Low-Level Laser for Mitigation of Low Salivary Flow Rate in Head and Neck Cancer Patients Undergoing Radiochemotherapy: A Prospective Longitudinal Study

Photobiomodulation for the prevention of oral side effects secondary to head and neck cancer therapy: results of a randomised, single-blind clinical trial

INTRODUCTION

A significant increase of 61.6 % in new cases of head and neck cancer (HNC) worldwide is projected by 2050. Multimodal treatments for HNC often result in debilitating oral side effects like oral mucositis (OM). Photobiomodulation (PBM) therapy shows promise in managing these side effects, yet standardized protocols are lacking. This randomized clinical trial aims to evaluate PBM's effectiveness in preventing and treating oral side effects and related symptoms in HNC patients.

METHODS

We compared PBM with standard treatment in HNC patients at a single centre. PBM efficacy was evaluated on OM, pain, dysgeusia, hyposalivation, dry mouth, and trismus. Additionally, we controlled for analgesic use and fungal infection presence. The study adhered to the CONSORT checklist, is registered on the ClinicalTrials platform, and statistical analysis was performed using SPSS.

RESULTS

The study included 53 patients. The PBM group experienced a significant reduction in OM progression, better salivary function preservation, and lower severity of pain and dysgeusia by the end of treatment. However, no significant differences were found between the PBM and standard treatment groups regarding xerostomia, trismus, analgesic use, or oral candidiasis incidence.

CONCLUSION

PBM showed effectiveness in delaying onset and reducing the severity of oral mucositis and hyposalivation, as well as alleviating pain and dysgeusia at critical moments. However, it had no significant impact on xerostomia, trismus, analgesic use, or oral candidiasis.

Management of radiotherapy-induced hyposalivation using photobiomodulation therapy: a case series

It is not uncommon for individuals receiving radiotherapy for head and cancers to experience dry mouth sensation (xerostomia), salivary hypofunction (hyposalivation) and taste changes. The present study aimed to evaluate the short-term effectiveness of biweekly photobiomodulation therapy (PBMT) in managing these radiotherapy-induced adverse effects and its impact on oral health-related quality of life. Ten patients who developed xerostomia and hyposalivation secondary to radiotherapy for head and neck cancer were included. The study assessments included clinician-based [the stimulated (SSF) and unstimulated salivary flow (USSF) and taste change questionnaire] and patient-based measures [Shortened Xerostomia Inventory (SXI) and Oral Health Impact Profile (OHIP-5)]. The 10 participants (males = 5, females = 5) had a mean age of 52 (± 15) years. Half were diagnosed with nasopharyngeal squamous cell carcinoma. From visits 1 to 8, 80% showed increased USSF and/or SSF, but these were limited and not significant (p > 0.05). Nevertheless, 80% of the patients had lower xerostomia scores, 60% had less dryness frequency, and 40% showed taste improvement. Improvement in oral health-related quality of life was only observed in 30% of the participants. Strong proportional correlations were found between USSF and SSF as well as SXI and OHIP-5 at study visits 1 and 8 (p < 0.05). The findings showed the usefulness of PBMT in reducing xerostomia and taste changes and possibly increasing salivary flow over a 4-week duration. However, randomised clinical trials are needed to assess the long-term effectiveness of PBMT compared to other management options.Clinical study registration: The study was prospectively registered with the US National Library of Medicine's clinical trial registry on 13 September 2022 [ClinicalTrials.gov ref: NCT05538169].

A systematic review of salivary gland hypofunction and/or xerostomia induced by non-surgical cancer therapies: prevention strategies

PURPOSE

This systematic review aimed to assess the updated literature for the prevention of salivary gland hypofunction and xerostomia induced by non-surgical cancer therapies.

METHODS

Electronic databases of MEDLINE/PubMed, EMBASE, and Cochrane Library were searched for randomized controlled trials (RCT) that investigated interventions to prevent salivary gland hypofunction and/or xerostomia. Literature search began from the 2010 systematic review publications from the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) up to February 2024. Two independent reviewers extracted information regarding study design, study population, cancer treatment modality, interventions, outcome measures, methods, results, risk of bias (RoB version 2), and conclusions for each article.

RESULTS

A total of 51 publications addressing preventive interventions were included. Eight RCTs on tissue-sparing radiation modalities were included showing significant lower prevalence of xerostomia, with unclear effect on salivary gland hypofunction. Three RCTs on preventive acupuncture showed reduced prevalence of xerostomia but not of salivary gland hypofunction. Two RCTs on muscarinic agonist stimulation with bethanechol suggested a preventive effect on saliva flow rate and xerostomia in patients undergoing head and neck radiation or radioactive iodine therapy. Two studies on submandibular gland transfer showed higher salivary flow rates compared to pilocarpine and lower prevalence of xerostomia compared to no active intervention. There is insufficient evidence on the effectiveness of vitamin E, amifostine, photobiomodulation, and miscellaneous preventive interventions.

CONCLUSION

This systematic review continues to support the potential of tissue-sparing tecniques and intensity-modulated radiation therapy (IMRT) to preserve salivary gland function in patients with head and neck cancer, with limited evidence on other preventive strategies, including acupuncture and bethanecol. Preventive focus should be on optimized and new approaches developed to further reduce radiation dose to the parotid, the submandibular, and minor salivary glands. As these glands are major contributors to moistening of the oral cavity, limiting the radiation dose to the salivary glands through various modalities has demonstrated reduction in prevalence and severity of salivary gland hypofunction and xerostomia. There remains no evidence on preventive approaches for checkpoint inhibitors and other biologicals due to the lack of RCTs.

Underexplored Areas of Photobiomodulation in Oral Oncology: An Expert Analysis

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

The supportive use of photobiomodulation on salivary glands: a narrative review and meta-analysis

PURPOSE

Radiotherapy is one of the main strategies used in the treatment of cancer patients and it can cause early or late xerostomia and/or hyposalivation. Therapeutic management of xerostomia includes oral hygiene, sialogenic agents among others.

METHODS

This study reviews the use of extra-oral salivary glands photobiomodulation in treating xerostomia and/or hyposalivation after radiotherapy and performs a meta-analysis of this data.

RESULTS

After a broad search of the literature, eight clinical studies were selected.

DISCUSSION

In a safe way, the studies found that extra-oral stimulation of the salivary glands has benefits in the hyposalivation and changes in salivary flow resulting from lesions by radiotherapy. A meta-analysis found significant values in pain comparing the pre- and post-treatment moments (MD - 3.02, I2 95%, IC - 5.56; - 0.48) and for stimulated salivary flow at 30 days after the end of radiotherapy (MD 2.90, I2 95%, IC 1.96; 3.84).

CONCLUSION

The most promising parameters comprise wavelengths between 630 and 830 nm, radiant exposure from 2 to 10 J/cm2, two-to-three times a week, before the radiotherapy damage, and homogeneously in the glands. Therefore, Light-Emitting Diode (LED) stimulation of larger areas than the punctual stimulation of small millimeters of the Low-Level Laser Therapy (LLLT) appears to be promising.

Evaluation of the Effect of Photobiomodulation on Radiation-Induced Xerostomia in Head and Neck Cancer Patients: A Randomized Clinical Trial

Introduction: Radiotherapy-induced xerostomia is an important side effect of head and neck cancer (HNC) treatment. Photobiomodulation (PBM) is one of the new emerging methods for preventing or reducing this problem. The aim of this study is to evaluate the effect of PBM on radiation-induced xerostomia in HNC patients. Methods: Thirty-seven patients with HNC who were referred for radiotherapy to Mashhad cancer center. In the case group, an infrared diode laser was used in contact mode on 16 points (covering minor and major salivary glands). The device emitted a wavelength of 810 nm and operated at the power of 200 mW and continuous wave mode. Each area was irradiated for 4 seconds in contact mode with gentle pressure, and the laser energy was 0.8 J with an energy density of 2.85 J/cm2 at the surface of the probe (spot size, 0.28 cm2 ). The total dose was 45.6 J/cm2. The power density was 714.2 w/cm2. In the control group, the sham laser device was used. Subjective xerostomia was evaluated through the LENT SOMA scale (LSS). Stimulated and unstimulated saliva was also assessed. Data were analyzed with SPSS ver22 statistical software. Results: The study included 26 men and 11 women with a mean age of 55.6±15.3 years. In the sixth week, the case group produced more stimulated saliva than the control group (P=0.006). They also had less subjective xerostomia than the control group in weeks four to six. Conclusion: In the present study, PBM had a preventive effect on stimulated saliva and subjective xerostomia and can be recommended as an adjunctive treatment. Further studies with a higher sample size and the use of a low-level laser in more sessions are needed for definitive comment.

Randomized Double-Blind Placebo-Controlled Study of Salivary Substitute with Enzymatic System for Xerostomia in Patients Irradiated in Head and Neck Region

This study aims to compare whether the use of a salivary substitute including an enzymatic system clinically reduces the intensity of xerostomia, as well as exploring the impact that this has on the quality of life, in patients who had received radiotherapy in the head and neck (HNC) region. Forty patients who had completed radiotherapy treatment within 6 months to 1 year previously were allocated into an Enzymatic Spray group (n = 21) or a Placebo arm (n = 19). It should be noted that two patients in the Placebo arm declined to participate during phase 2 of the study. All patients were randomized and used both products three times a day for 30 days. For analysis, xerostomia grade, unstimulated (UWS) and stimulated (SWS) salivary flow rate, and quality of life through the University of Washington Quality of Life Questionnaire validated in Portuguese (UW-QoL) were assessed in two phases: Phase 1 (before the use of the products) and Phase 2 (after 30 days of using the products). All clinical data were collected from medical records. Analyzing the salivary substitute with the enzymatic system, an improvement in xerostomia complaints was observed 30 days after using the product; however, this difference was not statistically significant (p > 0.05). Regarding quality of life, no significant differences were observed in relation to the UW-QoL and saliva domain between the groups in the two phases of the study (p > 0.05). The salivary substitute with the enzymatic system may be effective in reducing radio-induced xerostomia symptoms; however, further research is necessary to evaluate the efficacy of this salivary substitute on oral health.

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

Disclaimer

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

Objective

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

Background

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

Methods

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

Results

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

Conclusions

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

Quality Assessment of PBM Protocols for Oral Complications in Head and Neck Cancer Patients: Part 1

Background

Radiotherapy and chemotherapy are frequently employed in head and neck cancer (HNC) patients causing significant side effects that impair life quality and prognosis. Photobiomodulation (PBM) has become a growing approach to managing such oral complications. Despite its proven efficacy and absence of contraindications, there is still a lack of universally accepted disease-specific PBM protocols.

Objective

A narrative review was conducted to identify the current proposals relating to the use of PBM to treat complications of oncological treatments in HNC patients.

Methods

An electronic search in PubMed and Scopus databases was performed with the following keywords: (“photobiomodulation” OR “PBM” OR “laser therapy” OR “LLLT” OR “laser”) AND (“head and neck cancer” OR “oral cancer”) AND (“mucositis” OR “oral mucositis” OR “dysgeusia” OR “oedema” OR “xerostomia” OR “dermatitis” OR “trismus”) until October 2021.

Results

A total of 35 papers were included in the narrative review. Oral mucositis was the most studied complication, and advisable protocols are conceivable. Although there is a growing interest in PBM to manage of xerostomia, radiodermatitis, pain, and trismus, literature is still scarce to propose a universally feasible protocol.

Conclusions

PBM therapy could significantly prevent or reduce the severity of many side effects related to cancer therapies. More research is needed to obtain recommendations over the preferable parameters.

Efficacy of Photobiomodulation in Reducing Symptomatology and Improving the Quality of Life in Patients with Xerostomia and Hyposalivation: A Randomized Controlled Trial

Objectives: To evaluate the efficacy of photobiomodulation (PBM) treatment in patients with xerostomia and hyposalivation and assess their quality of life over a one year of follow-up. Material and methods: A single-blind randomized controlled trial. A total of 60 patients with xerostomia were included (30 PBM cases and 30 placebo controls). Photobiomodulation was performed with a diode laser (810 nm, 6 J/cm2), while the controls underwent simulated treatment. One weekly session was carried out for a total of 6 weeks (total six sessions). The study parameters were recorded at baseline, after three and six weeks, and at one year post-treatment. Xerostomia was assessed using a salivary flow visual analog scale (VAS) and the Xerostomia Inventory (XI). The Hospital Anxiety and Depression (HAD) scale, Oral Health Impact Profile (OHIP-14), Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) were also administered. Results: The patients subjected to PBM therapy showed a significant improvement of xerostomia based on the drainage test, and of oral quality of life (p < 0.001). The depression score of the HAD (HAD-D) and the ESS showed improvement, though without reaching statistical significance (p > 0.05). The placebo group showed significant changes in the xerostomia VAS score at 6 weeks (p = 0.009), with no variations in any of the other studied parameters (p > 0.05). The beneficial effects of the diode laser in the PBM group persisted at one year post-treatment. Conclusions: Photobiomodulation with the diode laser is effective in patients with xerostomia and hyposalivation, and thus should be taken into account as a treatment option.

Salivary Gland Dysfunction Secondary to Cancer Treatment

The number of cancer survivors are increasing and so are the oral toxicities from cancer therapy. Most patients receiving treatment for cancer develop some form of oral adverse events including, but not limited to, mucositis, opportunistic infections, dry mouth, and/or osteonecrosis of the jaw. One of the most common complications from head and neck cancer radiation therapy is salivary gland dysfunction (SGD). SGD is an umbrella term that includes the subjective sensation of dry mouth (xerostomia) and hyposalivation (objective reduction of the salivary flow rate). Dry mouth in cancer patients may lead to functional defects (e.g., eating, speaking, and swallowing), increase the risk of dental caries and oral candidiasis, and can have a negative effect on the nutritional and psychological status of the patients. The aim of this mini review was to summarize the current criteria for diagnosis and management of SGD associated with cancer treatment.

Antibiotic therapy for the prevention of osteoradionecrosis following tooth extraction in head-and-neck cancer patients postradiotherapy: An 11-year retrospective study

Introduction:

One of the most important complications of radiotherapy (RT) for head-and-neck cancer (HNC) is osteoradionecrosis (ORN) of the jaws, which mostly arises from tooth extractions. The ORN treatment still represents a great challenge; therefore, the prevention is of paramount importance. Thus, the present study aimed to evaluate retrospectively a perioperative systemic antibiotic therapy protocol for the prevention of ORN following tooth extraction in head-and-neck patients post-3D conformal RT.

Materials and Methods:

A retrospective medical record review was performed considering HNC patients submitted to RT in the period between 2008 and 2019. They necessarily received oral antibiotic therapy with Clindamycin 300 mg every 8 h for 10 days, with the first dose 3 days before the tooth extraction.

Results:

Forty-nine patients met the study criteria, with a total of 107 teeth extracted. Regarding the 47 patients who did not develop ORN, 103 tooth extractions were identified (96.3%). Only two patients developed ORN at two adjacent teeth sites (3.7%).

Conclusion:

The proposed perioperative systemic antibiotic therapy protocol seems to be efficient to prevent ORN following tooth extraction in postirradiated HNC patients.

Effects of low-level light therapy on xerostomia related to hyposalivation: a systematic review and meta-analysis of clinical trials

Hyposalivation is a condition represented by a reduced salivary flow and may include symptoms such as mouth dryness (xerostomia), loss of taste, pain, dysphagia, and dysphonia, all of which greatly affect an individual's quality of life.The aim of the present study was to systematically review the effects of low-level light therapy irradiation (photobiomodulation) on salivary gland function in patients with hyposalivation.The main question of the systematic review was: "Does low-level light irradiation therapy of the salivary glands affect salivary flow rate or indicators of salivary function (ion and protein concentrations) in patients with xerostomia or hyposalivation?" The question was based on the PICO (participant, intervention, control, outcome) principle and followed the PRISMA guidelines. Databases were explored and papers published between the years 1997 and 2020 were reviewed for the following Mesh-term keywords and their corresponding entry terms in different combinations: "Low-level light therapy," "Xerostomia," "Saliva," "Salivary glands," "Salivation."The initial sample consisted of 220 articles. Of those, 47 articles were used for full-text analysis and 18 were used for a systematic review, 14 were used in meta-analysis. According to their individual quality, most articles were classified as high quality of evidence according to the GRADE score. Meta-analysis of the evidence observed increase of unstimulated salivary flow 0.51 SMD compared to placebo (95% CI: 0.16-0.86), I² = 50%, p = 0.005.The findings of our review revealed evidence of a beneficial effect of photobiomodulation therapy on salivary gland function. The therapy alleviates xerostomia and hyposalivation. However, these effects are reported short term only and did not induce lasting effects of photobiomodulation therapy on patients' quality of life.

Salivary Gland Hypofunction and/or Xerostomia Induced by Nonsurgical Cancer Therapies: ISOO/MASCC/ASCO Guideline

PURPOSE

To provide evidence-based recommendations for prevention and management of salivary gland hypofunction and xerostomia induced by nonsurgical cancer therapies.

METHODS

Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. PubMed, EMBASE, and Cochrane Library were searched for randomized controlled trials published between January 2009 and June 2020. The guideline also incorporated two previous systematic reviews conducted by MASCC/ISOO, which included studies published from 1990 through 2008.

RESULTS

A total of 58 publications were identified: 46 addressed preventive interventions and 12 addressed therapeutic interventions. A majority of the evidence focused on the setting of radiation therapy for head and neck cancer. For the prevention of salivary gland hypofunction and/or xerostomia in patients with head and neck cancer, there is high-quality evidence for tissue-sparing radiation modalities. Evidence is weaker or insufficient for other interventions. For the management of salivary gland hypofunction and/or xerostomia, intermediate-quality evidence supports the use of topical mucosal lubricants, saliva substitutes, and agents that stimulate the salivary reflex.

RECOMMENDATIONS

For patients who receive radiation therapy for head and neck cancer, tissue-sparing radiation modalities should be used when possible to reduce the risk of salivary gland hypofunction and xerostomia. Other risk-reducing interventions that may be offered during radiation therapy for head and neck cancer include bethanechol and acupuncture. For patients who develop salivary gland hypofunction and/or xerostomia, interventions include topical mucosal lubricants, saliva substitutes, and sugar-free lozenges or chewing gum. For patients with head and neck cancer, oral pilocarpine and oral cevimeline, acupuncture, or transcutaneous electrostimulation may be offered after radiation therapy.Additional information can be found at www.asco.org/supportive-care-guidelines.

Effects of photobiomodulation in salivary glands of chronic kidney disease patients on hemodialysis

This randomized placebo-controlled trial evaluates the impact of photobiomodulation (PBMT) on the salivary flow and biochemistry of patients with chronic kidney disease (CKD) on hemodialysis. Forty-four patients on hemodialysis self-responded two questionnaires for oral health and salivary gland function perception. The subjects were evaluated for function of salivary glands and randomly allocated to two groups: PBMT group (three irradiations at 808 nm, 100 mW, 142 J/cm², and 4 J per site); and placebo group. Patients were submitted to non-stimulated and stimulated sialometry and after the treatment at baseline and 14 days. Salivary volume and biochemical of the saliva were analyzed. At baseline, most subjects had self-perception of poor oral health (52.6%) and salivary dysfunction (63.1%). Clinical exam revealed that 47.3% of subjects presented dry mucosa. PBMT promoted increase of the non-stimulated (p = 0.027) and stimulated saliva (p = 0.014) and decrease of urea levels in both non-stimulated (p = 0.0001) and stimulated saliva (p = 0.0001). No alteration was detected in total proteins and calcium analysis. Patients with kidney disease can present alteration in flow, concentrations, and composition of saliva, affecting oral health, but our findings suggest that PBMT is effective to improve hyposalivation and urea levels in saliva of patients with CKD.

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.

Impact of radiotherapy on mandibular bone: A retrospective study of digital panoramic radiographs

Purpose

The purpose of this study was to investigate the impact of radiotherapy on mandibular bone tissue in head and neck cancer patients through an analysis of pixel intensity and fractal dimension values on digital panoramic radiographs.

Materials and Methods

Thirty patients with radiographic records from before and after 3-dimensional (3D) conformational radiotherapy were selected. A single examiner carried out digital analyses of pixel intensity values and fractal dimensions, with the areas of interest unilaterally located in the right angle medullary region of the mandible below the mandibular canal and posterior to the molar region.

Results

Statistically significant decreases were observed in the mean pixel intensity (P=0.0368) and fractal dimension (P=0.0495) values after radiotherapy.

Conclusion

The results suggest that 3D conformational radiotherapy for head and neck cancer negatively affected the trabecular microarchitecture and mandibular bone mass.

Low-Level Laser Therapy Stimulates Proliferation in Head and Neck Squamous Cell Carcinoma Cells

Objectives: Low-level laser therapy (LLLT) is a promising non-invasive treatment option for oropharyngeal mucositis, which is a common side effect of many oncological treatments. LLLT is known for its wound healing properties due to the stimulation of cellular processes, such as proliferation, migration and differentiation. Controversy exists on the possible stimulatory effect of LLLT on head and neck cancer (HNSCC) cells in patients treated with radiotherapy. The aim of this study was to evaluate the biostimulatory effect together with the underlying mechanisms of LLLT on HNSCC cancer cells and normal epithelial cells. Materials and methods: HNSCC cell lines (SCC154, SQD9, and SCC61) and human tonsil epithelial cells were exposed to a Gallium-Aluminum-Arsenide diode laser (830 nm, 150 mW) with energy densities of 0, 1, and 2 J/cm2. The proliferation potential of the cells was assessed by Sulforhodamine B assay, immunoblotting (mitogenic pathways), immunocytochemistry (Ki67), and flow cytometry (PI cell cycle staining). Results: Cell proliferation was increased in HNSCC cell lines after laser irradiation with 1 J/cm2, whereas no significant increase was seen after laser irradiation with 2 J/cm2. In contrast, no effect on cell proliferation was seen in the human tonsil epithelial cells after laser irradiation with any of the energy densities. The increased proliferation was associated with elevated levels of pAKT, pERK, and Ki67 protein expression and cell cycle progression. Conclusion: Our results show that LLLT increases cell proliferation in a dose-dependent manner in HNSCC cells but not in normal epithelial tonsil cells. These results suggest that LLLT has to be used with caution when treating oropharyngeal mucositis in HNSCC patients since tumor cells present in the LLLT irradiation field could be triggered by LLLT.

A novel method to evaluate salivary flow rates of head and neck cancer patients after radiotherapy: a pilot study

Introduction

The procedure used to evaluate salivary flow rate is called sialometry. It can be performed through several techniques, but none appears to be really efficient for post-radiotherapy patients.

Objective

To adequate sialometry tests for head and neck cancer patients submitted to radiotherapy.

Methods

22 xerostomic patients post-radiotherapy (total radiation dose ranging from 60 to 70 Gy) were included in this study. Ten patients were evaluated using sialometries originally proposed by the Radiation Therapy Oncology Group and twelve were assessed by our modified methods. Unstimulated and stimulated sialometries were performed and the results were classified according a grading scale and compared between both groups.

Results

There was no statistically significant difference between the salivary evaluations of both groups (p = 0.4487 and p = 0.5615). Also, most of these rates were classified as very low and low.

Conclusion

This novel method seems to be suitable for patients submitted to radiotherapy.