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

Clinical evaluation of photodynamic therapy for oral leukoplakia: a retrospective study of 50 patients

BACKGROUND

Topical photodynamic therapy (PDT) has demonstrated encouraging results in the treatment of oral leukoplakia (OLK). However, data on the clinical efficacy of PDT in Chinese patients with OLK are still limited.

METHODS

Fifty patients diagnosed with OLK were enrolled, including patients with various dysplastic tissues. All patients received topical PDT with 5-aminolevulinic acid (5-ALA) as a photosensitizer. Clinical efficacy was evaluated 4 weeks after treatment. Follow-up was performed every 3 months during the first year and every 6 months during the second year.

RESULTS

The overall response rate was 68% (34/50): 12% (n = 6) complete and 56% (n = 28) partial responses. Aneuploidy was reduced in the patients with dysplastic lesions. Oral pain and local ulcers developed in 52% of the patients (n = 26). Patients with a long history of OLK including hyperplasia and dysplastic lesions, as well as those with non-homogenous lesions, were more likely to develop pain and ulcer. During follow-up, the recurrence rate of hyperplasia and dysplastic lesions was 32% (n = 16) and the malignant transformation rate of dysplastic lesions was 4% (n = 2). Lesions on the buccal mucosa were associated with recurrence (P = 0.044; OR: 0.108, 95% CI: 0.013-0.915).

CONCLUSION

Topical 5-ALA-mediated PDT is an effective treatment for OLK, particularly for homogenous leukoplakia, with few side effects. The buccal mucosa may be a protective factor that can reduce recurrence.

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).

Developmental synergism in the management of oral potentially malignant disorders

Oral potentially malignant disorders (OPMDs) are associated with an increased risk of occurrence of cancers of the oral cavity or lips. The unifying theme of OPMDs is their potential risk for cancer development. Therefore, the primary objective of the management should be to prevent carcinogenesis. Beyond diagnosis, current strategies for the management of OPMDs predominantly include non-surgical and surgical interventions and a "watch-and-see" approach, such as disease monitoring or surveillance, and preventive strategies. Though no optimal clinical treatment has gained universal approval for reducing or preventing malignant development of OPMDs. Therefore, an urgent need exits for improved treatment properties and effective predictive markers for OPMDs treatment. This review aims to outline recent synergism regarding to the management of OPMDs. Developing new technologies and improved application parameters to promote the treatment efficacy and a novel management prescription approach to OPMDs are proposed.

Chlorin e6: A Promising Photosensitizer in Photo-Based Cancer Nanomedicine

Conventional cancer treatment modalities are often associated with major therapeutic limitations and severe side effects. Photodynamic therapy is a localized noninvasive mode of treatment that has given a different direction to cancer research due to its effectivity against a wide range of cancers and minimal side effects. A photosensitizer is the key component of photodynamic therapy (PDT) that generates cytotoxic reactive oxygen species to eradicate cancer cells. As the therapeutic effectivity of PDT greatly depends upon the photosensitizer, great efforts have been made to search for an ideal photosensitizer. Chlorin e6 is a FDA approved second generation photosensitizer that meets the desired clinical properties for PDT. It is known for its high reactive oxygen species (ROS) generation ability and anticancer potency against many types of cancer. Hydrophobicity is a major drawback of Ce6 that leads to its poor biodistribution and rapid clearance from the circulatory system. To overcome this drawback, researchers have designed and fabricated several types of nanosystems, which can enhance Ce6 solubility and thereby enhance its bioavailability. These nanosystems also improve tumor accumulation of Ce6 by selectively targeting the cancer cells through passive and active targeting. In addition, Ce6 has been employed in many combination therapies like chemo-photodynamic therapy, photoimmunotherapy, and combined photodynamic-photothermal therapy. A combination therapy is more curative than a single therapy due to the synergistic effects of individual therapies. Ce6-based nanosystems for combination therapies have shown excellent results in various studies and provide a promising platform for cancer treatment.

A nanomedicine enables synergistic chemo/photodynamic therapy for pancreatic cancer treatment

Pancreatic cancer is one of the leading causes of cancer-related deaths worldwide. Gemcitabine (Gem) has been a key chemotherapy agent for pancreatic cancer treatment by suppressing cell proliferation and inducing apoptosis. However, the overexpression of inhibitors of apoptosis (IAP) family of proteins during the carcinogenesis of pancreatic cancer can develop resistance to chemotherapy treatment and result in poor efficacy. To achieve the synergistic combinations of multiple strategies for this dismal disease, we developed a robust nanomedicine system, consisting of a photodynamic therapeutic agent (chlorine e6, Ce6) and a pro-apoptotic peptide-Gem conjugate. To have spatiotemporally controlled drug release, the pro-apoptotic peptide-Gem conjugate was designed to have a vinyldithioether linker that was sensitive to reactive oxygen species (ROS). The nanomedicine was fabricated by the direct self-assembly of the pro-apoptotic peptide-Gem conjugate with Ce6. After being delivered into tumors, the nanomedicine disassembled and rapidly released Gem, Ce6, and the pro-apoptotic peptide upon light illumination (660 nm). Both in vitro and in vivo studies in pancreatic cancer models confirmed the tumor inhibition efficacy with low systemic toxicity to animals.

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.

Multifunctional photodynamic/photothermal nano-agents for the treatment of oral leukoplakia

Oral leukoplakia (OLK) has gained extensive attention because of the potential risk for malignant transformation. Photosensitizers (PSs) played an indispensable role in the photodynamic therapy (PDT) of OLK, but the poor light sensitivity greatly hampered its clinical application. Herein, a novel organic photosensitive ITIC-Th nanoparticles (ITIC-Th NPs) were developed for OLK photodynamic/photothermal therapy (PTT). ITIC-Th NPs present both high photothermal conversion efficiency (~ 38%) and suitable reactive oxygen species (ROS) generation ability under 660 nm laser irradiation, making them possess excellent PDT and PTT capability. In 4-nitroquinoline 1-oxide (4NQO)-induced oral precancerous animal models, ITIC-Th NPs effectively suppress the OLK's cancerization without apparent topical or systemic toxicity in vivo. This study offers a promising therapeutic strategy for PDT and PTT in OLK treatment, and this study is the first interdisciplinary research in the field of multimodal therapy for OLK.

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.

Successful treatment of chronic hyperplastic candidiasis with 5-aminolevulinic acid photodynamic therapy: A case report

Chronic hyperplastic candidiasis (CHC) is a chronic oral mucosal infection caused by Candida. Refractory hyperplastic lesions may lead to epithelial dysplasia and carcinogenesis. Traditional surgical resection may cause irreversible damage and effect the patient's quality of life. This paper reports the case of a 63-year-old man with CHC. After routine treatment, local hyperplastic lesions remained. Photodynamic therapy with ALA was applied to the hyperplastic lesions and yielded satisfactory results, with no recurrence at 1 year. This case report describes a promising, effective method for the treatment of CHC.

Ablative fractional laser-assisted photodynamic therapy vs. ablative fractional laser for oral leukoplakia treatment: A randomized, controlled pilot study

BACKGROUND

Ablative fractional laser-assisted photodynamic therapy (AFL-PDT) is explored as an effective method in some premalignant diseases, whereas the effect of AFL-PDT on oral leukoplakia (OL), the best-known precursor of oral squamous cell carcinoma, remains undetermined.

METHODS

Forty-eight patients, histologically diagnosed with OL, were randomized (1:1) to receive either AFL-PDT or ablative fractional laser (AFL) treatment. All patients were followed up at 1, 3, 6 and 12 months postoperatively. The primary endpoints of efficacy and clinical recurrence and the secondary endpoint of side effects were assessed.

RESULTS

Forty-four patients completed the study. The 100% effective cure rate in the AFL-PDT group was higher than that in AFL group (80.9%, P<0.05) with 19.1% difference (95%CI: 0.7-40.0%). Compared to AFL group, recurrence observed at 6 and 12 months post-treatment tended to occur in fewer patients in the AFL-PDT group (P<0.05). No severe adverse events or systemic side effects were observed in either group.

CONCLUSIONS

AFL-PDT may effectively reduce recurrence of OL with high clinical efficacy and good tolerability, suggesting it may be a promising treatment for OL.

Human papillomavirus, Epstein-Barr virus, and Candida albicans co-infection in oral leukoplakia with different degrees of dysplasia

OBJECTIVES

To identify human papillomavirus (HPV), Epstein-Barr virus (EBV), and Candida albicans in oral leukoplakia with different degrees of dysplasia.

MATERIALS AND METHODS

An observational, cross-sectional, descriptive study was performed using 30 formalin-fixed and paraffin-embedded tissues from patients with clinical suspicion of leukoplakia and confirmed diagnosis of oral dysplasia. Histological analyses were performed by two pathologists (interobserver) and dysplasias were classified as mild, moderate, or severe. Conventional PCR was used to detect HPV and EBV viruses and C. albicans. To determine the association between each microorganism with different degrees of dysplasia a Chi-square test was employed.

RESULTS

The tongue was the most common site for leukoplakias (71.4%) in females with a mean age of 50 years (ranging between 30 to 50 years old; 57.1%). EBV was the most frequently detected (73.3%), followed by HPV (43.3%), mainly of type 16 (40%), and C. albicans (23.3%). Significant differences were observed between degrees of dysplasia and HPV presence (p = 0.005). In lesions positive for HPV, EBV, and C. albicans the most frequent histological changes were hyperkeratosis, irregular interpapillary ridges, and loss of basal stratum cell polarity.

CONCLUSION

Co-infection with human papillomavirus, Epstein Barr virus, and Candida albicans in oral leukoplakia could be associated with dysplastic changes.

Sublingual administration of 5-aminolevulinic acid for laser-induced photodiagnostics and photodynamic therapy of oral cavity and larynx cancers

BACKGROUND

The study aimed to develop a method for sublingual administration of 5-aminolevulinic acid to patients and evaluate its effectiveness in fluorescence diagnostics and photodynamic therapy of neoplasms of the oral cavity and larynx.

METHODS

The boundaries of the neoplasms were established by the video-fluorescence diagnostics and clarified using spectral-fluorescent diagnosis before and after photodynamic therapy.

RESULTS

The fluorescence diagnostics demonstrated a high accumulation of protoporphyrin IX, induced by sublingual administration of 5-aminolevulinic acid to patients before the photodynamic therapy and photobleaching of protoporphyrin IX in pathologically altered tissues after the photodynamic therapy. Glucose contained in the sublingual dose supports active transport of 5-ALA into the cells. It increases the PpIX accumulation in the cells, therefore improving the PD and PDT efficacy.

CONCLUSION

The study and the initially obtained results demonstrated the possibility and effectiveness of laser-induced photodiagnostics and photodynamic therapy with sublingual administration of 5-ALA to patients with premalignant lesions of the oral cavity and larynx. It can eliminate the threat of the transformation of these diseases into malignant tumors and prevent the need for surgical treatment.

Management of oral leukoplakia: a position paper of the Society of Oral Medicine, Chinese Stomatological Association

OBJECTIVE

The objective of this study was to develop the first edition of a Chinese evidence-based position paper on the management of oral leukoplakia (OLK).

STUDY DESIGN

The consultant group for drafting the position paper consisted of 31 oral medicine specialists and 2 evidence-based medicine specialists. English studies (searched in PubMed, EMBASE, and the Cochrane Library) and Chinese studies (searched in China National Knowledge Infrastructure and WanFang) published before January 2018 were used. The quality of the study was assessed using the Grading of Recommendations Assessment, Development, and Evaluation grid, and the strength of the recommendations was determined based on the results of 3 rounds of voting among the consultant group members using the Delphi method.

RESULTS

Twenty-two evidence-based guidelines for clinical management and monitoring of OLK were established in this position paper. A clinical path diagram for oral health practitioners was constructed based on the recommendations.

CONCLUSION

Current evidence suggests that management and monitoring of patients with OLK should be performed by experienced clinicians to control the lesion and for early detection of malignant transformation. However, all recommendations are based on evidence of low or extremely low quality and may require further modification as new evidence is produced.

Topical photodynamic therapy in the treatment of benign oral mucosal lesions: A systematic review

BACKGROUND

The introduction of photodynamic therapy (PDT) in various branches of the dental field such as endodontics, implantology, periodontology, and restorative dentistry and oral medicine has become useful in recent decades. This systematic review presents an overview of the literature to evaluate the usefulness of topical PDT for the treatment of benign oral soft tissue lesions and to identify limitations in prior studies to improve PDT applications.

METHODS

We performed a review of the literature using different search engines (PubMed, ISI Web of Science, and the Cochrane Library) employing MeSH terms such as "Photodynamic therapy" and "PDT" in conjunction with other terms. We utilized the Population, Intervention, Comparison, Outcomes, and Study design (PICOS) method to define our study eligibility criteria.

RESULTS

Initial results were 1513. Finally, there were only 21 studies that met our selection criteria. We divided the 21 selected items into two groups: inflammatory diseases and infective diseases.

CONCLUSIONS

Although topical PDT is an easy to perform and well-tolerated treatment and appears to be a valid method with promising results in the treatment of benign lesions of the oral cavity's soft tissues, further studies are needed to complete the current knowledge of this technique.

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.

Photoactive Liposomal Formulation of PVP-Conjugated Chlorin e6 for Photodynamic Reduction of Atherosclerotic Plaque

Background: Liposomes serve as delivery systems for biologically active compounds. Existing technologies inefficiently encapsulate large hydrophilic macromolecules, such as PVP-conjugated chlorin e6 (Photolon). This photoactive drug has been widely tested for therapeutic applications, including photodynamic reduction of atherosclerotic plaque. Methods: A novel formulation of Photolon was produced using “gel hydration technology”. Its pharmacokinetics was tested in Sus scrofa f. domestica. Its cellular uptake, cytotoxicity, and ability to induce a phototoxic reaction were demonstrated in J774A.1, RAW264.7 macrophages, and vascular smooth muscle (T/G HA-VSMC) as well as in vascular endothelial (HUVEC) cells. Results: Developed liposomes had an average diameter of 124.7 ± 0.6 nm (polydispersity index (PDI) = 0.055) and contained >80% of Photolon). The half-life of formulation in S. scrofa was 20 min with area under the curve (AUC) equal to 14.7. The formulation was noncytotoxic in vitro and was rapidly (10 min) and efficiently accumulated by macrophages, but not T/G HA-VSMC or HUVEC. The accumulated quantity of photosensitizer was sufficient for induction of phototoxicity in J774A.1, but not in T/G HA-VSMC. Conclusions: Due to the excellent physical and pharmacokinetic properties and selectivity for macrophages, the novel liposomal formulation of Photolon is a promising therapeutic candidate for use in arteriosclerosis treatment when targeting macrophages but not accompanying vascular tissue is critical for effective and safe therapy.

Photodynamic therapy for oral potentially malignant disorders

To assess the impact of photodynamic therapy (PDT) parameters in the management of oral potentially malignant disorders (OPMDs). We conducted a systematic review and meta-analysis of studies that assessed the curative effect of PDT published in PubMed and Embase until Dec 2018. Random or fixed effects models for pooled estimates calculation were used. A pooled estimate calculation revealed that lesion size decreased by 1.38 cm² (95% CI: 0.39-2.36) after PDT, and the overall complete response (CR) was 0.52 (95% CI: 0.36-0.68), while partial response (PR) reached 0.82 (95% CI: 0.74-0.88). Subgroup analyses revealed that the lesion response (CR: 0.21 [95% CI: 0.12-0.33]) of oral lichen planus was worse than that of other disease entities. 20% aminolevulinic acid was more effective than other photosensitizers, with the overall CR was 0.68 (95% CI: 0.42-0.86), while the PR was 0.88 (95% CI: 0.76-0.94). Topical use of photosensitizers can yield desirable results, while gargling methylene blue yields poor response (0.82 [95% CI: 0.75-0.88] vs. 0.59 [95% CI: 0.44-0.72], respectively). PDT is an effective treatment modality in the management of OPMDs, the overall efficacy of which is influenced by several factors.

Photodynamic therapy guidelines for the management of oral leucoplakia

With recent developments in photosensitizers and light delivery systems, topical 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) has become the fourth alternative therapeutic approach in the management of oral leucoplakia (OLK) due to its minimally invasive nature, efficacy, and low risk of systemic side effects and disfigurement. This report presents step-by-step guidelines for applying topical ALA-PDT in the management of OLK based on both the clinical experience of the authors and a systematic review of the current literature. Studies using protocols with standardized parameters and randomized clinical trials at multiple centres with adequate sample sizes and both interim and long-term follow-ups are needed before universally applicable guidelines can be produced in this field.

Porphyrinoids in photodynamic diagnosis and therapy of oral diseases

Photodynamic methods have found application not only in the treatment process as photodynamic therapy but also for the early detection of neoplastic lesions and tumors as photodynamic diagnosis. Early detection of the disease allows not only to avoid the patient’s lifetime risk but also significantly reduce the costs of anticancer therapy, which are increasing every year. There is a constant search for new and more effective photosensitizers which will provide safety in therapy while maintaining efficiency. This paper summarizes recent reports focused on the photodynamic diagnosis of oral cancers. Moreover, it shows methods of the photodynamic treatment of oral verrucous hyperplasia, erythroleukoplakia, and oral leukoplakia. The treatment of choice for these diseases is a surgical excision, which always leads to scar formation. Photodynamic therapy provides a new scar-less tool for the treatment.

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.

Photodynamic therapy mediated by chlorin-type photosensitizers against Streptococcus mutans biofilms

Photodynamic therapy (PDT) can be used for the control of oral pathogens and different photosensitizers (PS) have been investigated. This study evaluated the efficacy of PDT against Streptococcus mutans biofilms using two second-generation PS derived from chlorin: Photoditazine® (PDZ) and Fotoenticine® (FTC). These PS were compared to methylene blue (MB), a dye with proven antimicrobial activity against S. mutans. Suspensions of S. mutans were cultured in contact with bovine tooth disks for biofilm formation. After 48 h, the biofilms were treated with PDZ (0.6 mg/mL), FTC (0.6 mg/mL) or MB (1 mg/mL) and submitted to laser irradiation (660 nm, 50 mW/cm²). The biofilms were quantified by the determination of CFU/mL count and analyzed by scanning electron microscopy (SEM). All PS used for PDT reduced the number of S. mutans, with a statistically significant difference compared to the untreated groups. PDT achieved microbial reductions of 4 log with MB and 6 log with PDZ, while the use of FTC resulted in the complete elimination of S. mutans biofilms. SEM analysis confirmed the CFU/mL results, showing that all PS, particularly FTC, were able to detach the biofilms and to eliminate the bacteria. In conclusion, PDT mediated by chlorin-type PS exhibited greater antimicrobial activity against S. mutans than MB-mediated PDT, indicating that these PS can be useful for the control of dental caries.

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.

Endoscopic ultrasonography-guided tumor ablation

Real-time guidance of needle advancement has transformed endoscopic ultrasound (EUS) from a diagnostic to an interventional procedure. EUS-guided fine-needle puncture has application in various interventional procedures (drainage of pseudocyst, biliary intervention, and injection of drugs). Celiac plexus or ganglion neurolysis for pain control is the major current EUS-guided fine-needle injection procedure. Feasibility and safety to accurately position needle devices and/or inject under real-time EUS imaging with precise delivery of interventional agent have expanded the use of EUS to ablate tumors. These include radiofrequency ablation, or delivery of fiducial markers, potential antitumor agents, or radioactive seeds, in the cancer mass. Minimally invasive EUS-guided antitumor therapy is primarily used for pancreatic cancer because of better anatomic access (vs other imaging modality) and the dismal prognosis (despite improvements in surgery and chemoradiation). Also, the response to parenteral chemotherapy in pancreatic cancer is poor because of suboptimal drug delivery resulting from hypovascularity and abundant desmoplasia. Other targets for EUS-guided tumor ablation are pancreatic neuroendocrine tumor and pancreatic cyst lesion, which are less aggressive and curable by resection. However, patients non-eligible for surgery may benefit from local EUS-guided ablation.

Photodynamic therapy in the upper aerodigestive tract. Overview and outlook

The gold standard in the treatment of (pre)malignancies of the upper aerodigestive tract (UADT) is either surgery or (chemo)radiotherapy. Nevertheless, there are special indications where an alternative treatment, such as photodynamic therapy (PDT), might be as effective for and better tolerated by the patients concerned. This article aims to present a contemporary and comprehensive review on the role of photodynamic therapy in the treatment of (pre)malignancies of the UADT. PubMed was searched for "photodynamic therapy larynx/oral cavity/oropharynx/head and neck" in 01/2016. PDT can be efficient in the treatment of recurrent, residual or multiple carcinomas of the UADT without other treatment options. It has also been used with success in the treatment of early oral or laryngeal carcinomas, widespread precancerous lesions or "difficult-to-treat" skin cancer, even though these treatments are off-label. For now, unsolved scientific and economical challenges hinder the methods spread. In special cases, PDT is a highly effective method to treat head and neck (pre)malignancies. Nevertheless, further clinical studies are needed to better define its true value in head and neck oncology.

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.

Precancerous lesions of oral mucosa

Precancerous lesions of oral mucosa, known as potentially malignant disorders in recent years, are consists of a group of diseases, which should be diagnosed in the early stage. Oral leukoplakia, oral submucous fibrosis, and oral erythroplakia are the most common oral mucosal diseases that have a very high malignant transformation rate. Oral lichen planus is one of the potentially malignant disorders that may be seen in six different subtypes including papular, reticular, plaque-like, atrophic, erosive, and bullous type, clinically. Atrophic and erosive subtypes have the greater increased malignant transformation risk compared to another subtypes. Although there are various etiological studies, the etiology of almost all these diseases is not fully understood. Geographically, etiologic factors may vary. The most frequently reported possible factors are tobacco use, alcohol drinking, chewing of betel quid containing areca nut, and solar rays. Early diagnosis is very important and can be lifesaving, because in late stages, they may be progressed to severe dysplasia and even carcinoma in situ and/or squamous cell carcinoma. For most diseases, treatment results are not satisfactory in spite of miscellaneous therapies. While at the forefront of surgical intervention, topical and systemic treatment alternatives such as corticosteroids, calcineurin inhibitors, and retinoids are widely used.

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.