Class IV laser therapy as treatment for chemotherapy-induced oral mucositis in onco-haematological paediatric patients: a prospective study

Effect of Photobiomodulation on Salivary Nitrite in Patients with Chemotherapy-Induced Oral Mucositis: A Randomized Clinical Trial

Background: Oral mucositis (OM) is a severe inflammatory and ulcerative condition of the oral mucosa commonly induced by chemotherapy. Photobiomodulation (PBM) therapy has been proposed for preventing and treating OM. However, the understanding of light interaction with biological tissues and the variability in light sources and protocols limit its widespread application. This study aimed to evaluate the impact of PBM on salivary nitrite levels, a marker of oxidative stress associated with inflammation and tissue damage. Materials and Methods: This prospective, randomized, double-blind clinical trial included 45 patients, evenly divided into three age- and sex-matched groups. Group 1 received basic oral care instructions prior to chemotherapy. Group 2 received these instructions plus PBM using a 650 nm intraoral diode laser. Group 3 received basic oral care instructions combined with PBM using both a 650 nm intraoral diode laser and a 980 nm extraoral diode laser. OM severity was assessed using World Health Organization criteria, and salivary nitrite levels were measured using the Griess reagent kit (Biotium®) according to the manufacturer's instructions 1 and 2 weeks after the first chemotherapy session. Results: Our study included 45 patients who were evenly distributed into three groups, matched for age, sex, tumor type, and type of chemotherapy. Significant differences in OM severity were observed among the groups at both 1 and 2 weeks (p = 0.000). Salivary nitrite levels also showed significant differences between groups at these time points (p = 0.00). Significant differences were found between the control group and both laser treatment groups, but no significant difference was noted between the two laser treatment groups. Conclusions: PBM effectively reduces OM severity, whether used intraorally alone or combined with extraoral application. This effect is likely due to PBM's ability to lower salivary nitrite levels, indicating reduced oxidative stress and inflammation.

Oral mucositis assessment in pediatric and adolescent oncological patients: A systematic review

Oral mucositis (OM) is a prevalent acute adverse effect of various cancer treatments. Accurate assessment of OM is vital for effective prevention and treatment strategies. However, a lack of validated pediatric instruments for evaluating OM can lead to unreliable data, and hinder interventional and epidemiological research. This study aims to evaluate the methods used for assessing OM in pediatric oncology patients. A systematic review of four databases and a manual search yielded 113 articles. Nine different scales were identified, with the World Health Organization (WHO) scale being the most commonly used (61.9%). The Children's International Mucositis Evaluation Scale (ChIMES) was used in 7.9% of the studies. Of the 8155 pediatric patients evaluated, 47.7% had both hematological malignancies and malignant solid tumors, while 46% had solely hematological malignancies. Despite the prevalence of the WHO scale, it lacks pediatric-specific criteria. Future OM research should incorporate validated tools like ChIMES for improved pediatric assessment.

Underexplored Areas of Photobiomodulation in Oral Oncology: An Expert Analysis

Objective: This study aimed to review the current body of literature on underexplored areas of photobiomodulation (PBM) for preventing and/or treating oral adverse events. Background: Recent studies suggest that PBM may offer potential benefits in managing cancer-related toxicities other than oral mucositis. Nevertheless, further research to establish conclusive evidence is still missing. Methods: A panel of specialists conducted a narrative review to evaluate the evidence on PBM therapy for oral mucositis, xerostomia, dysgeusia, dysphagia, and trismus/fibrosis. Each topic was reviewed by two specialists who discussed treatment rationale, summarized current evidence, evaluated risk/benefit ratio, and identified future research directions. Results: The current evidence suggests promising outcomes in nonroutine uses of PBM for xerostomia, dysgeusia, odynophagia, oral mucositis (extraoral PBM and the pediatric population), and trismus/fibrosis. However, the primary studies are often small and may have biases that require further evaluation, particularly regarding treatment safety. Conclusion: Despite the overall positive impression of PBM therapy for oral adverse events of cancer treatment, robust evidence from large multicentered studies is necessary to support its widespread clinical use.

Photobiomodulation therapy: Ushering in a new era in personalized supportive cancer care

The human body can utilize light for a broad range of pathophysiological responses, such as circadian rhythm, Vitamin D metabolism, and vision, among others. The therapeutic use of light has spanned many ancient health practices. Recent advances in using low-dose light therapy, termed photobiomodulation (PBM), have made tremendous progress in unravelling precise biological mechanisms and clinical dosimetry, enabling this treatment modality's clinical safety and effectiveness. The evidence for PBM has received its strongest endorsement via recent systematic reviews and meta-analyses recommending its routine use to address various acute and chronic side effects associated with cancer treatment. Carefully done studies have noted unequivocal evidence demonstrating its effectiveness in managing oral mucositis in patients undergoing radiotherapy for head and neck cancer, chemotherapy, or hematopoietic stem cell transplantation. This brief narrative review will explore the therapeutic benefits of PBM therapy, supported by recent research findings, to provide a comprehensive understanding of its potential in clinical settings. Additionally, the review will highlight our current understanding of molecular mechanisms underlying PBM and the importance of novel harmonized dosing that enables its optimal clinical implementation and utilization.

High-power laser photobiomodulation therapy for immediate pain relief of refractory oral mucositis

PURPOSE

We aimed to evaluate the efficacy of high-power (class IV) laser photobiomodulation (PBM) therapy for immediate pain relief due to oral mucositis (OM) refractory to recommended first-line therapy.

METHODS

This retrospective study included 25 cancer patients with refractory chemotherapy- or radiotherapy-induced OM (16 and 9 patients, respectively) that were treated for pain relief with an intraoral InGaAsP diode laser (power density = 1.4 W/cm2). Pain was self-assessed immediately before and after laser treatment using a 0-to-10 numeric rating scale ([NRS], "0" = no pain, "10" = intolerable pain).

RESULTS

Patients reported an immediate decrease in pain following 94% (74 of 79) of the PBM sessions, in 61% (48 sessions) the pain reduction was over 50%, and in 35% (28 sessions) the initial pain was completely eliminated. There were no reports of increased pain post-PBM. For chemotherapy and radiotherapy-treated patients, mean reduction in pain NRS post-PBM was 4.8 ± 2.5 (p < 0.001) and 4.5 ± 2.8 (p = 0.001), indicating a post-PBM reduction of 72% and 60% of the initial pain level, respectively. The analgesic benefit of PBM remained for a mean of 6.0 ± 5.1 days. One patient reported a transient burning sensation after one PBM session.

CONCLUSIONS

High-power laser PBM may provide nonpharmacologic, patient-friendly, long-lasting, rapid pain relief for refractory OM.

Preventive versus curative photobiomodulation for oral mucositis in patients with multiple myeloma undergoing hematopoietic stem cell transplantation: which approach is more effective?

PURPOSE

There is increasing evidence that photobiomodulation (PBM) therapy is both an effective and safe approach in hematopoietic stem cell transplantation (HSCT) for both prevention and management of oral mucositis (OM), but its use in clinical practice is still limited and the timing of application is under discussion. The aim of this retrospective study was to evaluate possible differences between patients treated either with preventive or curative PBM therapy.

METHODS

The retrospective case series included 24 patients suffering from multiple myeloma who underwent the same conditioning and transplantation protocol. Patients were treated either with preventive PBM starting from the first day of conditioning up to two days post-HSCT or with curative PBM (starting at OM onset for four consecutive days). OM score, pain, and functional parameters were recorded.

RESULTS

All patients developed OM. Preventive PBM was significantly more effective in reducing OM severity (p < 0.0001) and pain (p < 0.0001) post-HSCT than curative PBM. Furthermore, we found a lower number of patients reporting discomfort in all subjective parameters (pain during swallowing, chewing, and speaking) in the preventive PBM group. No adverse events related to PBM therapy were recorded in both groups.

CONCLUSION

The timing for PBM therapy in patients undergoing HSCT is crucial: when started on the first day of conditioning, it significantly reduces both pain and OM severity, providing an important benefit also in subjective oral functions such as speaking, swallowing, and chewing, thus increasing the overall adherence to the oncological therapies.

[Photobiomodulation in the prevention and the management of side effects of cancer treatments: Bases, results and perspectives]

BACKGROUND

Assess the current and potential indications of photobiomodulation (PBM) therapy and their level of evidence in the prevention or treatment of side effects related to oncology treatments (radiation therapy, and to a minimal extent favored and hematopoietic stem cell transplants). And report on the recommended modalities (parameters and doses) of PBM therapy.

MATERIALS AND METHODS

The Embase, Medline/PubMed, Cochrane, EBSCO, Scopus, and LILACS databases were systematically reviewed to include and analyze publications of clinical studies that evaluated PBM in the prevention or management side effects related to cancer treatments. The keywords used were "photobiomodulation"; "low level laser therapy"; "acute oral mucositis"; "acute dysphagia"; "acute radiation dermatitis"; "lymphedema"; "xerostomia"; "dysgeusia"; "hyposalivation"; "lockjaw"; "bone necrosis"; "osteoradionecrosis"; "radiation induced fibrosis"; "voice and speech alterations"; "palmar-plantar erythrodysesthesia"; "graft versus host disease"; "peripheral neuropathy"; "chemotherapy induced alopecia". Prospective studies were included, while retrospective cohorts and non-original articles were excluded from the analysis.

RESULTS

PBM in the red or infrared spectrum has been shown to be effective in randomized controlled trials in the prevention and management of certain complications related to radiotherapy, in particular acute mucositis, epitheliitis and upper limb lymphedema. The level of evidence associated with PBM was heterogeneous, but overall remained moderate. The main limitations were the diversity and the lack of precision of the treatment protocols which could compromise the efficiency and the reproducibility of the results of the PBM. For other effects related to chemo/radiation therapy (dysgeusia, osteonecrosis, peripheral neuropathy, alopecia, palmar-plantar erythrodysaesthesia) and haematopoietic stem cell transplantation (graft versus host disease), treatment with PBM suffers from a lack of studies or limited studies at the origin of a weakened level of proof. However, based on these results, it was possible to establish safe practice parameters and doses of PBM.

CONCLUSION

Published data suggest that PBM could therefore be considered as supportive care in its own right for patients treated with radiation, chemotherapy, immunotherapy, hormone therapy or targeted therapies, whether in clinical practice or clinical trials. therapies. However, until solid data have been published on its long-term safety, the use of PBM should be considered with caution and within the recommended parameters and doses, particularly when practiced in areas of known or possible tumours. In this case, the patient should be informed of the theoretical benefits and risks of PBM in order to obtain informed consent before treatment.

Preconditioning with Photobiomodulation as an Effective Method in Preventing Chemotherapy-Induced Oral Mucositis: A Systematic Review

Background: Given the suffering experienced by cancer patients, effective solutions must be found to prevent the most painful and debilitating side effects of anticancer treatment. The use of photobiomodulation (PBM) with specific parameters has been proposed to prevent oral mucositis in adults undergoing hematopoietic stem cell transplantation as well as in head and neck cancer patients receiving radiotherapy alone without chemotherapy. No recommendations were possible for patients undergoing chemotherapy alone. This systematic review aims to analyze the effectiveness of preconditioning by PBM in preventing chemotherapy-induced oral mucositis. Methods: This study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, PRISMA, Checklist and registered at the International Prospective Register of Systematic Reviews (PROSPERO). We searched and identified articles of the subsequent bibliographic databases: PubMed and Cochrane. Revised Cochrane risk-of-bias tool for randomized trials (RoB 2.0) was used to assess the risk of bias of studies included in this review. Results: There were only six clinical trials examining the efficacy of PBM therapy in the primary prevention of chemotherapy-induced oral mucositis. All of the studies used lasers, except for one study that compared lasers with light-emitting diodes. The wavelength ranges from 630 to 830 nm. Irradiation parameters varied among the included studies. All studies showed good results for the use of PBM in the prevention of oral mucositis except for one study that found no benefit for the laser application. Conclusions: PBM has been shown to be effective in preventing oral mucositis when applied to healthy tissues. Finding the optimal protocol has been difficult due to the variability between studies, and therefore, further well-designed, controlled, blinded studies are recommended to precisely determine irradiation parameters and the number of sessions. This review has been registered at the International Prospective Register of Systematic Reviews (PROSPERO) under number CRD42023397771.

Effect of near-infrared and blue laser light on vero E6 cells SARS-CoV-2 infection model

Photobiomodulation therapy (PBMT) employing laser light has been emerging as a safe strategy to challenge viruses. In this study the effect of blue and near-infrared (NIR) laser light was assessed in an in vitro model of SARS-CoV-2 infection. PBMT at blue wavelength inhibited viral amplification when the virus was directly irradiated and then transferred to cell culture and when cells already infected were treated. The NIR wavelength resulted less efficacious showing a minor effect on the reduction of the viral load. The cells receiving the irradiated virus or directly irradiated rescued their viability to level comparable to not treated cells. Virion integrity and antigenicity were preserved after blue and NIR irradiation, suggesting that the PBMT antiviral effect was not correlated to viral lipidic envelope disruption. Our results suggested that PBMT can be considered a valid strategy to counteract SARS-CoV-2 infection, at least in vitro.

Photobiomodulation therapy in management of cancer therapy-induced side effects: WALT position paper 2022

Disclaimer

This article is based on recommendations from the 12th WALT Congress, Nice, October 3-6, 2018, and a follow-up review of the existing data and the clinical observations of an international multidisciplinary panel of clinicians and researchers with expertise in the area of supportive care in cancer and/or PBM clinical application and dosimetry. This article is informational in nature. As with all clinical materials, this paper should be used with a clear understanding that continued research and practice could result in new insights and recommendations. The review reflects the collective opinion and, as such, does not necessarily represent the opinion of any individual author. In no event shall the authors be liable for any decision made or action taken in reliance on the proposed protocols.

Objective

This position paper reviews the potential prophylactic and therapeutic effects of photobiomodulation (PBM) on side effects of cancer therapy, including chemotherapy (CT), radiation therapy (RT), and hematopoietic stem cell transplantation (HSCT).

Background

There is a considerable body of evidence supporting the efficacy of PBM for preventing oral mucositis (OM) in patients undergoing RT for head and neck cancer (HNC), CT, or HSCT. This could enhance patients’ quality of life, adherence to the prescribed cancer therapy, and treatment outcomes while reducing the cost of cancer care.

Methods

A literature review on PBM effectiveness and dosimetry considerations for managing certain complications of cancer therapy were conducted. A systematic review was conducted when numerous randomized controlled trials were available. Results were presented and discussed at an international consensus meeting at the World Association of photobiomoduLation Therapy (WALT) meeting in 2018 that included world expert oncologists, radiation oncologists, oral oncologists, and oral medicine professionals, physicists, engineers, and oncology researchers. The potential mechanism of action of PBM and evidence of PBM efficacy through reported outcomes for individual indications were assessed.

Results

There is a large body of evidence demonstrating the efficacy of PBM for preventing OM in certain cancer patient populations, as recently outlined by the Multinational Association for Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO). Building on these, the WALT group outlines evidence and prescribed PBM treatment parameters for prophylactic and therapeutic use in supportive care for radiodermatitis, dysphagia, xerostomia, dysgeusia, trismus, mucosal and bone necrosis, lymphedema, hand-foot syndrome, alopecia, oral and dermatologic chronic graft-versus-host disease, voice/speech alterations, peripheral neuropathy, and late fibrosis amongst cancer survivors.

Conclusions

There is robust evidence for using PBM to prevent and treat a broad range of complications in cancer care. Specific clinical practice guidelines or evidence-based expert consensus recommendations are provided. These recommendations are aimed at improving the clinical utilization of PBM therapy in supportive cancer care and promoting research in this field. It is anticipated these guidelines will be revised periodically.

Photobiomodulation Treatment in Chemotherapy-Induced Oral Mucositis in Young Haematological Patients—A Pilot Study

Background and Objectives: One of the most debilitating side effects of chemotherapy is oral mucositis (OM). Photobiomodulation (PBM) demonstrates high efficacy in the management of OM. The aim of the study was to investigate the incidence of oral mucositis and evaluation of the effectiveness of PBM therapy. Materials and Methods: A total of 23 children diagnosed with leukaemia or lymphoma affected by chemotherapy-induced OM were enrolled in the study. OM grade was assessed with the World Health Organization (WHO) scale. Patients completed an approved questionnaire, and blood cell counts were read every 2 days. OM lesions were treated with class IV laser therapy with a frequency of every 48 h and density of 2, 4, 8, 16 or 30 J/cm2. The level of pain was measured with VAS scale. Results: The 23 patients developed a total of 41 OM episodes with a mean duration of 7.61 days ± 4.70. Laser therapy showed a great reduction regarding pain and a better function of patients even with neutropenia. Conclusions: Oral mucositis represents a significant burden to children. PBM brings positive aspects for patients; however, the optimal treatment parameters require further study.

Oral mucositis in paediatric cancer patients undergoing allogeneic hematopoietic stem cell transplantation preventively treated with professional dental care and photobiomodulation: Incidence and risk factors

BACKGROUND

Oral mucositis (OM) is an important side effect related to allogeneic hematopoietic stem cell transplantation (allo-HSCT), and it has been associated with a significative reduction of quality of life. A negative impact of OM in paediatric patients could result in increased use of parenteral feeding and opioids, longer periods of hospitalization, and a higher risk of systemic infection.

AIM

To investigate the clinical features and clinical outcomes associated with OM development and severity in hematological cancer paediatric patients undergoing allo-HSCT who underwent professional dental care (PDC) and photobiomodulation (PBM) as prophylactic treatment.

DESIGN

Medical data and OM presentation were retrieved retrospectively from all patients younger than 18 years who received allo-HSCT between 2013 and 2016. The incidence of OM was assessed and graded by two oral medicine specialists following the WHO guidelines, and it was correlated with clinical parameters.

RESULTS

Forty-nine consecutive paediatric patients were included. OM was diagnosed in 73.5% of patients, and in 36.1% of patients, OM was classified as severe. Acute lymphoblastic leukemia as a primary diagnosis and the use of a myeloablative regimen were associated with OM development. The primary diagnosis and use of total body irradiation (TBI) were associated with aggressive OM. Neither the incidence nor the severity of OM affected the overall survival, whereas only the use of a myeloablative regimen and a high body mass index (BMI) were determinants of lower OM-free survival rates.

CONCLUSIONS

A myeloablative conditioning and a high BMI were observed to be independent prognostic determinants of a lower OMFS rate. The cluster analysis allowed us to outline patient profiles with greater susceptibility to the development and severity of oral mucositis, which seems to be a useful tool to determine the risk of OM in paediatric patients.

Photobiomodulation as an Adjunct Therapy in Wound Healing

"Light amplification by stimulated emission of radiation" or more commonly known as Laser has become very popular in the field of dermatology and aesthetic medicine over the past decades. For the treatment of wound healing, a combination of different wavelengths for laser therapy has been introduced which includes 660, 800, and 970 nm. The aim of this study was to note wound healing utilizing photobiomodulation as an adjunct therapy by measuring the wound size in terms of length and width (area measurement). Study participants were selected randomly from a pool of patients who were attending for their routine follow-up visits in the Wound Care Unit in Hospital Kuala Lumpur. Eleven patients with chronic wounds of different etiologies, ie, diabetic foot ulcer and nonhealing ulcer, were recruited for this study . Wound assessment was done prior to cleansing using distilled water and followed by debridement if necessary. Subsequently, the laser technician and patients used protective goggles before applying a super intense continuous flow of laser with 3 wavelengths, ie, 660, 800, and 970 nm with 30 kJ of energy with the handpiece over a 3 min period whereby it is focused on the wound milieu and then rotated around the periwound area. There were 9 diabetic foot ulcers and 2 nonhealing ulcers treated with photobiomodulation as an adjunct therapy. All wounds were managed with the standard of care. Three wounds ie, 3 diabetic foot ulcers and 1 nonhealing ulcer were closed completely. Meanwhile, the other 7 ulcers are at 68.2% to 99% in terms of wound area reduction and new granulomatous tissue was present indicating high healing potential. Therefore, the photobiomodulation was effective as an adjunct in the management of diabetic foot and nonhealing ulcers in this case series. A larger sample size would be able to show the significance of this finding.

Patient Centeredness in Orthognathic Surgery

Patient centeredness in planning treatment and research has become paramount. The goal of this report was to describe a complex case in which untreated chronic pain was not properly addressed to reflect on the need to establish alternative protocols for controlling chronic orofacial pain. When a female underwent orthognathic surgery to correct her occlusion, she not only ended up with a worse occlusion, she developed chronic orofacial pain that could not be treated by opioids and only improved after the use of neuropathic medication, and finally disappeared after the use of low-level laser therapy. There is a need to incorporate alternative nonpharmacological approaches to manage chronic pain. Further, what the patient’s goals are for their treatments should be given priority in case of elective procedures.

In vitro effects of photobiomodulation therapy on 50B11 sensory neurons: evaluation of cell metabolism, oxidative stress, mitochondrial membrane potential (MMP), and capsaicin-induced calcium flow

The analgesic properties of photobiomodulation therapy (PBMT) have been raising increasing interest in the clinical community due to the positive effects observed on patients, nevertheless the mechanistic basis of its action on peripheral sensory neurons remains still elusive. In this study, the effect of near-infrared (NIR) PBMT at 800 and 970 nm of wavelength was investigated on the 50B11 immortalized nociceptive sensory neuronal cell line by evaluating capsaicin-induced calcium flow and different markers correlated to mitochondria, that is, ATP, reactive oxygen species (ROS), and mitochondrial membrane potential (MMP). Calcium peak stimulated by capsaicin, the ligand of TRPV1 channel, was decreased in neurons pre-irradiated with the combination of the two wavelengths. Furthermore, delivering the 800 and 970 nm separately an increment of ATP, as well as MMP hyperpolarization were detected; notably, the 800 nm wavelength also increased ROS and O₂^- levels. Our findings, obtained on an in vitro model of nociception, show the positive effect of PBMT on two potential photo-targets of NIR light, namely the TRPV1 channel and the mitochondria.

MASCC/ISOO clinical practice guidelines for the management of mucositis: sub-analysis of current interventions for the management of oral mucositis in pediatric cancer patients

OBJECTIVE

The aim of this sub-analysis was to highlight the MASCC/ISOO clinical practice guidelines for the management of oral mucositis (OM) in pediatric patients and to present unique considerations in this patient population.

METHODS

This sub-analysis of the pediatric patient population is based on the systematic review conducted by the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISSO) published in 2019/2020. Studies were scored and assigned a level of evidence based on previously published criteria. Data regarding adverse effects and compliance was collected from the original publications.

RESULTS

A total of 45 papers were included and assessed in this sub-analysis, including 21 randomized controlled trials (RCTs). Chewing gum was demonstrated to be not effective in preventing OM in pediatric cancer patients in 2 RCTs. The efficacy of all other interventions could not be determined based on the available literature.

CONCLUSION

There is limited or conflicting evidence about interventions for the management of OM in pediatric cancer patients, except for chewing gum which was ineffective for prevention. Therefore, currently, data from adult studies may need to be extrapolated for the management of pediatric patients. Honey and photobiomodulation therapy in this patient population had encouraging potential. Implementation of a basic oral care protocol is advised amid lack of high level of evidence studies.

Photobiomodulation modulates inflammation and oral microbiome: a pilot study

INTRODUCTION

Oral mucositis (OM) is a severe side effect in patients undergoing anticancer therapies, which negatively impacts on their quality of life often leading to either the interruption of the therapy. Photobiomodulation (PBM) is emerging as an effective strategy allowing a faster wound healing.

OBJECTIVES

This pilot study aims at verifying whether PBM modulates the inflammatory response in patients and its effect on the oral microbiome composition.

MATERIALS AND METHODS

Buccal swabs were collected from four patients affected by OM, both on ulcerated and clinically healthy areas, before and on the last day of PBM therapy, as well as on the first day after treatment discontinuation. The concentration of 38 cytokines and the composition of oral microbiome were measured.

RESULTS

Most of the pro-inflammatory cytokines were reduced, whereas anti-inflammatory cytokines resulted up-regulated by PBM. In addition, PBM influenced the composition of oral microbiome, by decreasing the amount of pathogenic species and promoting the growth of commensal bacteria. These changes were even more evident when separately analysing patients who clinically responded to PBM and the only patient who did not respond.

CONCLUSIONS

PBM reduces inflammatory burden in patients affected by OM and positively influences the composition of the oral microbiome.

Photobiomodulation Therapy in Oral Mucositis and Potentially Malignant Oral Lesions: A Therapy Towards the Future

Photobiomodulation therapy (PBMT) is an effective treatment modality, which has the significant advantage of enhancing a patient’s quality of life (QoL) by minimising the side effects of oral cancer treatments, as well as assisting in the management of potentially cancerous lesions. It is important to note that the major evidence-based documentation neither considers, nor tackles, the issues related to the impact of PBMT on tumour progression and on the downregulation of cellular proliferation improvement, by identifying the dose- and time-dependency. Moreover, little is known about the risk of this therapy and its safety when it is applied to the tumour, or the impact on the factor of QoL. The review aimed to address the benefits and limitations of PBMT in premalignant oral lesions, as well as the conflicting evidence concerning the relationship between tumour cell proliferation and the applied dose of photonic energy (fluence) in treating oral mucositis induced by head and neck cancer (H&N) treatments. The objective was to appraise the current concept of PBMT safety in the long-term, along with its latent impact on tumour reaction. This review highlighted the gap in the literature and broaden the knowledge of the current clinical evidence-based practice, and effectiveness, of PBMT in H&N oncology patients. As a result, the authors concluded that PBMT is a promising treatment modality. However, due to the heterogeneity of our data, it needs to undergo further testing in well-designed, long-term and randomised controlled trial studies, to evaluate it with diligent and impartial outcomes, and ensure laser irradiation’s safety at the tumour site.

Optimization of Photobiomodulation Protocol for Chemotherapy-Induced Mucositis in Pediatric Patients

Objective: To determine optimal settings of a specific diode laser for reducing the severity of oral mucositis (OM) in pediatric patients. Background: Photobiomodulation (PBM) has been reported to reduce the severity of chemotherapy-induced OM. Treatment parameters for PBM are difficult to determine due to different reports in the literature. Materials and methods: Patients with OM graded WHO 3 or 4 were randomly assigned to three groups with different laser settings (group A: power 250 mW, the energy density 8.8 and 15.5 J/cm² for WHO grade 3 and 4, respectively; group B: power 500 mW, energy density as in group A; group C: power 250 mW, energy density was half of groups A and B). PBM was performed on all lesion areas. The mean number of PBM sessions to a decrease from WHO 3 or 4 to WHO 2, 1, or 0 was calculated for each patient. Multiple linear regression was used to determine whether the test groups differed in the mean number of sessions to a decrease of OM. Results: The mean number of PBM sessions to reduce from severe mucositis to mild or no mucositis was 3.8 [standard deviation (SD) = 3.5] in group A, 4.4 (SD = 2.3) in group B, and 4.0 (SD = 2.7) in group C. The differences in the number of PBM sessions for OM severity decrease were not statistically significantly different among the three study groups. Conclusions: Because of the lack of statistically significant differences between the groups, more patient practical laser parameters could be applied, that is, a shorter irradiation time.

Prophylactic photobiomodulation therapy using 660 nm diode laser for oral mucositis in paediatric patients under chemotherapy: 5-year experience from a Brazilian referral service

The use of photobiomodulation therapy (PBMT) in the prevention of oral mucositis (OM) in paediatric care has increased. In this article, we report data of paediatric oncology/haematopoietic stem cell transplantation (HSCT) patients treated with PBMT to prevent chemotherapy-induced OM. A retrospective study was conducted at a Brazilian referral service. Prophylactic PBMT was used in children and adolescents (≤ 17 years) following the protocol: InGaAIP, 660 nm, 100 mW, 2 J, 3.33 W/cm², and 20 s per point. Demographic data and OM severity scores were assessed. A regression model tested the association between OM with prophylactic PBMT and antineoplastic therapy. A total of 148 individuals who had undergone 358 chemotherapy cycles were analysed. A higher occurrence of OM was observed in HSCT and osteosarcoma (OS) patients. Except for HSCT, OM was associated with methotrexate (MTX) use in all disease groups. PBMT significantly reduced OM severity in acute lymphoblastic leukaemia (ALL) and OS patients. OM grade was 3.16 and 5.45 times higher among individuals with ALL and OS, who had not undergone prophylactic PBMT compared with those who had undergone prophylactic PBMT (p < 0.001). PBMT prevented chemotherapy-induced OM. Individuals who used MTX and did not undergo prophylactic PBMT were at increased risk of OM.

Analgesic effect of Photobiomodulation Therapy: An in vitro and in vivo study

Laser therapy, also known as Photobiomodulation (PBM) is indicated to reduce pain associated with different pathologies and applied using protocols that vary in wavelength, irradiance and fluence. Its mechanisms of action are still unclear and possibly able to directly impact on pain transmission, reducing nociceptor response. In our study, we examined the effect of two specific laser wavelengths, 800 and 970 nm, extensively applied in the clinical context and known to exert important analgesic effects. Our results point to mitochondria as the primary target of laser light in isolated dorsal root ganglion (DRG) neurons, reducing adenosine triphosphate content and increasing reactive oxygen species levels. Specifically, the 800 nm laser wavelength induced mitochondrial dysregulation, that is, increased superoxide generation and mitochondrial membrane potential. When DRG neurons were firstly illuminated by the different laser protocols and then stimulated with the natural transient receptor potential cation channel subfamily V member 1 (TRPV1) ligand capsaicin, only the 970 nm wavelength reduced the calcium response, in both amplitude and frequency. Consistent results were obtained in vivo in mice, by subcutaneous injection of capsaicin. Our findings demonstrate that the effect of PBM depends on the wavelength used, with 800 nm light mainly acting on mitochondrial metabolism and 970 nm light on nociceptive signal transmission.

Photobiomodulation at Multiple Wavelengths Differentially Modulates Oxidative Stress In Vitro and In Vivo

Photobiomodulation (PBM) is emerging as an effective strategy for the management of multiple inflammatory conditions, including oral mucositis (OM) in cancer patients who receive chemotherapy or radiotherapy. Still, the poor understanding of the mechanisms by which the light interacts with biological tissues and the heterogeneity of light sources and protocols employed worldwide significantly limits its applicability. Reactive oxygen species (ROS) are massively generated during the early phases of OM and play a major role in the pathogenesis of inflammation in general. Here, we report the results of a clinical and experimental study, aimed at evaluating the effect of laser light at different wavelengths on oxidative stress in vivo in oncologic patients suffering from OM and in vitro in two cell types abundantly present within the inflamed oral mucosa, neutrophil polymorphonuclear (PMN) granulocytes, and keratinocytes. In addition to standard ROS detection methods, we exploited a roGFP2-Orp1 genetically encoded sensor, allowing specific, quantitative, and dynamic imaging of redox events in living cells in response to oxidative stress and PBM. We found that the various wavelengths differentially modulate ROS production. In particular, the 660 nm laser light increases ROS production when applied either before or after an oxidative stimulus. In contrast, the 970 nm laser light exerted a moderate antioxidant activity both in the saliva of OM patients and in both cell types. The most marked reduction in the levels of ROS was detected in cells exposed either to the 800 nm laser light or to the combination of the three wavelengths. Overall, our study demonstrates that PBM exerts different effects on the redox state of both PMNs and keratinocytes depending on the used wavelength and prompts the validation of a multiwavelength protocol in the clinical settings.

Multicenter randomized, double-blind controlled trial to evaluate the efficacy of laser therapy for the treatment of severe oral mucositis induced by chemotherapy in children: laMPO RCT

OBJECTIVES

To demonstrate the efficacy of laser photobiomodulation (PBM) compared to that of placebo on severe oral mucositis (OM) in pediatric oncology patients. The primary objective was the reduction of OM grade (World Health Organization [WHO] scale) 7 days after starting PBM. Secondary objectives were reduction of pain, analgesic consumption, and incidence of side effects.

METHODS

One hundred and one children with WHO grade > 2 chemotherapy-induced OM were enrolled in eight Italian hospitals. Patients were randomized to either PBM or sham treatment for four consecutive days (days +1 to +4). On days +4, +7, and +11, OM grade, pain (following a 0-10 numeric pain rating scale, NRS) and need for analgesics were evaluated by an operator blinded to treatment.

RESULTS

Fifty-one patients were allocated to the PBM group, and 50 were allocated to the sham group. In total, 93.7% of PBM patients and 72% of sham patients had OM grade < 3 WHO on day +7 (P = 0.01). A significant reduction of pain was registered on day +7 in the PBM versus sham group (NRS 1 [0-3] vs. 2.5 [1-5], P < 0.006). Reduced use of analgesics was reported in the PBM group, although it was not statistically significant. No significant adverse events attributable to treatment were recorded.

CONCLUSIONS

PBM is a safe, feasible, and effective treatment for children affected by chemotherapy-induced OM, as it accelerates mucosal recovery and reduces pain.

Oral Mucositis in Pediatric Patients in Treatment for Acute Lymphoblastic Leukemia

Oral mucositis in oncologic patients is the most undesirable event of the chemotherapeutic treatment. This study aimed to identify damage to the oral cavity resulting from chemotherapy in pediatric patients with acute lymphoblastic leukemia (ALL). This is a prospective study with a sample of 42 children and adolescents evaluated for 10 consecutive weeks after diagnosis. The modified Oral Assessment Guide (OAG) was used, and data were analyzed by Spearman’s rank correlation coefficient (α = 5%). Changes to the normal lips and saliva were positively related to an increase in the OAG score during all 10 weeks of evaluation. Alterations to the labial mucosa were correlated with an increase in the OAG score from the 2nd to 10th week, which was also found for changes in the tongue and in the swallowing function in Weeks 1, 6, 8, 9, and 10 and for gum changes from the 5th to 7th week. No significant vocal changes were correlated with the total OAG score at any point during the monitoring period. Changes in lips, cheek and/or palatal mucosa, labial mucosa, and gum areas and in swallowing function were positively correlated with an increase in the severity of oral mucositis in patients with ALL after beginning chemotherapeutic treatment.

Laser Therapy Inhibits Tumor Growth in Mice by Promoting Immune Surveillance and Vessel Normalization

Laser therapy, recently renamed as photobiomodulation, stands as a promising supportive treatment for oral mucositis induced by oncological therapies. However, its mechanisms of action and, more importantly, its safety in cancer patients, are still unclear. Here we explored the anti-cancer effect of 3 laser protocols, set at the most commonly used wavelengths, in B16F10 melanoma and oral carcinogenesis mouse models. While laser light increased cell metabolism in cultured cells, the in vivo outcome was reduced tumor progression. This striking, unexpected result, was paralleled by the recruitment of immune cells, in particular T lymphocytes and dendritic cells, which secreted type I interferons. Laser light also reduced the number of highly angiogenic macrophages within the tumor mass and promoted vessel normalization, an emerging strategy to control tumor progression. Collectively, these results set photobiomodulation as a safety procedure in oncological patients and open the way to its innovative use for cancer therapy.

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Laser light reduces tumor progression while increasing metabolism of cultured cells

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Laser-treated tumors contain mature vessels and less pro-angiogenic macrophages

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Tumors treated by photobiomodulation are surrounded by lymphocytes and dendritic cells

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Laser light promotes secretion of type I interferons in vitro and in vivo

Laser therapy, also named photobiomodulation, is recommended to heal mucositis induced by oncological treatments, raising concerns on its safe use in cancer patients. Ottaviani et al. showed that laser light inhibits tumor progression, induces tumor vessel normalization and stimulates the immune system to produce type I interferons, proving the safety and extending the use of laser-based therapies to cancer.

Effects of near-infrared laser radiation on the survival and inflammatory potential of Candida spp. involved in the pathogenesis of chemotherapy-induced oral mucositis

Candida spp. usually colonize ulcerative lesions of atrophic mucosa in patients with chemotherapy-induced oral mucositis inducing severe inflammation. The spread of antifungal-resistant strains strongly encouraged the search of complementary or alternative therapeutic strategies to cure inflamed mucosa. In this paper, we studied the effects of a near-infrared (NIR) laser system with dual-wavelength emission (808 nm + 904 nm) on the survival and inflammatory potential of C. albicans, C. glabrata, and C. parapsilosis. Laser treatment was performed with a Multiwave Locked System laser. Survival and apoptosis of fungal strains were evaluated by colony-forming units (CFU) counting and annexin V staining. Cytokine production was evaluated by ImmunoPlex array. Laser treatment significantly affected the survival of Candida spp. by inducing apoptosis and induced a lower production of inflammatory cytokines by dendritic cells compared to untreated fungi. No differences in the survival and inflammatory potential were recorded in treated or untreated Saccharomyces cerevisiae cells, used as the control non-pathogenic microorganism. Laser treatment altered the survival and inflammatory potential of pathogenic Candida spp. These data provide experimental support to the use of NIR laser radiation as a co-adjuvant of antifungal therapy in patients with oral mucositis (OM) complicated by Candida infections.

Oral mucositis in pediatric patients undergoing hematopoietic stem cell transplantation: clinical outcomes in a context of specialized oral care using low-level laser therapy

OM is a painful inflammatory condition of the oral mucosa, derived from the toxic effects of chemotherapy and radiotherapy. High OM severity is frequently present in HSCT pediatric patients, who exhibit multiple painful ulcers that limit their mastication and swallowing, leading to poor nutritional status. Few studies have demonstrated OM clinical outcomes in young patients undergoing HSCT. Feasibility of oral care and LLLT on OM prophylaxis and treatment is also poorly discussed. The aim of this study was to describe a specialized oral care protocol that included LLLT for pediatric patients undergoing transplantation and to demonstrate the clinical outcomes after OM prevention and treatment. Data from OM-related morbidity were collected from 51 HSCT pediatric patients treated daily with LLLT, followed by standard oral care protocols. All the patients, even infants and young children, accepted the daily oral care and LLLT well. The majority (80.0%) only exhibited erythema in the oral mucosa, and the maximum OM degree was WHO II. Patients who had undergone autologous and HLA-haploidentical transplants showed OM with the lowest severity. The frequency of total body irradiation and methotrexate prescriptions was higher in adolescents when compared with infants (p = 0.044), and adolescents also exhibited OM more severely than infants and young children. We found that good clinical outcomes were obtained using this therapy, mainly in regard to the control of OM severity and pain reduction in the oral cavity. Specialized oral care, including LLLT, is feasible and affordable for HSCT pediatric patients, although some adaptation in the patient's oral hygiene routine must be adopted with help from parents/companions and clinical staff.

Oral complications and dental care in children with acute lymphoblastic leukaemia

Acute leukaemia is the most common type of childhood cancer, the acute lymphoblastic type accounting for the majority of cases. Children affected by leukaemia receive various forms of treatments including chemotherapeutic agents and stem cell transplants. Leukaemia and its treatment can directly or indirectly affect oral health and further dental treatments. The oral complications include mucositis, opportunistic infections, gingival inflammation and bleeding, xerostomia and carious lesions. An additional consideration in children is the impact of the treatments on the developing dentition and on orofacial growth. The aim of this review is to describe the oral complications in children with acute lymphoblastic leukaemia and the methods of prevention and management before, during and after the cancer treatment.