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

Low-level laser therapy/photobiomodulation in the management of side effects of chemoradiation therapy in head and neck cancer: part 2: proposed applications and treatment protocols

PURPOSE

There is a large body of evidence supporting the efficacy of low-level laser therapy (LLLT), more recently termed photobiomodulation (PBM) for the management of oral mucositis (OM) in patients undergoing radiotherapy for head and neck cancer (HNC). Recent advances in PBM technology, together with a better understanding of mechanisms involved and dosimetric parameters may lead to the management of a broader range of complications associated with HNC treatment. This could enhance patient adherence to cancer therapy, and improve quality of life and treatment outcomes. The mechanisms of action, dosimetric, and safety considerations for PBM have been reviewed in part 1. Part 2 discusses the head and neck treatment side effects for which PBM may prove to be effective. In addition, PBM parameters for each of these complications are suggested and future research directions are discussed.

METHODS

Narrative review and presentation of PBM parameters are based on current evidence and expert opinion.

RESULTS

PBM may have potential applications in the management of a broad range of side effects of (chemo)radiation therapy (CRT) in patients being treated for HNC. For OM management, optimal PBM parameters identified were as follows: wavelength, typically between 633 and 685 nm or 780-830 nm; energy density, laser or light-emitting diode (LED) output between 10 and 150 mW; dose, 2-3 J (J/cm(2)), and no more than 6 J/cm(2) on the tissue surface treated; treatment schedule, two to three times a week up to daily; emission type, pulsed (<100 Hz); and route of delivery, intraorally and/or transcutaneously. To facilitate further studies, we propose potentially effective PBM parameters for prophylactic and therapeutic use in supportive care for dermatitis, dysphagia, dry mouth, dysgeusia, trismus, necrosis, lymphedema, and voice/speech alterations.

CONCLUSION

PBM may have a role in supportive care for a broad range of complications associated with the treatment of HNC with CRT. The suggested PBM irradiation and dosimetric parameters, which are potentially effective for these complications, are intended to provide guidance for well-designed future studies. It is imperative that such studies include elucidating the effects of PBM on oncology treatment outcomes.

Effects of pre-radiation exposure to LLLT of normal and malignant cells

PURPOSE

Low-level laser therapy (LLLT) efficacy for the prevention of cancer treatment-induced oral mucositis (OM) has been amply described. However, potential protection of malignant cells remains a legitimate concern for clinicians. We tested LLLT-induced protection from ionizing radiation killing in both malignant and normal cells.

METHODS

We treated six groups each of normal human lymphoblasts (TK6) and human leukemia cells (HL60) with He-Ne LLLT (632.8 nm, 35 mW, CW, 1 cm(2), 35 mW/cm(2) for 3-343 s, 0.1-12 J/cm(2)) prior to exposure to ionizing radiation (IR). Cells were then incubated and counted daily to determine their survival. Optimization of IR dose and incubation time was established prior to testing the effect of LLLT.

RESULTS

Growth curves for both cell lines showed significant declines after exposure to 50-200 cGy IR when compared to controls. Pre-radiation exposure to LLLT (4.0 J/cm(2)) followed by 1-h incubation blocked this decline in TK6 but not in HL60 cells. The latter cells were sensitized to the killing effects of IR in a dose-dependent manner.

CONCLUSION

This study shows that pre-IR LLLT treatment results in a differential response of normal vs. malignant cells, suggesting that LLLT does not confer protection and may even sensitize cancer cells to IR killing.

A critical assessment of oral care protocols for patients under radiation therapy in the regional University Hospital Network of Madrid (Spain)

BACKGROUND

This research was aimed to critically evaluate, under the light of the available scientific evidence, the oral care protocols recommended by different hospitals in head and neck cancer (HNC) patients under radiation therapy.

MATERIAL AND METHODS

A questionnaire requesting all the relevant information for the oral care of these patients was sent to the 9 University Hospitals in Madrid. The answers were categorized and analyzed. In addition, an electronic search was conducted to identify the most relevant papers (systematic reviews [SR] and randomized clinical trials [RCTs]) assessing oral care protocols for patients treated for HNC with radiation therapy.

RESULTS

Eight out of nine centers answered the questionnaire and the retrieved information was tabulated and compared. These recommendations were analyzed by a computerized search on MEDLINE and the Cochrane Oral Health Collaboration Database. The results of the analysis clearly shown a great heterogeneity, in terms of oral health care protocols, regarding the management of irradiated patients (for HNC) within the Hospitals of Madrid region. In addition, some of the recommendations lack solid scientific support.

CONCLUSIONS

The present survey revealed that the recommendations provided by the different hospitals were clearly different. The available evidence, supported by SR and RCTs, suggested the need of an oral assessment before cancer treatment, in order to prevent and treat dental pathologies and avoiding potential complications; during cancer treatment, it is relevant monitoring the patient in order to decrease the severity of the side effects, and to avoid any tooth extraction or surgery and special attention should be paid to mucositis, xerostomia and candidiasis; after cancer treatment, the following are relevant aspects: the risk of osteoradionecrosis, trismus, caries and the risks associated to dental implants.

KEY WORDS

Head and neck cancer, supportive care in cancer, radiotherapy complications, management and oral care on cancer treatment.

Gold-nanorods-siRNA nanoplex for improved photothermal therapy by gene silencing

Nanomaterials-mediated photothermal therapy (PTT) often suffers from the fundamental cellular defense mechanism of heat shock response which leads to therapeutic resistance of cancer cells and reduces the therapeutic efficacy. Herein, a gold nanorods (GNRs)-siRNA platform with gene silencing capability is produced to improve the PTT efficiency. After surface modification, the GNRs show the ability to deliver siRNA oligos targeting BAG3 which is an efficient gene to block the heat-shock response. The synthesized GNRs-siRNA nanoplex exhibits excellent ability in the delivery of siRNA into cancer cells with high silencing efficiency which is even better than that of commercial Lipofectamine 2000. The in vitro and in vivo studies demonstrate the ability of the GNRs-siRNA nanoplex to sensitize the cancer cells to PTT under moderate laser irradiation by down-regulating the increased BAG3 expression and enhancing apoptosis. The GNRs-siRNA mediated PTT has large potential in clinical cancer therapy due to the elimination of therapeutic resistance and enhanced photothermal therapeutic efficacy by means of gene silencing. It also suggests an efficient platform for gene delivery and controllable gene therapy.

Regulatory systemic effect of postsurgical polychromatic light (480-3400 nm) irradiation of breast cancer patients on the proliferation of tumor and normal cells in vitro

OBJECTIVE

The aim of this work was to study the effect of phototherapy (PT) with percutaneous exposures to polychromatic visible and IR light (pVIS + pIR) on breast cancer (BC) patients at the early postmastectomy period, on the growth-promoting (GP) properties of their blood serum, by evaluating its capability to support proliferation of normal and tumor human cells in vitro.

MATERIAL AND METHODS

After mastectomy, one group of patients was treated daily for 1 week on the sacral area with pVIS + pIR light (480-3400 nm, 40 mW/cm(2), 95% polarization, 24 J/cm(2)). The second group used as a control was sham irradiated. Blood serum samples collected before surgery, and 1 and 8 days after surgery, were added (2.5%) into nutrition media for cells instead of 10% of fetal calf serum. Cell targets were cultures of human fibroblasts (FBs), keratinocytes (KCs), three lines of the human BC cells (BT-474, HBL-100, Hs 578T) and cells of human epidermoid carcinoma (A-431). Cell number was evaluated by staining cell nuclei with crystal violet and a spectrometric assay of the extracted dye.

RESULTS

The day after mastectomy there were no significant changes in the GP activity of sera. After a 7-day PT course, an increase of this activity was recorded for normal FBs and KCs by 18% and 24%, respectively, in comparison with presurgical levels. GP activity of the same patients' sera for all tumor cells, BT-474, HBL-100, Hs 578T and A-431, decreased by 32%, 17%, 11%, and 7% respectively. As a result, enhancement of proliferation of KCs and FBs and inhibition of proliferation of tumor cells was seen.

CONCLUSIONS

The results suggest an effect at the systemic level where pVIS + pIR light may stimulate growth of human skin cells and simultaneously downregulate the proliferation of tumor cells, including BC cells. This argues in favor of the oncological safety of PT for BC patients postsurgically.

Supportive Management of Mucositis and Metabolic Derangements in Head and Neck Cancer Patients

Oral mucositis (OM) is among the most undesirable, painful, and expensive toxicities of cytotoxic cancer therapy, and is disheartening for patients and frustrating for caregivers. Accurate assessment of the incidence of OM has been elusive, but accumulating data suggests that reported OM frequency is significantly less than its actual occurrence. It has been suggested that over 90% of head and neck cancer (HNC) patients receiving radiotherapy (RT) with concurrent cisplatin experience severe OM with symptoms of extreme pain, mucosal ulceration and consequent limitations in swallowing and achieving adequate nutritional intake. This panoply of symptoms inevitably impacts a patients' quality of life and their willingness to continue treatment. In spite of all the advances made in understanding the pathophysiology of OM, there is still no prophylactic therapy with proven efficacy. Strategies to limit the extent of OM and to manage its symptomatology include basic oral care, supportive medications, nutritional support and targeting aggressive treatments to high-risk patients. This review focuses on OM recognition, preventive measurements, and symptom-management strategies.

Radiobiological modifiers in clinical radiation oncology: current reality and future potential

Radiation therapy can successfully ablate tumors. However, the same ionization process that destroys a cancer can also permanently damage surrounding organs resulting in unwanted clinical morbidity. Therefore, modern radiation therapy attempts to minimize dose to normal tissue to prevent side effects. Still, as tumors and normal tissues intercalate, the risk of normal tissue injury often may prevent tumoricidal doses of radiation therapy to be delivered. This paper will review current outcomes and limitations of radiobiological modifiers that may selectively enhance the radiosensitivity of tumors as well as parallel techniques that may protect normal tissues from radiation injury. Future endeavors based in part upon newly elucidated genetic pathways will be highlighted.

Biomodulation of Inflammatory Cytokines Related to Oral Mucositis by Low-Level Laser Therapy

This study evaluated the effects of LLLT on the expression of inflammatory cytokines related to the development of oral mucositis by gingival fibroblasts. Primary gingival fibroblasts were seeded on 24-well plates (10(5) cells/well) for 24 h. Fresh serum-free culture medium (DMEM) was then added, and cells were placed in contact with LPS (Escherichia coli, 1 μg mL(-1)), followed by LLLT irradiation (LaserTABLE-InGaAsP diode prototype-780 nm, 25 mW) delivering 0, 0.5, 1.5 or 3 J cm(-2)². Cells without contact with LPS were also irradiated with the same energy densities. Gene expression of TNF-α, IL-1β, IL-6 and IL-8 was evaluated by Real-Time PCR, and protein synthesis of these cytokines was determined by enzyme-linked immunosorbent (ELISA) assay. Data were statistically analyzed by the Kruskal-Wallis test, complemented by the Mann-Whitney test (P < 0.05). LPS treatment increased the gene expression and protein synthesis of TNF-α, IL-6 and IL-8, while the expression of IL-1β was not affected. For LPS-treated groups, LLLT promoted significant decreases in the expression of TNF-α, IL-6, and IL-8 at 1.5 J cm(-2) and 3 J cm(-2). These results demonstrate that LLLT promoted a beneficial biomodulatory effect on the expression of inflammatory cytokines related to oral mucositis by human gingival fibroblasts.

Morphine mouthwash for the management of oral mucositis in patients with head and neck cancer

Background:

Oral mucositis is a debilitating side effect of cancer treatment for which there is not much successful treatments at yet. We evaluated the effectiveness of topical morphine compared with a routine mouthwash in managing cancer treatment-induced mucositis.

Materials and Methods:

Thirty head and neck cancer patients with severe mucositis (World Health Organization Grade III or IV) were randomized into the morphine and magic mouthwash groups. Patients received morphine sulfate 2% or magic solution (contained magnesium aluminum hydroxide, viscous lidocaine, and diphenhydramine), 10 ml for every 3 h, six times a day, for 6 days. Both groups received same dietary and oral hygiene instructions and care. Mucositis was graded at baseline and every 3 days after treatment. Patients’ satisfaction and drug effect maintenance were also evaluated.

Results:

Twenty-eight patients (mean age of 49.5 ± 13.2 years, 63.3% female) completed the trial; 15 in the morphine group and 13 in the magic group. There was a decrease in mucositis severity in both of the morphine (P < 0.001) and magic (P = 0.049) groups. However, at the 6^th day, more reduction was observed in mucositis severity in the morphine compared with magic group (P = 0.045). Drug effect maintenance was similar between the two groups, but patients in the morphine group were more satisfied by their treatments than those in the magic group (P = 0.008).

Conclusions:

Topical morphine is more effective and more satisfactory to patients than the magic mouthwash in reducing severity of cancer treatment-induced oral mucositis. More studies with larger sample size and longer follow-up are required in this regard.

The effects of laser treatment in tendinopathy: a systematic review

Tendons have as main function transmit forces from the muscle to the bones. Tendinopathy is an inflammatory process that occurs in and around the tendon, when these are affected by some injury. Low level laser therapy consists in a local application of a monochromatic, coherent and short wavelength light. Its use began in 60's and since then several benefits for tendon injuries have been reported. The objective of this study is to collect the most recent studies about the use of laser on the tendinopathy treatment. We performed searches on the following electronic databases PubMed, Medline, CAPES journals portal and LILACS. After the analysis, we selected three articles that showed that the use of low-level laser therapy, compared to placebo, is effective in treatment of tendinopathy. Despite the need for more studies about this theme, the low-level laser therapy demonstrates consistent results in the treatment of tendinopathy.

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

BACKGROUND

Oral mucositis is a debilitating side effect of chemotherapy. Laser therapy has recently demonstrated efficacy in the management of oral mucositis (OM).

AIM

This prospective study was conducted to evaluate the efficacy of class IV laser therapy in patients affected by OM.

DESIGN

Eighteen onco-haematological paediatric patients receiving chemotherapy and/or haematopoietic stem cell transplantation, prior to total body irradiation, affected by OM, were enrolled in this study. Patients were treated with class IV laser therapy for four consecutive days; the assessment of OM was performed through WHO Oral Mucositis Grading Objective Scale, and pain was evaluated through visual analogue scale. Patients completed a validated questionnaire, and photographs of lesions were taken during each session. Patients were re-evaluated 11 days after the first day of laser therapy.

RESULTS

All patients demonstrated improvement in pain sensation, and all mucositis was fully resolved at the 11-day follow-up visit, with no apparent side effects. Laser therapy was well tolerated with remarkable reduction in pain associated with oral mucositis after 1-2 days of laser therapy.

CONCLUSIONS

Given class IV laser therapy appears to be safe, non-invasive, and potentially effective, prospective, randomized, controlled trials are necessary to further assess efficacy and to determine optimal treatment parameters.

Effect of prophylactic low level laser therapy on oral mucositis: a systematic review and meta-analysis

BACKGROUND

Objective was to determine whether prophylactic low level laser therapy (LLLT) reduces the risk of severe mucositis as compared to placebo or no therapy.

METHODS

MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were searched until February 2014 for randomized controlled trials (RCTs) comparing prophylactic LLLT with placebo or no therapy in patients with cancer or undergoing hematopoietic stem cell transplantation (HSCT). All analyses used random effects models.

RESULTS

Eighteen RCTs (1144 patients) were included. Prophylactic LLLT reduced the overall risk of severe mucositis (risk ratio (RR) 0.37, 95% confidence interval (CI) 0.20 to 0.67; P = 0.001). LLLT also reduced the following outcomes when compared to placebo/no therapy: severe mucositis at the time of anticipated maximal mucositis (RR 0.34, 95% CI 0.20 to 0.59), overall mean grade of mucositis (standardized mean difference -1.49, 95% CI -2.02 to -0.95), duration of severe mucositis (weighted mean difference -5.32, 95% CI -9.45 to -1.19) and incidence of severe pain (RR 0.26, 95% CI 0.18 to 0.37).

CONCLUSION

Prophylactic LLLT reduced severe mucositis and pain in patients with cancer and HSCT recipients. Future research should identify the optimal characteristics of LLLT and determine feasibility in the clinical setting.

Phototherapy 660 nm for the prevention of radiodermatitis in breast cancer patients receiving radiation therapy: study protocol for a randomized controlled trial

BACKGROUND

Breast neoplasms are the second most common type of cancer worldwide, and radiation therapy is a key component of their treatment. Acute skin reactions are one of the most common side effects of radiation therapy, and prevention of this adverse event has been investigated in several studies. However, a clinically applicable, preventative treatment remains unavailable. It has been demonstrated that application of a low-power laser can promote tissue repair. Therefore, the aim of this trial is to evaluate the effectiveness of an indium gallium aluminum phosphorus (InGaAIP) laser operated at 660 nm in preventing radiodermatitis in women undergoing adjuvant radiotherapy for breast cancer.

METHODS/DESIGN

This is a two-arm, randomized controlled trial. A total of 52 patients undergoing radiotherapy for breast cancer (stages I to III) will be enrolled. Patients will be randomly assigned to an intervention group to receive laser therapy (n = 26) or a control group to receive a placebo (n = 26). The laser or placebo will be applied five days a week, immediately before each radiotherapy session. Skin reactions will then be graded weekly by a nurse, a radiotherapist, and an oncologist (all of whom will be blinded) using the Common Toxicity Criteria (CTC) developed by the National Cancer Institute and the Acute Radiation Morbidity Scoring Criteria developed by the Radiation Therapy Oncology Group. Patients will also answer a modified visual analogue scale for pain (a self-evaluation questionnaire). Primary and secondary outcomes will be the prevention of radiodermatitis and pain secondary to radiodermatitis, respectively.

DISCUSSION

The ideal tool for preventing radiodermatitis is an agent that mediates DNA repair or promotes cell proliferation. Application of a low-power laser has been shown to promote tissue repair by reducing inflammation and inducing collagen synthesis. Moreover, this treatment approach has not been associated with adverse events and is cost-effective. Thus, the results of this ongoing trial may establish whether use of a low-power laser represents an ideal treatment option for the prevention of radiodermatitis.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02003599. Registered on 2 December 2013.

[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.

Role of rehabilitation medicine and physical agents in the treatment of cancer-associated pain

PURPOSE

To provide an overview of rehabilitation medicine- and physical modality-based approaches to cancer pain management, and to highlight the fact that these approaches are generally used in conjunction and that a majority are focused on minimizing pain during periods of mobility and the performance of activities of daily living.

METHODS

We performed a nonsystematic literature review and provide a description of the current standard of care.

RESULTS

Rehabilitative and physical modalities used to manage pain can be grouped into four categories: those that modulate nociception, stabilize or unload painful structures, influence physiological processes that indirectly influence nociception, or alleviate pain arising from the overloading of muscles and connective tissues that often occurs after surgery or with sarcopenia in late-stage cancer. Most modalities have been pragmatically refined over the years, and many have an evidence base, although few have been explicitly validated in the oncologic setting. With few exceptions, they are patient controlled and free of adverse effects.

CONCLUSION

Physical modalities and rehabilitation medicine offer a range of pain management approaches that may serve as beneficial adjuncts to the conventional systemic and interventional analgesic strategies used to control cancer-related pain. These approaches may be particularly beneficial to patients with movement-associated pain and those who are ambivalent regarding pharmacoanalgesia.

Significant errors and misdirection in class IV laser therapy study

This Correspondence relates to the article by Ottaviani et al (Effect of Class IV Laser Therapy on Chemotherapy-Induced Oral Mucositis: A Clinical and Experimental Study. Am J Pathol 2013, 183:1747-1757.).

Developments in low level light therapy (LLLT) for dentistry

OBJECTIVES

Low level light/laser therapy (LLLT) is the direct application of light to stimulate cell responses (photobiomodulation) in order to promote tissue healing, reduce inflammation and induce analgesia. There have been significant studies demonstrating its application and efficacy at many sites within the body and for treatment of a range of musculoskeletal injuries, degenerative diseases and dysfunction, however, its use on oral tissues has, to date, been limited. The purpose of this review is to consider the potential for LLLT in dental and oral applications by providing background information on its mechanism of action and delivery parameters and by drawing parallels with its treatment use in analogous cells and tissues from other sites of the body.

METHODS

A literature search on Medline was performed on laser and light treatments in a range of dental/orofacial applications from 2010 to March 2013. The search results were filtered for LLLT relevance. The clinical papers were then arranged to eight broad dental/orofacial categories and reviewed.

RESULTS

The initial search returned 2778 results, when filtered this was reduced to 153. 41 were review papers or editorials, 65 clinical and 47 laboratory studies. Of all the publications, 130 reported a positive effect in terms of pain relief, fast healing or other improvement in symptoms or appearance and 23 reported inconclusive or negative outcomes. Direct application of light as a therapeutic intervention within the oral cavity (rather than photodynamic therapies, which utilize photosensitizing solutions) has thus far received minimal attention. Data from the limited studies that have been performed which relate to the oral cavity indicate that LLLT may be a reliable, safe and novel approach to treating a range of oral and dental disorders and in particular for those which there is an unmet clinical need.

SIGNIFICANCE

The potential benefits of LLLT that have been demonstrated in many healthcare fields and include improved healing, reduced inflammation and pain control, which suggest considerable potential for its use in oral tissues.

Low level laser therapy for the treatment of diabetic foot ulcers: a critical survey

Diabetic foot ulcers as one of the most common complications of diabetes mellitus are defined as nonhealing or long-lasting chronic skin ulcers in diabetic patients. Multidisciplinary care for the diabetic foot is common, but treatment results are often unsatisfactory. Low level laser therapy (LLLT) on wound areas as well as on acupuncture points, as a noninvasive, pain-free method with minor side effects, has been considered as a possible treatment option for the diabetic foot syndrome. A systematic literature review identified 1764 articles on this topic. Finally, we adopted 22 eligible references; 8 of them were cell studies, 6 were animal studies, and 8 were clinical trials. Cell studies and animal studies gave evidence of cellular migration, viability, and proliferation of fibroblast cells, quicker reepithelization and reformed connective tissue, enhancement of microcirculation, and anti-inflammatory effects by inhibition of prostaglandine, interleukin, and cytokine as well as direct antibacterial effects by induction of reactive oxygen species (ROS). The transferral of these data into clinical medicine is under debate. The majority of clinical studies show a potential benefit of LLLT in wound healing of diabetic ulcers. But there are a lot of aspects in these studies limiting final evidence about the actual output of this kind of treatment method. In summary, all studies give enough evidence to continue research on laser therapy for diabetic ulcers, but clinical trials using human models do not provide sufficient evidence to establish the usefulness of LLLT as an effective tool in wound care regimes at present. Further well designed research trials are required to determine the true value of LLLT in routine wound care.

Effects of low-level laser therapy on M1-related cytokine expression in monocytes via histone modification

Low-level laser therapy (LLLT) has been used in the treatment of radiotherapy-induced oral mucositis and allergic rhinitis. However, the effects of LLLT on human monocyte polarization into M1 macrophages are unknown. To evaluate the effects of LLLT on M1-related cytokine and chemokine production and elucidate the mechanism, the human monocyte cell line THP-1 was treated with different doses of LLLT. The expression of M1-related cytokines and chemokines (CCL2, CXCL10, and TNF-α) was determined by ELISA and real-time PCR. LLLT-associated histone modifications were examined by chromatin immunoprecipitation (ChIP) assays. Mitochondrial involvement in the LLLT-induced M1-related cytokine expression was evaluated by quantitative real-time PCR. Flow cytometry was used to detect the cell surface markers for monocyte polarization. The results showed that LLLT (660 nm) significantly enhanced M1-related cytokine and chemokine expression in mRNA and protein levels. Mitochondrial copy number and mRNA levels of complex I-V protein were increased by LLLT (1 J/cm(2)). Activation of M1 polarization was concomitant with histone modification at TNF-α gene locus and IP-10 gene promoter area. This study indicates that LLLT (660 nm) enhanced M1-related cytokine and chemokine expression via mitochondrial biogenesis and histone modification, which may be a potent immune-enhancing agent for the treatment of allergic diseases.

Efficacy of cryotherapy associated with laser therapy for decreasing severity of melphalan-induced oral mucositis during hematological stem-cell transplantation: a prospective clinical study

Melphalan followed by hematopoietic stem-cell transplantation (HSCT) is the standard treatment for multiple myeloma and other hematopoietic neoplasms. However, high doses of melphalan cause severe oral mucositis (OM). The objective was to verify the efficacy of cryotherapy plus laser therapy on reduction of OM severity. HSCT patients undergoing melphalan chemotherapy (n = 71) were randomly divided into two groups according to OM treatment: oral cryotherapy performed with ice chips for 1 h 35 min followed by low-level laser therapy (InGaAIP, 660 nm, 40 mW, 6 J/cm(2) ) (n = 54) and laser therapy alone with the same protocol (n = 17). A control group (n = 33) was composed of HSCT patients treated with melphalan who received no specific treatment for OM. OM scores and clinical information were collected from D0 to D + 11. The cryotherapy/laser therapy group showed the lowest OM scores (maximum Grade I) and the lowest mean number of days (8 days) with OM in comparison with the other groups (p < 0.001). OM Grades III and IV were present with high frequency only in the control group. The association of cryotherapy with laser therapy was effective in reducing OM severity in HSCT patients who underwent melphalan conditioning.

Prevention and treatment of oral mucositis in patients receiving chemotherapy

Oral mucositis is one of the most common side effects of cancer treatment (chemotherapy and/or radiotherapy). It is an inflammatory process that affects the mucosa of the oral cavity, giving rise to erythematous areas in combination with ulcers that can reach a large size. The true importance of oral mucositis is the complications it causes - fundamentally intense pain associated to the oral ulcers, and the risk of overinfection. This in turn may require reduction or even suspension of the antineoplastic treatment, with the risk of seriously worsening the patient prognosis. This points to the importance of establishing therapeutic tools of use in the prevention and/or treatment of mucositis. The present study offers a literature review of all the articles published over the last 10 years referred to the prevention and/or treatment of oral mucositis associated to chemotherapy. Key words:Oral mucositis, management, prevention, treatment, chemotherapy.

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.

A pilot study into the effect of low-level laser therapy in patients with chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a common inflammatory disease of the nose and paranasal sinuses that has a significant impact on patients' quality of life. No study has examined the effectiveness of applying low-level laser therapy (LLLT) locally over the sinuses in patients with CRS. The aim of this study was to evaluate the effect of LLLT in patients with CRS. Fifteen adult patients with CRS participated in this pilot pretest-posttest clinical study. Patients were treated with a 830-nm Ga-Al-As laser in continuous-wave mode at a power output of 30 mW and energy dose of 1 J. Laser irradiation was delivered on six points over each maxillary or frontal sinus with 33 sec irradiation for each point and a total treatment duration of 198 sec for each sinus. Patients were given LLLT three times per week for ten treatment sessions. Patients were asked to score their symptoms in accordance with a four-point scale (0-3), and a total symptom score (TSS) for each patient was calculated. Percentage improvement of TSS was considered as the primary outcome measure. TSS was calculated at baseline (T0), at 2 weeks (T1) and at 4 weeks (T2). The TSS was improved significantly at T1 (39%) and at T2 (46.34%). A large effect size for LLLT was found (ηp(2) ηp(2)  =  0.63). The therapeutic effect was sustained for a mean of 5 months. This pilot study indicates that LLLT applied for 4 weeks improves symptoms in patients with CRS.

Low-level laser therapy for fat layer reduction: a comprehensive review

BACKGROUND AND OBJECTIVE

Low-level laser (light) therapy (LLLT) is a noninvasive, nonthermal approach to disorders requiring reduction of pain and inflammation and stimulation of healing and tissue regeneration. Within the last decade, LLLT started being investigated as an adjuvant to liposuction, for noninvasive body contouring, reduction of cellulite, and improvement of blood lipid profile. LLLT may also aid autologous fat transfer procedures by enhancing the viability of adipocytes. However the underlying mechanism of actions for such effects still seems to be unclear. It is important, therefore, to understand the potential efficacy and proposed mechanism of actions of this new procedure for fat reduction.

MATERIALS AND METHODS

A review of the literature associated with applications of LLLT related to fat layer reduction was performed to evaluate the findings from pre-clinical and clinical studies with respect to the mechanism of action, efficacy, and safety.

RESULTS

The studies as of today suggest that LLLT has a potential to be used in fat and cellulite reduction as well as in improvement of blood lipid profile without any significant side effects. One of the main proposed mechanism of actions is based upon production of transient pores in adipocytes, allowing lipids to leak out. Another is through activation of the complement cascade which could cause induction of adipocyte apoptosis and subsequent release of lipids.

CONCLUSION

Although the present studies have demonstrated safety and efficacy of LLLT in fat layer reduction, studies demonstrating the efficacy of LLLT as a stand-alone procedure are still inadequate. Moreover, further studies are necessary to identify the mechanism of action.

Potentiated anti-inflammatory effect of combined 780 nm and 660 nm low level laser therapy on the experimental laryngitis

Reflux laryngitis is a common clinic complication of nasogastric intubation (NSGI). Since there is no report concerning the effects of low level laser therapy (LLLT) on reflux laryngitis, this study aimed to analyze the protective effect of single and combined therapies with low level laser at the doses of 2.1J and 2.1+1.2 J with a total irradiation time of 30s and 30+30 s, respectively, on a model of neurogenic reflux laryngitis. NSGI was performed in Wistar rats, assigned into groups: NGI (no treatment), NLT17.5 (single therapy), and NLT17.5/10.0 (combined therapy, applied sequentially). Additional non-intubated and non-irradiated rats were use as controls (CTR). Myeloperoxidase (MPO) activity was assessed by colorimetric method after the intubation period (on days 1, 3, 5, and 7), whereas paraffin-embedded laryngeal specimens were used to carry out histopathological analysis of the inflammatory response, granulation tissue, and collagen deposition 7 days after NSGI. Significant reduction in MPO activity (p<0.05) and in the severity of the inflammatory response (p<0.05), and improvement in the granulation tissue (p<0.05) was observed in NLT17.5/10.0 group. Mast cells count was significantly decreased in NGI and NLT17.5 groups (p<0.001), whereas no difference was observed between NLT17.5/10.0 and CTR groups (p>0.05). NLT17.5/10.0 group also showed better collagenization pattern, in comparison to NGI and NLT17.5 groups. This study suggests that the combined therapy successfully modulated the inflammatory response and collagenization in experimental model of NSGI-induced neurogenic laryngitis.

Low-level laser therapy: a standard of supportive care for cancer therapy-induced oral mucositis in head and neck cancer patients?

BACKGROUND AND AIMS

Oral mucositis (OM) is still a common and severe acute side-effect of many oncologic treatments, especially in patients treated for head and neck cancer. It may affect quality of life, require supportive care and impact treatment planning and its efficacy. Low-level laser therapy (LLLT) seems to promote pain relief and reduces OM incidence and its severity. It has been recommended for these patients as a treatment option but without any consensus in the LLLT procedure. New recommendations and perspectives for clinical trials will be discussed. Materials (Subjects) and Methods: Step by step, the efficacy of soft laser in the management of iatrogenic oral mucositis has been evaluated during the last two decades. Its effectiveness and level of recommendation got stronger with time. We will report and discuss some major results and the latest recommendations published on this topic.

RESULTS

The major clinical results have been reported and analysed last year in a first meta-analysis (1)). 11 randomized placebo-controlled trials were selected with a total of 415 patients treated with chemotherapy and/or radiotherapy for head and neck cancer. The relative risk for developing OM was significantly reduced after LLLT but only for a dose between 1 to 6 Joules per point. Pain, severity and duration of OM grade ≥ 2 were also reduced without difference with placebo for possible side-effects. Nine years after the positive results published for patients treated by radiotherapy alone (2)), a new French randomized, multicentric, phase III trial for patients treated with new standard treatment, using LLLT in accordance to recent recommendations is ongoing. Seven centers are specifically established for this trial which should include a hundred patients.

CONCLUSIONS

The very encouraging results of LLLT in the prevention and treatment of OM in patients treated by chemotherapy or radiotherapy for advanced head and neck cancer could soon be proposed as a new standard of care, according to the multinational Association of Supportive care in Cancer (MASCC) criteria. Modern lasers are less time consuming and extraoral applicators for a possible use by trained paramedical staff could be helpful to complete clinician practice. A preventive dose of 2 J/cm(2) and a curative dose of 4 J/cm(2) if using a red wavelength lasers are now recommended.