Low-energy laser therapy for prevention of oral mucositis in hematopoietic stem cell transplantation

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Low-Level Laser Therapy for the Treatment of Oral Mucositis Induced by Hematopoietic Stem Cell Transplantation: A Systematic Review with Meta-Analysis

Oral mucositis is a common and debilitating side effect induced by stem cell transplantation that is experienced by cancer patients undergoing chemotherapy or radiation therapy. This condition involves inflammation and ulceration of the oral mucosa, leading to pain, difficulty with eating and speaking, and an increased risk of infections. Mucositis not only compromises the quality of life for cancer patients, but also affects treatment outcomes and may necessitate dose reductions or treatment delays. This scientific article provides a comprehensive overview of mucositis. The purpose of this literature review with a meta-analysis is to evaluate the efficacy of laser therapy in treating post-transplant mucositis. Materials and methods: A search of the literature from 3 May 2023 was carried out on three online databases, PubMed, Scopus, and Web of Science. Only studies that treated patients with laser therapy were considered; only studies with the placebo-treated control group were considered. Review Manager version 5.2.8 (Cochrane Collaboration) was used for the pooled analysis. We measured the std. mean difference between the two groups (laser and placebo). Results: There were 230 papers included in this review. Two hundred twenty-seven were excluded. Furthermore, a manual search was performed. After the search phase, three articles were considered in the study. The overall effect showed differences in the degree of mucositis in the laser-treated patients compared with the placebo group. The meta-analysis shows a reduction in the degree of mucositis in the patients treated with laser therapy (std. mean difference -1.34 [-1.98; -0.98]; C.I. 95%). Conclusions: The application of laser therapy results in decreased severity of oral mucositis from radiation and chemotherapy. Our study shows that the application of low-level laser therapy in the treatment of transplant mucositis has excellent efficacy in relieving the symptoms and severity of mucositis.

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.

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.

Low-Level Laser Therapy: A Literature Review of the Prevention and Reduction of Oral Mucositis in Patients Undergoing Stem Cell Transplantation

BACKGROUND

Oral mucositis (OM) is a highly debilitating complication of high-dose chemotherapy and total body irradiation used in conditioning regimens for hematopoietic stem cell transplantation (HSCT). Research has studied low-level laser therapy (LLLT) as an alternative treatment for OM because of its anti-inflammatory activity, biomodulation, and analgesic effects.

OBJECTIVES

This study reviews evidence on the effectiveness of LLLT using diode lasers on the prevention and reduction in severity of OM in patients with cancer undergoing HSCT.

METHODS

A literature search was performed in PubMed®, CINAHL®, Scopus®, and MEDLINE® databases. Six randomized controlled trials and one cohort study met the inclusion criteria.

FINDINGS

The data demonstrate promising outcomes for reducing the incidence and severity of OM using LLLT. Larger, tightly controlled clinical trials are needed in the future.

Effects of photobiomodulation on the redox state of healthy and cancer cells

Photobiomodulation therapy (PBMT) uses light to stimulate cells. The molecular basis of the effects of PBMT is being unveiled, but it is stated that the cytochrome-c oxidase enzyme in mitochondria, a photon acceptor of PBMT, contributes to an increase in ATP production and modulates the reduction and oxidation of electron carriers NADH and FAD. Since its effects are not fully understood, PBMT is not used on tumors. Thus, it is interesting to investigate if its effects correlate to mitochondrial metabolism and if so, how it could be linked to the optical redox ratio (ORR), defined as the ratio of FAD/(NADH + FAD) fluorescences. To that end, fibroblasts (HDFn cell line) and oral squamous cell carcinoma (SCC-25 cell line) were irradiated with a light source of 780 nm and a total dose of 5 J/cm2, and imaged by optical microscopy. PBMT down-regulated the SCC-25 ORR by 10%. Furthermore, PBMT led to an increase in ROS and ATP production in carcinoma cells after 4 h, while fibroblasts only had a modest ATP increase 6 h after irradiation. Cell lines did not show distinct cell cycle profiles, as both had an increase in G2/M cells. This study indicates that PBMT decreases the redox state of oral cancer by possibly increasing glycolysis and affects normal and tumor cells through distinct pathways. To our knowledge, this is the first study that investigated the effects of PBMT on mitochondrial metabolism from the initiation of the cascade to DNA replication. This is an essential step in the investigation of the mechanism of action of PBMT in an effort to avoid misinterpretations of a variety of combined protocols.

Long-term safety of photobiomodulation therapy for oral mucositis in hematopoietic cell transplantation patients: a 15-year retrospective study

Photobiomodulation therapy (PBMT) has demonstrated efficacy in the prevention and treatment of oral mucositis (OM) in hematopoietic cell transplantation (HCT). However, based on the cell stimulation properties, its long-term safety has been questioned, mainly in relation to risk for secondary malignancies in the oral cavity. The aim of this study was to investigate if different PBMT protocols for OM control have association with immediate and late adverse effects in HCT patients. Data on autologous and allogeneic transplantation, conditioning regimen, PBMT protocols, and OM severity were retrospectively collected from medical and dental records. Presence of secondary malignancies in the oral cavity was surveyed during a 15-year follow-up. Impact of OM on overall survival was also analyzed. Different PBMT protocols for prevention and treatment of OM were recorded over the years. Severe OM (grades 3 and 4) was infrequently observed. When present, we observed a significant decrease of the overall survival. No immediate adverse effect and secondary malignancy was associated to PBMT. In conclusion, the PBMT protocols used in the study were considered safe. The low frequency of severe OM observed encourages the implementation of this technique, with a special emphasis on the dosimetry adjustments focused on the HCT context.

Intraoral versus extraoral photobiomodulation therapy in the prevention of oral mucositis in HSCT patients: a randomized, single-blind, controlled clinical trial

To compare the efficacy of intraoral and extraoral photobiomodulation (PBM) protocols for the prevention of oral mucositis (OM) in hematopoietic stem cell transplantation (HSCT) patients. A total of 60 patients was randomized into intraoral PBM (IOPBM) and extraoral PBM (EOPBM) groups. Both PBM protocols were well tolerated and no side effects were observed. EOPBM session times were one fourth of IOPBM durations. Of 60 patients, 35 (58.3%) developed ulcerated OM between day +3 and day +12. No intergroup difference was observed in OM healing times (p = 0.424). The lateral border of the tongue was the most common site affected in both groups. However, the incidence of mucositis on buccal mucosa was significantly reduced in the EOPBM group (p = 0.021). Young patients (OR.5.35, 95%CI 0.94-30.4, p = 0.058) and those who had received myeloablative conditioning (OR.55.1, 95%CI 2.69-1129.3, p = 0.009) were more likely to develop ulcerated OM, whereas autologous HSCT recipients (OR 0.079, 95% CI 0.009-0.67, p = 0.021) had a lower probability of developing ulcerated OM independent of PBM protocol. EOPBM protocol was as effective as IOPBM in the management of OM in HSCT patients, with the advantage of shorter treatment sessions. Trial registration number: RBR-7nww56. Date of trial registration submission: 30th September 2019.

Three photobiomodulation protocols in the prevention/treatment of radiotherapy-induced oral mucositis

PURPOSE

To compare three Photobiomodulation protocols to prevent/treat oral mucositis associated to radiotherapy.

METHODS

Seventy-three patients with cancer in oral cavity, oropharynx, and nasopharynx, who underwent RT with dose in facial fields equal or higher than 6000 cGy were randomized into three groups (mean RT dose = 66 cGy ±4.9). Protocols of Group 1 was 660 nm, 15 mW, 3.8 J/cm2, Group 2 660 nm, 25 mW, 6.3 J/cm2 both starting on the first day of radiotherapy, and group 3 660 nm, 15 mW, 3.8 J/cm2 for therapeutic purpose. The patients of group 1 and 2 were irradiated at 40 points daily covering non-keratinizing oral mucosa. The spot size (probe's tip surface size) was 0.040 cm2 for all groups. Oral mucositis was evaluated according to both WHO and NCI scales, and pain related to oral mucositis was scored using the VAS.

RESULTS

Patients from group 1 presented with grade II oral mucositis later than groups 2 and 3 (p < 0.001). Moreover, groups 2 and 3 also presented with a mean higher of oral mucositis grade than group 1, p < 0.001. Pain scores were lower in group 1 (p = 0.002).

CONCLUSIONS

The Photobiomodulation used in Group 1 was more effective than the protocols used in groups 2 and 3 in controlling the grade II oral mucositis intensity, and mean pain scores.

Tumor safety and side effects of photobiomodulation therapy used for prevention and management of cancer treatment toxicities. A systematic review

Photobiomodulation therapy (PBMT), also known as low-level laser therapy (LLLT), has been increasingly used for the treatment of toxicities related to cancer treatment. One of the challenges for the universal acceptance of PBMT use in cancer patients is whether or not there is a potential for the light to stimulate the growth of residual malignant cells that evaded oncologic treatment, increasing the risk for tumor recurrences and development of a second primary tumor. Current science suggests promising effects of PBMT in the prevention and treatment of breast cancer-related lymphedema and oral mucositis, among other cancer treatment toxicities. Nevertheless, this seems to be the first systematic review to analyze the safety of the use of PBMT for the management of cancer-related toxicities. Scopus, MEDLINE/PubMed, and Embase were searched electronically. A total of 27 articles met the search criteria. Selected studies included the use of PBMT for prevention and treatment of oral mucositis, lymphedema, radiodermatitis, and peripheral neuropathy. Most studies showed that no side effects were observed with the use of PBMT. The results of this systematic review, based on current literature, suggest that the use of PBMT in the prevention and management of cancer treatment toxicities does not lead to the development of tumor safety issues.

Variability of high-dose melphalan exposure on oral mucositis in patients undergoing prophylactic low-level laser therapy

The present study outlines the clinical impact and risk factors of oral mucositis in 79 patients with multiple myeloma following high-dose melphalan for autologous transplant. All patients underwent daily prophylactic low-level indium gallium aluminum phosphate diode laser therapy (660 nm, 15 mW, 3.75 J/cm², 10 s per point) from the beginning of the conditioning regimen up to day +2. Oral mucositis assessments were made daily until hospital discharge. For analysis, oral mucositis was divided into two groups according to severity: group 1, patients with oral mucositis grade <III (n = 71) and group 2, patients with oral mucositis grade ≥III (n = 8). Univariate logistic models were used to determine the risk factors. Patients in group 1 were found to have statistically fewer days of oral pain than those in group 2 (3.94 and 6.25 days, respectively, p = 0.014). Morphine was required in 75% of patients in group 2, versus 42.25% in group 1 (p = 0.06). Risk of severe oral mucositis was associated with higher serum creatinine levels (OR = 6.10; 95% CI 1.25-31.60; p = 0.02) and older age (OR = 1.21; 95% CI 1.05-1.47; p = 0.027). Severe oral mucositis was associated with worse clinical outcomes. Older patients and those with renal dysfunction previous autologous transplant had the greatest risk for severe oral mucositis despite prophylactic laser treatment. Our results highlight the importance of further research to define the dose, application time, and number of prophylactic laser sessions in those patients with the greatest risk for severe oral mucositis.

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).

Low-level laser therapy prevents severe oral mucositis in patients submitted to hematopoietic stem cell transplantation: a randomized clinical trial

PURPOSE

The purpose of this study is to evaluate the effectiveness of low-level laser therapy for the prevention of oral mucositis in patients undergoing hematopoietic stem cell transplantation.

METHODS

This is a randomized, parallel, superiority trial including 35 patients divided into the following: laser (n = 17) and sham (n = 18). The variables assessed were oral mucositis (grade 2 of the World Health Organization oral toxicity scale), severe oral mucositis (grade 3 or 4), and pain (according to a visual analogue scale). In the laser group, a InGaAlP laser, wavelength of 650 nm, power 100 mW, energy per point of 2 J, time 20 s by point, extremity fiber optic 0.028 cm(2), and energy density 70 J/cm(2), was used, applied the first day of conditioning until D + 5, while the sham group received simulated laser over the same period.

RESULTS

No statistically significant difference was found in the incidence of oral mucositis (p = 0.146). Severe mucositis was found in 40% of the patients (14/35), 3 in the intervention group (17.65%) and 11 in the sham group (61.11%) (p = 0.015). The cumulative probability of survival with respect to the development of severe oral mucositis was >0.6 for the intervention group and 0 for the control group (p = 0.0397). On the day on which pain was considered the worst, patients in the sham group were more likely to classify their pain as severe compared to those in the laser group (p = 0.041).

CONCLUSION

Low-level laser therapy proved effective for the prevention of severe oral mucositis and intense oral pain in patients submitted to hematopoietic stem cell transplantation.

[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.

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.

Systematic review of laser and other light therapy for the management of oral mucositis in cancer patients

BACKGROUND

The aim of this study was to review the available literature and define clinical practice guidelines for the use of laser and other light therapies for the prevention and treatment of oral mucositis.

METHODS

A systematic review was conducted by the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology. The body of evidence for each intervention, in each cancer treatment setting, was assigned an evidence level. Based on the evidence level, one of the following three guideline determinations was possible: recommendation, suggestion, and no guideline possible.

RESULTS

A new recommendation was made for low-level laser (wavelength at 650 nm, power of 40 mW, and each square centimeter treated with the required time to a tissue energy dose of 2 J/cm(2) (2 s/point)) for the prevention of oral mucositis in adult patients receiving hematopoietic stem cell transplantation conditioned with high-dose chemotherapy, with or without total body irradiation. A new suggestion was made for low-level laser (wavelength around 632.8 nm) for the prevention of oral mucositis in patients undergoing radiotherapy, without concomitant chemotherapy, for head and neck cancer. No guideline was possible in other populations and for other light sources due to insufficient evidence.

CONCLUSIONS

The increasing evidence in favor of low-level laser therapy allowed for the development of two new guidelines supporting this modality in the populations listed above. Evidence for other populations was also generally encouraging over a range of wavelengths and intensities. However, additional well-designed research is needed to evaluate the efficacy of laser and other light therapies in various cancer treatment settings.

Honey and a mixture of honey, beeswax, and olive oil-propolis extract in treatment of chemotherapy-induced oral mucositis: a randomized controlled pilot study

In spite of being one of the most investigated subjects among supportive care in cancer, no therapy has been found effective in treatment of chemotherapy-induced oral mucositis. Based on the observations that honey bees products have anti-inflammatory and wound healing effects, the present study tried to evaluate the effect of topical application of honey and a mixture of honey, olive oil-propolis extract, and beeswax (HOPE) in treatment of oral mucositis. This was a randomized controlled clinical trial conducted on 90 patients with acute lymphoblastic leukemia and oral mucositis grades 2 and 3. The mean age of enrolled patients was 6.9 years. The patients were assigned into 3 equal treatment groups: Honey, HOPE, and control groups. Topical treatment for each patient consists of honey, HOPE, and benzocaine gel for honey, HOPE, and control groups, respectively. Recovery time in grade 2 mucositis was significantly reduced in the honey group as compared with either HOPE or controls (P < .05). In grade 3 mucositis, recovery time did not differ significantly between honey and HOPE (P = 0.61) but compared with controls, healing was faster with either honey or HOPE (P < .01). Generally, in both grades of mucositis, honey produced faster healing than either HOPE or controls (P < .05). Based on our results that showed that honey produced faster healing in patients with grade 2/3 chemotherapy-induced mucositis, we recommend using honey and possibly other bee products and olive oil in future therapeutic trials targeting chemotherapy-induced mucositis.

Evaluation of low-level laser therapy in the prevention and treatment of radiation-induced mucositis: a double-blind randomized study in head and neck cancer patients

The purpose of this prospective study was to determine the effect of the low-level laser in the prevention and treatment of mucositis in head and neck cancer patients. A total of 70 patients with malignant neoplasms in the oral cavity or oropharynx were evaluated. The patients were randomized into two low-level laser therapy groups: Group 1 (660nm/15mW/3.8J/cm(2)/spot size 4mm(2)) or Group 2 (660nm/5mW/1.3J/cm(2)/spot size 4mm(2)) starting on the first day of radiotherapy. Oral mucositis was assessed daily and weekly using the NCI and WHO scales. Oral pain was scored daily with a visual analogue scale before laser application. The patients in Group 1 had a mean time of 13.5days (range 6-26days) to present mucositis grade II, while the patients in Group 2 had a mean time of 9.8days (range 4-14days) (both WHO and NCI p=0.005). In addition, Group 2 also presented a higher mucositis grade than Group 1 with significant differences found in weeks 2 (p=0.019), 3 (p=0.005) and 4 (p=0.003) for WHO scale and weeks 2 (p=0.009) and 4 (p=0.013) for NCI scale. The patients in Group 1 reported lower pain levels (p=0.004). Low-level laser therapy during radiotherapy was found to be effective in controlling the intensity of mucositis and pain.

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.

Effects of low-level laser therapy on collagen expression and neutrophil infiltrate in 5-fluorouracil-induced oral mucositis in hamsters

BACKGROUND AND OBJECTIVES

Several studies have suggested that low-level laser therapy (LLLT) can ameliorate oral mucositis; however, the mechanisms involved are not well understood. The aim of this study was to investigate the mechanisms of action of LLLT on chemotherapy-induced oral mucositis, as related to effects on collagen expression and inflammation.

MATERIALS AND METHODS

A hamster cheek pouch model of oral mucositis was used with all animals receiving intraperitoneal 5-fluorouracil, followed by surface irritation. Animals were randomly allocated into three groups, and treated with an InGaAIP diode laser at a wavelength of 660 nm and output power of 35 or 100 mW laser, or no laser. Clinical severity of mucositis was assessed at four time-points by a blinded examiner. Buccal pouch tissue was harvested from a subgroup of animals in each group at four time-points. Collagen was qualitatively and quantitatively evaluated after picrosirius staining. The density of the neutrophil infiltrate was also scored.

RESULTS

Peak clinical severity of mucositis was reduced in the 35 mW laser group as compared to the 100 mW and control groups. The reduced peak clinical severity of mucositis in the 35 mW laser group was accompanied by a decrease in the number of neutrophils and an increase in the proportion of mature collagen as compared to the other two groups. The total quantity of collagen was significantly higher in the control (no laser) group at the day 11 time-point, as compared to the 35 mW laser group, consistent with a more prolonged inflammatory response in the control group.

CONCLUSION

This study supports two mechanisms of action for LLLT in reducing mucositis severity. The increase in collagen organization in response to the 35 mW laser indicates that LLLT promotes wound healing. In addition, LLLT also appears to have an anti-inflammatory effect, as evidenced by the reduction in neutrophil infiltrate.

Use of therapeutic laser for prevention and treatment of oral mucositis

Oral mucositis (OM) affects patients who are submitted to hematopoietic stem cell transplantation (HSCT) due to high doses of chemotherapy and/or radiotherapy. The purpose of this investigation was to perform a comparative study of the frequency and evolution of OM among patients subjected to therapeutic laser and to the conventional therapy (use of mouthwash called 'Mucositis Formula'). The patients were subjected to a myeloablative conditioning regimen before the allogeneic HSCT. Twenty-two patients were selected and divided into 2 groups: group I was irradiated with InGaAlP laser (660 nm) and GaAlAs laser (780 nm), 25 mW potency, 6.3J/cm(2) dose, in 10-s irradiation time, followed to conventional treatment; group II was subjected only to the conventional treatment. Both World Health Organization (WHO) scale and the Oral Mucositis Assessment Scale (OMAS) were used to evaluate the results. Data were analyzed by the non-parametric Wilcoxon test, with p<0.05 considered as statistically significant. Group I presented a lower frequency of OM (p=0.02) and lower mean scores, according to WHO and OMAS scales (p<0.01 and p=0.01, respectively). In conclusion, laser reduced the frequency and severity of OM, suggesting that therapeutic laser can be used both as a new form of prevention and treatment of OM.

Cyclooxygenase-2 and vascular endothelial growth factor expression in 5-fluorouracil-induced oral mucositis in hamsters: evaluation of two low-intensity laser protocols

GOAL OF WORK

The aim of this study was to investigate the mechanisms whereby low-intensity laser therapy may affect the severity of oral mucositis.

MATERIALS AND METHODS

A hamster cheek pouch model of oral mucositis was used with all animals receiving intraperitoneal 5-fluorouracil followed by surface irritation. Animals were randomly allocated into three groups and treated with a 35 mW laser, 100 mW laser, or no laser. Clinical severity of mucositis was assessed at four time-points by a blinded examiner. Buccal pouch tissue was harvested from a subgroup of animals in each group at four time-points. This tissue was used for immunohistochemistry for cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), and factor VIII (marker of microvessel density) and the resulting staining was quantified.

MAIN RESULTS

Peak severity of mucositis was reduced in the 35 mW laser group as compared to the 100 mW laser and control groups. This reduced peak clinical severity of mucositis in the 35 mW laser group was accompanied by a significantly lower level of COX-2 staining. The 100 mW laser did not have an effect on the severity of clinical mucositis, but was associated with a decrease in VEGF levels at the later time-points, as compared to the other groups. There was no clear relationship of VEGF levels or microvessel density to clinical mucositis severity.

CONCLUSION

The tissue response to laser therapy appears to vary by dose. Low-intensity laser therapy appears to reduce the severity of mucositis, at least in part, by reducing COX-2 levels and associated inhibition of the inflammatory response.

Severity of oral mucositis in patients undergoing hematopoietic cell transplantation and an oral laser phototherapy protocol: a survey of 30 patients

BACKGROUND DATA AND OBJECTIVE

Oral mucositis (OM) is one of the worst cytotoxic effects of chemotherapy and radiotherapy in patients undergoing hematopoietic cell transplantation (HCT), and it causes severe morbidity. Laser phototherapy has been considered as an alternative therapy for prevention and treatment of OM. The aim of this study was to describe the incidence and severity of OM in HCT patients subjected to laser phototherapy, and to discuss its effect on the oral mucosa.

PATIENTS AND METHODS

Information concerning patient age and gender, type of basic disease, conditioning regimen, type of transplant, absence or presence of pain related to the oral cavity, OM grade, and adverse reactions or unusual events were collected from 30 patients undergoing HCT (allogeneic or autologous). These patients were given oral laser phototherapy with a InGaAIP laser (660 nm and 40 mW) daily. The data were tabulated and their frequency expressed as percentages.

RESULTS

In the analysis of those with OM, it was observed that 33.4% exhibited grade I, 40% grade II, 23.3% grade III, and 3.3% grade IV disease. On the most critical post-HCT days (D+5 and D+8), it was observed that 63.3% of patients had grade I and 33.3% had grade II disease; no patients had grade III or IV disease in this period. This severity of OM was similar to that seen in other studies of laser phototherapy and OM.

CONCLUSION

The low grades of OM observed in this survey show the beneficial effects of laser phototherapy, but randomized clinical trials are necessary to confirm these findings.