A systematic review with meta-analysis of the effect of low-level laser therapy (LLLT) in cancer therapy-induced oral mucositis

Assessment of Integrative Therapeutic Methods for Improving the Quality of Life and Functioning in Cancer Patients-A Systematic Review

Background: Cancer rehabilitation represents a series of measures adopted for the recovery of psychological, emotional, social, and financial functioning in the case of cancer patients. The purpose of this study is to identify the main elements of therapeutic management in the field of medical rehabilitation, as well as integrative, complementary medicine and holistic approaches that can be performed on the oncological patient. Methods: This systematic literature review follows the methodology outlined in the "Preferred Reporting Items for Systematic Reviews and Meta-Analysis" ("PRISMA") statement, which is an internationally recognized and widely accepted standard. Results: Active rehabilitative therapies offer therapeutic options for improving the functioning and quality of life of oncological patients; these therapies comprehensively address both the physical and psychological aspects of the disease. This review also includes the latest novelties and nanotechnologies applied in oncological rehabilitation, for example, drugs (or supplements) inspired by nature. Conclusions: Physical and rehabilitation medicine, mostly using stimulating therapeutic methods, was recently added to the list of contraindications in the management of oncological patients, both as an approach to the pathological concept itself and as an approach to the main clinical consequences and functional aspects of oncological therapies. Integrative, complementary medicine presents an important therapeutic resource in the case of oncological patients. Advanced studies are needed in the future to further ascertain the role of these therapies.

Photobiomodulation CME part II: Clinical applications in dermatology

Photobiomodulation (PBM) is an emerging treatment modality in dermatology with increasing office and home-based use. PBM is the use of various light sources in the red light (620-700 nm) and near-infrared (700-1440 nm) spectrum as a form of light therapy. PBM is often administered through low-level lasers or light-emitting diodes. Studies show that PBM can be used effectively to treat conditions secondary to cancer therapies, alopecia, ulcers, herpes simplex virus, acne, skin rejuvenation, wounds, and scars. PBM offers patients many benefits compared to other treatments. It is noninvasive, cost-effective, convenient for patients, and offers a favorable safety profile. PBM can be used as an alternative or adjuvant to other treatment modalities including pharmacotherapy. It is important for dermatologists to gain a better clinical understanding of PBM for in-office administration and to counsel patients on proper application for home-use devices to best manage safety and expectations as this technology develops. PBM wavelengths can induce varied biological effects in diverse skin types, races, and ethnicities; therefore, it is also important for dermatologists to properly counsel their skin of color patients who undergo PBM treatments. Future clinical trials are necessary to produce standardized recommendations across conditions and skin types.

Unveiling the Multifaceted Management of Oral Mucositis in Cancer Patients: A Narrative Review

Oral mucositis (OM) is a major and common adverse reaction to cancer treatment, occurring in all patients who undergo radiation therapy or chemotherapy that includes the mucosal areas of the oral and oropharyngeal region. The pathophysiology of OM remains incompletely understood, and there are many unanswered questions about the risk factors for developing OM. Multidisciplinary clinicians and researchers must collaborate to better understand and expand treatment strategies for OM and other inflammatory conditions in oncology. This will lead to the development of more effective treatments and reduce the burden of OM in cancer patients. This article comprehensively reviews the risk factors and patient factors associated with OM, its pathogenesis, clinical presentation, grading, and management.

Comparison of three different dosages of low-level laser therapy on expression of cell proliferation and inflammatory markers following ovariohysterectomy in rats

The objective of the current study was to evaluate Low-level laser therapy (LLLT) on the healing of incisional wounds following ovariohysterectomy in rats, by means of subjective histopathological and immunohistochemical analysis. A total of 72 female Wistar rats were categorised into four treatment groups (Group I; sacrification 4 hours following only one LLLT application, Group II; sacrification 7 days following only one LLLT application, Group III; sacrification 4 hours after two LLLT applications, and Group IV; sacrification 7 days after two LLLT applications). Each group was further divided into four different doses subgroups (Group Control [C, off mode LLLT application], L1 [1 J/cm2], L3 [3 J/cm2], and L6 [6 J/cm2]), with equal representation in each subgroup. Ovariohysterectomy was employed using two 2-cm-length midline abdominal incisions in the left and right sides of line alba. The Group C was assigned to the left side incision to each rat in the study. After irradiation, the tissue was subjected to histopathological analysis to determine the extent of mononuclear cell infiltration, edoema, and epithelialization. Additionally, immunohistochemical analysis was performed to evaluate the expression of proliferating cell nuclear antigen (pCNA) and inducible nitric oxide synthase (iNOS). Group L1 and L3 significantly decreased mononuclear cell infiltration compared with Group C in all treatment groups (p < 0.05). Group L3 significantly decreased edoema compared with Group C in all groups except for treatment Group I (p < 0.05). Group L2 and L3 significantly increased epithelization in treatment Group IV (p < 0.05). Moreover, Group L2 and L3 significantly increased pCNA in all groups, while L2 and L3 significantly decreased iNOS expression in treatment Group II, III, and IV (p < 0.05). However, no statistical difference was found between subgroups of treatment Group I in iNOS expiration (p > 0.05). The results of the current examination demonstrated that LLLT can modulate mononuclear cell infiltration and edoema, and improve epithelization, as well as increase pCNA expression, whereas decrease iNOS expression during the wound healing process, therefore enhancing wound healing following ovariohysterectomy in rats.

Management of Cancer Therapy-Induced Oral Mucositis Using Photobiomodulation Therapy: An Overview of Systematic Reviews

Objective: To systematically summarize the evidence for photobiomodulation therapy (PBMT) in the prevention and treatment of oral mucositis (OM) in patients undergoing cancer treatment. An electronic search was conducted in 8 databases and grey literature. Background: PBMT is recommended for the management of OM resulting from cancer treatment, with several systematic reviews (SRs) being published in recent years on this topic. Methods: Only SRs with outcomes from clinical trials were included, with no language or year restriction. The AMSTAR 2 tool was used to assess the methodological quality of the SRs. Results: Five thousand eight hundred fifty-six references were found, and 16 were selected for this review. OM prevention and treatment were favorable for PBMT in most studies, with a significant reduction in OM severity. Most studies obtained moderate confidence. Conclusions: PBMT represents an effective strategy in the management of OM, and this evidence is supported by studies with acceptable methodological quality.

An extraoral approach to intraoral cooling-a feasibility study in non-cancer patients

BACKGROUND

Cryotherapy, using ice chips (IC) is an effective strategy to prevent chemotherapy-induced oral mucositis (OM) in selected cancer patient cohorts. However, although effective, use of IC may cause adverse reactions, e.g., nausea, numbness, and shooting pain in the teeth, which could have an adverse impact on the medical treatment. Furthermore, IC requires water of good quality to minimize risk of serious systemic infections. To eliminate these disadvantages, novel cooling devices have emerged as alternative cooling modalities. Thus, the aim was to evaluate the efficacy and tolerability profile of extraoral cooling for intraoral temperature reduction.

SUBJECTS AND METHODS

This experimental pilot study was conducted at the Institute of Odontology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. In total, six healthy volunteers were enrolled in this study. At baseline and following 30-, and 60 min of cooling with the extraoral cooling device, intraoral mucosal temperatures were measured using a thermographic camera, and a questionnaire related to tolerability was completed.

RESULTS

Following 30-, and 60 min of cooling, the intraoral temperature decreased with 2.0 °C and 2.3 °C, respectively. Extraoral cooling was well tolerated, and all subjects endured the entire cooling session of 60 min.

CONCLUSION

Extraoral cooling reduces intraoral mucosal temperatures and is a well-tolerated cooling modality.

Photobiomodulation enhances M2 macrophage polarization properties of tonsil-derived mesenchymal stem cells

In this study, the effect of photobiomodulation (PBM) treatment using 630 nm light emitting diode (LED) array (continuous wave type, 10 mW power) on tonsil-derived mesenchymal stem cells (TMSCs) and its interaction with RAW 264.7 macrophage cells via co-culture in vitro were investigated. PBM treatment was used as a priming method for TMSCs to improve therapeutic efficacy. TMSCs were subjected to multi-dose PBM treatments before co-culture with M1 activated (1 μg/mL lipopolysaccharide, LPS) macrophage cells with total energy doses of 0, 15, 30, and 60 J. Irradiation set at 15 J (1500 s treatment time) was performed once, twice for 30 J, and four times for 60 J in an incubator kept at 37 °C and 5% CO2. No significant anti-inflammatory response was observed for TMSCs co-cultured with macrophage cells without PBM. But PBM treatment of TMSCs with 630 nm LED array at 30 J reduced expression of inducible nitric oxide synthase, iNOS (M1) and increased expression of Arginase-1, Arg-1 (M2) phenotype macrophage markers. Anti-inflammatory cytokine interleukin-1 receptor antagonist (IL-1RA) gene expression also increased significantly. Based on the results, PBM priming of TMSCs supports M2 macrophage polarization. PBM can be used to improve the therapeutic efficacy of TMSCs for potential applications in oral mucositis and wound healing.

Effectiveness of Photobiomodulation and Oral Cryotherapy on Oral Mucositis Among Patients Undergoing Chemotherapy Conditioning Prior to Hematological Stem Cell Transplantation

OBJECTIVES

This review evaluated the best available evidence concerning the effectiveness of photobiomodulation compared to oral cryotherapy in oral-mucositis prevention among patients with hematological stem cell transplantation (HSCT) receiving chemo-conditioning.

DATA SOURCES

An extensive search for published and unpublished studies was conducted in 11 electronic databases and reference lists. Only randomized controlled trials (RCTs) were included. Two reviewers independently screened relevant studies for eligibility, extracted data using a standardized data collection form, and appraised data using the Cochrane Risk of Bias Tool and Grading Recommendations, Assessment, Development and Evaluation (GRADE). Meta-analyses using a random-effect model was performed using Review Manager software. Subgroup analyses were conducted to examine the differential effect of interventions across subgroups and to explore potential sources of heterogeneity. Meta-analyses included 18 RCTs (involving 1,018 patients). Both photobiomodulation and cryotherapy were effective in reducing oral-mucositis severity, severe oral-mucositis incidence, duration, and pain with small to large effect sizes. No significant differences were detected between photobiomodulation and cryotherapy across all outcomes. Subgroup analyses showed significant differences for chemo-conditioning regimens. The overall Grading Recommendations, Assessment, Development and Evaluation quality of evidence was low.

CONCLUSION

Both photobiomodulation and cryotherapy were effective nonpharmacological oral-mucositis prophylaxis and analgesia, with no significant difference in effectiveness. Chemo-conditioning regimens may influence their effectiveness. Future RCTs may directly compare the effectiveness of photobiomodulation and cryotherapy on the HSCT patients. Rigorous cost-effectiveness studies are also required.

IMPLICATIONS FOR NURSING PRACTICE

Photobiomodulation and cryotherapy can be offered to HSCT patients in clinical settings. A clinical guideline of both interventions can be also developed.

Quality assessment of PBM protocols for oral complications in head and neck cancer patients: part 2

PURPOSE

To investigate the role of photobiomodulation (PBM) in patients undergoing head and neck cancer (HNC) treatment. We focused on the consequences of the main complications, such as quality of life (QoL), analgesia, functional impairment, and nutritional status, as well as on the impact on survival/ recurrences, radiotherapy (RT) interruption, adherence, cost-effectiveness, safety, feasibility, and tolerability.

METHODS

An electronic search in PubMed and Scopus databases was performed. Full texts were carefully assessed, and data were assimilated into a tabular form for discussion and consensus among the expert panel.

RESULTS

A total of 22 papers were included. Overall, a beneficial effect of PBM was evidenced in the amelioration of QoL, nutritional status, the reduction of pain, and functional impairment. Preventive PBM may reduce the incidence and duration of RT interruptions, potentially contributing to improved cancer treatment outcomes. PBM treatments are safe and recommended for routine use, with the caveat of avoiding direct tumor exposures where feasible. However, it does not appear to impact cancer survivorship/recurrences directly. Despite additional clinical efforts involving routine PBM use, the individual and public health benefits will positively impact oncology care.

CONCLUSIONS

Quality of life, pain and functional impairment, nutritional status, and survival may be effectively improved with PBM. Given its established efficacy also in reducing RT interruptions and its safety, feasibility, and tolerability, PBM should be included in the field of supportive cancer care in HNC patients. Improved understanding of PBM mechanisms and precise dose parameters is enabling the generation of more robust, safe, and reproducible protocols; thus, it is imperative to support further clinical implementation as well as both applied and basic science research in this novel field.

Twenty-year analysis of photobiomodulation clinical studies for oral mucositis: a scoping review

OBJECTIVE

Our objective was to review the first 20 years of photobiomodulation (PBM) clinical studies for oral mucositis (OM) mitigation.

STUDY DESIGN

A scoping review screened controlled clinical studies. The PBM devices, protocols, and clinical outcomes were analyzed.

RESULTS

Seventy-five studies met the inclusion criteria. The first study dated from 1992, and the term "PBM" was first published in 2017. Public services, placebo-controlled randomized trials, and patients with head and neck chemoradiation were predominant among included studies. Prophylactic red intraoral laser protocols were mostly used. Comparing the outcomes of all protocols was unfeasible due to missing treatment parameters and nonhomogeneous measurements.

CONCLUSIONS

The main barrier to optimizing clinical protocols of PBM for OM was the lack of standardization in clinical studies. Although PBM use is now globally present in oncology settings and generally marked by good outcomes reported, additional randomized clinical trials with well-described methods are necessary.

A phase Ⅱ prospective trial of photobiomodulation therapy in limiting oral mucositis in the treatment of locally advanced head and neck cancer patients

OBJECTIVE

This study aimed to compare the historical incidence rate of severe oral mucositis (OM) in head and neck cancer patients undergoing definitive concurrent chemoradiation therapy (CRT) versus a prospective cohort of patients with locally advanced head and neck squamous cell carcinoma (HNSCC) treated with prophylactic photobiomodulation therapy (PBMT).

METHODS

This US-based, institutional, single-arm, phase Ⅱ prospective clinical trial was initiated in 50 patients (age ≥ 18 years, Karnofsky Performance Scale Index > 60, with locally advanced HNSCC (excluding oral cavity) receiving definitive or adjuvant radiation therapy (RT) with concurrent platinum-based chemotherapy (CT). PBMT was delivered three times per week throughout RT utilizing both an intraoral as well extraoral delivery system. Primary outcome measure was incidence of severe OM utilizing both the National Cancer Institute Common Toxicity Criteria, version 4.0 (NCI-CTCAE) Grade ≥3 and the World Health Organization Mucositis Grading Scale (WHO) Grade ≥3 versus historical controls; secondary outcome measures included time to onset of severe OM following therapy initiation.

RESULTS

At baseline, all patients included in final analysis (N = 47) had OM Grade 0. Average RT and CT dose was (66.3 ± 5.1) Gy and (486.1 ± 106.8) mg/m2, respectively. Severe OM was observed in 11 of 47 patients (23%, confidence interval: 12, 38). OM toxicity grade trended upward during treatment, reaching a maximum at 7 weeks (WHO: 1.8 vs. NCI-CTCAE: 1.7). Subsequently, OM grade returned to baseline 3 months following completion of RT. The mean time to onset of severe OM was (35 ± 12) days. The mean time to resolution of severe OM was (37 ± 37) days.

CONCLUSIONS

Compared to historical outcomes, PBMT aides in decreasing severe OM in patients with locally advanced HNSCC. PBMT represents a minimally invasive, prophylactic intervention to decrease OM as a major treatment-related side effect.

Effects of Photobiomodulation on Oral Mucositis: Visualization and Analysis of Knowledge

This review article mapped and analyzed the most cited articles on the association of photobiomodulation (PBM) with oral mucositis (OM) and the evolution of clinical protocols in the area. A comprehensive search was performed on the Web of Science Core Collection (WoS-CC) database, leading to the extraction of information such as title, authors, abstract, journal name, number, average of citations, study design, year of publication, institutions, continents, countries, type of laser used, irradiated anatomical points, primary anti-cancer therapy, and laser parameters. Among those, clinical trials and literature reviews were the most common study designs. The main type of laser used was the InGaAlP diode, with a wavelength ranging from 630-660 nm, power going in 40-100 mW, and energy density ranging from 0.375-22 J/cm². As for the anatomical sites irradiated by PBM, the cheek mucosa, upper and lower lips, lateral tongue, and bottom of the mouth stood out. This analysis highlights an increasing interest in PBM as a supportive treatment in cases of OM, as well as the evolution of the technique, types of laser devices, and protocols used.

Stimulatory effects of wavelength-dependent photobiomodulation on proliferation and angiogenesis of colorectal cancer

In recent decades, the laser treatment of cancer has been introduced as a promising treatment option. Because of the maldistribution of optical energy and an ambiguous boundary between the normal and tumor tissues, laser irradiation can stimulate residual cancer cells, leading to a cancer regrowth. As photobiomodulation (PBM) is involved in an extensive range of cellular responses, profound comprehension of photo-stimulated mechanisms against the cancer cells is required to establish a safety margin for PBM. Therefore, we aimed to identify the stimulant effects of PBM at various wavelengths against the tumor cells to establish a safety margin for the laser treatment. CT26 murine colon cancer cells were exposed to either 405 (BL), 635 (VIS), or 808 (NIR) nm laser lights at the fluences of 0, 10, 30, and 50 J/cm². In addition, CT26 tumor-bearing mice were irradiated with BL, VIS, or NIR at a fluence of 30 J/cm². Both the proliferation and angiogenesis potential of the CT26 cells and tumors were evaluated using the MTT assay, western blot, and immunohistochemistry (IHC) staining analyses. Although cell viability was not statistically significant, BL significantly induced p-ERK upregulation in the CT26 cells, indicating that PBM with BL can stimulate proliferation. In vivo tests showed that the NIR group exhibited the maximum relative tumor volume, and BL yielded a slight increase compared to the control. In the IHC staining and western blot analyses, both BL and NIR increased the expression of EGFR, VEGF, MMP-9, and HIF-1α, which are related to the proliferation and angiogenesis-related factors. Further investigations will be pursued to clarify the molecular pathways that depend on the cancer cell types and laser wavelengths for the establishment of safety guidelines in clinical environments.

Photobiomodulation: a promising innovative approach for preventing oral mucositis in patients undergoing hematopoietic stem cell transplantation

PURPOSE

This single-center retrospective study aims to assess the feasibility, safety, and tolerability of CareMin650, a new photobiomodulation device, for both preventing oral mucositis (OM) and reducing its severity in the setting of hematopoietic stem cell transplantation (HCT).

METHODS

Patients who underwent autologous HCT for hematological malignancies between November 2020 and October 2021 could be included. Prophylactic photobiomodulation (PBM) was used daily from day 1 of conditioning until the day of neutrophil recovery at a dose of 3 J/cm². Curative PBM was started at a dose of 6 J/cm² when at least one grade 1 OM had occurred. For each OM case, time of onset, National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) v5.0 grade for OM, analgesic dose, and time to resolution were reported.

RESULTS

Twenty-five consecutive patients were included. The median age was 58 years (range, 39-74) and 14 (56%) were male. Twenty-one patients (84%) received a high-dose melphalan conditioning regimen for multiple myeloma, and 4 (16%) patients received BEAM conditioning for aggressive lymphoma. A total of 178 CareMin650 sessions were performed, with a median of 7 days of application (range, 4-12), with no device-related adverse events (AEs). According to the NCI-CTCAE v5.0 scale, 76% (19 of 25) of patients presented grade 0 or 1 mucositis (no ulcers), five patients (20%) developed small ulcers (grade 2), and only one patient developed grade 4 mucositis. Satisfaction rates were high among patients and users.

CONCLUSION

Photobiomodulation provides excellent safety and tolerance, as well as promising efficacy, both as a preventive and curative strategy, in patients undergoing autologous HCT.

Regulation of interleukin-6 and matrix metalloproteinases syntheses by bioflavonoids and photobiomodulation in human gingival fibroblasts

This study aimed to evaluate the separately effects of bioflavonoids proanthocyanidins, from grape seed extract (GSE) and synthetic naringenin (NA), as well as photobiomodulation (PBM) by low-level laser therapy on interleukin (IL)-6 and matrix metalloproteinases (MMPs) syntheses by human gingival fibroblasts (HGF). For this purpose, a connective tissue exposure (ulceration) model of HGF, stimulated with tumor necrosis factor-alpha (TNF-α), was used. Initially, the highest non-cytotoxic and non-genotoxic concentrations of bioflavonoids were determined by cell viability and micronuclei formation assays. Then, HGF were exposed to different stimuli: culture medium (negative control), dimethyl sulfoxide (DMSO), TNF-α, NA, GSE, TNF-α + NA, TNF-α + GSE, PBM (3 J/cm², 0.025 W, 780 nm), and TNF-α + PBM. Next, IL-6, MMP-2, and MMP-9 syntheses were assessed. The concentration of 10 μg/mL of bioflavonoids increased cell viability at 24 and 48 h and did not present cytotoxic or genotoxic effects on HGF after 24, 48, and 72 h of contact. This concentration was selected for the assessment of bioflavonoids potential in modulating inflammatory mediators. TNF-α exposure enhanced IL-6 (170%), MMP-2 (10%), and MMP-9 (20%) syntheses, while a decrease of MMP-2 by 55% after exposure to TNF-α + GSE and 20% after TNF-α + NA and TNF-α + PBM was observed. MMP-9 synthesis was decreased by 35% after TNF-α + NA, 20% after TNF-α + GSE, and 30% after PBM. IL-6 was down-regulated by GSE in the presence of TNF-α (80%). In conclusion, TNF-α up-regulated IL-6 and MMPs, while bioflavonoids and PBM down-regulated MMP-2 and MMP-9 syntheses; GSE also decreased IL-6 synthesis, demonstrating the individual promising potential of these therapies for ulceration management.

Oral cryotherapy for management of chemotherapy-induced oral mucositis in haematopoietic cell transplantation: a systematic review

Background

Oral mucositis (OM) is known to be the most common and challenging side effect of conditioning chemotherapy in haematopoietic cell transplant (HCT). This side effect causes significant morbidity and may delay the treatment plan, as well as increase therapeutic expenses. There are few clinical trials in the literature that indicate any kind of treatment or prevention methods are effective. Therefore, the aim of this study is to perform a systematic review of literature and examine the effectiveness of oral cryotherapy (OC) in management of chemotherapy-induced OM in patients with haematological malignancies undergoing a HCT.

Methods

A systematic literature search was conducted, using the electronic databases PubMed, Embase, MEDLINE and Scopus. A total of 322 papers were identified and 9 papers were analysed based on defined inclusion and exclusion criteria. The quality of the chosen primary studies was appraised using the COCHRANE risk of bias assessment tool.

Results

Nine randomized controlled trials, analysing 658 participants; control group (n = 289, age mean ± SD; 41.15 ± 21) and treatment group (n = 369, age mean ± SD; 39.15 ± 20), were included in this systematic review. Seven studies had significantly addressed the effectiveness of OC (p value < 0.05), in reducing the incidence of developing severe OM in the adult population undergoing HCT, especially when the conditioning regimen protocols included high dose of alkylating agent such as melphalan.

Conclusion

This review supports the use of OC for prevention of OM in patients undergoing HCT, with high-dose of melphalan conditioning protocols. It is recommended that more studies be conducted to compare efficacy and duration of OC with other chemotherapeutic agents with relatively short plasma half-lives. The heterogeneity of the trials demonstrated the need to regulate the validated assessment tools and similar interventions that would enable comparisons and analyses of treatment effects based on well-designed RCTs.

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.

Femtosecond-laser stimulation induces senescence of tumor cells in vitro and in vivo

Tumor cells present anti-apoptosis and abnormal proliferation during development. Senescence and stemness of tumor cells play key roles in tumor development and malignancy. In this study, we show the transient stimulation by a single-time scanning of tightly focused femtosecond laser to tumor cells can modulate the stemness and senescence in vitro and in vivo. The laser-induced cellular senescence and stemness present distinct transitions in vitro and in vivo. The cells 1.2 mm deep in tumor tissue are found with significant senescence induced by the transient photostimulations in 100-200 µm shallow layer in vivo, which suppresses the growth of whole tumor in living mice.

Is Low-level Laser Therapy a Candidate to Be a Good Alternative in the Treatment of Mucositis in Childhood Leukemia?

BACKGROUND AND AIM

Oral mucositis (OM) is a common side effect of systemic chemotherapy (CT) in cancer patients. The aim was to evaluate the effect of low-level laser therapy (LLLT) for the treatment of CT-induced OM children.

PATIENTS AND METHODS

The study was carried out in 40 pediatric patients 3 to 18 years of age, who were hospitalized for the diagnosis of leukemia and underwent CT between June 1, 2019, and December 31, 2019. They were randomly divided into 2 groups with 20 cases in each group. The LLLT group was treated with GaAlAs diode laser (l): 830 nm (infrared), power: 150 mW, dose: 4.5 J/cm2 and the control group underwent bicarbonate treatment. Patients received intervention for 3 days. The grade of OM was clinically assessed by the World Health Organization (WHO) Common Toxicity Criteria Scale. Visual Analog Scale was used on the same days with OM grade to evaluate the pain status.

RESULTS

While there was no significant difference between the groups in terms of OM grade at the beginning of the treatment and on the first, second, fourth, and 11th days of the treatment, the average OM grade of the LLLT group was found to be statistically significantly lower on the third, fifth, sixth, and seventh days of the treatment. The Visual Analog Scale score of the LLLT group was statistically significantly lower compared with the control group at all examinations starting from the first day of treatment (P<0.05).

CONCLUSION

In the treatment of oral OM that occurs in children after CT, both standard care and LLLT treatment improve the grade and pain of OM.

Oral mucositis: Current knowledge and future directions

Oral mucositis secondary to head and neck chemoradiation displays a complex molecular pathogenesis involving epithelial and microvascular injury, release of pro-inflammatory cytokines, and host-microbiome communications. These processes lead to oxidative stress and the release of reactive oxygen species that stifle the structural integrity of the oral mucosa, with emergence of erosions and ulcers. The consequences are malnutrition, psychological/psychiatric symptoms, poor quality of life, and occurrence of opportunistic infections. The latter pose a major challenge due to the risk of interruption of anti-neoplastic therapy, tumour recurrence and, ultimately, death. This article aims to present the clinical characteristics, molecular pathogenesis, and an overview of the predisposing factors and current management of oral mucositis. It is anticipated that the future direction of the management of oral mucositis will focus on evidence-based prehabilitation and pre- and per-chemoradiation therapy monitoring.

Extraoral photobiomodulation for prevention of oral and oropharyngeal mucositis in head and neck cancer patients: interim analysis of a randomized, double-blind, clinical trial

Purpose

To assess the safety and efficacy of prophylactic extraoral photobiomodulation (PBM) for the prevention of oral and oropharyngeal mucositis (OM) on clinical outcomes and survival in patients with oral cavity and oropharyngeal squamous cell carcinoma (OOPSCC).

Methods

OOPSCC patients who received radiotherapy (RT) were prospectively randomized to two groups: prophylactic extraoral PBM and placebo. OM grade (NCI), pain (VAS), analgesia, and anti-inflammatory prescriptions were assessed weekly. Quality of life questionnaires (QoL) were performed at the first and last day of RT. Following RT, participants were evaluated quarterly for oncological outcomes follow-up.

Results

Fifty-five patients met the inclusion criteria. The first occurrence of OM was observed at week 1, for the placebo group (p = 0.014). Later, OM onset and severity was observed for the PBM group, with first occurrence at week 2 (p = 0.009). No difference in severe OM incidence was observed (p > 0.05). Lower mean pain score was noted at week 7 for the PBM group (2.1) compared to placebo group (4.5) (p = 0.009). Less analgesics (week 3; p = 0.009/week 7; p = 0.02) and anti-inflammatory prescription (week 5; p = 0.0346) were observed for the PBM group. Better QoL scores were observed for the PBM group at last day of RT (p = 0.0034). No difference in overall survival among groups was observed in 1 year of follow-up (p = 0.889).

Conclusion

Prophylactic extraoral PBM can delay OM onset, reduce pain, and reduce analgesic and anti-inflammatory prescription requirements. Extraoral PBM was associated with better QoL. There was no evidence of PBM impact on oncological outcomes.

Trial registration

TRN:RBR-4w4swx (date of registration: 01/20/2020).

Supplementary Information

The online version contains supplementary material available at 10.1007/s00520-021-06625-8.

Low-Level Laser Therapy Effects on Rat Blood Hemostasis Via Significant Alteration in Fibrinogen and Plasminogen Expression Level

Introduction: There are many documents about the significant role of low-level laser therapy (LLLT) in different processes such as regenerator medicine and bone formation. The aim of this study is to assess the role of LLLT in blood hemostasis in rats via bioinformatic investigation. Methods: The differentially expressed plasma proteins of treated rats via LLLT from the literature and the added 50 first neighbors were investigated via network analysis to find the critical dysregulated proteins and biological processes by using Cytoscape software, the STRING database, and ClueGO. Results: A scale-free network including 55 nodes was constructed from queried and added first neighbor proteins. Fibrinogen gamma, fibrinogen alpha, and plasminogen were highlighted as the central genes of the analyzed network. Fibrinolysis was determined as the main group of biological processes that were affected by LLLT. Conclusion: Findings indicate that LLLT affects blood hemostasis which is an important point in approving the therapeutic application of LLLT and also in preventing its possible complication.

New photobiomodulation device for prevention and cure of radiotherapy-induced oral mucositis and dermatitis: results of the prospective Safe PBM study

Purpose

The study aims to assess the feasibility, safety, and tolerability of CareMin650, a new photobiomodulation device, in patients treated by radiotherapy (RT) and to collect preliminary data on efficacy for prevention and treatment of oral mucositis (OM) and radiation dermatitis (RD).

Methods

Safe PBM is a French, multicentric, prospective, non-comparative study which include patients with head and neck cancer (H&NC, cohort A) or breast cancer (BC, cohort B) treated in prophylactic (cohorts A1 and B1) or curative setting (cohort A2 and B2). Prophylactic treatment was administered from D1 to end of RT, at a dose of 3 J/cm². Curative treatment started when a grade 1 to grade 3 lesion had occurred and was pursued until end of RT. Primary endpoint was incidence of device-related adverse events (AEs). OM and RD lesions were graded according to CTCAE V3.

Results

Overall, 72 patients were included (22, 9, 23, and 18 in cohorts A1, A2, B1, and B2, respectively). No device-related AE was reported after 1312 CareMin650 sessions. In cohorts A1 and B1, median time to first OM or RD lesion was 20 days. One BC patient developed G3 RD after completion of RT and discontinuation of CareMin650. Four H&NC patients developed G3 OM. In cohorts A2 and B2, lesions improved or stabilized in 71% of patients. Rates of satisfaction were high among patients and users.

Conclusion

CareMin650 is feasible, safe, and well tolerated for preventive or curative treatment of OM and RD in cancer patients treated with RT. Preliminary efficacy results are promising.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00520-021-06574-2.

Local application of low level laser therapy in mice ameliorates ovarian damage induced by cyclophosphamide

The aim of the present study is to assess whether low level laser therapy (LLLT) can protect ovaries from chemotherapy-induced gonadotoxicity using a mice model of premature ovarian failure induced by cyclophosphamide (CTX). LLLT (64 J/cm²) increased the number of antral follicles whilst decreasing the number of atretic follicles compared to CTX alone. LLLT increased the number of primordial follicles compared with those in the CTX group but they did not differ from those in the control group. LLLT treatment increased the number of AMH-positive follicles compared to CTX alone. LLLT application increased ovarian weight, serum progesterone concentration and P450scc protein levels compared to CTX alone. LLLT reduced the apoptosis in antral follicles and the BAX/BCL-2 ratio compared to CTX alone. Vascular morphology, analysed by CD31 and α-SMA immunostaining, was restored in LLLT-treated ovaries compared to CTX alone. In conclusion, application of LLLT prior to CTX might serve as a promising and novel protocol to preserve female fertility in cancer survivors.

Chemotherapy drugs and inflammatory cytokines enhance matrix metalloproteinases expression by oral mucosa cells

OBJECTIVE

Oral mucositis (OM), the most common side effect of cancer therapy, is associated with pro-inflammatory cytokines and matrix metalloproteinases (MMPs) increased expression. Although there are approaches for OM management, none is infallible, thus, elucidation of molecular events related to OM etiopathogenesis may improve current therapeutic strategies. This study assessed the influence of pro-inflammatory cytokines and chemotherapy drugs on MMPs expression and synthesis by oral mucosa cells.

DESIGN

Human gingival fibroblasts (HGF) were exposed to different concentrations of methotrexate (MTX) and 5-fluorouracil (5-FU); subsequentially, cell viability, nitric oxide and interleukin(IL)-6 production were evaluated to select the concentration of these drugs that could stimulate inflammatory phenotype without cytotoxic effects. Then, HGF and primary gingival keratinocytes (PGK) were subjected to different stimuli: culture medium (negative control), tumor necrosis factor-alpha (TNF-α - positive control), IL-6, IL-8, MTX, and 5-FU for 3, 6, 12, and 24 h. Next, gene expression and synthesis of MMP-2 and MMP-9 by HGF and MMP-3 by PGK were assessed.

RESULTS

At 6 h, MMP-2 synthesis increased 60 % after exposure to TNF-α and MTX, 40 % after IL-6, and 15 % after IL-8. At 12 h, MMP-9 synthesis increased 15 % after exposure to TNF-α, while MMP-3 synthesis increased 30 % after TNF-α, and 10 % after IL-8. TNF-α-treated groups presented increased gene expression of all MMPs evaluated. IL-8 and 5-FU increased MMP-2 and MMP-3 expression, while IL-6 and MTX augmented MMP-2 expression.

CONCLUSIONS

The chemotherapy drugs and cytokines investigated up-regulated MMPs expression by oral mucosa cells, which may lead to OM establishment and severity.

Mechanisms of PhotoBioModulation (PBM) focused on oral mucositis prevention and treatment: a scoping review

Background

Oral mucositis (OM) is a severe complication cancer patients undergo when treated with chemoradiotherapy. Photobiomodulation (PBM) therapy also known as low-level laser therapy has been increasingly used for the treatment of such oral toxicity. The aim of this review is to discuss the mechanisms of photobiomodulation (PBM) regarding OM prevention and treatment, and more precisely to focus on the effect of PBM on tumor and healthy cells.

Methods

MEDLINE/PubMed, and google scholar were searched electronically. Selected studies were focusing on PBM effects on tumor and healthy cells.

Results

PBM interactions with the tissue and additional mechanism in OM therapy were detailed in this review. Moreover, this review highlighted a controversy about the carcinogenic effect of PBM. Indeed, Many studies reported that PBM could enhance malignant cell proliferation; suggesting that PBM would have no protective effect. In addition to acting on cancer cells, PBM may damage healthy cells.

Conclusion

More prospective studies are needed to assess the effect of PBM on cancer cells in order to improve its use for OM prevention and treatment.

Effectiveness of low level laser therapy versus cryotherapy in cancer patients with oral mucositis: Systematic review and network meta-analysis

OBJECTIVE

The purpose of this network meta-analysis was to analyze the relative effects of low level laser therapy (LLLT) and/or cryotherapy in cancer patients with oral mucositis (OM).

METHODS

This literature search followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and the Physiotherapy Evidence Database (PEDro) up to 2020. Only randomized control trials which involved comparisons of groups receiving the interventions of combined cryotherapy and LLLT, LLLT, cryotherapy and usual care (the control group) in patients with cancer were eligible for inclusion. The effect sizes are presented as odds ratios for the occurrence of severe, moderate and none/mild OM. The mixed treatment comparison was conducted using generalized linear mixed models to analyze the direct and indirect comparisons of interventions. The critical appraisal was assessed using Cochrane Collaboration's tool. Heterogeneity between studies was assessed using I² statistics, and publication bias was evaluated by constructing a funnel plot.

RESULTS

Twenty-six randomized controlled trials with a total enrollment of 1830 cancer patients with OM were included. The outcome of none/mild OM is desirable, and odds ratios of more than 1 favor the intervention group. Moderate and severe OM are defined as adverse outcomes, and ORs less than 1 favor the intervention group. The treatment effects of the combined cryotherapy and LLLT were better than those of usual care for none/mild and severe OM (ORs = 106.23 [95% CI = 12.15 to 929.17] and 0.01 [95% CI = 0 to 0.57], respectively). Treatment effects with cryotherapy alone and LLLT alone were better than those with usual care for none/mild and severe OM (ORs = 3.13 [95%CI = 1.56 to 6.27]; ORs = 7.56 [95%CI = 3.84 to 14.88] and 0.25 [95%CI = 0.11 to 0.54]; ORs = 0.13 [95%CI = 0.07 to 0.24], respectively). Nevertheless, for patients with none/mild OM, treatment effects with combined use of cryotherapy and LLLT were better than those with only LLT or cryotherapy (ORs = 14.06 [95%CI = 1.79 to 110.30] and 33.95 [95%CI = 3.50 to 329.65], respectively). For patients with moderate OM, treatment effect did not reach statistical significance among comparisons. The limitations include the wide variability in treatment protocols and the non-uniform outcome measurements across the studies examined.

CONCLUSION

Compared with no intervention, the treatment effects of combined cryotherapy and LLLT, laser alone, and cryotherapy alone are beneficial for the reduction of severe OM. There is no difference in treatment effects among cryotherapy and/or LLLT intervention in cancer patients with moderate OM. Results of this study provide an implicative basis for LLLT and cryotherapy as viable interventions that can significantly improve severe OM.

Adherence of head and neck cancer patients to laser photobiomodulation in a public health service: Pilot study

OBJECTIVE

The aim of this study was to evaluate the adherence of patients with head and neck cancer who underwent radiotherapy or radio-chemotherapy combined to the preventive laser photobiomodulation protocol in a public health service.

MATERIALS AND METHODS

This was a cross-sectional study, whose population sample included patients with malignant head and neck neoplasms. Thirty head and neck cancer patients undergoing cancer treatment, were examined and interviewed through a record of signs and symptoms of oral mucositis (OM) and adherence to the preventive laser photobiomodulation protocol, that began in the first session of radiotherapy, and included the laser application three times a week during the 3-week period. The collected data were documented, and the descriptive and inferential statistics were performed with a significance level of p < 0.05.

RESULTS

It was observed that 66.6% of patients developed OM. There was a predominance of degrees I and II, with 36.8% and 31.6%, respectively. A total of fifteen patients (50%) missed one or more laser photobiomodulation sessions. A positive association was found between patients who missed at least two laser photobiomodulation sessions with the development of OM degrees III (p < 0.05).

CONCLUSIONS

There was moderate adherence of patients with head and neck cancer to the laser photobiomodulation protocol and the development of more severe degrees of OM was related to individuals that didn't attend scheduled sessions.

Evaluation of Efficacy of Low-Level Laser Therapy

Introduction: Given the inconsistencies in the literature regarding laser performance in non-surgical treatments, this study investigated the available literature to determine the advantages and disadvantages of low-power lasers in treating non-surgical complications and diseases. Methods: Authentic information from articles was extracted and evaluated to assess low-power laser performance for non-surgical treatments. A systematic search of studies on low-level laser therapy (LLLT) for non-surgical treatments was conducted mainly in PubMed and google scholar articles. Results: Four categories of diseases, including brain-related diseases, skin-related diseases, cancers, and bone-related disorders, which were treated by LLLT were identified and introduced. The various types of LLLT regarding the studied diseases were discussed. Conclusion: Positive aspects of LLLT versus a few disadvantages of its application imply more investigation to find better and efficient new methods.

Phototherapy With LED as an Effective Treatment for Chemotherapy-Induced Oral Mucositis in Hamsters

Introduction: Oral mucositis (OM) has been considered one of the most feared collateral effects of oncological treatments. Some therapies have been used, such as light-emitting diode (LED), with promising results, but with no sufficient evidence in the literature. Objective: Our study aimed to evaluate, by clinical and histological analysis, the effect of LED on the treatment of chemotherapy-induced OM (CIOM) in an animal model. Methods: Twenty male hamsters were equally distributed to two groups: control (C), which received anesthesia and CIOM induction; and LED (L), which received anesthesia, CIOM induction, and LED treatment (635 nm, 120 mW, 0.48 J). The clinical analysis was performed through two specific scales for OM analysis on days 5, 7 and 10 of the experiment. In addition, the injured area of all hamsters check pouch mucosa was removed and processed for histological analysis on the last experimental day. Results: After statistical analysis, group L showed less severity of OM when compared with the C group (P <0.05); beyond that, both healed completely on day 10. Conclusion: Our results suggested that the phototherapy with LED had a positive effect on accelerating repair, reducing the severity of CIOM.

Effects of 660 nm and 810 nm Low-Power Diode Laser on Proliferation and Invasion of Oral Cancer Cells in Cell Culture Media

In the present study, the effects of 660 and 810 nm diode laser on the proliferation and invasion of cancer cells were investigated. Sixteen plates of oral cancer cells originated from tongue SCC were irradiated with diode laser at 660 nm (40 and 80 mW) and 810 nm (100 and 200 mW) with the energy density of 4 J cm^-2 . One plate received no irradiation (the control). Irradiation was performed at four times (0, 24, 72 and 168 h). Cell proliferation was measured by MTT assay. The Ki67 and vascular endothelial growth factor (VEGF) markers were examined by real-time polymerase chain reaction (RT-PCR). Cyclin D1, E-cadherin, β-catenin and matrix metalloproteinase-9 (MMP-9; flow cytometry) were also evaluated. Proliferation was lower in the irradiated groups. This result was significant for all groups at 24 h. The percentages of cyclin D1 and MMP-9 were higher in 810 nm groups, β-catenin and E-cadherin were higher in 660 nm groups, VEGF marker was significantly lower in 810 nm/200 mW group, and Ki67 marker has no difference between the groups. According to the results of this study, laser irradiation at 0 and 24 h resulted in a significant inhibitory effect on cell proliferation especially in 660 nm/80 mW and 810 nm/200 mW. Further studies are needed in this respect.

Photobiomodulation by a new optical fiber device: analysis of the in vitro impact on proliferation/migration of keratinocytes and squamous cell carcinomas cells stressed by X-rays

Photobiomodulation-based (PBM-based) therapies show promising results in mucositis and dermatitis treatment by stimulating wound healing mechanisms such as cell proliferation and migration. The aim of the present study is to investigate the in vitro effects of CareMin650 on the proliferation and migration of two different types of cells, namely cancer and non-cancer cells, with or without X-ray radiation. Study design used PBM through a combination of 0-3-6 J/cm² doses-with or without X-ray radiation-on the proliferation and migration capabilities of a keratinocyte cell line (HaCaT) and a squamous cell carcinoma line (SCC61). PBM is delivered by a new woven optical fiber device, namely CareMin650 prototype (light emission by LEDs (light-emitting diodes), peak at 660 nm, irradiance of 21.6 mW/cm²). The effectiveness of PBM to increase HaCaT proliferation and migration (with or without X-ray radiation) supports the capability of PBM to favor wound healing. It also highlights that PBM does not provide any anti-radiation effect to previously X-rays radiated SCC (p < 0.001). Such data supports the beneficial effect of PBM delivered by an optical fiber device to heal wounds, without promoting cancer development.

Photobiomodulation reduces the impact of radiotherapy on oral health-related quality of life due to mucositis-related symptoms in head and neck cancer patients

To assess the effectiveness of photobiomodulation therapy (PBMT) in the oral health-related quality of life (OHRQoL) of patients with head and neck cancer undergoing radiotherapy (RT), using the Oral Health Impact Profile-14 (OHIP-14) and the Patient-Reported Oral Mucositis (OM) Symptoms Scale (PROMS), and to correlate OM degree with the PROMS and OHIP-14 scores. Forty-eight patients undergoing RT for head and neck cancer were randomly assigned into two groups: PBMT group (n = 25)-daily PBMT associated with a preventive oral care program (POCP); and control group (n = 23)-receiving POCP exclusively. OHRQoL was assessed using the PROMS and OHIP-14 questionnaires. OM degrees were classified according to the World Health Organization and the National Cancer Institute scales. Assessments were performed at the 1st, 7th, 14th, 21st, and 30th RT sessions. PBMT was effective in preventing and treating severe OM. Both groups showed increased OHRQoL impacts throughout the RT sessions; however, higher impacts were observed in the control group, mainly at the final stage of treatment (21st and 30th RT sessions). Significant correlations were found between the severity of OM and PROMS scores in the total sample and the control group at all RT periods. PROMS and OM scores were positive correlated at 14th, 21st, and 30th RT sessions in the control group, suggesting that this instrument is useful in classifying OM. PBMT was effective in treating and preventing severe OM and OM-related symptoms, and with consequent positive impacts in OHRQoL in head and neck patients undergoing RT. The PROMS scale was helpful instrument for assessment of the severity of OM. Brazilian Clinical Trials database (ReBEC - RBR-5h4y4n), registered in Aug, 24th 2017.

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.

Effects of photobiomodulation on cellular viability and cancer stem cell phenotype in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most common head and neck malignancy; it has been shown that cancer stem cells (CSC) are present in OSCC and associated with tumor growth, invasion, metastasis, and therapeutic resistance. Photobiomodulation (PBM) is an alternative tool for oncologic treatment adverse effects such as oral mucositis (OM); however, controversy exists regarding the undesirable effects of PBM on tumor or CSC. This study aimed to evaluate in vitro, the effects of PBM, with the same dosimetric parameters as those used in the clinic for OM prevention and treatment, on OSCC cellular viability, as well as PBM's effect on CSC properties and its phenotype. OSCC cell lines were submitted to single or daily PBM with 3 J/cm² and 6 J/cm² and then the cellular viability was evaluated by MTT, NRU (neutral red uptake), and CVS (crystal violet staining). The CSC populations were evaluated by clonogenic formation assay, flow cytometry, and RT-qPCR. The single PBM with the 3 J/cm² group was associated with increased cellular viability. Daily PBM with 3 J/cm² and 6 J/cm² was associated with a significant decrease in cellular viability. Additionally, daily PBM was not able to promote CSC self-renewal or the CD44^high/ESA^low and CD44^high/ESA^high cellular phenotypes. Moreover, a decrease in the number of spheres and in the expression of the CSC related gene BMI1 was observed after daily PBM with 6 J/cm². Daily PBM with 3 J/cm² and 6 J/cm² showed an inhibitory effect on cellular viability and was not able to promote the CSC self-renewal or phenotype.

Evaluation of Aquaporins 1 and 5 Expression in Rat Parotid Glands After Volumetric Modulated Arc Radiotherapy and Use of Low-Level Laser Therapy at Different Times

Introduction: This experimental study investigated the mRNA expression of aquaporins (AQPs) 1 and 5 in the parotid glands of rats irradiated with volumetric modulated arc therapy (VMAT) and subjected to low-level laser therapy (LLLT) at different time points. Methods: The sample consisted of 30 Wistar rats (Rattus norvegicus) divided into the following groups: control, LLLT alone (LG), radiotherapy alone (RG), and experimental groups that received LLLT at 24 hours (early experimental group [EEG], n=12) and 120 hours (late experimental group [LEG], n=12) after radiotherapy. VMAT was delivered at a single dose (12 Gy) and LLLT was performed with an aluminium-gallium-arsenide diode laser (660 nm, 100 mW), spot area of 0.0028 cm2, energy of 2 J/cm² applied to 3 spots in the region corresponding to the right parotid gland, for 10 consecutive days. The right parotid gland was resected and prepared for RNA extraction. The gene expression of AQPs was evaluated by quantitative polymerase chain reaction (qPCR) using specific TaqMan probes, with the HPRT gene as an internal control. Results: The lowest AQP1 gene expression was 0.83 (0.27) with the use of LLLT 24 hours after radiotherapy (EEG), and the highest was 1.56 (0.80) with the use of LLLT alone (LG). Likewise, the lowest AQP5 gene expression was found in the EEG (mean = 0.88; SD = 0.49) and the highest in the LG (mean = 1.29; SD = 0.33). Conclusion: The use of LLLT after radiotherapy may contribute to the maintenance and an increase of these proteins, even when used at a later time point after radiotherapy.

Photobiomodulation and Oral Mucositis: A Systematic Review

Oral mucositis (OM) is a debilitating complication of chemotherapy, and head and neck radiotherapy. In an effort to offer the best possible advice within the limitations of published research, a systematic review with an extended discussion and commentary on dosimetry and dose delivery is presented. Using keywords as listed, Pubmed, Google Scholar and Cochrane databases were searched during a period extending from 1995 to 2019. A total of 782 abstracts were identified. A total of 50 papers were analysed, and of these, 29 satisfied criteria required for systematic review in accordance with an optimized PRISMA statement. Clinical outcome as reported was subject to analysis with respect to time of intervention, incidence and severity of oral mucositis, and pain amelioration, and a comprehensive combined univariate and multivariate statistical analysis of the methods employed was performed. Recommendations are made with respect to the timing of the intervention. Moreover, there is an extended discussion available on the treatment care rationale of photobiomodulation (PBM), and its adjunctive association with OM. In conclusion, early prophylactic application offers clear advantages in clinical management. The many studies and associated variables and covariables assessed here revealed a choice of delivery techniques, associated wavelengths and many further indices to consider with regard to the accomplishment of optical parameters. It is therefore our recommendation that clinicians use PBM as a therapy with a full and proper understanding and training in order to optimise the clinical effects achievable.

Laser-photobiomodulation on experimental cancer pain model in Walker Tumor-256

CONTEXT

Cancer Pain is considered a common and significant clinical problem in malignant neoplasms, comprising 20% to 50% of all patients with tumor progression. Laser photobiomodulation (L-PBM) has been used in a multitude of pain events, ranging from acute trauma to chronic articular. However, L-PBM has never been tested in cancer pain.

OBJECTIVES

Evaluate hyperalgesia, edema, COX-1, COX-2, IL-10, and Bdkrb1 mRNA in low-level laser irradiated Walker-256 tumor-bearing rats.

METHODS

Rat hind paw injected with Walker Tumor-256 (W-256) and divided into six groups of 6 rats: G1 (control) - W-256 injected, G2- W-256 + Nimesulide, G3- W-256 + 1 J, G4- W-256 + 3 Jand G5- W256 + 6 J. Laser parameters: λ = 660 nm, 3.57 W/cm², Ø = 0.028 cm². Mechanical hyperalgesia was evaluated by Randall-Selitto test. Plethysmography measured edema; mRNA levels of COX-1, COX-2, IL-10, and Bdkrb1were analyzed.

RESULTS

It was found that the W-256 + 1 J group showed a decrease in paw edema, a significant reduction in pain threshold. Higher levels of IL-10 and lower levels of COX-2 and Bdkrb1 were observed.

CONCLUSION

Results suggest that 1 J L-PBM reduced the expression of COX-2 and Bdkrb1 and increasing IL-10 gene expression, promoting analgesia to close levels to nimesulide.

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.

Effect of Topical 2% Eucalyptus Extract on 5-FU-Induced Oral Mucositis in Male Golden Hamsters

Oral mucositis is a common inflammatory complication among patients with cancer. This study evaluated the histopathological, stereological, and antioxidant markers of 2% eucalyptus extract in induced oral mucositis in male golden hamsters. In this animal study, oral mucositis was induced in 30 male golden hamsters by 5-FU (60 mg/kg) on days 0, 5, and 10 of the study. The cheek pouch was scratched with a sterile needle once daily on days 3 and 4. On days 14-17, 2% eucalyptus hydroalcoholic extract gel and Calendula officinalis extract gel groups were treated and then compared with a non-treated control group. The histopathological and stereological scores and the pouch content of malondialdehyde, as well as the activities of glutathione and myeloperoxidase in the pouch tissue, were evaluated. Histopathologic scores of oral mucositis were lower in the eucalyptus gel group than those of the calendula and control groups (p<0.05). Also, a lower malondialdehyde level and higher myeloperoxidase and glutathione activities were detected in the eucalyptus group in comparison to the calendula and control groups (p<0.001). The thickness of the mucosa and submucosa increased in the eucalyptus group. The numerical density of the fibroblast and the volume density of the collagen significantly increased in the eucalyptus group. In conclusion, the use of eucalyptus hydroalcoholic extract may be associated with reduced intensity of oral mucositis, diminished concentration of malondialdehyde, increased activity of myeloperoxidase and glutathione, increased volume of mucosa and submucosa, increased fibroblast and collagen in the induced oral mucositis in golden hamsters undergoing 5-FU consumption.

Oncological-Therapy Related Oral Mucositis as an Interdisciplinary Problem-Literature Review

Oral mucositis is a toxic side effect of non-surgical cancer treatments: chemotherapy and radiotherapy, which strongly impair quality of life and can not only cause strong pain, but also lead to problems with basic physiological needs as eating and swallowing. Development of oral mucositis is associated with type, dosage, and schedule of radiation or chemotherapy and other factors related to patients. Management of oral mucositis is a valid problem, requiring topical application of anesthetics, coating agents, cryotherapy, low level laser therapy, pharmacological methods as usage of keratinocyte growth factors, supplementation of vitamins, and a proper diet. Another approach to oral mucositis measurement includesphotobiomodulation, which brings analgesic and anti-inflammatory effects.Although oral mucositis is a general health issues, the role of proper dental care is essential. It should include elimination of all potential sources of mucosal injury and microorganisms inhabiting theoral cavity through oral hygiene education,professional management ofdental plaque,and treatment of the caries and periodontium, which are necessary to reduce the risk of inflammation in the oral cavity. This paper describes the possibilities of monitoring oral mucositis,taking into account the latest therapeutic achievements.

Effectiveness of low-level laser therapy for oral mucositis prevention in patients undergoing chemoradiotherapy for the treatment of head and neck cancer: A systematic review and meta-analysis

Oral Mucositis is a frequent and debilitating inflammatory complication in patients with head and neck malignancies and may lead to unplanned treatment interruptions due to intense pain and dysphagia. This systematic review with meta-analysis was performed to determine the effectiveness of low-level laser therapy in preventing oral mucositis in this context. The following databases were searched through September 2018, with last search performed on May 2019, for clinical trials: MEDLINE via PubMed, Cochrane Central, Scopus, Lilacs, ISI Web of Science and SIGLE via Open Grey. From 14,525 records, 4 studies were included in the review and 3 studies were included in meta-analysis. Data from 500 patients (mean age of 53.595 and 54.14 for intervention and control groups, respectively) were analysed. Meta-analysis showed that laser therapy prevents oral mucositis incidence in 28% and 23% of cases during the third and fourth follow-up week, respectively, in comparison to a placebo-treated control group. There was no statistically significant difference the prevention of pain; dysphagia and quality of life were not analysed due to missing. Laser therapy was effective in preventing oral mucositis from the 15th to the 45th days of chemoradiotherapy. However, new primary studies with low risk of bias are needed so a higher scientific evidence can be obtained.

Photobiomodulation and photodynamic therapy for the treatment of oral mucositis in patients with cancer

BACKGROUND

Photobiomodulation therapy (PBM-T) can penetrate soft tissues and exert analgesic and healing effects, and is thus a promising alternative for prevention and treatment of oral mucositis (OM). The aim of this study was to evaluate the efficacy of PBM-T, alone or combined with photodynamic therapy (PDT), for treatment of OM in cancer patients.

METHODS

Fifty-six patients were recruited from the Oncology Department of a teaching hospital. Patients underwent grading of OM and were divided into two groups (n = 28 each): PBM-T and PBM-T + PDT. In the PBM-T group, low-level laser was applied to 61 points in the oral cavity, once weekly for 4 weeks (wavelength 660 nm, power 100 mW, energy density 142 J/cm², spot energy 4 J, irradiation time 40 s). In the PBM-T + PDT group, in addition to PBM-T as described above, patients rinsed with 20 ml of photosensitizing mouthwash (curcumin 1.5 g/L) and the oral cavity was irradiated with a blue (468 nm) LED for 5 min.

RESULTS

Significant reductions in OM grade were observed after application of PBM-T or PBM-T + PDT (p < 0.0001). PBM-T + PDT resulted in a shorter time to resolution of lesions compared to PBM-T alone (p = 0.0005).

CONCLUSIONS

PBM-T, alone or combined with PDT, can be used for the treatment of OM. PDT + PBM-T in particular accelerated the OM healing process, reducing time to lesion remission from 15 to 11 days.