Terapia fotodinâmica em dermatologia: princípios básicos e aplicações

Use of photodynamic therapy to combat recurrent pharyngotonsillitis: Three case reports

BACKGROUND

Pharyngotonsillitis (PT) is an inflammatory and infectious condition affecting the tonsils in the oropharynx, predominantly caused by a variety of viral, fungal, and bacterial pathogens, including Streptococcus pyogenes. With the increasing challenge of antibiotic resistance, alternative therapeutic approaches are needed.

METHODS

This study explores the effectiveness and safety of Photodynamic Therapy (PDT) as a therapeutic approach for managing acute PT. PDT involves the use of a photosensitizer, light, and molecular oxygen. We utilized a curcumin-based photosensitizer incorporated into a gum formulation, followed by exposure to blue LED irradiation (455 ± 30 nm, intensity of 200 mW for 6 min) with 1 to 2 PDT sessions depending on the clinical case.

RESULTS

The treatment's impact was assessed through systematic monitoring of clinical progression post-treatment, encompassing clinical history, examination, and follow-up. In all three cases examined, PDT was observed to effectively eradicate the infection and prevent its recurrence during the period evaluated.

CONCLUSION

Photodynamic Therapy, using a curcumin-based photosensitizer and blue LED light, appears to be a promising alternative to traditional antibiotics for the treatment of PT, demonstrating both efficacy in infection eradication and safety in application. Further studies are recommended to substantiate these findings and explore long-term outcomes.

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.

Temperature effect on the PpIX production during the use of topical precursors

Decreasing incubation time, as well as enhanced PpIX production, are present challenges for topical photodynamic therapy (PDT). There are reports concerning the existence of a strong relationship between site temperature and porphyrin synthesis in biological tissue, that suggest temperature increase in the tissue can improve the formation of PpIX. The main objective of this study is to determine whether the temperature change of the tissue favors the production of PpIX. Creams containing aminolevulinic acid (ALA) and methyl aminolevulinate (MAL) were topically administered for 30 min on healthy skin of rats' back and the formation of PpIX was evaluated for 180 min. The animals were divided into 5 groups: cooling tissue to 20 °C or heating tissue to 40 °C (either before or after incubation of the cream) and control group (unchanged temperature). The tissue temperature was evaluated by thermography. The influence of temperature was evaluated both concerning cream penetration and the production of PpIX. It was found that both ALA and MAL led to an increase of about 20% PpIX production when the tissue was warmed before incubation of the cream, suggesting that the penetration improved. When the thermal change was promoted after incubation of the cream, the production of PpIX decreased both by heating and cooling, probably related to enzyme modification. The results found in this study suggest that the increase of tissue temperature before the cream incubation can improve the clinical protocols of topical PDT using ALA or MAL, improving the efficiency of the procedure by increasing the production of PpIX and allowing the decrease of the incubation period.

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.

Genotoxic effects of photodynamic therapy in laryngeal cancer cells - An in vitro study

IMPACT STATEMENT

Recently, the use of photodynamic therapy grows as an alternative treatment for cancer, since it has a noninvasive characteristic and affinity to the tumor tissue. Accordingly, understanding the therapy's foci of action is important for the technique improvement. This work aims to understand the genotoxic effect triggered by the therapy action, thus evidencing the permanent changes caused to the genetic material of the tumor cell after the treatment. Therefore, to increase the knowledge in this study field, the methodology of the comet assay and count of micronucleus formed after the therapy was adopted in order to understand if the damage caused to the DNA of tumor cell makes its replication process unfeasible in future generations. The study allows a better therapeutic approach to the cancer treatment, making the process of association between therapies a more effective option during the disease treatment.

Evaluation of aluminum phthalocyanine chloride and DNA interactions for the design of an advanced drug delivery system in photodynamic therapy

The aim of this study was to evaluate the interaction of aluminum phthalocyanine chloride (AlClPc) with double-stranded DNA. Absorption and fluorescence spectra, resonance light scattering, and circular dichroism were evaluated in water and water/ethanol mixtures with different concentrations of DNA or AlClPc. AlClPc showed a high ability to bind to DNA in both water and 4/6 water/ethanol mixture (v/v), with a majority of monomeric and aggregated initial forms of AlClPc, respectively. In this interaction, AlClPc bound preferentially to the grooves of DNA. The monomeric/aggregate state of AlClPc in DNA was dependent on the AlClPc/DNA ratio. At low concentrations of AlClPc, the interaction of AlClPc with few DNA sites caused a curvature in the DNA structure that provided a favorable environment for the intercalation of AlClPc aggregates. Increase in AlClPc concentration induced interactions with a high number of binding sites on DNA, which prevented bending and therefore aggregation of AlClPc molecules throughout the double-stranded DNA. These results are relevant to the understanding of the behavior and interaction of AlClPc with double-stranded DNA in the design of novel drug delivery systems for clinical application in photodynamic therapy as a new approach to treat skin or oral cancer, scars, or wound healing.

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

Background

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

Methods

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

Discussion

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

Trial registration

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

Some activities of PorphyChem illustrated by the applications of porphyrinoids in PDT, PIT and PDI

Photodynamic therapy is an innovative approach to treat diverse cancers and diseases that involves the use of photosensitizing agents along with light of an appropriate wavelength to generate cytotoxic reactive oxygen species.

Successful treatment of Rosai-Dorfman disease using ALA-PDT

Rosai-Dorfman disease is a rare inflammatory cutaneous histiocytosis with the involvement of lymph nodes. Therapeutic interventions include thalidomide, corticosteroids, surgical excision and radiotherapy . In this article, we report a case that was successfully treated with ALA photodynamic therapy.

Evaluation of the efficacy of photodynamic therapy for the treatment of actinic cheilitis

INTRODUCTION

Actinic cheilitis (AC) is a lip intraepithelial neoplasia, whose cells present alterations similar to those presented by invasive squamous cell carcinomas (SCCs).

OBJECTIVE

To conduct clinical and laboratory evaluation by histopathology and immunohistochemistry of the efficacy of actinic cheilitis treatment using photodynamic therapy (PDT) with methyl aminolevulinate (MAL) and noncoherent red light.

MATERIALS AND METHODS

Patients with actinic cheilitis detected by histopathological examination were submitted to two sessions of photodynamic therapy with a two-week interval between them. They were examined immediately after the sessions, four, six, and twelve weeks after beginning treatment when a new biopsy was carried out. Clinical histopathological and immunohistochemical parameters were evaluated before and after treatment.

RESULTS

Of the 23 patients who underwent biopsy, 16 completed two photodynamic therapy sessions and the material of one patient was insufficient for immunohistochemistry. Complete clinical response was achieved in 62.5% (10 of 16 patients) and 37.5% still remained with clinical evidence of AC. In spite of this, no case of cure by histopathological analysis was found. There was no significant statistical change among the values of Ki-67, survivin, and p53 observed before and after treatment.

CONCLUSION

Photodynamic therapy, as carried out in this trial, was not an efficacious therapeutic option for treating patients with actinic cheilitis included in this sample.

Effects of 5-aminolevulinic acid photodynamic therapy on TLRs in acne lesions and keratinocytes co-cultured with P. acnes

OBJECTIVE

To investigate the effect of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) on the expression of Toll like receptors (TLRs) in human keratinocytes and its role in acne treatment.

METHODS

TLR2 and TLR4 expression in acne lesions before and after ALA-PDT were examined by immunohistochemical assay. Primary keratinocytes were obtained from acne lesions, co-cultured with P. acnes and then treated with ALA-PDT using red or blue LED. Cytokines production were examined by ELISA, TLR2 and TLR4 gene expression by real-time PCR, and TLR2 and TLR4 protein expression by Western-blot assay.

RESULTS

The overexpression of TLR2 and TLR4 in acne lesion were detected, which became negative or weaker after ALA-PDT. The infection of P. acnes in keratinocytes could significantly increase the levels of early inflammatory cytokines (e.g. IL-1α, TNF-α and IL-8) (P<0.05). Such responses could be inhibited by ALA-PDT. P. acnes infection could also significantly increase TLR2 and TLR4 expressions in keratinocytes (P<0.05), which could be down-regulated by ALA-PDT.

CONCLUSIONS

ALA-PDT could inhibit innate immune responses in keratinocytes treated with P. acnes via TLRs pathways.

Spectroscopic analysis of aluminum chloride phthalocyanine in binary water/ethanol systems for the design of a new drug delivery system for photodynamic therapy cancer treatment

This study evaluated the behavior of aluminum chloride phthalocyanine in a binary water/ethanol mixture using electronic absorption spectroscopy and static and time-resolved fluorescence spectroscopy. The electronic absorption spectra, resonance light scattering and fluorescence quenching of aluminum chloride phthalocyanine in water/ethanol mixtures were studied at several concentrations. The electronic absorption spectra and fluorescence quenching changed significantly at approximately 50% water (v/v). Below 50% water, the dimerization constant values were negative (-2609.2 M(-1) and -506.5 M(-1) at 30% and 40% of water, respectively), indicating that the formation of aggregates under these conditions is not favored. However, at 50% water, the dimerization constant value was estimated to be 559.7 M(-1), which indicates the presence of dimers. Above 60% water, the aggregation process was responsible for the balance between large complexes (such as trimers, tetramers or oligomers) formed in the medium under these conditions. The appearance of new absorption bands at 387 nm and 802 nm and their bathochromic shift relative to the monomer bands suggested that some J-type aggregates form. These results are relevant to understanding the behavior and use of aluminum chloride phthalocyanine in the design of new drug delivery systems for clinical application in photodynamic therapy as a new approach to treat skin cancer.

Prospective study of topical 5-aminolevulinic acid photodynamic therapy for the treatment of severe adolescent acne in Chinese patients

Acne vulgaris is one of the most common skin diseases in adolescents. In the present study, we aimed to evaluate the effectiveness and safety of topical 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) for the treatment of severe acne in Chinese adolescent patients. Twenty-one Chinese adolescent patients aged 12-18 years with Pillsbury III-IV severe facial acne were treated with three courses of ALA-PDT. A 5% ALA lotion was applied topically for 60 min followed by irradiation with light-emitting diode light at 633 nm with a light intensity of 75-80 mW/cm(2) and a light dose of 90-96 J/cm(2) . Clinical assessment was conducted before and after each treatment, and at each follow-up session. The total effective rates were 85.71%, 90.48%, and 95.23% after the three PDT sessions, and at the 4- and 8-week follow ups, respectively. ALA-PDT is an effective treatment for severe adolescent acne vulgaris, and is associated with mild and reversible side-effects.

Cutaneous field cancerization: clinical, histopathological and therapeutic aspects

The concept of "field cancerization" was first introduced by Slaughter in 1953 when studying the presence of histologically abnormal tissue surrounding oral squamous cell carcinoma. It was proposed to explain the development of multiple primary tumors and locally recurrent cancer. Organ systems in which field cancerization has been described since then are: head and neck (oral cavity, oropharynx, and larynx), lung, vulva, esophagus, cervix, breast, skin, colon, and bladder. Recent molecular studies support the carcinogenesis model in which the development of a field with genetically altered cells plays a central role. An important clinical implication is that fields often remain after the surgery for the primary tumor and may lead to new cancers, designated presently as "a second primary tumor" or "local recurrence," depending on the exact site and time interval. In conclusion, the development of an expanding pre-neoplastic field appears to be a critical step in epithelial carcinogenesis with important clinical consequences. Diagnosis and treatment of epithelial cancers should not only be focused on the tumor but also on the field from which it developed. The most important etiopathogenetic, clinical, histopathological and therapeutic aspects of field cancerization are reviewed in this article.

Conservative treatment of penile carcinoma - a retrospective study of 10 years

Conservative treatment of penile squamous cell carcinoma has been advocated as a method of choice for tumours at early stages. Thirty patients with a mean age of 63.2 years were treated with CO2 laser ablation, radical local excision with preputial flap, direct closure or healing by secondary intention, circumcision alone or associated with CO2 laser and topical imiquimod. Sixteen patients had local recurrence. Partial penectomy was necessary in 3 patients. Conservative treatments of penile squamous cell carcinoma in early stages (< T1a) do not seem to compromise the survival rate, so it may be advisable for this subset of patients.

Photodynamic therapy in actinic cheilitis: clinical and anatomopathological evaluation of 19 patients

BACKGROUND

Actinic cheilitis, a common disease caused by chronic solar exposure and tobacco use, is considered a premalignant lesion with potential to develop into squamous cell carcinoma. Some of the available treatments are invasive, have unaesthetic results and require multiple sessions.

OBJECTIVE

To assess the efficacy of a therapy and its cosmetic results.

METHODS

In this uncontrolled clinical trial a single photodynamic therapy (PDT) session using 16% methyl-aminolevulinate was performed on actinic cheilitis of the lower lip. A standardized questionnaire was applied in order to assess the clinical improvement from the patients' point of view and the satisfaction with the treatment. Anatomopathological evaluation was performed before the treatment and two months afterwards.

RESULTS

The sample was composed of 19 patients (10 males and 9 females), phototypes I to III, with average age of 62 years. Main adverse effects were: sudden pain, scabs, herpes flare-up, and edema. The average score of pain during the procedure was 5,8+2,9. At the final assessment the patients reported improvement of 80% and satisfaction of 85% (p<0.01). Anatomopathological analysis showed a significant decrease of dysplasia (p=0.03) in spite of its presence in 84% of cases. There was no significant correlation between the level of dysplasia with either the subjective impression of clinical improvement (p=0.82) or with the patients' final satisfaction (p=0.96).

CONCLUSION

PDT is effective in the treatment of actinic cheilitis, but it is associated with a significant level of pain. Due to the persistence of dysplasia, more research needs to be done in order to define the ideal number of sessions for the effective treatment of these lesions.

Pain in photodynamic therapy: mechanism of action and management strategies

Photodynamic therapy involves administration of a photosensitizing drug and its subsequent activation by irradiation with a light source at wavelengths matching the absorption spectrum of the photosensitizer. In many countries around the world, topical photodynamic therapy has been approved for treatment of cutaneous oncologic conditions such as actinic keratosis, Bowen's disease, and superficial basal cell carcinoma. Multicenter, randomized, controlled studies have confirmed its efficacy and superior cosmetic outcomes compared to conventional therapies. Nevertheless, this therapeutic method presents some adverse effects, such as erythema, edema, pigmentation, pustules, and pain. There is no doubt that pain is the most severe of the adverse effects, being sometimes responsible for definitive treatment interruption. The pain mechanism has not yet been fully understood, which makes complete pain control a challenge to be conquered. In spite of that, this literature review presents some useful pain management strategies as well as the most important pain-related factors in photodynamic therapy.

Continuous or fractionated photodynamic therapy? Comparison of three PDT schemes for ovarian peritoneal micrometastasis treatment in a rat model

OBJECTIVE

This experimental study aimed to compare three illumination schemes to optimize hexaminolaevulinate (HAL)-PDT in a rat tumor model with advanced ovarian cancer.

MATERIALS AND METHODS

Peritoneal carcinomatosis was induced by intraperitoneal 5×10(6)NuTu-19 cells injection in 60 female rats Fisher 344. Carcinomatosis was obtained 50 days post-tumor induction. Four hours post-intraperitoneal HAL (Photocure ASA, Oslo, Norway) injection, three different schemes of PDT were performed during 25 min on a 1cm(2) area. (A) Fractionated illumination (n=20) with an on-off cycle ("on": 2 min and "off": 1 min) at 30mW cm(-2) until a fluence of 30J cm(-2), (B) continuous illumination (n=20) at 30mW cm(-2) with a fluence of (45J cm(-2)C) continuous illumination (n=20) at 20mW cm(-2) with a fluence of 30J cm(-2). Laser light was generated using a 532nm KTP laser (Laser Quantum, Stockport, UK). Biopsies were taken 24h after treatment. Quantitative histology was performed. Necrosis value was determined: 0-no necrosis to 4-full necrosis. Depth of necrosis was then measured for each sample and correlated to Necrosis value.

RESULTS

HAL-PDT was efficient in producing necrosis irrespective of the scheme. Tumor destruction was superior with fractionated illumination compared to both continuous illumination schemes regarding to the depth of necrosis (213±113μm vs 154±133μm vs 171±155μm) (p<0.05) or to the full necrosis rate (50% vs 30% vs 10%) (p<0.0001).

CONCLUSION

Fractionated illumination during photodynamic therapy (PDT) was shown to improve tumor response. Fractionated illumination with short intervals should be considered for an effective PDT of advanced ovarian cancer.

Terapia fotodinâmica para tratamento de múltiplas lesões no couro cabeludo na síndrome do nevobasocelular: relato de caso

A terapia fotodinâmica é uma alternativa eficaz de tratamento para neoplasias cutâneas não melanoma e tem como princípio a utilização de substâncias fotossensibilizantes que, após serem irradiadas com uma fonte de luz de comprimento de onda adequado, destroem seletivamente as células neoplásicas. A Síndrome do Nevobasocelular é uma genodermatose que cursa com o desenvolvimento de inúmeros carcinomas basocelulares em uma idade precoce, submetendo os pacientes a vários procedimentos cirúrgicos, muitas vezes desfigurantes. Este artigo tem como objetivo demonstrar o excelente resultado do tratamento de carcinomas basocelulares no couro cabeludo de uma paciente com a Síndrome do Nevobasocelular.

Terapia fotodinâmica: revisão da literatura e documentação iconográfica

A terapia fotodinâmica é uma reação química ativada por luz usada para destruição seletiva de um tecido e requer um agente fotossensibilizante no tecido-alvo, uma fonte de luz e oxigênio. Estão disponíveis, no momento, o ácido 5-aminolevulínico para tratamento de ceratoses actínicas e o metilaminolevulinato, aprovado para tratamento de ceratoses actínicas, carcinoma basocelular e doença de Bowen. As fontes de luz utilizadas para a terapia fotodinâmica devem emitir comprimentos de onda no espectro de absorção do fotossensibilizante escolhido. As lâmpadas LED (light emitting diode) são as indicadas para terapia fotodinâmica tópica no tratamento do câncer de pele não melanoma. A terapia fotodinâmica deve ser considerada, em particular, para pacientes que apresentam lesões superficiais, múltiplas, disseminadas e para pacientes imunossuprimidos. Mais recentemente, a terapia fotodinâmica tem sido indicada no tratamento do fotoenvelhecimento, acne, hidrosadenite, esclerodermia, psoríase, verrugas, leishmaniose, entre outras. Por este trabalho será possível ter acesso a uma extensa revisão da literatura sobre terapia fotodinâmica, seus mecanismos, indicações e resultados, seguida de comentários e críticas pertinentes ao assunto.