Improvement in Quality of Life of An Oncological Patient by Laser Phototherapy

Efficacy of photobiomodulation in the treatment of oral mucositis in patients undergoing antineoplastic therapy: systematic review and meta-analysis

PURPOSE

To evaluate the effectiveness of photobiomodulation in the treatment of oral mucositis.

METHODS

Systematic review and meta-analysis encompassing in the electronic databases: LILACS, MEDLINE, EMBASE, COCHRANE, SCOPUS, WEB OF SCIENCE, and CINAHL and in http://clinicaltrials.gov . Eligibility criteria were randomized, non-randomized, and observational studies that used photobiomodulation for the treatment of oral mucositis. The endpoints were reduction in the severity of oral mucositis, duration of lesions, and pain reduction. For data analysis, the Review Manager 5.4 program was used.

RESULTS

A total of 316 studies were identified, 297 in the electronic databases and 19 in http://clinicaltrials.gov . After removing duplicates, 260 studies were selected for title and abstract reading, of which 223 were excluded. A total of 37 studies were chosen for full reading, of which 6 were included in the review, totaling 299 patients. The treatment used was photobiomodulation. The patients were divided into two groups: the laser group used only photobiomodulation or associated with other therapies, and the control group did not use photobiomodulation. For the endpoint reduction in the severity of oral mucositis (OM), the chance of reduction of the OM was greater in the laser group as compared to the control group. For the endpoints duration of OM lesions and pain reduction, it was not possible to carry out a meta-analysis due to the high heterogeneity between studies. In the interpretation of the meta-analysis, the reduction in the severity of oral mucositis was greater in the group that received photobiomodulation.

CONCLUSION

Photobiomodulation was effective in the treatment of oral mucositis.

Red, infrared, and simultaneous laser-wavelengths irradiation effects on 5-fluorouracil-induced oral mucositis in hamsters

The association of more than one wavelength for photobiomodulation therapy (PBMT) to treat oral mucositis (OM) is unusual in the literature. Thus, this study aims to compare the simultaneous irradiation effects with their isolated application to treat OM. In order of that, 48 male Syrian hamsters were divided into 4 groups: Chemotherapy (Ch), which received only a OM induction protocol (5-fluorouracil chemotherapy and superficial oral mucosa scratches); red laser (RL), which received the OM induction and a PBMT protocol at 660 nm; infrared laser (IRL), which received the OM induction, and a PBMT protocol at 808 nm; and the RL + IRL group, which received the simultaneous application, of 660 and 808 nm wavelengths. Clinical (OM grade classification), histological (light microscopy analysis with H&E and collagen staining), immunohistochemical (TNF-α expression), and biochemical (TNF-α and hydroxyproline concentration) analyzes were performed after 7 and 10 days. Mainly on the 10th day, the RL and IRL groups showed lower OM grades and faster microscopic repair process, with greater expression of collagen fibers and lower TNF-α levels, besides the higher hydroxyproline concentrations, mainly in comparison with the Ch group. In conclusion, in this study, the simultaneous protocol did not present superior results than the isolated irradiations.

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.

5G Electromagnetic Radiation Attenuates Skin Melanogenesis In Vitro by Suppressing ROS Generation

Recently, the impacts of 5G electromagnetic radiation (EMR) with 28 GHz on human health have been attracting public attention with the advent of 5G wireless communication. Here, we report that 5G (28 GHz) EMR can attenuate the skin pigmentation in murine melanoma cells (B16F10) and a 3D pigmented human epidermis model (Melanoderm™). B16 cells were exposed to 5G (28 GHz) with or without α-MSH for 4 h per day. Interestingly, 5G attenuated α-MSH-induced melanin synthesis. Fontana-Masson staining confirmed that the dendritic formation of α-MSH stimulated B16 cells was diminished by 5G exposure. To confirm the anti-melanogenic effect of 5G EMR, MelanoDerm™ was irradiated with 5G at a power intensity of 10 W/m² for 4 h a day for 16 days and melanin distribution was detected with Fontana-Masson staining, which supported the anti-melanogenic effect of 5G EMR. Consistently, 5G EMR suppressed α-MSH induced upregulation of melanogenic enzymes; tyrosinase, TRP-1, and TRP-2. Of note, 5G EMR attenuated ROS production stimulated by α-MSH and H₂O₂, suggesting that 5G EMR may dissipate ROS generation, which is pivotal for the melanin synthesis. Collectively, we demonstrated that 5G EMR can attenuate skin pigmentation by attenuating ROS generation.

Heptamethine Cyanine-Loaded Nanomaterials for Cancer Immuno-Photothermal/Photodynamic Therapy: A Review

The development of strategies capable of eliminating metastasized cancer cells and preventing tumor recurrence is an exciting and extremely important area of research. In this regard, therapeutic approaches that explore the synergies between nanomaterial-mediated phototherapies and immunostimulants/immune checkpoint inhibitors have been yielding remarkable results in pre-clinical cancer models. These nanomaterials can accumulate in tumors and trigger, after irradiation of the primary tumor with near infrared light, a localized temperature increase and/or reactive oxygen species. These effects caused damage in cancer cells at the primary site and can also (i) relieve tumor hypoxia, (ii) release tumor-associated antigens and danger-associated molecular patterns, and (iii) induced a pro-inflammatory response. Such events will then synergize with the activity of immunostimulants and immune checkpoint inhibitors, paving the way for strong T cell responses against metastasized cancer cells and the creation of immune memory. Among the different nanomaterials aimed for cancer immuno-phototherapy, those incorporating near infrared-absorbing heptamethine cyanines (Indocyanine Green, IR775, IR780, IR797, IR820) have been showing promising results due to their multifunctionality, safety, and straightforward formulation. In this review, combined approaches based on phototherapies mediated by heptamethine cyanine-loaded nanomaterials and immunostimulants/immune checkpoint inhibitor actions are analyzed, focusing on their ability to modulate the action of the different immune system cells, eliminate metastasized cancer cells, and prevent tumor recurrence.

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.

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.

Evaluation of the salivary function of patients in treatment with radiotherapy for head and neck cancer submitted to photobiomodulation

Background

Head and neck radiotherapy is typically associated with toxicities that can have profound effects on the patient's quality of life. Xerostomia, which may or may not be related to hypofunction of the salivary gland, leading to negative consequences, mainly in quality of life, leaving patients more susceptible to the development of oral mucositis, dental caries, oral infection and difficulties in speech is one of the most common side effects of such treatment. The aim of the present study was to evaluate salivary function of patients in treatment with radiotherapy for head and neck cancer submitted to photobiomodulation.

Material and Methods

A cross-sectional study with a quantitative approach was carried out in the Dentistry Department of the Hospital de Câncer de Pernambuco between February and September 2019.

Results

The study sample comprised 23 patients of both genders, treated with radiotherapy for cancer in the head and neck region. The patients were submitted to photobiomodulation with infrared laser, as intraoral applications in order to prevent mucositis and extraoral applications to stimulate salivary glands. The applications were undertaken three times a week on alternate days throughout the radiotherapy period. The following parameters were used: Intraoral 15mW, 12J / cm2, 10s / point, 2.4 J / point, and extraoral 30mW, 7.5J / cm2, 10s / point, 0.3J / point, both with a wavelength of 830nm and area of 0.028cm². Subjective and objective symptoms were evaluated by measuring the unstimulated salivary flow (USF) using the spitting technique before, during and after radiotherapy treatment. For statistical analysis, a significance level of 5% was adopted. Most patients were male (70%) with 60 years of age on average. At the beginning of treatment, 22 patients had USF> 0.2 ml / min (grade 1), at the end of which 15 patients remained unchanged and only 3 patients progressed to grade 3. As for the subjective classification, most (52%) remained in grade 1 (absence of disability) throughout the treatment.

Conclusions

Based upon the results of this study it was possible to conclude that the use of photobiomodulation did not significantly interfere with the xerostomia complaint of patients in treatment with radiotherapy, however, it does seem to prevent patients from reaching higher degrees of xerostomia taking into account salivary flow measures.

Key words:Photobiomodulation, head and neck neoplasms, radiotherapy, xerostomia, saliva.

Does laser photobiomodulation prevent hyposalivation in patients undergoing head and neck radiotherapy? A systematic review and meta-analysis of controlled trials

INTRODUCTION

Head and neck radiotherapy can cause hypofunction of the salivary glands. Many studies report that laser photobiomodulation (PBM) is able to minimize radiation-induced hyposalivation, yet there is no consensus about its effects.

OBJECTIVE

To carry out a meta-analysis of controlled clinical trials that used PBM to prevent radiation-induced hyposalivation.

METHODS

A systematic search was performed through Embase, Medline/PubMed, Cochrane, EBSCO, Scopus, LILACS and Web of Science databases. The strategy included comparisons of the effect of PBM with placebo/clinical follow-up on unstimulated and/or stimulated salivary flow in patients undergoing head and neck radiotherapy.

RESULTS

Six clinical trials were included, five of which were used for meta-analysis. Evidence was observed between the use of PBM and increased unstimulated salivary flow (MD 0.20 mL/min, 95 % Cl 0.10-0.30, I² = 96 %, p < 0.00001) and in stimulated salivary flow (MD 0.27 mL/min, 95 % CI 0.08-0.46, I² = 95 %, p < 0.00001).

CONCLUSION

PBM appears to minimize radiation-induced hyposalivation.

Local tissue electrical parameters predict oral mucositis in HNSCC patients: A diagnostic accuracy double-blind, randomized controlled trial

Oral Mucositis (OM) is a common adverse effect of head and neck squamous cell carcinoma (HNSCC) treatment. The purpose of this study was to investigate the significance of early changes in tissue electrical parameters (TEPs) in predicting the development of OM in HNSCC patients receiving radiation therapy (RT). The current study combined two study designs. The first was a case-control study. The control group comprised of RT patients who did not receive head and neck RT, and patients with HNSCC who received RT comprised the case group. In the second part of the study, the case group was included in a parallel cohort. A total of 320 patients were assessed for eligibility, and 135 patients were enrolled. Double blinding was performed, and neither the patients nor the care providers knew the measured parameters. The primary outcome was the detection of between-group changes in local TEPs over the follow-up period. The secondary outcome was the appearance of OM grades II, III, or IV and the predictive value of local TEPs in determining the incidence of OM after RT. The variables, impedance module, resistance, reactance, phase angle, and capacitance, were analyzed by the receiver operator curves (ROC). The case and control groups did not differ in demographic and clinical characteristics. Radiation therapy increased the local impedance module, resistance, reactance, and phase angle and reduced the local tissue capacitance in both groups. Evaluation of TEPs in the first week of RT correlated with the development of OM lesions during cancer therapy. ROC analysis showed that local impedance module and resistance presented higher specificity than did other parameters in predicting OM. In conclusion, local tissue electrical parameters measured at the first RT week can be useful tools to predict oral mucositis.

Improvement of full-thickness rat skin wounds by photobiomodulation therapy (PBMT): A dosimetric study

Basic dosimetric studies are necessary to support the use of photobiomodulation therapy (PBMT), since the great variety of laser parameters that are reported in the literature have created an obstacle to identifying reproducible results. Thus, the present study evaluates the process of tissue repair after the photobiomodulation therapy, taking into consideration the dose, frequency and the mode of energy delivery used. For this, 6 mm diameter wounds were created on dorsal skin of Wistar rats, and the animals were divided in control and irradiated groups, where L1 and L4 (irradiated with 1 point of 10 J/cm2), L2 and L5 (5 points of 10 J/cm2), L3 and L6 (1 point of 50 J/cm2), respectively for one or multiple days of irradiations. A diode laser, λ 660 nm, 40 mW of power and 0.028 cm2 of spot area was used. Our data showed that the group receiving multiple treatments over the first week post wounding, applied at 10 J/cm2 at each of 5 points on and around the wound (group L5) presented the best improvement of wound closure, higher cytokeratin 10, lower macrophage infiltration, and greater tissue resistance to rupture. We conclude that PBMT improves the skin wound healing process, and the outcomes were directly related to the chosen laser parameters and irradiation mode.

Treatment of mucositis with combined 660- and 808-nm-wavelength low-level laser therapy reduced mucositis grade, pain, and use of analgesics: a parallel, single-blind, two-arm controlled study

Oral squamous cell carcinoma (OSCC) is the most frequent oral malignant neoplasia. As consequence of OSCC treatment, oral mucositis (OM) is one of the most common adverse effects of OSCC treatment. Currently, there is no consensus for OM treatment. The purpose of the current study was to test the combination of red and infrared low-level laser therapy (LLLT) for OM treatment. Primary culture of human fibroblast was performed to identify LLLT dose. After laboratory tests, a two-arm parallel, single-blind, controlled study was conducted. The two arms were group 1, both 660- and 808-nm wavelengths (300 J/cm², 9 J of total energy, 100 mW, spot size 3 mm²), and group 2, only 660-nm wavelength (300 J/cm², 9 J of total energy, 100 mW, spot size 3 mm²). Both treatments were performed twice a week. Group 1 presented a reduction of mucositis grade in comparison to group 2. Group 1 also presented reduction of analgesics prescription. But no significant differences between groups 1 and 2 were observed according to the pain scale. In conclusion, the current study demonstrated that a combination of red and infrared at a higher dose (300 J/cm²) reduced both oral mucositis grade and analgesics prescription. The effects of the combination of RT and LLLT are unclear and need more studies.

High-power diode laser on management of drug-induced gingival overgrowth: Report of two cases and long-term follow-up

BACKGROUND

Drug-induced gingival overgrowth (DIGO) is attributed mainly to the prolonged use of calcium channel blocking agents, anticonvulsants, and anti-calcineurin inhibitors . The management of DIGO depends on the severity of the disease and includes surgical intervention and plaque control. Compared to conventional surgical treatment, the recent literature data have shown that gingivectomy using a high-power laser (HPL) is a short and easy procedure, which results in minimal postoperative discomfort and greater patient accep- tance.

OBJECTIVE AND METHODS

The purpose of this study was to report two cases of recurrent DIGO treated surgically using HPL (λ 808nm, 1.5W).

RESULTS

Minimal bleeding and discomfort were observed during surgery, and patients reported no pain or bleeding after the procedure. After 1 year of follow-up, patients presented a minimal increase of gingival volume, indicating that laser technology can improve the efficiency and prognosis of DIGO.

CONCLUSIONS

The HPL was able to preventing hemorrhage and improving the patient's collaboration with the treatment and quality of life.

Comparative study among three different phototherapy protocols to treat chemotherapy-induced oral mucositis in hamsters

In this study, clinical, biochemical and histological analysis were used to compare different phototherapies, including LED, low and high-power laser (HPL) for the treatment of chemotherapy (CT)-induced oral mucositis (OM). One-hundred-fifty hamsters were divided into five groups: C: control; CH: CT/OM induction; L: CT/OM induction and treatment with LED (635 nm, 1.2 J), HL: CT/OM induction and treatment with HPL (808 nm, 10 J), LL: CT/OM induction and treatment with low-level laser therapy (LLLT) (660 nm, 1.2 J). OM was induced by scratches performed on check pouch mucosa after two injections of 5-Fluorouracil. The experiment lasted 10 days and OM was analyzed by specific clinical scales on days 5, 7 and 10. The animals were euthanized and the cheek pouch mucosa removed for biochemical (TNF-α concentration) and histological (light microscopy) analysis. After statistical analysis, the authors' results showed LED and LLLT therapies were efficient treatments for OM, decreasing TNF-α concentration on day 7 (p < 0.05) and completely healing the mucosa on day 10. HPL showed no interference in final healing of OM. According to the methodology used and the results obtained in the present study, LLLT and LED therapies were the best choices to decrease the severity of OM, accelerating tissue repair and decreasing the inflammatory process. Clinical evaluation of OM in Groups CH, LL, L and HL and their respective arrangement of phototherapy treatments at different time intervals (5, 7 and 10 days).

The Effectiveness of Low-Level Laser Therapy in Patients with Drug-Induced Hyposalivation: A Pilot Study

OBJECTIVE

The aim of this study was to compare switched on and switched off (sham) low-level laser therapy (LLLT) in the treatment of drug-induced hyposalivation.

BACKGROUND DATA

Hyposalivation is decreased salivary flow rate most frequently present in patients who take a lot of medication, suffer from Sjögren's syndrome, or were irradiated. Available therapies provide only short-term relief.

MATERIALS AND METHODS

Forty-three participants (40 females and 3 males, average age 72.3 ± 8.9) participated in the study. Before therapy or after therapy, every participant fulfilled quality-of-life assessment scale (OHIP-CRO14). Unstimulated and stimulated salivary flow rates were measured before and after treatment. The LLLT was performed by the use of gallium-aluminum-arsenide (GaAlAs) laser (830 nm) on parotid, submandibular, and sublingual glands every day except during weekends for 14 days.

RESULTS

Significant difference in unstimulated salivary flow rate after the treatment was found in the study group (p = 0.002) compared with the sham group. No significant difference in stimulated salivary flow rate after treatment was found in the laser group (p = 0.626) nor in the sham laser group (p = 0.233). No significant difference in patient's quality-of-life score was found after both treatments.

CONCLUSIONS

The results of this study showed that the LLLT increased unstimulated salivary flow rate significantly. However, stimulated salivary flow rate did not increase significantly after the LLLT. In patients who underwent sham laser therapy, neither unstimulated nor stimulated salivary flow rate increased significantly.

Low-level laser therapy for the prevention of low salivary flow rate after radiotherapy and chemotherapy in patients with head and neck cancer

Objective

To determine whether low-level laser therapy can prevent salivary hypofunction after radiotherapy and chemotherapy in head and neck cancer patients.

Materials and Methods

We evaluated 23 head and neck cancer patients, of whom 13 received laser therapy and 10 received clinical care only. An InGaAlP laser was used intra-orally (at 660 nm and 40 mW) at a mean dose of 10.0 J/cm² and extra-orally (at 780 nm and 15 mW) at a mean dose of 3.7 J/cm², three times per week, on alternate days. Stimulated and unstimulated sialometry tests were performed before the first radiotherapy and chemotherapy sessions (N0) and at 30 days after the end of treatment (N30).

Results

At N30, the mean salivary flow rates were significantly higher among the laser therapy patients than among the patients who received clinical care only, in the stimulated and unstimulated sialometry tests (p = 0.0131 and p = 0.0143, respectively).

Conclusion

Low-level laser therapy, administered concomitantly with radiotherapy and chemotherapy, appears to mitigate treatment-induced salivary hypofunction in patients with head and neck cancer.

Low-level laser irradiation promotes the proliferation and maturation of keratinocytes during epithelial wound repair

Low-level laser therapy (LLLT) has been extensively employed to improve epithelial wound healing, though the exact response of epithelium maturation and stratification after LLLT is unknown. Thus, this study aimed to assess the in vitro growth and differentiation of keratinocytes (KCs) and in vivo wound healing response when treated with LLLT. Human KCs (HaCaT cells) showed an enhanced proliferation with all the employed laser energy densities (3, 6 and 12 J/cm(2) , 660 nm, 100 mW), together with an increased expression of Cyclin D1. Moreover, the immunoexpression of proteins related to epithelial proliferation and maturation (p63, CK10, CK14) all indicated a faster maturation of the migrating KCs in the LLLT-treated wounds. In that way, an improved epithelial healing was promoted by LLLT with the employed parameters; this improvement was confirmed by changes in the expression of several proteins related to epithelial proliferation and maturation. Immunofluorescent expression of cytokeratin 10 (red) and Cyclin D1 (green) in (A) Control keratinocytes and (B) Low-level laser irradiated cells. Blue color illustrates the nuclei of the cells (DAPI staining).

Antimicrobial Photodynamic Therapy to treat chemotherapy-induced oral lesions: Report of three cases

The development of Angular Cheilitis and the reactivation of Herpes Simplex Virus, could be related to a decrease in the resistance of the immune system in the infected host, being common in cancer patients receiving antineoplastic chemotherapy. The objective of the present manuscript is to report Antimicrobial Photodynamic Therapy as a treatment of infected oral lesions of patients submitted to chemotherapy.

Clinical, biochemical and histological study of the effect of antimicrobial photodynamic therapy on oral mucositis induced by 5-fluorouracil in hamsters

Oral mucositis (OM) is a debilitating side effect of chemotherapy, which can be relieved by phototherapy. Antimicrobial photodynamic therapy (aPDT) may be used for the treatment of OM, when infection is present. However, there are no studies showing that aPDT affects tissue repair process when used in the treatment of lesions caused by OM. This work aims to evaluate the effect of aPDT in healing OM induced by 5-Fluorouracil (5-FU). Two hundred forty-five hamsters were divided into two groups, control (C) and experimental, which were subdivided into 4 subgroups (Ch, ChP, ChL, aPDT). C group received only the vehicle of chemotherapy and anesthesia, whereas all animals of the experimental groups received anesthesia and chemotherapy agent 5-FU to induce OM. Ch group received no OM treatment; ChP group received an application of methylene blue (MB) 0.01%; ChL received irradiation with low-power-laser (LPL-660 nm/120 J /cm(2)/40 mW/4.4 J per point); and aPDT received MB and LPL irradiation. OM Clinical severity were daily assessed by a blinded examiner. The animals were sacrificed after 5, 7 and 10 days of experiment and their oral mucosa were removed for biochemical (enzymatic activity of SOD and catalase) and histological analyzes (light microscopy). After statistical analysis was performed, results showed that aPDT reduced the severity of OM on the tenth day of the experiment, when compared to the initial OM score (p < 0.05), as well as increased keratinization with organized collagen deposition in the lamina propria. In conclusion, aPDT can be safely used in animals with infected OM because it does not affect lesion-repairing processes.

[Use of laser for the prevention and treatment of oral mucositis induced by radiotherapy and chemotherapy for head and neck cancer]

One of the complications of radiotherapy and chemotherapy is oral mucositis. Since the low energy laser is one of the most frequently recommended interventions by authors and international societies, the aim of this study is to review the scientific evidence on the use of lasers as a preventive and therapeutic in oral mucositis associated with treatment of cancer. We performed a literature search in PubMed and The Cochrane Collaboration Library, limiting the search to the last 20 years. We finally included 29 articles that contained 30 studies. Low energy laser phototherapy seems a promising intervention in both the prevention and treatment of oral mucositis associated with cancer treatment. Virtually all studies reviewed showed good results with no adverse effects and reductions in both incidence and severity of mucositis in all types of cancer treatments.

Laser phototherapy accelerates oral keratinocyte migration through the modulation of the mammalian target of rapamycin signaling pathway

Keratinocytes play a central role in wound healing by responding to tissue injury through the activation of cellular proliferation and migration. Current clinical evidence suggests that the laser phototherapy (LPT) accelerates wound healing in a variety of oral diseases; however, the molecular mechanisms involved in response to LPT are not fully understood. Oral keratinocytes (NOK-SI) maintained under nutritional-deficit culture medium (2% fetal bovine serum) were irradiated with InGaAlP laser (660 nm; 40 mW; 0.04  cm2 spot size) in punctual and contact modes. The energy densities used were 4 and 20  J/cm2 corresponding to 4 and 20 s of exposure times and 0.16 and 0.8 J of energy per point, respectively. Three sessions of irradiations were applied with 6-h intervals. Further, the impact of LPT over cellular migration, proliferation, and activation of the mammalian target of rapamycin (mTOR) pathway, known to play a major role in epithelial migration and wound healing, was analyzed. Compared with control cells, the LPT-treated cells showed accelerated cellular migration without any changes in proliferation. Furthermore, LPT resulted in an increase in the phospho-S6 ribosomal protein, indicating activation of the mTOR signaling pathway. Collectively, these findings suggest that the LPT activates mTOR signaling pathway, promotes epithelial cell migration, and accelerates healing of oral mucosa.

Chemotherapy-induced oral mucositis: effect of LED and laser phototherapy treatment protocols

BACKGROUND AND OBJECTIVE

Over the last few decades, many studies have focused on the effect of lasers on the management of oral mucositis in oncologic patients treated with chemotherapy and/or radiotherapy. However, the effect of light-emitting diode (LED) has been poorly studied, and was not compared with that of laser phototherapy (LPT). For this reason, the aim of the present study was to clinically compare the effect of these two therapies on chemotherapy-induced oral mucositis (CIOM) and pain.

METHODS

Forty patients with CIOM were divided into two groups: G1, patients treated with LPT; G2, patients treated with LED. The treatment was administered during 10 consecutive days, with exception of weekends. LPT was applied using an InGaAlP laser (660 nm/40 mW/6.6 J cm-(2)/0.24 J per point/0.036 cm(2) of spot size). LED phototherapy was applied using 0.24 J per point/80 mW/630 nm/1 cm(2) of spot size. CIOM was assessed during each session in accordance to the World Health Organization (WHO) score. The patient self-assessed pain was scored on a visual analog scale (VAS).

RESULTS

The mean VAS and WHO scores were significantly smaller in the LED group (p<0.05). However, both groups required the same number of days to reach score zero for mucositis and pain (p>0.05). Moreover, in the group with severe mucositis (score III), there was a lower frequency of patients with complete healing and pain relief, with the exception of analgesia in G2, in which almost all patients were completely relieved from pain.

CONCLUSIONS

These findings suggest that LED therapy is more effective than LPT in the treatment of COIM, with the parameters used in the present study.

Effect of laser phototherapy on enzymatic activity of salivary glands of hamsters treated with 5-Fluorouracil

The chemotherapeutic agent 5-Fluorouracil (5-FU) can induce salivary gland hypofunction (SGH); however, previous studies did not reach final conclusions on the influence of this drug on glandular tissue. Thus, the aim of this study was to investigate the effect of 5-FU on submandibular (SMs) and sublingual glands (SLs), as well as, the effect of laser phototherapy (LPT) on SGH induced by 5-FU. Eighty-five hamsters were divided into three groups: control (C), chemotherapy (CT) and laser (L), and the SGH was induced by two injections of 5-FU in groups CT and L. The irradiation was performed using a diode (λ780 nm/20 mW/5 J cm(-2)/0.2 J and 10 s per point/spot size of 0.04 cm(2)) and applied daily. On the euthanasia day, SMs and SLs were removed and biochemical analyses were carried out. The lactate dehydrogenase activity was increased in group CT when compared with group C for SLs and SMs (P < 0.05). In addition, the peroxidase and catalase activities were increased and superoxide dismutase was decreased by 5-FU (P < 0.05). However, LPT appears to be a protective mechanism against oxidative stress, tending to alter the activity of these antioxidant enzymes, suggesting LPT as a promising therapy to modulate the 5-FU harmful effect.

Repercussões da radioterapia na região orofacial e seu tratamento

A radioterapia em região de cabeça e pescoço provoca inúmeras sequelas ao paciente irradiado, afetando o sistema estomatognático e com repercussões sistêmicas importantes. As sequelas da radiação ionizante podem ser extensas e, algumas vezes, permanentes, em especial nas glândulas salivares e no tecido ósseo. É relevante que o cirurgião dentista tenha conhecimento das reações adversas e das formas adequadas de prevenção e tratamento para amenizar o desconforto e melhorar a condição de vida do paciente irradiado. Portanto, a conscientização e motivação deste paciente, com a promoção de saúde oral através da adequação do meio bucal e orientações sobre ações preventivas, são essenciais para se obter o melhor prognóstico.

Laser phototherapy as a treatment for radiotherapy-induced oral mucositis

Oral mucositis is a harmful side effect of radiotherapy (RT) on the head and neck region. There are encouraging reports on the beneficial aspects of the use of laser light on the treatment of oral mucositis. This paper reports the efficacy of laser phototherapy (LPT) on the treatment of oral mucositis in a patient undergoing RT after surgical removal of a squamous cell carcinoma with osseous invasion of the maxilla. Palatal and commissural lesions were treated with λ660 nm, 40 mW, ∅=4 mm(2), in contact mode, 5 x 2.4 J/cm(2) per point, 14.4 J/cm(2) per session. For treating the lesion on the patient's nasal mucosa, LPT (∅=4 mm(2), λ780 nm, 70 mW, 3 x 2.1 J/cm(2) per point, 6.3 J/cm(2) per session, contact mode) was used on the external area of the nose. A single dose (2.4 J/cm(2)) with the λ660 nm laser, as described before, was applied on the entrance of each nostril. LPT was used 3 times/week during 4 weeks. Treatment results indicate that the use of LPT on oral mucositis was effective and allowed the patient to carry on the RT without interruption. However, long-term and controlled clinical trials are necessary to establish both preventive and curative protocols using LPT.

Low-level infrared laser effect on plasmid DNA

Low-level laser therapy is used in the treatment of many diseases based on its biostimulative effect. However, the photobiological basis for its mechanism of action and adverse effects are not well understood. The aim of this study, using experimental models, was to evaluate the effects of laser on bacterial plasmids in alkaline agarose gel electrophoresis and Escherichia coli cultures. The electrophoretic profile of bacterial plasmids in alkaline agarose gels were used for studying lesions in DNA exposed to infrared laser. Transformation efficiency and survival of Escherichia coli AB1157 (wild-type), BH20 (fpg/mutM(-)), BW9091 (xth(-)), and DH5αF'Iq (recA(-)) cells harboring pBSK plasmids were used as experimental models to assess the effect of laser on plasmid DNA outside and inside of cells. Data indicate low-level laser: (1) altered the electrophoretic profile of plasmids in alkaline gels at 2,500-Hz pulsed-emission mode but did not alter at continuous wave, 2.5- and 250-Hz pulsed-emission mode; (2) altered the transformation efficiency of plasmids in wild-type and fpg/mutM(-) E. coli cells; (3) altered the survival fpg/mutM(-), xthA(-) and recA(-) E. coli cultures harboring pBSK plasmids. Low-level infrared laser with therapeutic fluencies at high frequency in pulsed-emission modes have effects on bacterial plasmids. Infrared laser action can differently affect the survival of plasmids in E. coli cells proficient and deficient in DNA repair mechanisms, therefore, laser therapy protocol should take into account fluencies, frequencies and wavelength of laser, as well as tissue conditions and genetic characteristics of cells before beginning treatment.

Effect of intraoral low-level laser therapy on quality of life of patients with head and neck cancer undergoing radiotherapy

BACKGROUND

Low-level laser therapy has been used to reduce complications of head and neck cancer treatment. The aim was to assess the impact of laser in the quality of life (QOL) of patients receiving radiotherapy.

METHODS

Sixty outpatients were randomly assigned into 2 groups. The laser group received applications and the placebo group received sham laser. QOL was assessed using the University of Washington QOL questionnaire. A repeated-measures analysis of variance (ANOVA) was used for comparisons of overall QOL scores and Mann-Whitney test compared changes in domain scores.

RESULTS

A decrease in QOL scores was observed in both groups and the reduction in the laser group was significantly lower (p < .01). Changes in QOL scores regarding pain, chewing, and saliva domains were evident in the placebo group. Both health-related QOL and overall QOL were rated higher by patients who received laser therapy.

CONCLUSION

Laser therapy reduces the impact of radiotherapy on the QOL of patients with head and neck cancer.

Photodynamic therapy mediated by methylene blue dye in wound healing

OBJECTIVE

We sought to investigate the wound-healing process after photodynamic therapy (PDT) mediated by methylene blue dye (MB).

BACKGROUND DATA

Few scientific studies show the PDT roles in wound healing.

MATERIALS AND METHODS

One hundred rats were given a circular wound on the back, inflicted with a 6-mm-diameter punch. The animals were divided into four groups: control (no treatment); dye (topical application of MB); laser (InGaAlP, 117.85 J/cm(2), 100 mW, 660 nm, single point); and PDT (topical application of MB followed by laser irradiation). After 1, 3, 5, 7, and 14 days, the cutaneous wounds were photographed and assessed with histopathologic examination by using light microscope. Changes seen in edema, necrosis, inflammation, granulation tissue, re-epithelialization, and number of young fibroblasts were semiquantitatively evaluated. The wound-area changes were measured with special software and submitted to statistical analysis.

RESULTS

The laser group demonstrated the smallest wound area at 14 days after the surgical procedure (p < 0.01). Concerning complete re-epithelialization, the laser group showed it at 5-7 days after surgery, whereas the PDT and the other groups showed it at 14 days.

CONCLUSIONS

Laser interaction with tissue is somehow changed when exposed to the MB. PDT mediated by MB was not prejudicial to wound healing, as no delay occurred compared with the control group.

Laser phototherapy for Stevens-Johnson syndrome: a case report

BACKGROUND AND OBJECTIVE

Stevens-Johnson syndrome (SJS) is a life-threatening dermatosis characterized by epidermal sloughing and stomatitis. We report the case of a 7-year-old boy in whom laser phototherapy (LPT) was highly effective in reversing the effects of an initial episode of SJS that had apparently developed in association with treatment with phenobarbital for a seizure disorder. The patient was first seen in the intensive care unit (ICU) of our institution with fever, cutaneous lesions on his extremities, trunk, face, and neck; mucosal involvement of his genitalia and eyes (conjunctivitis); ulcerative intraoral lesions; and swollen, crusted, and bleeding lips. He reported severe pain at the sites of his intraoral and skin lesions and was unable to eat, speak, swallow, or open his mouth.

MATERIALS AND METHODS

Trying to prevent and minimize secondary infections, gastric problems, pain, and other complications, the patient was given clindamycin, ranitidine, dipyrone, diphenhydramine (Benadryl) drops, and morphine. In addition, he was instructed to use bicarbonate solution and Ketoconazole (Xylogel) in the oral cavity. Because of the lack of progress of the patient, the LPT was selected.

RESULTS

At 5 days after the initial session of LPT, the patient was able to eat gelatin, and on the following day, the number and severity of his intraoral lesions and his labial crusting and swelling had diminished. By 6 days after his initial session of LPT, most of the patient's intraoral lesions had disappeared, and the few that remained were painless; the patient was able to eat solid food by himself and was removed from the ICU. Ten sessions of LPT were conducted in the hospital. The patient underwent three further and consecutive sessions at the School of Dentistry, when complete healing of his oral lesions was observed.

CONCLUSION

The outcome in this case suggests that LPT may be a new adjuvant modality for SJS complications.

Laser light may improve the symptoms of oral lesions of cicatricial pemphigoid: a case report

OBJECTIVE

The aim of this work is to report the handling of a patient suffering from cicatricial pemphigoid (CP) treated with laser phototherapy (LPT) and systemic steroids.

BACKGROUND DATA

CP is a group of rare chronic autoimmune blistering diseases that predominately affect the mucous membranes and occasionally the skin. The gingiva is most commonly involved, followed by the palate and the buccal mucosa. High-dosage systemic steroids are widely used for its treatment. LPT has been shown to improve wound healing and relieve pain. Its efficacy depends on the amount of energy delivered to the tissue, exposure time, and delivery method.

MATERIALS AND METHODS

A white 47-y-old man with CP who used systemic steroids for the previous 5 y was examined at our clinic. Extra- and intraoral examination revealed classic signs of the condition. LPT (GaAlAs diode laser, 660 nm wavelength, 30 mW, continuous wave, diameter approximately 3 mm, 60 J/cm(2) per session) was used in association with the steroids. LPT was performed in a punctual contact manner every other day on the oral mucosa. Maintenance of the treatment was carried out weekly because interruption of the LPT resulted in the recurrence of the lesions. At the time that this report was written, the patient had been undergoing twice weekly treatments for 6 months without signs of lesion recurrence.

CONCLUSION

Concomitant use of systemic steroids and LPT showed a positive effect on controlling oral CP lesions and on improving both oral health and the quality of life of the patient.