial membrane depolarization, residual proteasome and mitochondrial enzymatic activities, colony-forming capabilities, and changes in protein expression profiles in A549 and H1299 cells under a combined therapeutic regimen gave results consistent with our hypothesis.

Melanoma resistance to photodynamic therapy: new insights

Melanoma is the most dangerous form of skin cancer, with a steeply rising incidence and a poor prognosis in its advanced stages. Melanoma is highly resistant to traditional chemotherapy and radiotherapy, although modern targeted therapies such as BRAF inhibitors are showing some promise. Photodynamic therapy (PDT, the combination of photosensitizing dyes and visible light) has been tested in the treatment of melanoma with some promising results, but melanoma is generally considered to be resistant to it. Optical interference by the highly-pigmented melanin, the antioxidant effect of melanin, the sequestration of photosensitizers inside melanosomes, defects in apoptotic pathways, and the efflux of photosensitizers by ATP-binding cassette transporters have all been implicated in melanoma resistance to PDT. Approaches to overcoming melanoma resistance to PDT include: the discovery of highly active photosensitizers absorbing in the 700-800-nm near infrared spectral region; interventions that can temporarily reduce the amount or pigmentation of the melanin; compounds that can reverse apoptotic defects or inhibit drug-efflux of photosensitizers; and immunotherapy approaches that can take advantage of the ability of PDT to activate the host immune system against the tumor being treated.

Effect of methylene blue-mediated photodynamic therapy for treatment of basal cell carcinoma

Photodynamic therapy (PDT) is regarded as a treatment option for basal cell carcinoma (BCC). The aim of this study is to investigate the efficacy of methylene blue (MB)-based PDT in patients suffering from nodular or ulcerative BCCs. This study is a prospective clinical trial with a 6-months follow-up. The study setting is at the Dermatology Clinic at NILES, Cairo University, Egypt. Seventeen patients complaining of nodular BCC (nBCC) and three patients complaining of ulcerative BCC (uBCC) were taken as samples. Methylene blue, the photosensitizer, was prepared in two different formulas: liposomal-loaded MB (LMB) was prepared and formulated in hydrogel (MB 0.2%) to be used topically alone for treating BCCs <2 cm in diameter or to be combined with intralesional injection (ILI) of free MB 2% aqueous solution for treating BCCs ≥2 cm in diameter. A session was performed every 2 weeks until complete response (CR) of the lesion or for a maximum of six sessions. Clinical assessments of clinical improvement, dermatological photography, monthly follow-up visits for 6 months, and skin biopsy after 3 months of follow-up to confirm the response, recurrence, or both in cases in which the clinical evaluation was ambiguous. Seventeen patients of the 20 completed the study, 11 patients achieved CR with very good cosmetic outcome, photosensitizer tolerance, and minimal reported side effects. MB is a cheap promising alternative photosensitizer for PDT of nBCC.

Modulation of PPIX synthesis and accumulation in various normal and glioma cell lines by modification of the cellular signaling and temperature

Effective therapies for malignant gliomas are still elusive and limited survival improvements are provided only by Temozolomide or fluorescence guided resection. The efficacy of photodynamic therapy (PDT) in this indication is limited by the higher sensitivity of normal brain structures compared to glioma necessitating a modulation of its sensitivity. We evaluate the influence of hypothermia and the tyrosine kinase inhibitor Erlotinib on cell's ability to synthesize PPIX following the administration of ALA which was not previously investigated. We demonstrate that both hypothermia and Erlotinib are favorable in PPIX selectivity as only glioma cell lines demonstrate an increased PPIX synthesis, whereas the neuronal and astrocytic synthesis is remaining unaffected. The results are encouraging to consider hypothermia and Erlotinib as adjuvant therapies to increase the PDT therapeutic index between GBM and normal intracranial tissues, as well as to improve contrast in fluorescence guided resection.

Experience with 5-aminolevulinic Acid in fluorescence-guided resection of a deep sylvian meningioma

The 5-aminolevulinic acid (5-ALA)-induced tumor fluorescence is a useful intraoperative marker for the diagnosis and the detection of various malignancies, but its use in meningioma is only reported infrequently. In meningioma, a complete resection of the tumor mass is crucial for the prevention of recurrence and postoperative morbidities. Deep sylvian meningioma is a rare type of meningioma where complete tumor removal is complicated by its deep anatomical location and close involvement with the middle cerebral artery. From our experience, 5-ALA-mediated fluorescence facilitated a safe excision whilst preserving critical neurovascular structures. To our best knowledge, this is first report from use of 5-ALA in a deep sylvian meningioma.

Intralesional therapy for psoriasis

Localized resistant plaques of psoriasis often remain despite highly effective anti-psoriasis treatment. Intralesional therapy is often used to treat various malignant, infectious or inflammatory cutaneous diseases, including psoriasis. Despite the presence of many review articles on the treatment of psoriasis, no articles exist which review the use of intralesional therapy for psoriasis. In this article, we review the published literatures of intralesional therapy for psoriasis. Corticosteroids, methotrexate, cyclosporin, biologics, botulinum toxin type-A, 15-hydroxyeicosatetraenoic acid, and chemotherapy agents such as 5-fluorouracil are discussed. Also, agents which may be used intralesionally and have the potential to treat psoriasis will also be reviewed such as bleomycin, vincristine or vinblastine, mitomycin-C, aminophylline, 5-aminolevulinic acid, rituximab, bevacizumab and pentoxifylline are included.

Topical delivery for the treatment of psoriasis

IMPORTANCE OF THE FIELD

Psoriasis is one of the most common human skin diseases. Topical therapy forms the cornerstone in the management of mild-to-moderate psoriasis. Topical therapies are also used as adjunctive to systemic therapy in moderate and severe forms of the disease.

AREAS COVERED IN THIS REVIEW

In this review, an overview of psoriasis pathogenesis, new topical medications for psoriasis, new targets and molecules, combination topical therapies and combination of topical and phototherapy is provided. Over the past decade several efficacious and acceptable treatment options have emerged from the age-old therapies. The development of sophisticated formulation options has led to an enhancement in the rate and extent of drug delivery across the skin, increasing therapeutic value and improving patient compliance.

WHAT THE READER WILL GAIN

Readers will learn about monotherapy and combination topical products as well as new topical drug delivery technology to achieve optimal clinical outcomes. This review will highlight the need to generate more dermal pharmacokinetic data for better understanding of the impact of formulation change on skin pharmacokinetics to help design improved topical drug delivery systems.

TAKE HOME MESSAGE

New topical formulations have the potential to achieve better efficacy with improved safety profile.

Review of Neurosurgical Fluorescence Imaging Methodologies

Fluorescence imaging in neurosurgery has a long historical development, with several different biomarkers and biochemical agents being used, and several technological approaches. This review focuses on the different contrast agents, summarizing endogenous fluorescence, exogenously stimulated fluorescence and exogenous contrast agents, and then on tools used for imaging. It ends with a summary of key clinical trials that lead to consensus studies. The practical utility of protoporphyrin IX (PpIX) as stimulated by administration of δ-aminolevulinic acid (ALA) has had substantial pilot clinical studies and basic science research completed. Recently multi-center clinical trials using PpIx fluorescence to guide resection have shown efficacy for improved short term survival. Exogenous agents are being developed and tested pre-clinically, and hopefully hold the potential for long term survival benefit if they provide additional capabilities for resection of micro-invasive disease or certain tumor sub-types that do not produce PpIX or help delineate low grade tumors. The range of technologies used for measurement and imaging ranges widely, with most clinical trials being carried out with either point probes or modified surgical microscopes. At this point in time, optimized probe approaches are showing efficacy in clinical trials, and fully commercialized imaging systems are emerging, which will clearly help lead to adoption into neurosurgical practice.

Mitochondrial gateways to cancer

Mitochondria are required for cellular survival, yet can also orchestrate cell death. The peculiar biochemical properties of these organelles, which are intimately linked to their compartmentalized ultrastructure, provide an optimal microenvironment for multiple biosynthetic and bioenergetic pathways. Most intracellular ATP is generated by mitochondrial respiration, which also represents the most relevant source of intracellular reactive oxygen species. Mitochondria participate in a plethora of anabolic pathways, including cholesterol, cardiolipin, heme and nucleotide biosynthesis. Moreover, mitochondria integrate numerous pro-survival and pro-death signals, thereby exerting a decisive control over several biochemical cascades leading to cell death, in particular the intrinsic pathway of apoptosis. Therefore, it is not surprising that cancer cells often manifest the deregulation of one or several mitochondrial functions. The six classical hallmarks of cancer (i.e., limitless replication, self-provision of proliferative stimuli, insensitivity to antiproliferative signals, disabled apoptosis, sustained angiogenesis, invasiveness/metastatic potential), as well as other common features of tumors (i.e., avoidance of the immune response, enhanced anabolic metabolism, disabled autophagy) may directly or indirectly implicate deregulated mitochondria. In this review, we discuss several mechanisms by which mitochondria can contribute to malignant transformation and tumor progression.

Treatment options for premalignant and malignant cutaneous tumors

Whenever possible, surgical excision of skin cancers should be the gold standard of treatment. There are many considerations when choosing one treatment modality over another. These include the lesion's location, the surgeon's experience and comfort level, the patient's health status and their potential compliance, access to available technology, and economic considerations for the patient and the provider. Regardless of the type of therapy, all forms of treatment share the following goals: complete disease cure, preservation of normal tissue, preservation of function, and optimal cosmesis.

Blue and red light combination LED phototherapy for acne vulgaris in patients with skin phototype IV

BACKGROUND AND OBJECTIVES

Blue light is effective for acne treatment, inducing photodynamic destruction of Propionibacterium acnes (P. acnes). This study was designed to investigate the efficacy of combined blue and red light-emitting diode (LED) phototherapy for acne vulgaris.

MATERIALS AND METHODS

Twenty-four patients with mild to moderately severe facial acne were treated with quasimonochromatic LED devices, alternating blue (415 nm) and red (633 nm) light. The treatment was performed twice a week for 4 weeks. Objective assays of the skin condition were carried out before and after treatment at each treatment session. Clinical assessments were conducted before treatment, after the 2nd, 4th, and 6th treatment sessions and at 2, 4, and 8 weeks after the final treatment by grading and lesion counting.

RESULTS

The final mean percentage improvements in non-inflammatory and inflammatory lesions were 34.28% and 77.93%, respectively. Instrumental measurements indicated that the melanin levels significantly decreased after treatment. Brightened skin tone and improved skin texture were spontaneously reported by 14 patients.

CONCLUSION

Blue and red light combination LED phototherapy is an effective, safe and non-painful treatment for mild to moderately severe acne vulgaris, particularly for papulopustular acne lesions.

Contrast enhanced MRI-guided photodynamic therapy for site-specific cancer treatment

Photodynamic therapy (PDT) is a minimally invasive and effective approach for cancer treatment. It is potentially useful for treating tumors that are not accessible to surgery, radiation, or destructive ablations, and are resistant to chemotherapy. Efficacious treatment of interstitial tumors with PDT requires efficient delivery of photosensitizers and accurate location of tumor tissues for effective light irradiations. In this study we performed contrast-enhanced (CE) MRI-guided PDT with a bifunctional polymer conjugate containing both a magnetic resonance imaging (MRI) contrast agent and a photosensitizer, poly(L-glutamic acid) (PGA)-(Gd-DO3A)-mesochlorin e(6) (Mce(6)). The efficacy of the bifunctional conjugate in cancer CE-MRI and cancer treatment was evaluated in athymic nude mice bearing MDA-MB-231 human breast carcinoma xenografts, with PGA-(Gd-DO3A) used as a control. The polymer conjugates preferentially accumulated in the solid tumor due to the hyperpermeability of the tumor vasculature, resulting in significant tumor enhancement for accurate tumor detection and localization by MRI. Significant therapeutic response was observed for PDT with the bifunctional conjugate as compared to the control. CE-MRI-guided PDT with the bifunctional conjugate is effective for tumor detection and minimally invasive cancer treatment.

Frataxin deficiency alters heme pathway transcripts and decreases mitochondrial heme metabolites in mammalian cells

Deficiency of the frataxin mRNA alters the transcriptome, triggering neuro- and cardiodegeneration in Friedreich's ataxia. We microarrayed murine frataxin-deficient heart tissue, liver tissue and cardiocytes and observed a transcript down-regulation to up-regulation ratio of nearly 2:1 with a mitochondrial localization of transcriptional changes. Combining all mouse and human microarray data for frataxin-deficient cells and tissues, the most consistently decreased transcripts were mitochondrial coproporphyrinogen oxidase (CPOX) of the heme pathway and mature T-cell proliferation 1, a homolog of yeast COX23, which is thought to function as a mitochondrial metallochaperone. Quantitative RT-PCR studies confirmed the significant down-regulation of Isu1, CPOX and ferrochelatase at 10 weeks in mouse hearts. We observed that mutant cells were resistant to aminolevulinate-dependent toxicity, as expected if the heme pathway was inhibited. Consistent with this, we observed increased cellular protoporphyrin IX levels, reduced mitochondrial heme a and heme c levels and reduced activity of cytochrome oxidase, suggesting a defect between protoporphyrin IX and heme a. Fe-chelatase activities were similar in mutants and controls, whereas Zn-chelatase activities were slightly elevated in mutants, supporting the idea of an altered metal-specificity of ferrochelatase. These results suggest that frataxin deficiency causes defects late in the heme pathway. As ataxic symptoms occur in other diseases of heme deficiency, the heme defect we observe in frataxin-deficient cells could be primary to the pathophysiological process.

The new age of acne therapy: light, lasers, and radiofrequency

BACKGROUND

Current treatments for acne vulgaris include topical and oral medications that counteract microcomedone formation, sebum production, Propionibacterium acnes, and inflammation. Concerns about the short- and long-term consequences of these medications, along with technological advancements, have to significant progress in the management of acne. These developments include light, laser, and radio frequency, which may offer faster onset of action, equal or greater efficacy, and greater convenience than traditional approaches.

CONCLUSION

Research emphasizing long-term follow-up and comparative, randomized trials is necessary to determine whether these emerging technologies will become a viable alternative to standard therapies such as antibiotics.

Lasers and Light Therapy for Acne Vulgaris

Acne vulgaris remains an emotionally and debilitating dermatologic disease, and is conventionally treated with a variety of oral and topical therapies with a number of significant side effects. An evolving understanding of laser-tissue interactions involving Propionibacterium acnes-produced porphyrins, and the development of infrared nonablative lasers to target sebaceous glands, has lead to the development of an escalating number of laser, light and radiofrequency devices for acne. Used as monotherapy or in combination, these devices are showing promise as a method to clear acne in a convenient, non-invasive manner, though there remains a clear need for long-term data and randomized, blinded studies.

Successful treatment of oral verrucous hyperplasia and oral leukoplakia with topical 5-aminolevulinic acid-mediated photodynamic therapy

BACKGROUND AND OBJECTIVES

Our recent studies showed that a new topical 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) protocol using a light-emitting diode (LED) light source is an effective and successful treatment modality for five cases of oral verrucous hyperplasia (OVH) and one case of verrucous carcinoma. In this study, we treated eight OVH lesions with the same topical ALA-PDT protocol to further confirm the efficacy of this protocol on OVH lesions. In addition, our recent study demonstrated an unsatisfactory clinical outcome for 24 oral leukoplakia (OL) lesions treated once a week by the same topical ALA-PDT protocol. Therefore, in this study 24 OL lesions were treated twice a week by the same protocol to compare whether the twice-a-week treatment modality could result in a better clinical outcome than the once-a-week treatment modality.

STUDY DESIGN/MATERIALS AND METHODS

In this study, 8 OVH and 24 OL lesions were treated by the same topical ALA-PDT once a week and twice a week, respectively.

RESULTS

All the former eight OVH lesions treated once a week showed complete response (CR) after 2-5 (mean, 3.8) treatments of ALA-PDT. The latter 24 OL lesions treated twice a week demonstrated CR in 8, partial response (PR) in 16, and no response in none. The present 24 OL lesions treated twice a week had a significantly better clinical outcome than the previous 24 OL lesions treated once a week (P = 0.000, chi-square test).

CONCLUSIONS

We conclude that complete regression of OVH lesions can be achieved by less than six treatments of topical ALA-PDT once a week. Although the response of OL lesions to the topical ALA-PDT is not as good as the response of OVH lesions to the same therapy, all OL lesions can have at least PR after eight treatments with the topical ALA-PDT twice a week. In addition, OL lesions treated twice a week have a significantly better clinical outcome than OL lesions treated once a week.

Photodynamische Therapie mit Methylaminooxopentanoat (MetvixR) und einer Breitbandlichtquelle (PhotoDyn 501): Praktische Erfahrungen bei Problem-Patienten mit Aktinischen Keratosen und Basalzellkarzinomen. Photodynamic therapy with methylaminooxopentanoate (MetvixR) and a broad band light source (PhotoDyn 501): Experiences in complicated patients with actinic keratoses and basal cell carcinomas

BACKGROUND

Actinic keratoses (AK) and basal cell carcinomas (BCC) may represent a therapeutic challenge because of special subtypes, location, previous therapy or accompanying diseases. Photodynamic therapy (PDT) offers a semi-conservative treatment option for selected indications.

PATIENTS AND METHODS

28 outpatients who had been admitted as complicated dermato-oncologic cases because of AK (n = 22) and BCC (n = 6) were treated with PDT, using methylaminooxopentanoate (MAOP, Methyl-Ala, Metvix) and a broad band light source (PhotoDyn 501). The treatment was evaluated for efficacy and subjective tolerance (local discomfort and pain).

RESULTS

A complete remission (CR) was achieved in 11/22 AK (50%) and 4/6 BCC (67%) cases. All three cases of a superficial BCC subtype underwent a CR. Among responders, tolerance was good in 12/15 cases (80%), as compared to 4/13 cases (31%) in non-responders. Focusing on 16/28 patients with good tolerance (57%), there was a CR in 12 cases (75% rate), whereas for the 12/28 patients with moderate to poor tolerance a CR was achieved in only 3 cases (25% rate). In a subgroup of 8 patients who, partly due to secondary diseases, were taking systemic retinoids or immunosuppressive-cytostatic medications, a CR was achieved in 3/8 cases (38%) with a good tolerance in only 1/8 cases (13%).

CONCLUSION

These observations confirm a good efficacy and tolerance of PDT in > or = 50% of a AK/BCC problem patient cohort. We found indications for 1) a positive correlation between efficacy and subjective tolerance as well as 2) the presumptive existence of a retinoid-dependent cutaneous PDT hyperalgesia. Effective pain control seems to be an essential cofactor for the success of PDT.

Acne: Physical treatment

Different physical treatments may be used in acne therapy. The main indications are for treating retentional lesions (open and comedones), inflamed lesions, and scars.