Photodynamic therapy (PDT) using topically applied delta-aminolevulinic acid (ALA) for the treatment of oral leukoplakia

CLINICAL EFFICACY OF PHOTODYNAMIC THERAPY IN MANAGEMENT OF ORAL POTENTIALLY MALIGNANT DISORDERS: A SYSTEMATIC REVIEW AND META-ANALYSIS

OBJECTIVES

Despite phototherapy (in the form of photodynamic therapy (PDT)-mediated oxidative stress) being utilized in the management of oral potentially malignant disorders (OPMDs), the evidence of certainty remains unclear. Hence, this systematic review and meta-analysis (PROSPERO # CRD42021218748) is aimed to evaluate the clinical efficacy of PDT-induced oxidative stress in OPMDs METHODS: PubMed, Embase, Web of Science, Scopus, and Cochrane Library databases were searched without restriction of language or year of publication. In addition, gray literature was searched and a manual search was performed. Two independent reviewers screened all the studies, assessing data extraction, risk of bias and certainty of evidence. A narrative synthesis was carried out. For the meta-analysis, random effects were considered to determine the prevalence of a total and a partial remission (PR) of oral potentially malignant disorders (OPMDs). The certainty of evidence was explored using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Twenty-three studies were included in the qualitative and quantitative syntheses. A total of 880 patients were included (564 males; 218 females) with an age range between 24 and 89-years-old. The results showed the prevalence of the total and partial remissions respectively for the following OPMLs: actinic cheilitis (AC): 69.9% and 2.4%; oral leukoplakia (OL): 44% and 36.9%; oral verrucous hyperplasia (OVH): 98.5%; oral erythroleukoplakia (OEL): 92.1% and 7.9%. The prevalence of no remission of OL was 18.8%.

CONCLUSIONS

PDT demonstrated significant results in clinical remission of OPMDs and most of the eligible studies have shown a total or a partial remission of the included lesions, but at a low or a very low certainty of evidence. Hence, further clinical studies with robust methodology are warranted to offer further validated data. Also, further evidence is required to understand further the mechanism of PDT-induced oxidative stress.

Efficacy of adjunctive photodynamic therapy to conventional mechanical debridement for peri-implant mucositis

OBJECTIVE

This meta-analysis was conducted to assess the effectiveness of photodynamic therapy (PDT) as an adjunct to conventional mechanical debridement (CMD) for the management of peri-implant mucositis (p-iM).

METHODS

We systematically searched four databases (PubMed, Embase, Web of Science, and Cochrane Library) for randomized controlled trials (RCTs) investigating PDT + CMD for p-iM from their inception to March 13, 2023. Meta-analysis was performed using RevMan 5.4 software.

RESULTS

Seven RCTs met the inclusion criteria. The meta-analysis revealed that PDT + CMD treatment was more effective than CMD alone in reducing probing depth (PD) (Mean Difference [MD]: -1.09, 95% Confidence Interval [CI]: -1.99 to -0.2, P = 0.02) and plaque index (PI) (MD: -2.06, 95% CI: -2.81 to -1.31, P < 0.00001). However, there was no statistically significant difference in the improvement of bleeding on probing (BOP) between the PDT + CMD groups and CMD groups (MD: -0.97, 95% CI: -2.81 to 0.88, P = 0.31).

CONCLUSIONS

Based on the current available evidence, this meta-analysis indicates that the addition of PDT to CMD significantly improves PD and PI compared to CMD alone in the treatment of p-iM. However, there is no significant difference in improving BOP.

Photodynamic Therapy for Eye, Ear, Laryngeal Area, and Nasal and Oral Cavity Diseases: A Review

Photodynamic therapy (PDT) has emerged as a promising modality for the treatment of various diseases. This non-invasive approach utilizes photosensitizing agents and light to selectively target and destroy abnormal cells, providing a valuable alternative to traditional treatments. Research studies have explored the application of PDT in different areas of the head. Research is focusing on a growing number of new developments and treatments for cancer. One of these methods is PDT. Photodynamic therapy is now a revolutionary, progressive method of cancer therapy. A very important feature of PDT is that cells cannot become immune to singlet oxygen. With this therapy, patients can avoid lengthy and costly surgeries. PDT therapy is referred to as a safe and highly selective therapy. These studies collectively highlight the potential of PDT as a valuable therapeutic option in treating the head area. As research in this field progresses, PDT may become increasingly integrated into the clinical management of these conditions, offering a balance between effectiveness and minimal invasiveness.

Evaluating photodynamic therapy for oral precancerous lesions: Highlighting outcome measure of malignant transformation

The main outcome measure assessed in previous studies on photodynamic therapy (PDT) for oral precancerous lesions (OPL) is clinical response based on the alteration in lesion size after treatment. However, the primary and secondary outcome measures of the interventions for OPL should be malignant transformation and recurrence. Thus, the objective of this short communication is to summarize the evidence on PDT in preventing the recurrence and malignant transformation of OPL. There were 16 eligible studies which addressed the issue of OPL patients who received PDT with recurrence outcome, and the pooled recurrence rate (95% confidence interval) was analyzed to be 20.1% (16.2-24.6%). Notably, only 1 study reported that 7.5% of malignant transformation rate for OPL received PDT. These should be interpreted with caution due to low-level evidence, such as differences in study design, clinical and pathological features of patients enrolled, limited sample size, short follow-up time. Given few evaluated the effect of PDT on malignant transformation, we highlight that this primary outcome measure of OPL needs to be investigated in further well-designed longitudinal studies with adequate follow-up periods.

Photodynamic therapy (PDT) for oral leukoplakia: a systematic review and meta-analysis of single-arm studies examining efficacy and subgroup analyses

OBJECTIVE

This study aims to evaluate the efficacy of photodynamic therapy (PDT) in the treatment of oral leukoplakia and explore the subgroup factors that may influence its effectiveness.

METHODS

A systematic search was conducted in PubMed, Embase, the Cochrane Library, and Web of Science databases to identify relevant studies. Meta-analysis was performed using Stata15.0 software. Cochran's Q test and I2 statistics were used to evaluate heterogeneity, egger's test was used to evaluate publication bias.

RESULTS

The analysis of 17 studies included in this study suggests that PDT may be effective in achieving complete response (CR) [ES = 0.50, 95%CI: (0.33,0.66)], partial response (PR) [ES = 0.42, 95%CI: (0.27,0.56)], no response (NR) [ES = 0.19, 95%CI: (0.11,0.27)]in patients with oral leukoplakia. The recurrence rate was also evaluated [ES = 0.13, 95%CI: (0.08,0.18)]. Subgroup analysis showed that various factors such as light source, wavelength, medium, duration of application, clinical and pathological diagnosis classification influenced efficacy of PDT. The lesion areas of the leukoplakia after treatment were reduced by 1.97cm2 compared with those before treatment.

CONCLUSION

Our findings show that PDT is a viable treatment for oral leukoplakia. However, the effectiveness of the therapy may depend on several factors, as suggested by our subgroup analyses. (Registration no. CRD42023399848 in Prospero, 26/02/2023).

Photodynamic therapy in oral cancer: a review of clinical studies

A significant mortality rate is associated with oral cancer, particularly in cases of late-stage diagnosis. Since the last decades, oral cancer survival rates have only gradually improved despite advances in treatment. This poor success rate is mainly due to the development of secondary tumors, local recurrence, and regional failure. Invasive treatments frequently have a negative impact on the aesthetic and functional outcomes of survivors. Novel approaches are thus needed to manage this deadly disease in light of these statistics. In photodynamic therapy (PDT), a light-sensitive medication called a photosensitizer is given first, followed by exposure to light of the proper wavelength that matches the absorbance band of the photosensitizer. The tissue oxygen-induced cytotoxic free radicals kill tumor cells directly, harm the microvascular structure, and cause inflammatory reactions at the targeted sites. In the case of early lesions, PDT can be used as a stand-alone therapy, and in the case of advanced lesions, it can be used as adjuvant therapy. The current review article discussed the uses of PDT in oral cancer therapy based on recent advances in this field.

Management of oral leukoplakia by ablative fractional laser‐assisted photodynamic therapy: A 3‐year retrospective study of 48 patients

Objectives

This study aimed to review the results of oral leucoplakia (OL) using ablative fractional laser‐assisted photodynamic therapy (AFL‐PDT) and to further evaluate the risk factors for recurrence and malignant transformation.

Materials and Methods

Forty‐eight patients diagnosed with OL using histopathology were enrolled in this study. All patients received one session of AFL‐PDT. Therapeutic efficacy was evaluated 1 month posttreatment. Follow‐up was scheduled every 3 months in the first year and every 6 months thereafter.

Results

An overall positive response rate of 87.5% (42/48) was achieved, including 62.5% (30/48) complete responses and 25.0% (12/48) partial responses. During the 3‐year follow‐up period, the recurrence and malignant transformation rates were 37.5% (18/48) and 8.3% (4/48), respectively. Lesions on gingiva/palate seemed to be associated with recurrence (p < 0.001; odds ratio [OR]: 1.64, 95% confidence interval [CI]: 1.13–2.37). The severity of epithelial dysplasia (p = 0.02; OR: 2.93, 95% CI: 1.96–4.42) and recurrence (p = 0.016; OR: 3.14, 95% CI: 2.04–4.84) were associated with a predisposition to malignant transformation.

Conclusions

AFL‐PDT is an effective management of OL, but requires close follow‐up. OL lesions on the gingiva/palate are predisposed to recurrence. OLs that recur with moderate/severe epithelial dysplasia have a higher risk of transforming into oral squamous cell carcinoma.

Photodynamic therapy for oral potentially malignant disorders: A Systematic Review and Meta-analysis

OBJECTIVES

To evaluate the effectiveness of Photodynamic Therapy (PDT) in the treatment of Oral Potentially Malignant Disorders (OPMDs) patients.

METHODOLOGY

An electronic search was conducted to retrieve articles published until September 2021. Meta-analyses were conducted for the outcomes of complete response (CR) and any response (AR) after treatment with PDT using data from single-arm studies, case series and non-randomised controlled trials (NRCTs).

RESULTS

In total, 49 articles were included. RCTs revealed insignificant mean difference (MD) in efficacy index between PDT and comparison groups (MD: 1.32; 95% CI:-28.10-30.72, p=0.930). The likelihood of CR (OR:0.84; 95% CI: 0.42-1.71, p=0.637) or AR (OR:2.10; 95% CI: 0.31-14.25, p=0.448) was not different in PDT group when compared with any comparison treatments in NRCTs. CR/AR among single arm studies was 60.6% (95% CI: 50.5-70.7, P<0.001) and 93.7% (95% CI:91.5-95.8, P<0.001) respectively. Higher prevalence of CR and AR was observed for dysplasia or carcinoma insitu (CIS) (CR: 81%, 95% CI: 70.8-91.3, P<0.001; AR: 94.3%; 95% CI: 89-99.6, P<0.001) and actinic cheilitis (AC) (CR: 73.9%, 95% CI: 65.9-81.9, P<0.001; AR:97%; 95% CI:94.9-99, P<0.001).

CONCLUSIONS

More than half of the patients receiving PDT showed CR, with more than 90% responding to the treatment. PDT was most effective on oral dysplasias, followed by AC.

The potential role of Photodynamic therapy in oral premalignant and malignant lesions: A systematic review

BACKGROUND

Photodynamic therapy (PDT) is considered as a valid treatment option in various branches of dentistry. This systematic review aims to evaluate the usefulness of PDT for treatment of oral premalignant and malignant lesions.

METHODS

The MeSH terms "Photodynamic therapy" and "PDT," in combination with other terms, have been searched by three search engines (PubMed, ISI Web of Science, and the Cochrane Library), and a systematic review has been performed. The Population, Intervention, Comparison, Outcomes, and Study design (PICOS) has been applied as method to outline our study eligibility criteria. Risk of Bias in Non-randomized Studies of Intervention (ROBINS-I) has been performed too.

RESULTS

Initial results were 1513. Definitely, 27 studies met our selection criteria.

CONCLUSIONS

Topical PDT is an easy to perform technique, well-tolerated treatment and it appears to be an effective method with encouraging achievements in the treatment of premalignant and malignant lesions of the soft tissues of the oral cavity; nevertheless more studies are required to integrate the up-to-date experience of this application.

Photodynamic therapy using topical toluidine blue for the treatment of oral leukoplakia: A prospective case series

BACKGROUND

Photodynamic therapy (PDT) is a minimally invasive method for the treatment of oral leukoplakia (OL) through the activation of a photosensitizer, after exposure to a specific wavelength light source.

METHODS

To investigate the effectiveness of toluidine blue as topical photosensitizer. Eleven patients participated in this study; fifteen oral leukoplakia lesions were treated, in several sessions, with 2.5 % toluidine blue and an LED source of 630 nm wavelength. Patients were evaluated at baseline (t0), at the end of treatment cycles (t1) and one year from the end of treatment (t2). All the treated sites were photographed at each visit. Images were processed with ImageJ 1.52 software in order to obtain the areas (mm2) of the treated lesions. Comparison between data at different follow-up was performed using a paired T-test.

RESULTS

At t1, complete response was obtained in six lesions, partial response in seven lesions while only two lesions showed no response. At t2, a further improvement was observed in two patients. The analysis of the areas showed significant reduction of the lesion size from t0 to t1 (p = 0.003), and from t1 to t2 (p = 0.01).

CONCLUSION

Toluidine blue appears to be a promising photosensitizer in the photodynamic therapy of oral leukoplakia.

Monitoring PDT effects in basal cell carcinoma treatment using thermal imaging

BACKGROUND

One of the most frequent type of malignant skin lesion (almost 95 percent of all skin tumours) is basal cell carcinoma (BCC). It is often treated by radiotherapy using ionizing radiation as well by photodynamic therapy (PDT) which is a selective method directed only on cancer cells and well tolerated by patients.

MATERIALS AND METHODS

Eight male patients of the Department and Clinic of Internal Diseases, Angiology and Physical Medicine in Bytom, Medical University of Silesia, in Katowice, Poland suffering from basal cell carcinoma were monitored by thermovision during the photodynamic therapy. All lesions were diagnosed as superficial were confirmed by histopathological examination.

RESULTS

The dynamics of changes observed in the isotherm area during the therapy can provide physicians with additional information. The significant increase of observed isotherm area in comparison to the lesion area diagnosed by a physician was confirmed, which may be connected with the increased metabolism processes occurring in the tissue surrounded the lesion.

CONCLUSION

The obtained results based on the temperature gradient changes in the lesion vicinity area may bring some new information describing the range of biochemical and physiological processes occurring during photodynamic therapy.

Clinical Trials and Basic Research in Photodynamic Diagnostics and Therapies from the Center for Laser Diagnostics and Therapy in Poland

The purpose of this review is to present an overview of the development of photodiagnostic and photodynamic therapy (PDD and PDT) techniques in Poland. The paper discusses the principles of PDD, including fluorescent techniques in determining precancerous conditions and cancers of the skin, digestive tract, bladder and respiratory tract. Methods of PDT of cancer will be discussed and the current state of knowledge as well as future trends in the development of photodynamic techniques will be presented, including the possibility of using photodynamic antimicrobial therapy. Research pioneers in photodynamic medicine such as Thomas Dougherty are an inspiration for the development of methods of PDD and PDT in our Clinic. The Center for Laser Diagnostics and Therapy in Bytom, Poland, promotes the propagation of PDD and PDT through the training of clinicians and raising awareness among students in training and the general public. Physicians at the Center are engaged in photomedical research aimed at clinical implementation and exploration of new avenues in photomedicine while optimizing existing modalities. The Center promotes dissemination of clinical results from a wide range of topics in PDD and PDT and serving as representative authorities of photodynamic medicine in Poland and Europe.

Light Sources and Dosimetry Techniques for Photodynamic Therapy

Effective treatment delivery in photodynamic therapy (PDT) requires coordination of the light source, the photosensitizer, and the delivery device appropriate to the target tissue. Lasers, light-emitting diodes (LEDs), and lamps are the main types of light sources utilized for PDT applications. The choice of light source depends on the target location, photosensitizer used, and light dose to be delivered. Geometry of minimally accessible areas also plays a role in deciding light applicator type. Typically, optical fiber-based devices are used to deliver the treatment light close to the target. The optical properties of tissue also affect the distribution of the treatment light. Treatment light undergoes scattering and absorption in tissue. Most tissue will scatter light, but highly pigmented areas will absorb light, especially at short wavelengths. This review will summarize the basic physics of light sources, and describe methods for determining the dose delivered to the patient.

Primary Clinical Evaluation of Photodynamic Therapy With Oral Leukoplakia in Chinese Patients

Background: Photodynamic therapy (PDT) has demonstrated promising results in the treatment of oral leukoplakia. This study evaluated the clinical efficacy and side effects of PDT in the treatment of Chinese patients with oral leukoplakia.

Methods: Twenty-nine patients with oral leukoplakia were enrolled in this study, including patients with both homogenous and non-homogenous lesions and various dysplastic tissues. All patients received PDT using a 632 nm laser at 500 mW/cm² power density at a dosage of 90–180 J/cm² and with aminolevulinic acid (ALA) used as a photosensitizer. A fixing and restricting complex as well as high laser power density for PDT in oral cavity was applied.

Results: An overall response rate of 86.2% was achieved in this study, including 55.2% complete remission and 31.0% partial remission. The only adverse events observed in subjects were transient local ulcer and pain. It is observed the PDT utilizing ALA showed strong effectiveness in patients with moderate to severe dysplasia, as less treatment time per cm² of lesion is required.

Conclusion: Topic ALA-PDT is effective to treat oral leukoplakia, especially for that with the presence of dysplasia. A fixing and restricting complex as well as high laser power density for PDT in oral cavity should be considered as an optimal choice.

Photodynamic therapy in the treatment of oral leukoplakia: A systematic review

OBJECTIVE

The aim of the present study was to systematically review the efficacy of photodynamic therapy (PDT) in the management of oral leukoplakia (OLK).

METHODS

This systematic review aimed to address the following focused question: "Is photodynamic therapy effective in the management of oral leukoplakia?'' PubMed/Medline, EMBASE, ISI Web of Knowledge, OVID, CNKI, and WANFANG DATA were searched up to and including June 2018 using different combinations of the following keywords: photodynamic therapy, leukoplakia, oral dysplasia, oral precancers, and oral premalignant lesions.

RESULTS

Sixteen studies were included in the present study. A total of 352 patients was included in this review, with age ranging from 20 to 79 years. Photosensitizers used were aminolevulinic acid, Photofrin, methylene blue, and chlorine-e6. Laser wavelength, duration of irradiation, and power density were 420-660 nm, 60-1000 s, and 100-150 mW/cm², respectively. On the whole, the rates of complete response and partial response were 32.9% and 43.2%, and the sum was 76.1%. The follow-up period ranged from 1 month to 119 months. The recurrence rate of OLK was 0-60%.

CONCLUSION

PDT appears to be a useful therapeutic strategy in the management of oral leukoplakia as a non-surgical treatment. Further RCTs with long follow-up period, standardized PDT parameters, and comparing efficacy of PDT with various other therapies are needed to acquire definite conclusions.

Lesion oxygenation associates with clinical outcomes in premalignant and early stage head and neck tumors treated on a phase 1 trial of photodynamic therapy

BACKGROUND

We report on a Phase 1 trial of photodynamic therapy (PDT) for superficial head and neck (H&N) lesions. Due to known oxygen dependencies of PDT, translational measurements of lesion hemoglobin oxygen saturation (S_tO₂) and blood volume (tHb) were studied for associations with patient outcomes.

METHODS

PDT with aminolevulinc acid (ALA) and escalating light doses was evaluated for high-grade dysplasia, carcinoma-in-situ, and microinvasive carcinomas of the H&N. Among 29 evaluable patients, most (18) had lesions of the tongue or floor of mouth (FOM). Disease was intact in 18 patients and present at surgical margins in 11 patients. In 26 patients, lesion S_tO₂ and tHb was measured.

RESULTS

Local control (LC) at 24 months was 57.5% among all patients. In patients with tongue/FOM lesions LC was 42.7%, and it was 50.1% for those with intact lesions. Lesion tHb was not associated with 3-month complete response (CR), but S_tO₂ was higher in patients with CR. In tongue/FOM lesions, baseline S_tO₂ [mean(SE)] was 54(4)% in patients (n=12) with CR versus 23(8)% in patients (n=6) with local recurrence/persistence (p=0.01). Similarly, for intact disease, baseline S_tO₂ was 54(3)% in patients (n=10) with CR versus 28(8)% in patients (n=5) without CR (p=0.03). In patients with intact disease, higher baseline S_tO₂ associated with 24-month local control (p=0.02).

CONCLUSIONS

Measurement of the physiologic properties of target lesions may allow for identification of patients with the highest probability of benefiting from PDT. This provides opportunity for optimizing light delivery based on lesion characteristics and/or informing ongoing clinical decision-making in patients who would most benefit from PDT.

Photodynamic therapy in oral potentially malignant disorders-Critical literature review of existing protocols

INTRODUCTION

Oral cancer is a serious public health issue. Apart from its high rate of prevalence, incidence and mortality, it can often result in more complex and expensive treatment when diagnosed late. Potentially malignant disorders (PMDs) can precede oral cancer, and are usually treated by surgical excision. However, in many cases patients are elderly and multiple interventions may be required. Photodynamic therapy (PDT) is a simple alternative, which has been successfully used in the treatment of oral PMDs.

OBJECTIVE

Due to the lack of standardization regarding photosensitizers (PTSs), types of irradiation, and methods of application, the objective of this study was to analyze existing PDT protocols in an attempt to identify the one that demonstrates greater efficiency, reliability and feasibility in the treatment of oral PMDs for both researchers and clinicians.

METHODS

Original clinical studies published only in English between 1993 and 2016 were searched in Pubmed/Medline database using the following keywords: photodynamic therapy; oral potentially malignant disorder; oral premalignant lesions. Review articles; experimental studies; case-reports; commentaries; and letters to the Editor were excluded from the selection.

RESULTS AND CONCLUSION

Based on the 16 studies selected, the topical 5-ALA-20% PTS, associated to a LED light applied for 15min with a 7-day interval between sessions emerged as the most frequently used PDT protocol, with satisfactory results. Due to its low rate of side effects, this PDT protocol presents good potential for the treatment of oral PMDs. Further clinical studies are required to ascertain its long-term validity in preventing oral cancer.

Photodynamic treatment outcomes of potentially-malignant lesions and malignancies of the head and neck region: A systematic review

AIM

The aim of the present study was to systematically review the efficacy of photodynamic therapy (PDT) in the management of oral potentially-malignant disorders (PMDS) and head and neck squamous cell carcinoma (HNSCC).

METHODS

From 1985 to 2015, PubMed/Medline, Google Scholar, EMBASE, and ISI Web of Knowledge were searched using different combinations of the following key words: PDT, oral precancer, leukoplakia, erythroplakia, erythroleukoplakia, verrucous hyperplasia, oral submucous fibrosis, and HNSCC. Review articles, experimental studies, case reports, commentaries, letters to the editor, unpublished articles, and articles published in languages other than English were excluded.

RESULTS

Twenty-six studies were included in the present study. The number of patients ranged from 2 to 147, with a mean age of 50-67 years. The reported numbers of PMDS and HNSCC ranged between 5 and 225. Photosensitizers used were aminolevulinic acid, meta-tetrahydroxyphenylchlorin, Foscan, hematoporphyrin derivatives, Photofrin, Photosan, and chlorine-e6. Laser wavelength, power density, irradiation duration were 585-652 nm, 50-500 mW/cm² , and 1-143 minutes, respectively. Complete, partial, and no response to PDT was found in 22.58%-100%, 4%-66%, and 0%-38.70% of PMDS, respectively, and 16%-100% of complete response in HNSCC patients.

CONCLUSION

PDT is effective in the management of PMDS and HNSCC.

Topical agents for oral cancer chemoprevention: A systematic review of the literature

OBJECTIVES/HYPOTHESIS

We review the use of topical chemoprevention agents in patients with oral potentially malignant disorders (PMD).

METHODS

A systematic review of studies on topical chemoprevention agents for oral PMD from 1946 to November 2016 was conducted using the MEDLINE database, Embase, and Cochrane Library. Data were extracted and analyzed from selected studies including study type, sample size, demographics, treatment length, response rate, follow-up time, adverse effects, and recurrence.

RESULTS

Of 108 studies, twenty-four, representing 679 cases met the inclusion criteria. The clinical lesions evaluated included oral leukoplakia, erythroplakia (OEL), verrucous hyperplasia (OVH), oral lichen planus, larynx squamous cell carcinoma, and oral squamous cell carcinoma (OSCC). The mean complete response rate for topical retinoid therapy was 32%. The mean complete response rate for 1% bleomycin therapy and 0.5% bleomycin was 40.2% and 25%, respectively. The complete response rate of OVH, OEL, and OSCC to photodynamic therapy ranged from 66.7% to 100%.

CONCLUSION

There are a paucity of data examining topical treatment of oral PMDs. However, the use of topical agents among patients with oral lesions may be a viable complement or even alternative to traditional surgery, radiation, or systemic chemotherapy, with the advantage of reducing systemic side effects and sparing important anatomic structures. This study of 679 cases represents the largest pooled sample size to date, and the preliminary studies in this systematic review provide support for further inquiry.

Photodynamic Therapy in Dentistry

Photodynamic therapy (PDT), also known as photoradiation therapy, phototherapy, or photochemo-therapy, involves the use of a photoactive dye (photosensitizer) that is activated by exposure to light of a specific wavelength in the presence of oxygen. The transfer of energy from the activated photosensitizer to available oxygen results in the formation of toxic oxygen species, such as singlet oxygen and free radicals. These very reactive chemical species can damage proteins, lipids, nucleic acids, and other cellular components. Applications of PDT in dentistry are growing rapidly: the treatment of oral cancer, bacterial and fungal infection therapies, and the photodynamic diagnosis (PDD) of the malignant transformation of oral lesions. PDT has shown potential in the treatment of oral leukoplakia, oral lichen planus, and head and neck cancer. Photodynamic antimicrobial chemotherapy (PACT) has been efficacious in the treatment of bacterial, fungal, parasitic, and viral infections. The absence of genotoxic and mutagenic effects of PDT is an important factor for long-term safety during treatment. PDT also represents a novel therapeutic approach in the management of oral biofilms. Disruption of plaque structure has important consequences for homeostasis within the biofilm. Studies are now leading toward selective photosensitizers, since killing the entire flora leaves patients open to opportunistic infections. Dentists deal with oral infections on a regular basis. The oral cavity is especially suitable for PACT, because it is relatively accessible to illumination.

Utility of photodynamic therapy for the management of oral potentially malignant disorders and oral cancer

Photodynamic therapy (PDT), defined as “the light-induced inactivation of cells, microorganisms, or molecules,” combines the use of a photosensitive agent or photosensitizer (PS) activated by irradiation with a light source to produce reactive oxygen species and highly reactive singlet oxygen. PDT has been used for the treatment of different oral diseases with promising results. This review describes the basic principles of PDT, including the nature of PS and the light sources, and focuses on evaluating the efficacy of this method, according to the existing data, for the treatment of different oral diseases. PubMed was used as the source of the relevant literature, about the clinical application of PDT in actinic cheilitis (AC), leukoplakia, oral lichen planus, oral lichenoid lesions, and oral cancer. Complete response to PDT as high as 100% has been reported not only in cases of AC but also in dysplasias/carcinomas in situ, T1N0, and T2N0. According to the available data, PDT appears to be a safe, well-tolerated therapy with limited adverse effects and excellent cosmetic outcome. Although PDT is a very promising therapy, further research is needed in order to investigate the cases that fail to respond, to examine the long-term prognosis for cases of reported complete response and thus avoid the future recurrence of diseases.

Photodynamic Therapy - A Non-invasive Treatment Modality for Precancerous Lesions

INTRODUCTION

Oral premalignant lesions are conditions having high potential tendency for transformation into malignancy. The use of a conservative and effective treatment modality is one of the best strategies for cancer prevention. Photodynamic therapy (PDT) is a non-invasive method for topical and selective treatment of oral precancerous lesions. The present study was taken up to determine the efficacy of PDT in oral precancerous lesions.

METHODS

The study consisted 13 patients with 24 oral leukoplakia (OL) lesions and 8 with 20 oral lichen planus (OLP) lesions, divided into control and study groups. These lesions were affecting various intraoral sites, the buccal mucosa being the most common site followed by tongue and gingiva. The treatment regimen of PDT included 98% 5-aminolevulinic acid (5-ALA) which is topical applied and irradiated with light emitting diode (LED) of 420 nm wavelengths at several sessions.

RESULTS

In OL 16.6% of cases showed complete response, 66.6% partial response and 16.6% no response of the lesions to the treatment. In OLP 80% and 20% of the lesions showed partial and no response respectively. The differences with control groups for OL + OLP were found to be significant (P < 0.001).

CONCLUSION

Based on the results of the present study, we can conclude that PDT appears to be a feasible alternative to conventional therapy for oral premalignant lesions.

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.

Photodynamic therapy in treatment of oral lichen planus

Oral lichen planus (OLP) is a relatively common chronic immunologic mucocutaneous disorder. Although there are many presenting treatments, some of them proved its failure. Recently, the use of photodynamic therapy (PDT) has been expanding due to its numerous advantages, as it is safe, convenient, and non-invasive and has toxic effect towards selective tissues. This article provides comprehensive review on OLP, its etiology, clinical features and recent non-pharmacological treatments. We also describe the topical PDT and its mechanisms. Our purpose was to evaluate the efficacy of PDT in treatment of OLP through collecting the data of the related clinical studies. We searched in PubMed website for the clinical studies that were reported from 2000 to 2014 using specific keywords: "photodynamic therapy" and "treatment of oral lichen planus". Inclusion criteria were English publications only were concerned. In the selected studies of photodynamic treatment, adult patients (more than 20 years) were conducted and the OLP lesions were clinically and histologically confirmed. Exclusion criteria were classical and pharmacological treatments of OLP were excluded and also the using of PDT on skin lesions of lichen planus. We established five clinical studies in this review where all of them reported improvement and effectiveness of PDT in treatment of OLP lesions. The main outcome of comparing the related clinical studies is that the photodynamic is considered as a safe, effective and promising treatment modality for OLP.

Efficacy of photodynamic therapy in the management of oral premalignant lesions. A systematic review

OBJECTIVE

The aim was to systematically review the efficacy of photodynamic therapy (PDT) in the management of oral premalignant lesions.

METHODS

The addressed focused question was "Is PDT effective in the management of oral premalignant lesions?" PubMed/Medline, Google-Scholar, EMBASE and ISI Web of Knowledge databases were searched from 1984 till June 2014 using different combinations of the following keywords: photodynamic therapy; oral premalignant lesions; leukoplakia; erythroplakia; erythro-leukoplakia; verrucous hyperplasia; and submucous fibrosis. Review articles, experimental studies, case-reports, commentaries, letters to the Editor, unpublished articles and articles published in languages other than English were not sought. The pattern of the present study was customized to mainly summarize the relevant information.

RESULTS

Thirteen studies were included. In these studies, the number of patients ranged between 5 patients and 147 individuals with mean ages ranging between 51 years and 62.2 years. Oral premalignant lesions, which were investigated were leukoplakia, erythroplakia, erythro-leukoplakia and verrucous hyperplasia. Reported number of premalignant lesions ranged between 5 and 225. Laser wavelength, duration of irradiation and power density were 585-660nm, 60s to 16.6min and 100-150mW/cm(2), respectively. Aminolevulinic acid, chlorine-e6, meta-tetrahydroxyphenylchlorin and photofrin were used as photosensitizer. The frequency of PDT application ranged between once and 12 times. Complete, partial and no response to PDT was shown by 27-100%, 5-50% and 0-25% of pre-malignant lesions, respectively. The recurrence rate of pre-malignant lesions was up to 36%.

CONCLUSION

PDT is effective in the overall management of oral premalignant lesions.

Proliferative verrucous leukoplakia: recognition and differentiation from conventional leukoplakia and mimics

The majority of conventional leukoplakia remains constant and only a subset progress to high-grade dysplasia or invasive carcinoma. A less recognized form known as proliferative verrucous leukoplakia (PVL) represents a unique progressive and elusive variant. Identifying patients with this form can only be achieved through the keen clinical observation of the temporal gross and histologic progression in individual patients with squamous cell carcinoma. The difficulty in the early diagnosis of PVL stems from the overlapping clinical and pathologic features with conventional multifocal leukoplakia with dysplasia. We present the current view on the clinicopathologic and biological characteristics of PVL and discuss their diagnosis, differential diagnosis, and management.

Chitosan-based mucoadhesive films containing 5-aminolevulinic acid for buccal cancer's treatment

Photodynamic therapy (PDT) is a relatively new method to treat various kinds of tumors, including those of the oral cavity. The topical 5-ALA-PDT treatment for tumors of the oral mucosa is preferred, since when administered systemically, there is a general photosensitization drawback in the patient. However, 5-ALA is a hydrophilic molecule and its penetration and retention is limited by topical route, including oral mucosa. We propose a topical delivery system of chitosan-based mucoadhesive film, aiming to promote greater retention of 5-ALA in tissue. The chitosan (CHT) films (4% w/w) were prepared using the solvent evaporation/casting technique. They were tested without 5-ALA resulting in permeability to water vapor (W.V.P=2.15-8.54 g mm/(h cm(2)Pa) swelling ∼300.0% (±10.5) at 4 h or 24 h and in vitro residence time >24 h for all tests. CHT films containing 10.0% (w/w) 5-ALA have resulted in average weight of 0.22 g and thickness of 0.608 mm as suitable characteristics for oral application. In the presence of CHT films both in vitro permeation and retention of 5-ALA (1.0% or 10.0%) were increased. However, 10.0% 5-ALA presented highest values of permeation and retention (∼4 and 17 times respectively, compared to propylene glycol vehicle). On the other hand, in vitro mucoadhesion of CHT films was decreased (18.2-fold and 3.1-fold) by 5-ALA addition (1.0% or 10.0% respectively). However, CHT film containing 10.0% of 5-ALA can be a potential delivery system for topical use in the treatment of tumors of the oral cavity using PDT because it favored the retention of 5-ALA in this tissue and has shown convenient mucoadhesion.

Methotrexate enhances 5-aminolevulinic acid-mediated photodynamic therapy-induced killing of human SCC4 cells by upregulation of coproporphyrinogen oxidase

BACKGROUND/PURPOSE

Topical 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) is effective for treatment of oral precancerous and cancerous lesions. This in vitro study tried to examine whether the SCC4 cell killing by ALA-PDT was enhanced by pretreatment of methotrexate (MTX).

METHODS

To measure the SCC4 cell killing abilities by MTX-pretreated ALA-PDT (MTX-ALA-PDT), the SCC4 cells were pretreated with 0 mg/L, 0.001 mg/L, 0.01 mg/L, 0.1 mg/L, or 1 mg/L of MTX for 72 hours, then incubated with 0 mM, 0.0625 mM, 0.125 mM, 0.187 mM, 0.25 mM, or 0.375 mM ALA for 4 hours, and subsequently illuminated with a 640-nm light-emitting diode array at a light dose of 10 J/cm(2). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was conducted at 24 hours to quantify SCC4 cell survival rates after MTX-ALA-PDT treatment. Western blot analyses were used to examine the MTX-mediated enhancement in the expressions of the heme production-related enzymes, coproporphyrinogen oxidase (CPOX), protoporphyrinogen oxidase (PPOX), and ferrochelatase, in the MTX-preconditioned SCC4 cells.

RESULTS

Pretreatment of SCC4 cells by 0.001 mg/L MTX for 72 hours resulted in a significant augmentation in MTX-ALA-PDT-induced killing of SCC4 cells (p < 0.05). The SCC4 cells treated with 0.001 mg/L MTX for 72 hours showed a significant and 1.65-fold increase in CPOX expression compared with the control SCC4 cells without MTX treatment (p < 0.05). However, no significant changes in the expressions of PPOX and ferrochelatase were observed in the SCC4 cells pretreated with different concentrations of MTX.

CONCLUSION

MTX enhances ALA-PDT-induced SCC4 cell killing through upregulation of CPOX expression and subsequent increase in intracellular protoporphyrin IX production in SCC4 cells.

Clinical evaluation of photodynamic therapy efficacy in the treatment of oral leukoplakia

BACKGROUND

The aim of the study was clinical evaluation of photodynamic therapy efficacy in the treatment of oral leukoplakia lesions.

METHODS

Twenty-three consecutive patients aged 21-79 were included to the study. In all patients 44 homogeneous, flat leukoplakia lesions were clinically diagnosed and confirmed histopathologically. Photodynamic therapy was performed with the use of Photolon(®) photosensitizer, containing 20% Chlorine-e6 and 10% dimethyl sulfoxide and a semiconductor laser, with power up to 300mW and a wavelength of 660nm. Ten illumination sessions were conducted with the use of superficial light energy density of 90J/cm(2).

RESULTS

At baseline the mean size of leukoplakia lesion was 6.5±5.10cm(2) while after photodynamic therapy 3±2.99cm(2). Significant reduction (on average by 53.8%) of leukoplakia lesions sizes was observed after therapy. Twelve (27.27%) lesions had been completely cured, 22 (50%) partially cured, although 10 (22.73%) lasted unchanged. The efficacy of PTD was comparable in women and men irrespective of age. There have been no adverse site effects during therapy noted.

CONCLUSIONS

Within the limits of the study it can be concluded that photodynamic therapy with the use of Chlorine-e6 can lead to considerable reduction of oral leukoplakia lesions size thus may be useful in clinical practice. However there is a need of further studies on larger number of cases and longer follow-up time.

A phase I trial of aminolevulinic acid-photodynamic therapy for treatment of oral leukoplakia

BACKGROUND

Photodynamic therapy with aminolevulinic acid (ALA PDT) for oral leukoplakia has shown promising effects in regression of oral leukoplakia. Although ALA has been extensively studied and is an ideal photosensitizer, the optimal light dose for treatment of oral leukoplakia has not been determined. We conducted a phase I study to determine MTD and DLT of PDT in patients treated with ALA for leukoplakia.

METHODS

Patients with histologically confirmed oral leukoplakia received a single treatment of ALA PDT in cohorts with escalating doses of light (585nm). Clinical, histologic, and biologic markers were assessed.

RESULTS

Analysis of 11 participants is reported. No significant toxicity from ALA PDT was observed in patients who received ALA with a light dose of up to 4J/cm(2). One participant experienced transient grade 3 transaminase elevation due to ALA. One participant had a partial clinical response 3months after treatment. Biologic mucosal risk markers showed no significant associations. Determination of MTD could not be accomplished within a feasible timeframe for completion of the study.

CONCLUSIONS

ALA PDT could be safely administered with a light dose up to 4J/cm(2) and demonstrated activity. Larger studies are needed to fully elucidate the MTD and efficacy of ALA-PDT.

The role of fluorescence diagnosis in clinical practice

Fluorescence diagnosis is a fast, easy, noninvasive, selective, and sensitive diagnostic tool for estimation of treatment results in oncology. In clinical practice the use of photodynamic diagnosis is focused on five targets: detection for prevention of malignant transformation precancerous changes, detection of neoplasmatic tissue in the early stages for fast removal, prevention of expansion and detection of recurrence of the cancer, monitoring therapy, and the possibility of excluding neoplasmatic disease. In this article, selected applications of fluorescence diagnosis at the Center for Laser Diagnostics and Therapy in Bytom, Poland, for each of these targets are presented.

Direct and indirect photodynamic therapy effects on the cellular and molecular components of the tumor microenvironment

Photodynamic therapy (PDT) is a novel cancer treatment. It involves the activation of a photosensitizer (PS) with light of specific wavelength, which interacts with molecular oxygen to generate singlet oxygen and other reactive oxygen species (ROS) that lead to tumor cell death. When a tumor is treated with PDT, in addition to affect cancer cells, the extracellular matrix and the other cellular components of the microenvironment are altered and finally this had effects on the tumor cells survival. Furthermore, the heterogeneity in the availability of nutrients and oxygen in the different regions of a tridimensional tumor has a strong impact on the sensitivity of cells to PDT. In this review, we summarize how PDT affects indirectly to the tumor cells, by the alterations on the extracellular matrix, the cell adhesion and the effects over the immune response. Also, we describe direct PDT effects on cancer cells, considering the intratumoral role that autophagy mediated by hypoxia-inducible factor 1 (HIF-1) has on the efficiency of the treatment.

Does the temperature gradient correlate with the photodynamic diagnosis parameter numerical colour value (NCV)?

BACKGROUND

Photodynamic diagnosis (PDD) as well as thermovision belong to the category of non-invasive optical diagnosis techniques. Among many different skin cancer diseases, basal cell carcinoma (BCC) is the most frequently occurring one (almost 95% of all skin tumours). In contrast, seborrhoeic keratosis represents almost 70% of benign skin tumours. In this paper we present infrared thermography as an additional method, combined with PDD, to show the differentiation between these two skin mutations.

METHODS

The photodynamic diagnosis studies were performed by using the autofluorescence diagnosis system Xillix Onco. As an additional non-invasive diagnosis technique, thermovision studies were performed. Thermal imaging was done by using a Thermovision Camera A40M with a sensitivity of 0.07K. The thermograms of the chosen areas were performed in a special room with a temperature of 22.5±1°C. All patients were treated in the Chair and Clinic of Internal Diseases, Angiology and Physical Medicine in Bytom. Thirteen skin lesions were studied: 9 diagnosed as basal cell carcinoma and 4 as seborrhoeic keratosis. All skin lesions were confirmed in histopathological examinations.

RESULTS AND CONCLUSIONS

The results of the studies revealed significant differences in skin thermal mapping between patients suffering from basal cell carcinoma and seborrhoeic keratosis. It appears that benign skin lesions are characterised by a lower mean temperature than the surrounding healthy skin. To the contrary, cancerous skin mutations appeared on the thermal map at a higher mean temperature. Thermal images for the chosen skin lesions and temperature parameters derived from the thermograms are contiguous with the photodynamic diagnosis results and may give some additional diagnostic information.

Successful treatment of 7,12-dimethylbenz(a)anthracene-induced hamster buccal pouch precancerous lesions by topical 5-aminolevulinic acid-mediated photodynamic therapy

BACKGROUND

Our previous studies found that topical 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (ALA-PDT) with a light dose of 100 J/cm(2) is very effective for human oral precancerous lesions.

METHODS

In this study, 20 7,12-dimethylbenz(a)anthracene (DMBA)-induced hamster buccal pouch precancerous lesions were treated by topical ALA-PDT with a light dose of either 75 J/cm(2) (n = 10) or 100 J/cm(2) (n = 10) using a 640-nm light-emitting diode (LED) light to test which light dose could achieve a better clinical outcome.

RESULTS

The 10 precancerous lesions treated by 75-J ALA-PDT showed complete response in 8 after an average of 3.4 (range, 2-6) treatments and partial response in 2. The 10 precancerous lesions treated by 100-J ALA-PDT demonstrated complete response in 7 after an average of 4.4 (range, 3-6) treatments and partial response in 3. Fisher exact test showed no significant difference in clinical outcome between these two treatment modalities (p = 1.000). One complete-response precancerous lesion in the 75-J ALA-PDT group recurred at the end of 19-week follow-up and another complete response precancerous lesion in the 100-J ALA-PDT group recurred at the end of 16-week follow-up. Both recurrence lesions were treated by the original topical ALA-PDT regimen and demonstrated complete response after 3 PDT treatments. Furthermore, the 5 partial-response precancerous lesions developed into squamous cell carcinomas after 30-week follow-up.

CONCLUSION

Our findings indicate that both the 75-J and 100-J topical ALA-PDT treatment modalities are very effective for DMBA-induced hamster buccal pouch precancerous lesions and no significant difference in clinical outcome between these two treatment modalities.

Comparison of cryotherapy and photodynamic therapy in treatment of oral leukoplakia

Oral leukoplakia is a pre-malignant lesion of the oral mucosa. The aim of this study is to compare the curative effects of photodynamic therapy and cryotherapy in the treatment of oral leukoplakia. The first group, treated by photodynamic therapy (δ-aminolevulinic acid (ALA), 630-635 nm wavelength), consisted of 48 patients suffering from leukoplakia. The second group consisted of 37 patients treated using cryotherapy. Analyses and comparisons of the complete responses, recurrences, numbers of procedures and adverse effects after both PDT and cryotherapy were obtained. In the first group, a complete response was obtained in 35 patients (72.9%), with thirteen recurrences observed (27.1%) over a six-month period. In the second group, a complete response was obtained in 33 patients (89.2%), and recurrence was observed in nine patients (24.3%). Photodynamic therapy and cryotherapy appear to be comparative methods of treatment that may both serve as alternatives for the traditional surgical treatment of oral leukoplakia. The advantages of PDT are connected with minimally invasive and localized character of the treatment and with not damage of collagenous tissue structures, therefore normal cells will repopulate these arrangements. PDT is more convenient for patients, less painful, and more esthetic.

Photodynamic therapy in the management of pre-malignant head and neck mucosal dysplasia and microinvasive carcinoma

The management of head and neck mucosal dysplasia and microinvasive carcinoma is an appealing strategy to prevent the development of invasive carcinomas. While surgery remains the standard of care, photodynamic therapy (PDT) offers several advantages including the ability to provide superficial yet wide field mucosal ablative treatment. This is particularly attractive where defining the extent of the dysplasia can be difficult. PDT can also retreat the mucosa without any cumulative fibrotic complications affecting function. To date, clinical experience suggests that this treatment approach can be effective in obtaining a complete response for the treated lesion but long term follow-up is limited. Further research efforts are needed to define not only the risk of malignant transformation with PDT but also to develop site specific treatment recommendations that include the fluence, fluence rate and light delivery technique.

Local drug delivery for oral mucosal diseases: challenges and opportunities

There are few topical formulations used for oral medicine applications most of which have been developed for the management of dermatological conditions. As such, numerous obstacles are faced when utilizing these preparations in the oral cavity, namely enzymatic degradation, taste, limited surface area, poor tissue penetration and accidental swallowing. In this review, we discuss common mucosal diseases such as oral cancer, mucositis, vesiculo-erosive conditions, infections, neuropathic pain and salivary dysfunction, which could benefit from topical delivery systems designed specifically for the oral mucosa, which are capable of sustained release. Each condition requires distinct penetration and drug retention profiles in order to optimize treatment and minimize side effects. Local drug delivery may provide a more targeted and efficient drug-delivery option than systemic delivery for diseases of the oral mucosa. We identify those mucosal diseases currently being treated, the challenges that must be overcome and the potential of novel therapies. Novel biological therapies such as macromolecular biological drugs, peptides and gene therapy may be of value in the treatment of many chronic oral conditions and thus in oral medicine if their delivery can be optimized.

5-aminolevulinic acid induce apoptosis via NF-κB/JNK pathway in human oral cancer Ca9-22 cells

BACKGROUND

5-aminolevulinic acid-based photodynamic therapy (5-ALA-PDT) is being used to treat oral pre-cancerous and cancerous lesions with some encouraging clinical outcomes. However, the exact mechanisms behind the photodynamic treatment are still not fully elucidated.

METHOD

  Flow cytometry, TdT-mediated dUTP nick end labeling assay and Western blot analysis were used to investigate the effects of 5-ALA-PDT on human oral cancer Ca9-22 cells.

RESULTS

We found that 5-ALA-PDT induces apoptosis in Ca9-22 cells. Western blotting showed that 5-ALA-PDT activates both the caspase-8 and caspase-9 pathways, which differed from previous studies conducted in other cell types. Activation of JNK was evident as early as 30 min. The caspases activation was inhibited by JNK inhibitor SP600125. Treatment with NF-κB inhibitor Bay 11-7082 (Bay) completely abrogated ALA-PDT-induced JNK activation. In addition, Bay and SP600125 almost completely abolished ALA-PDT-induced apoptosis.

CONCLUSION

These results demonstrate significant involvement of caspase-8 and -9 and their upstream NF-κB-JNK pathways in ALA-PDT-induced apoptosis. Future studies on how NF-κB and JNK activity regulate ALA-PDT response should provide a better strategy for the treatment of oral cancer.

A review of the nonsurgical treatment of oral leukoplakia

The aim of this paper was to assess the nonsurgical treatment of oral leukoplakia (OL). A medline search from 1983 to 2009 was conducted. The topical or systemic nonsurgical treatments or combination of both was reviewed. The primary outcomes of interest were clinical resolution, malignant transformation, follow-up, and recurrence of OL. Studies showed a rate higher than 50% of clinical resolution with photodynamic therapy, beta-carotene, lycopene, or vitamin A. Few studies reported rates of recurrence from 5 to 67% and of malignant transformation from 8 to 23%. There is a lack of randomized clinical trials that assess the effectiveness of nonsurgical treatment of OL. At this time, randomized controlled trials for nonsurgical treatment of OL demonstrate no evidence of effective treatment in preventing malignant transformation and recurrence. It reinforces that even after clinical resolution, OL should be regularly followed.