The broadening scope of oral mucositis and oral ulcerative mucosal toxicities of anticancer therapies

Oral mucositis (OM) is a common, highly symptomatic complication of cancer therapy that affects patients' function, quality of life, and ability to tolerate treatment. In certain patients with cancer, OM is associated with increased mortality. Research on the management of OM is ongoing. Oral mucosal toxicities are also reported in targeted and immune checkpoint inhibitor therapies. The objective of this article is to present current knowledge about the epidemiology, pathogenesis, assessment, risk prediction, and current and developing intervention strategies for OM and other ulcerative mucosal toxicities caused by both conventional and evolving forms of cancer therapy.

A Review of Zinc-L-Carnosine and Its Positive Effects on Oral Mucositis, Taste Disorders, and Gastrointestinal Disorders

Zinc-L-carnosine (ZnC), also called polaprezinc known as PepZin GI™, is a chelated compound that contains L-carnosine and zinc. It is a relatively new molecule and has been associated with multiple health benefits. There are several studies that support ZnC’s benefits in restoring the gastric lining, healing other parts of the gastrointestinal (GI) tract, improving taste disorders, improving GI disorders, and enhancing skin and liver. Oral mucositis is a common complication of cytotoxic radiotherapy and/or chemotherapy. It occurs in almost every person with head and neck cancer who receive radiotherapy. It is often overlooked because it is not considered life threatening. However, mucositis often leads to a decreased quality of life and cessation of treatment, ultimately decreasing positive outcomes. Therefore, solutions to address it should be considered. The primary mechanisms of action are thought to be localized and related to ZnC’s anti-inflammatory and antioxidant functions. Therefore, the purpose of this review is to discuss the research related to ZnC and to explore its benefits, especially in the management of conditions related to damaged epithelial cells, such as oral mucositis. Evidence supports the safety and efficacy of ZnC for the maintenance, prevention, and treatment of the mucosal lining and other epithelial tissues. The research supports its use for gastric ulcers (approved in Japan) and conditions of the upper GI and suggests other applications, particularly for oral mucositis.

Daily Time of Radiation Treatment Is Associated with Subsequent Oral Mucositis Severity during Radiotherapy in Head and Neck Cancer Patients

BACKGROUND

Limited treatment options are available for oral mucositis, a common, debilitating complication of cancer therapy. We examined the association between daily delivery time of radiotherapy and the severity of oral mucositis in patients with head and neck cancer.

METHODS

We used electronic medical records of 190 patients with head and neck squamous cell carcinoma who completed radiotherapy, with or without concurrent chemotherapy, at Roswell Park Comprehensive Cancer Center (Buffalo, NY) between 2015 and 2017. Throughout a 7-week treatment course, patient mouth and throat soreness (MTS) was self-reported weekly using a validated oral mucositis questionnaire, with responses 0 (no) to 4 (extreme). Average treatment times from day 1 until the day before each mucositis survey were categorized into seven groups. Multivariable-adjusted marginal average scores (LSmeans) were estimated for the repeated- and maximum-MTS, using a linear-mixed model and generalized-linear model, respectively.

RESULTS

Radiation treatment time was significantly associated with oral mucositis severity using both repeated-MTS (n = 1,156; P = 0.02) and maximum-MTS (n = 190; P = 0.04), with consistent patterns. The severity was lowest for patients treated during 8:30 to <9:30 am (LSmeans for maximum-MTS = 2.24; SE = 0.15), increased at later treatment times and peaked at early afternoon (11:30 am to <3:00 pm, LSmeans = 2.66-2.71; SEs = 0.16/0.17), and then decreased substantially after 3 pm.

CONCLUSIONS

We report a significant association between radiation treatment time and oral mucositis severity in patients with head and neck cancer.

IMPACT

Although additional studies are needed, these data suggest a potential simple treatment time solution to limit severity of oral mucositis during radiotherapy without increasing cost.

Dosimetric measurement of scattered radiation for simulated head and neck radiotherapy with homemade oral phantom

During radiotherapy for head and neck tumours, the oral cavity and cheek area would be inevitably exposed to high energy radiation; thus, the material surface of the teeth, dental restorations with high atomic number, or alloy prosthodontics would generate backscatter electrons that cause the buccal mucosa adjacent to these materials to receive localized high dose enhancement, which primarily leads to side effects or oral mucositis. Based on the size of the adult oral cavity, this study aimed to use acrylic resin to create an oral phantom with two grooves on the left and right sides for placement of three molars. Moreover, the distance between the inner cheek and the side surface of the teeth could be accurately adjusted every 1 mm from 0 to 5 mm. This enhanced the dose in the buccal mucosa during head and neck radiotherapy and made the distribution measurement of the radiation dose simple and feasible at different depths (0-5 mm). Meanwhile, the study employed the film type optically stimulated luminescent dosimeter with a thickness of 0.3 mm to measure the absorbed dose inside the buccal mucosa to reduce the dose interference from radiotherapy. The study fixed three real molars in a row located at the left side of the phantom and employed 6 MV photons and intensity-modulated radiotherapy (IMRT) to treat and simulate oral cancer and measure the attenuation of the molar's backscatter dose from 0 to 5 mm in an up beam direction. The result showed that, in every 3 mm, the phantom had attenuated the enhancement of backscatter dose <3%. The irradiation dose enhancement in a single direction was twice higher than that through IMRT 7 field treatment. These measurement results were consistent with the results of previous studies.

Modulation of radiation-induced oral mucositis (mouse) by dermatan sulfate: effects on differentiation processes

PURPOSE

During head and neck cancer radiotherapy, oral mucositis is the most frequent early side effect. Systemic dermatan sulfate (DS) administration has been shown to significantly decrease oral mucosal radiation reactions during daily fractionated irradiation (IR) in an established mouse model. The aim of this study was to investigate the mechanism of the oral epithelial differentiation process, during IR alone and in combination with DS treatment in the same mouse model.

METHODS

Fractionated IR 5 × 3 Gy/week was given to the snouts of mice over two weeks, either alone (IR) or in combination with daily DS treatment of 4 mg/kg (IR + DS). Groups of mice (n = 3) were sacrificed every second day over the course of 14 days in both experimental arms. Their tongue was excised and subjected to immunohistochemical processing.

RESULTS

In the p16 analysis as a proliferation marker, the difference between IR alone and IR + DS in the germinal (proliferation) layer was not significant, not stimulating the proliferation process. For the p21 analysis as a differentiation marker on the functional (differentiation) layer, the difference between IR alone and IR + DS arms was significant, indicating that DS inhibited the differentiation process. In the cytokeratin (CK) analysis as the indicator of cellular skeletal integrity, the percentage of antibody-positive cells was above the normal level in both experimental arms and significantly superior in the IR + DS arm.

CONCLUSION

The mucosal protective activity of DS, instead of stimulating proliferation, is based on prevention of cell loss by a combination of effects leading to the inhibition of cellular differentiation and an increase in the expression of epithelial mechanical strength between intercellular mechanical junctions.

Heparin treatment mitigates radiation-induced oral mucositis in mice by interplaying with repopulation processes

PURPOSE

To investigate the mechanistic background of the muco-protective effect of systemic heparin treatment on the development of radiation-induced oral mucositis in mice.

MATERIALS AND METHODS

Fractionated irradiation was given to the snouts of male C3H/Neu mice over 2 weeks (10 × 3 Gy), either alone or in combination with daily subcutaneous application of unfractionated or low molecular weight heparin (40 or 200 I.U./mouse, respectively). Over this course of 14 days, groups of mice (n = 3) were sacrificed every second day, their tongues excised and processed for histological analysis. The epithelial radiation response with and without heparin treatment was evaluated in terms of tissue morphology, proliferation and expression of cell contact molecules.

RESULTS

Systemic treatment with heparins significantly reduced the cellular effects of irradiation to the oral epithelium. Heparin treated animals showed significantly higher total epithelial cell numbers and thickness throughout the study course. Bromodeoxyuridine (BrdU) incorporation analyses revealed that markedly more epithelial cells retained their proliferative capacity in the beginning of the first treatment week, but the proliferation of the mucosa was not stimulated during the rest of the study course. The expression of the adherens junction protein β‑catenin was slightly elevated in heparin treated animals, on day 2 the increase was statistically significant. The expression of e‑cadherin and occludin was mostly unaffected by the concomitant heparin treatment.

CONCLUSION

The findings of this study indicate an interplay of additional heparin treatment with the repopulation processes, leading to an earlier onset of this adaptive radiation response in oral mucosa. Importantly, we could demonstrate that the protective potential of heparin did not rely on stimulation of normal tissue proliferation. Since both heparin preparations are already approved for clinical use, they are considered as promising candidates for future clinical studies.

Buccal epithelial cell micronuclei: Sensitive, non-invasive biomarkers of occupational exposure to low doses of ionizing radiation

We have evaluated buccal epithelial cell micronucleus formation as a biomarker of genotoxic damage following occupational exposure to low doses of ionizing radiation. Buccal epithelial cells were collected from 42 occupationally exposed medical personnel and 39 non-exposed individuals (reference group). Each individual in the exposed group was routinely monitored with a personal radiation badge. The frequency of micronucleated cells (MNC) was significantly higher in the exposed group (5.26 vs. 1.33 MNC/2000 cells) and correlated strongly with accumulated radiation dose (Annual Deep Dose, mSv). Occupational exposure to low doses of ionizing radiation was associated with an 80% relative increase in the frequency of MNC (MRR = 1.8; 95% CI: 1.1-2.8), suggesting that such exposures cause DNA damage. This non-invasive biomonitoring method should be generally applicable to studies of workers who are exposed occupationally to low doses of IR.

Evaluation of Radiation-induced Cytological Changes in Lesional Oral Cancer Cells and Adjacent Normal Mucosal Cells

AIM

To assess various cytological changes for predicting radiosensitivity of oral squamous cell carcinoma by exfoliative cytology.

MATERIALS AND METHODS

Histologically proven 30 cases of oral squamous cell carcinoma who underwent fractionated radiotherapy in a dose of 45-60 Gy in 5 fractions/week were enrolled in the study. The exfoliative cytology smear was evaluated on lesional and adjacent oral mucosa before radiotherapy, during radiotherapy (8 and 11th fraction) and post radiotherapy (4, 6 and 8 weeks). Various parameters like multinucleation, cellular enlargement, nuclear enlargement, cytoplasmic vacuolation, cytoplasmic granulation, leukocytic infiltration were evaluated.

RESULTS

Statistical significant values were seen in the inter-group comparison of all the parameters when compared adjacent mucosa and normal mucosa for leukocytic infiltration in pretreatment smear.

CONCLUSION

The study showed that radiation-induced cytological changes in oral squamous cell carcinoma have a significant dose-related increase. This dose-response relationship and the high intratumoral variations suggest that serial assay of these changes has potential use for radiosensitivity prediction.

CLINICAL SIGNIFICANCE

Radiosensitivity prediction can be evaluated by means of cytological smears in one stop crisis centre (OSCC) individuals subjected to fractionated radiotherapy by evaluating the cytological parameters.

DNA damage in oral epithelial cells of individuals chronically exposed to indoor radon (222Rn) in a hydrothermal area

Hydrothermal areas are potentially hazardous to humans as volcanic gases such as radon (²²²Rn) are continuously released from soil diffuse degassing. Exposure to radon is estimated to be the second leading cause of lung cancer, but little is known about radon health-associated risks in hydrothermal regions. This cross-sectional study was designed to evaluate the DNA damage in the buccal epithelial cells of individuals chronically exposed to indoor radon in a volcanic area (Furnas volcano, Azores, Portugal) with a hydrothermal system. Buccal epithelial cells were collected from 33 individuals inhabiting the hydrothermal area (Ribeira Quente village) and from 49 individuals inhabiting a non-hydrothermal area (Ponta Delgada city). Indoor radon was measured with Ramon 2.2 detectors. Chromosome damage was measured by micronucleus cytome assay, and RAPD-PCR was used as a complementary tool to evaluate DNA damage, using three 10-mer primers (D11, F1 and F12). Indoor radon concentration correlated positively with the frequency of micronucleated cells (r _s = 0.325, p = 0.003). Exposure to radon is a risk factor for the occurrence micronucleated cells in the inhabitants of the hydrothermal area (RR = 1.71; 95% CI, 1.2-2.4; p = 0.003). One RAPD-PCR primer (F12) produced differences in the banding pattern, a fact that can indicate its potential for detecting radon-induced specific genomic alterations. The observed association between chronic exposure to indoor radon and the occurrence of chromosome damage in human oral epithelial cells evidences the usefulness of biological surveillance to assess mutations involved in pre-carcinogenesis in hydrothermal areas, reinforcing the need for further studies with human populations living in these areas.

[Effect of intensity modulated radiation therapy on oral mucosa and immune function in patients with nasopharyngeal carcinoma]

To study the potential effects of intensity modulated radiation therapy (IMRT) on clinical efficacy, oral mucosa reaction and immunological foundation; and to explore the effect of immunological changes on clinical efficacy and oral mucosa reaction in patients with nasopharyngeal carcinoma.
 Methods: A total of 200 patients with nasopharyngeal carcinoma, who came from First Department of Nasopharyngeal Radiotherapy, the First People's Hospital of Foshan from October 2008 to November 2011, were selected. The patients were treated with nasopharyngeal radiotherapy, and divided into an observation group and a control group (n=100 in each group). The control group underwent common conventional two-dimensional radiotherapy treatment, while the observation group underwent IMRT. The 5-year survival rates and recurrence rates were recorded at follow-up. After the radiotherapy, the oral mucosa in the patients were evaluated by the classification standard of acute radioactive mucositis by American Radiotherapy Oncology Group (RTOG), and the number of T lymphocyte subsets before and after treatment was detected.
 Results: There were significant difference in non-regional-recurrence survival rate, disease-free survival rate, local recurrence rate between the above 2 groups (all P<0.05), but no significant difference in the distant metastasis-free survival rate (P>0.05). The acute oral mucosa reactions of grade 1, 2, 3, 4 in the control group were 8.00%, 20.00%, 12.00%, 7.00%, respectively, and those were 7.00%, 22.00%, 15.00%, 1.00% respectively. There was no significant difference in the acute response of oral mucosa in grade 1, 2 and 3 in the 2 groups (all P>0.05), but there was significant difference in the grade 4 (P<0.05). There were significantly difference in CD8+, CD4+/ CD8+ and CD4+ T lymphocyte subsets before and after treatment in the above 2 groups (all P<0.01); there were also significantly difference after treatment between the observation group and the control group (all P<0.01).
 Conclusion: In the process of treatment in patients with nasopharyngeal carcinoma, the use of IMRT on the basis of chemotherapy is more effective than the conventional two-dimensional radiotherapy, which can reduce the proportion of grade 4 (severe) acute oral mucosa reaction. It may be related to the protective effect of IMRT on immune function in the patients.

The Efficacy of Orgotein in the Treatment of Acute Toxicity Due to Radiotherapy on Head and Neck Tumors

Aims and background

To assess the efficacy of orgotein in the treatment of acute secondary effects of radiotherapy on head and neck tumors.

Material and methods

Data were collected on 41 patients who received radiotherapy for tumors of the head and neck. Radiotherapy was the exclusive treatment in 19.5% of cases, with surgery in 24.4%, chemotherapy in 48.8%, and with both in 7.3%. The toxicity requiring use of orgotein was: oropharynx mucositis (26.8%), dysphagia (34.2%), or both (39%), in grade 2 or more according to the RTOG scale. Orgotein (8 mg im) was administered every 48 hrs until radiotherapy was finished.

Results

The overall response rate was 92.5%; a complete response was obtained in 12 patients (30%) and partial in 25 (62.5%). The reduction in toxicity at the end of radiotherapy was one grade in 18 patients (45%), 2 grades in 16 (40%), 3 in 2 patients (5%), and 4 grades in the only patient with grade 4 acute toxicity. A statistically significant influence was shown in obtaining complete response: laryngeal tumor location (P = 0.037), duration of radiotherapy of more than 53 days (P = 0.002), discontinuation for non-toxic reasons (P = 0.008).

Conclusions

We consider that orgotein is highly effective in dealing with acute secondary effects of radiotherapy on the head and neck area.

Comparison of Radiation-Induced Oral Mucositis Scoring Systems

Background

A number of oral toxicity scoring systems have been described, but their direct comparison has rarely been undertaken and little data exists. An impediment to mucositis research has been the lack of an accepted, validated scoring system. The objective of this study was to design a test and validation of scoring systems.

Materials and methods

Forty-three patients with head and neck malignancies who had been irradiated were evaluated. Five different mucositis scoring systems (World Health Organization, Radiation Therapy Oncology Group, “Hickey”, “Van der Schueren” and “Makkonen”) were compared with each other.

Results

Daily mucositis scores demonstrated a high correlation among scoring systems (P <0.05 and coefficient of correlation κ and r = 0.5 - 0.95). Objective mucositis scores demonstrated a strong correlation with symptoms.

Conclusions

All scoring systems were equally valid. The exact grading of mucositis is achieved by combining clinical information about pain and nutritional status with oral mucosal reactions.

Histological and Thermometric Examination of Soft Tissue De-Epithelialization Using Digitally Controlled Er:YAG Laser Handpiece: An Ex Vivo Study

OBJECTIVE

The purpose of this study was histological and thermometric examination of soft tissue de-epithelialization using digitally controlled laser handpiece (DCLH) - X-Runner.

BACKGROUND DATA

Commonly used techniques for de-epithelialization include scalpel, abrasion with diamond bur, or a combination of the two. Despite being simple, inexpensive and effective, these techniques are invasive and may produce unwanted side effects. It is important to look for alternative techniques using novel tools, which are minimally invasive and effective.

MATERIALS AND METHODS

114 porcine samples sized 6 × 6 mm were collected from the attached gingiva (AG) of the alveolar process of the mandible using 15C scalpel blade. The samples were irradiated by means of Er:YAG laser (LightWalker, Fotona, Slovenia), using X-Runner and HO₂ handpieces at different parameters; 80, 100, and 140 mJ/20 Hz in time of 6 or 16 sec, respectively. The temperature was measured with a K-type thermocouple. For the histopathological analysis of efficiency of epithelium removal and thermal injury, 3 random samples were de-epithelialized with an HO₂ handpiece, and 9 random samples with an X-Runner handpiece with different parameters. For the samples irradiated with DCLH, we have used three different settings, which resulted in removing 1 to 3 layers of the soft tissue. The efficiency of epithelium removal and the rise of temperature were analyzed.

RESULTS

DCLH has induced significantly lower temperature increase compared with HO₂ at each energy to frequency ratio. The histological examination revealed total epithelium removal when HO₂ handpiece was used at 100 and 140 mJ/20 Hz and when DCLH was used for two- and threefold lasing at 80, 100, and 140 mJ/20 Hz.

CONCLUSIONS

Er:YAG laser with DCLH handpiece may be an efficient tool in epithelium removal without excessive thermal damage.

A Sweet Solution: The Use of Medical-grade Honey on Oral Mucositis in the Pediatric Oncology Patient

INTRODUCTION

Pediatric patients develop mucositis when receiving treatments such as chemotherapy and radiation; the most common and sensitive is oral mucositis. Mouth rinses containing antimicrobial, antihistamine, and analgesic medications are the mainstay for pediatric patients; however, patients often refuse these rinses due to the taste or texture. Also, patients under 1 year of age are unable to use these products.

OBJECTIVE

Herein, the improvement of oral mucositis with standard oral care and additional use of active Leptospermum honey in pediatric oncology patients after chemotherapy is demonstrated.

MATERIALS AND METHODS

Patients received oral care every 4 hours followed by application of the honey paste 3 times daily. The honey paste was applied with a sponge swab to coat the mouth. Patients either swished and spit or had excess honey suctioned out. At completion of this evaluation, the honey treatment was used in 10 pediatric oncology patients between the ages of 9 months and 17 years.

RESULTS

The Leptospermum honey paste was easy to apply and was well received by all patients. Healing was observed within 3 days, and patients in all cases reported decreases in pain. Decreased wounds and bleeding were evident in all cases within 5 days.

CONCLUSIONS

Leptospermum honey paste proved to be effective in all participating patients.

In-vivo longitudinal imaging of microvascular changes in irradiated oral mucosa of radiotherapy cancer patients using optical coherence tomography

Mucositis is the limiting toxicity of radio(chemo)therapy of head and neck cancer. Diagnostics, prophylaxis and correction of this condition demand new accurate and objective approaches. Here we report on an in vivo longitudinal monitoring of the oral mucosa dynamics in 25 patients during the course of radiotherapy of oropharyngeal and nasopharyngeal cancer using multifunctional optical coherence tomography (OCT). A spectral domain OCT system with a specially-designed oral imaging probe was used. Microvasculature visualization was based on temporal speckle variations of the full complex signal evaluated by high-pass filtering of 3D data along the slow scan axis. Angiographic image quantification demonstrated an increase of the vascular density and total length of capillary-like-vessels before visual signs or clinical symptoms of mucositis occur. Especially significant microvascular changes compared to their initial levels occurred when grade two and three mucositis developed. Further, microvascular reaction was seen to be dose-level dependent. OCT monitoring in radiotherapy offers a non-invasive, convenient, label-free quantifiable structural and functional volumetric imaging method suitable for longitudinal human patient studies, furnishing fundamental radiobiological insights and potentially providing useful feedback data to enable adaptive radiotherapy (ART).

Long-term outcomes after carbon-ion radiotherapy for oral mucosal malignant melanoma

Oral mucosal malignant melanoma (OMM) is extremely rare and has a poor prognosis. Owing to its rarity, it has not yet been possible to establish an optimal treatment modality. The objective of this study was to evaluate the long-term efficacy of carbon-ion radiotherapy (C-ion RT) for OMM. Between 1997 and 2013, 19 patients with OMM were treated with C-ion RT alone. Patient ages ranged from 44 to 84 years (median, 69 years). Nine men and 10 women were included. OMMs were restaged in accordance with the seventh edition of the tumour/node/metastasis (TNM) Staging System of the International Union Against Cancer. Before treatment, 14 patients had T3 disease and 5 had T4a disease. Three patients were classified as having N1 disease. All patients were classified as having M0. The hard palate was the most frequently involved oral subsite. All patients were treated with 57.6 Gy (relative biological effectiveness) in 16 fractions. The median follow-up period was 61 months (range, 8-190 months). The 5-year local control, overall survival and progression-free survival rates were 89.5%, 57.4% and 51.6%, respectively. For local control and overall survival, T classification was found to be a significant prognostic factor. Grade 2 and 3 osteoradionecrosis was observed in three and four patients, respectively. The presence of teeth within the planning target volume was a significant risk factor for developing osteoradionecrosis. C-ion RT was an effective treatment option with acceptable toxicity for OMM.

Pediatric Phantom Dosimetry of Kodak 9000 Cone-beam Computed Tomography

PURPOSE

The purpose of the study was to evaluate the radiation dose of the Kodak 9000 cone-beam computed tomography (CBCT) device for different anatomical areas using a pediatric phantom.

METHODS

Absorbed doses resulting from maxillary and mandibular region three by five cm CBCT volumes of an anthropomorphic 10-year-old child phantom were acquired using optical stimulated dosimetry. Equivalent doses were calculated for radiosensitive tissues in the head and neck area, and effective dose for maxillary and mandibular examinations were calculated following the 2007 recommendations of the International Commission on Radiological Protection (ICRP).

RESULTS

Of the mandibular scans, the salivary glands had the highest equivalent dose (1,598 microsieverts [μSv]), followed by oral mucosa (1,263 μSv), extrathoracic airway (pharynx, larynx, and trachea; 859 μSv), and thyroid gland (578 μSv). For the maxilla, the salivary glands had the highest equivalent dose (1,847 μSv), followed closely by oral mucosa (1,673 μSv), followed by the extrathoracic airway (pharynx, larynx, and trachea; 1,011 μSv) and lens of the eye (202 μSv).

CONCLUSION

Compared to previous research of the Kodak 9000, completed with the adult phantom, a child receives one to three times more radiation for mandibular scans and two to 10 times more radiation for maxillary scans.

Normal Tissue Complication Probability (NTCP) Modelling of Severe Acute Mucositis using a Novel Oral Mucosal Surface Organ at Risk

AIMS

A normal tissue complication probability (NTCP) model of severe acute mucositis would be highly useful to guide clinical decision making and inform radiotherapy planning. We aimed to improve upon our previous model by using a novel oral mucosal surface organ at risk (OAR) in place of an oral cavity OAR.

MATERIALS AND METHODS

Predictive models of severe acute mucositis were generated using radiotherapy dose to the oral cavity OAR or mucosal surface OAR and clinical data. Penalised logistic regression and random forest classification (RFC) models were generated for both OARs and compared. Internal validation was carried out with 100-iteration stratified shuffle split cross-validation, using multiple metrics to assess different aspects of model performance. Associations between treatment covariates and severe mucositis were explored using RFC feature importance.

RESULTS

Penalised logistic regression and RFC models using the oral cavity OAR performed at least as well as the models using mucosal surface OAR. Associations between dose metrics and severe mucositis were similar between the mucosal surface and oral cavity models. The volumes of oral cavity or mucosal surface receiving intermediate and high doses were most strongly associated with severe mucositis.

CONCLUSIONS

The simpler oral cavity OAR should be preferred over the mucosal surface OAR for NTCP modelling of severe mucositis. We recommend minimising the volume of mucosa receiving intermediate and high doses, where possible.

Preventive Intervention Possibilities in Radiotherapy- and Chemotherapy-induced Oral Mucositis: Results of Meta-analyses

The aim of these meta-analyses was to evaluate the effectiveness of interventions for the prevention of oral mucositis in cancer patients treated with head and neck radiotherapy and/or chemotherapy, with a focus on randomized clinical trials. A literature search was performed for reports of randomized controlled clinical studies, published between 1966 and 2004, the aim of which was the prevention of mucositis in cancer patients undergoing head and neck radiation, chemotherapy, or chemoradiation. The control group consisted of a placebo, no intervention, or another intervention group. Mucositis was scored by either the WHO, the National Cancer Institute-Common Toxicity Criteria (NCI-CTC) score, or the absence or presence of ulcerations, or the presence or absence of grades 3 and 4 mucositis. The meta-analyses included 45 studies fulfilling the inclusion criteria, in which 8 different interventions were evaluated: i.e., local application of chlorhexidine; iseganan; PTA (polymyxin E, tobramycine, and amphotericin B); granulocyte macrophage-colony-stimulating factor/granulocyte colony-stimulating factor (GM-CSF/G-CSF); oral cooling; sucralfate and glutamine; and systemic administration of amifostine and GM-CSF/G-CSF. Four interventions showed a significant preventive effect on the development or severity of oral mucositis: PTA with an odds ratio (OR) = 0.61 (95% confidence interval [CI], 0.39–0.96); GM-CSF, OR = 0.53 (CI: 0.33–0.87); oral cooling, OR = 0.3 (CI: 0.16–0.56); and amifostine, OR = 0.37 (CI: 0.15–0.89). To date, no single intervention completely prevents oral mucositis, so combined preventive therapy strategies seem to be required to ensure more successful outcomes.

Effect of a single dose of low-level laser therapy on spontaneous and chewing pain caused by elastomeric separators

INTRODUCTION

The aim of this study was to see the effect of a single dose of low-level laser therapy on spontaneous and chewing pain after the placement of elastomeric separators.

METHODS

Eighty-eight patients were randomly selected for this single-blind study. Elastomeric separators were placed mesial and distal to the permanent first molars in all quadrants. Both arches were divided into experimental and control sides. The experimental sides were treated with low-level laser therapy on 3 points on the buccal mucosa for 20 seconds each, with a 940-nm gallium-aluminum-arsenic diode laser on continuous mode and power set at 200 mW. The other side received placebo laser therapy without turning on the laser. A numeric rating scale was used to assess the intensity of spontaneous and chewing pain for the next 7 days. The independent sample t test and repeated-measures analysis of variance with the post hoc Tukey test was used to analyze the results.

RESULTS

Significant differences were found in spontaneous and chewing pain among both groups (P <0.05).

CONCLUSIONS

A single dose of low-level laser therapy can be an efficient modality to reduce the postoperative pain associated with the placement of elastomeric separators.

Effect of Fractionated Dose of Radiotherapy on Oral Mucosa in Head and Neck Cancer Patients: A Cytological Assessment

BACKGROUND

Cancer therapy couples with it a plethora of complications of short and long term effects which can be so distressing that patient may tolerate only lower less-effective doses of therapy, may postpone treatments or will discontinue treatment entirely. Fractionated dose of radiotherapy coupled with therapy induce local or systemic infections due to high cellular turnover rates of the oral mucosa, diverse and complex microflora and trauma to oral tissues. Several mucosal abnormalities often results in epithelial and glandular destruction and inflammation, which can be so devastating that it may cause atypical changes on the area exposed to radiation. Thus, the aim of this study was to investigate the feasibility of using cytological evaluation to detect oral epithelial atypia among Head and Neck cancer patients receiving fractionated dose of radiotherapy.

METHODS

Study was conducted on 125 head and neck cancer patients receiving radiotherapy. Subjects were divided into 5 study groups on the basis of fractionated dose of radiotherapy from 10th-50th fractions respectively. Mucosal changes were evaluated by exfoliative cytology and atypical changes and inflammatory cell infiltration were assessed.

RESULTS

Without prior knowledge of the subjects' group, oral epithelial atypia was detected with increase fractionated dose of radiation. Dense inflammatory nfiltrate were identified in nearly all study groups irrespective of dose of radiotherapy.

CONCLUSION

Cytological atypia and inflammatory infiltrates were detected after exposure to radiotherapy.

Prediction of Acute Radiation Mucositis using an Oral Mucosal Dose Surface Model in Carbon Ion Radiotherapy for Head and Neck Tumors

PURPOSE

To evaluate the dose-response relationship for development of acute radiation mucositis (ARM) using an oral mucosal dose surface model (OMDS-model) in carbon ion radiotherapy (C-ion RT) for head and neck tumors.

METHODS

Thirty-nine patients receiving C-ion RT for head and neck cancer were evaluated for ARM (once per week for 6 weeks) according to the Common Terminology Criteria for Adverse Events (CTCAE), version 4.0, and the Radiation Therapy Oncology Group (RTOG) scoring systems. The irradiation schedule typically used was 64 Gy [relative biological effectiveness (RBE)] in 16 fractions for 4 weeks. Maximum point doses in the palate and tongue were compared with ARM in each patient.

RESULTS

The location of the ARM coincided with the high-dose area in the OMDS-model. There was a clear dose-response relationship between maximum point dose and ARM grade assessed using the RTOG criteria but not the CTCAE. The threshold doses for grade 2-3 ARM in the palate and tongue were 43.0 Gy(RBE) and 54.3 Gy(RBE), respectively.

CONCLUSIONS

The OMDS-model was useful for predicting the location and severity of ARM. Maximum point doses in the model correlated well with grade 2-3 ARM.

The Effects of Ionizing Radiation on the Oral Cavity

AIM

The aim of this study is to present a literature review on the effects of the ionizing radiation from radiotherapy treatment on dental tissues.

BACKGROUND

Among the effects of increasing global life expectancy and longevity of the teeth in the oral cavity, increasing rates of neoplastic diseases have been observed. One of the important treatment modalities for head and neck neoplastic diseases is radiotherapy, which uses ionizing radiation as the main mechanism of action. Therefore, it is essential for dentists to be aware of the changes in oral and dental tissues caused by ionizing radiation, and to develop treatment and prevention strategies.

RESULTS

In general, there is still controversy about the effects of ionizing radiation on dental structures. However, qualitative and quantitative changes in saliva and oral microbiota, presence of oral mucositis and radiation-related caries are expected, as they represent the well-known side effects of treatment with ionizing radiation. Points that still remain unclear are the effects of radiotherapy on enamel and dentin, and on their mechanisms of bonding to contemporary adhesive materials.

CONCLUSION

Ionizing radiation has shown important interaction with organic tissues, since more deleterious effects have been shown on the oral mucosa, salivary glands and dentin, than on enamel.

CLINICAL SIGNIFICANCE

With the increasing number of patients with cancer seeking dental treatment before and after head and neck radiotherapy, it is important for dentists to be aware of the effects of ionizing radiation on the oral cavity.

[The Buccal Epithelium as Environmental Indicator]

The use of the buccal mucosa cell micronucleus test for comparison of chemical, radiation, and radiation-chemical environmental pollution has been considered. The combined impact of chemical and radiation factors has been found to cause additive effects, synergism, and inhibition. It has been noted that the cytogenetic characteristics of the buccal epithelium may be used as a "biological dosimeter" of the total level of environmental pollution.

Effects of laser irradiation at different wavelengths (660, 810, 980, and 1064 nm) on transient receptor potential melastatin channels in an animal model of wound healing

The aim of the present study was to compare the effectiveness of four different laser wavelengths used for low-level laser therapy(LLLT) on healing of mucositis in an animal model of wound healing, by investigating expression of transient receptor potential melastatin(TRPM) ion channels. Forty-five rats were intraperitoneally injected with 100 mg/kg 5-fluorouracil on day 1 and 65 mg/kg on day 3. Superficial scratching on left cheek pouch mucosa was performed on days 3 and 5. After ulcerative mucositis was clinically detected, LLLT was started (660 nm, HELBO; 810 nm, Fotona-XD; 980 nm, ARC-Fox; and 1064 nm, Fidelis-Plus3) at 8 J/cm(2)/day from days 1 to 4. Oval excisional biopsy was performed at the wound site, and expression of TRPM2 to TRPM8 was evaluated. Student's t test was used for evaluation of significance of TRPM gene expression according to "0" value (α = 0.05). In 980-nm group, TRPM4, TRPM6, and TRPM7 were significantly higher than in the control group (p < 0.005). In 660, 810, and 1064 nm groups, only TRPM6 was significantly higher than in control group (p < 0.005). There were no significant differences between control and sham groups (p > 0.05). These findings suggest that expression of TRPM6 gene was significantly affected by irradiation with lasers at different wavelengths, whereas the TRPM4 and TRPM7 genes were only expressed in the 980-nm diode laser group. TRPM6 gene was highly expressed during LLLT, which may lead to accelerated wound healing and tissue repair. In contrast, there was some evidence that the 980-nm diode laser caused increased expression of TRPM4, TRPM6, and TRPM7 which are responsible for stimulation of Ca(2+) and Mg(2+) metabolism, as well as apoptotic pathways of controlled cell death.

Multi-institutional, randomized, double-blind, placebo-controlled trial to assess the efficacy of a mucoadhesive hydrogel (MuGard) in mitigating oral mucositis symptoms in patients being treated with chemoradiation therapy for cancers of the head and neck

BACKGROUND

The objective of this trial was to determine how a mucoadhesive hydrogel (MuGard), a marketed medical device, would fare when tested with the strictness of a conventional multi‐institutional, double‐blind, randomized, placebo‐controlled study format.

METHODS

A total of 120 subjects planned to receive chemoradiation therapy (CRT) for treatment of head and neck cancers were randomized to receive either MuGard or sham control rinse (SC) during CRT. Subjects completed the validated Oral Mucositis Daily Questionnaire. Weight, opiate use, and World Health Organization (WHO) oral mucositis (OM) scores were recorded. Subjects who dosed at least once daily during the first 2.5 weeks of CRT were included in the efficacy analysis.

RESULTS

Of 120 subjects enrolled, 78 (SC, N = 41; MuGard, N = 37) were eligible for efficacy analysis. Both cohorts were similar in demographics, baseline characteristics, primary tumor type, and planned CRT regimen. MuGard effectively mitigated OM symptoms as reflected by area under the curve of daily patient‐reported oral soreness (P = .034) and WHO scores on the last day of radiation therapy (P = .038). MuGard was also associated with nonsignificant trends related to therapeutic benefit including opioid use duration, and OM scores (WHO criteria) at CRT week 4. Rinse compliance was identical between cohorts. No significant adverse events were reported, and the adverse event incidence was similar between cohorts.

CONCLUSIONS

Testing MuGard, a rinse marketed as a device, in a standard clinical trial format demonstrated its superiority to SC in mitigating OM symptoms, delaying OM progression, and its safety and tolerability. Cancer 2014;120:1433–1440. © 2014 Access Pharmaceuticals, Inc. Cancer published by Wiley Periodicals. Inc. on behalf of American Cancer Society.

In a randomized, double‐blind, placebo‐controlled trial, the mucoadhesive hydrogel MuGard proved to be superior to saline‐bicarbonate rinse in mitigating oral mucositis (OM) symptoms and delaying OM progression. MuGard was safe and well‐tolerated, and favorably affected the rate and incidence of ulcerative lesions, consistent with the patient‐reported outcomes.

[The effectiveness of molixan as a means of correction of chemoradiation therapy negative manifestations in patients with oropharyngeal cancer]

The effectiveness of the peptide immunomodulator molixan as a means of support and correction of chemoradiation therapy of oral mucositis have been studied in 36 patients with primary regional cancer of the oral mucosa and the oropharynx. Combined chemotherapy of patients with cisplatin and standard radiotherapy was associated with progression of oral mucositis and hematopoietic disorders which manifested themselves in the form of neutro-, lympho- and thrombocytopenia. Therapeutic intramuscular application of molixan at a dose of 60 mg once a day after a fraction of irradiation made it possible to reduce the severity of oral mucositis (from grade III-IV to grade I-II), as well as to maintain in patients a higher level of white blood cells and platelets in the blood, which made it possible to complete the planned course of chemoradiation therapy.

Late oral mucosa alterations after radiotherapy for head and neck cancer assessed by exfoliative cytology

AIM

Late oral mucosa changes after radiotherapy for head and neck cancer have been poorly studied. This study aimed to determine long-term effects of radiotherapy on oral mucosa using exfoliative oral cytology.

PATIENTS AND METHODS

Fifty patients with cancer were enrolled, five of whom in order to validate microscopic analysis. Smears were collected at programmed visit; a score was used to rank possible cytological alterations. Presence of inflammation was also microscopically described and compared to blood count tests.

RESULTS

Epithelial cells revealed a peculiar 'folding' phenotype, not related to chemotherapy, total dose, or to the effective dose delivered to mucosa. Inflammation described was related to the score for 'folding' cells; moreover, score decreased in the presence of a higher lymphocyte count, while it was not altered by neutrophil count.

CONCLUSION

We suggest application of exfoliative cytology to study radiation injury and the variability of individual response of oral mucosa to radiation.

[Molecular mechanisms of combined extremely radiofrequency and infrared therapy in various age patients with chronic parodontitis]

The influence of extreme radiofrequency millimeter microwave (EHF) and infrared (IR) electromagnetic emanation on the molecular markers of cell renovation (Ki67, p53) and proinflammatory cytokine TNF-α expression in the buccal cells of various age patients with chronic parodontitis was investigated. The results show that EHF- and IR-electromagnetic emanation increased Ki67 proliferative marker expression and decreased expression of proapoptosis protein p53 and proinflammatory cytokine TNF-α in the buccal epithelium of young, middle-aged and elderly people with chronic parodontitis. The data obtained open the new ability for patogenetic treatment of various age patients with chronic parodontitis using the EHF- and IR-electromagnetic emanation method.

Influence of different energy densities of laser phototherapy on oral wound healing

The aim of the present prospective study was to evaluate the impact of laser phototherapy (LPT) on the healing of oral ulcers. Different power densities were used on oral wounds in Wistar rats (n=72) randomly divided into three groups: control (0 J/cm2), 4 J/cm2 laser, and 20 J/cm2 laser. Ulcers (3 mm in diameter) were made on the dorsum of the tongue with a punch. Irradiation with an indium-gallium-aluminum-phosphide laser (660 nm; output power: 40 mW; spot size: 0.04 cm2) was performed once a day in close contact with the ulcer for 14 consecutive days. A statistically significant acceleration in healing time was found with wounds treated with 4 J/cm2 LPT. Moreover, striking differences were found in the ulcer area, healing percentage, degree of reepithelialization, and collagen deposition. The most significant changes occurred after 5 days of irradiation. Based on the conditions employed in the present study, LPT is capable of accelerating the oral mucosa wound-healing process. Moreover, faster and more organized reepithelialization and tissue healing of the oral mucosa were achieved with an energy density of 4 J/cm2 in comparison to 20 J/cm2.

Oral mucosal injury caused by cancer therapies: current management and new frontiers in research

This invited update is designed to provide a summary of the state-of-the-science regarding oral mucosal injury (oral mucositis) caused by conventional and emerging cancer therapies. Current modeling of oral mucositis pathobiology as well as evidence-based clinical practice guidelines for prevention and treatment of oral mucositis are presented. In addition, studies addressing oral mucositis as published in the Journal of Oral Pathology and Medicine 2008-2013 are specifically highlighted in this context. Key research directions in basic and translational science associated with mucosal toxicity caused by cancer therapies are also delineated as a basis for identifying pathobiologic and pharmacogenomic targets for interventions. This collective portfolio of research and its ongoing incorporation into clinical practice is setting the stage for the clinician in the future to predict mucosal toxicity risk and tailor therapeutic interventions to the individual oncology patient accordingly.

Using GafChromic film to estimate the effective dose from dental cone beam CT and panoramic radiography

OBJECTIVES

To demonstrate the feasibility of GafChromic(®) XR-QA2 (ISP Corp., Wayne, NJ) as a dosemeter when performing measurements of the effective dose from three cone beam CT (CBCT) units and to compare the doses from examinations of three common dental clinical situations. A second aim was to compare the radiation doses for three digital panoramic units with the doses for the CBCT units.

METHODS

The CBCT units used were Veraviewepocs 3De(®) (J Morita MFG Corp., Kyoto, Japan), ProMax(®) 3D (Planmeca, Helsinki, Finland) and NewTom VGi(®) (Quantitative Radiology, Verona, Italy). GafChromic XR-QA2 films were placed between the selected layers of the head and neck of a tissue-equivalent human skull (RANDO(®) phantom; The Phantom Laboratory, Salem, NY). The exposure parameters were set using the automatic exposure control function of the units. Depending on the availability, medium and smaller field of view (FOV) scanning modes were used. The effective dose was estimated using the 2007 International Commission on Radiological Protection formalism.

RESULTS

The lowest effective dose of a CBCT unit was observed for ProMax 3D, FOV 4 × 5 cm (10 μSv), the highest for NewTom VGi, FOV 8 × 8 cm-high resolution (129 μSv). The range of effective doses for digital panoramic machines measured was 8-14 μSv.

CONCLUSIONS

This study demonstrates the feasibility of using radiochromic films for dental CBCT and panoramic dosimetry.

[Toxicity modifying action of remaxol by treatment of advanced oral cancer]

The efficiency of remaxol for prevention and treatment of chemoradiotherapy toxicity effects in patients with advanced oral cancer was evaluated. Ninety-five oral cancer patients were using remaxol both locally (mouth rinse solution) and by intravenous infusion, 87 patients were included in control group. Intravenous remaxol proved to be effective for mucositis and nephrotoxicity prevention by chemoradiotherapy.

Evidence-based oral care for oral mucositis

Nurses must intervene to provide evidence-based supportive care and symptom management for cancer patients. Oral mucositis, a distressing side effect of cancer treatment, is both a research and clinical priority. Nurses can lead improvements with evidence-based oral mucositis interventions. This article describes application of evidence-based clinical recommendations for oral mucositis across diverse patient populations.

mTOR inhibition prevents epithelial stem cell senescence and protects from radiation-induced mucositis

The integrity of the epidermis and mucosal epithelia is highly dependent on resident self-renewing stem cells, which makes them vulnerable to physical and chemical insults compromising the repopulating capacity of the epithelial stem cell compartment. This is frequently the case in cancer patients receiving radiation or chemotherapy, many of whom develop mucositis, a debilitating condition involving painful and deep mucosal ulcerations. Here, we show that inhibiting the mammalian target of rapamycin (mTOR) with rapamycin increases the clonogenic capacity of primary human oral keratinocytes and their resident self-renewing cells by preventing stem cell senescence. This protective effect of rapamycin is mediated by the increase in expression of mitochondrial superoxide dismutase (MnSOD), and the consequent inhibition of ROS formation and oxidative stress. mTOR inhibition also protects from the loss of proliferative basal epithelial stem cells upon ionizing radiation in vivo, thereby preserving the integrity of the oral mucosa and protecting from radiation-induced mucositis.

Genotoxicity of digital panoramic radiography on oral epithelial tissues

OBJECTIVE

To evaluate the genotoxic effects of x-rays on gingival and buccal epithelial cells during panoramic dental radiography using the micronucleus test.

METHOD AND MATERIALS

Eighty otherwise healthy subjects who required a diagnostic panoramic radiograph and met the selection criteria were included in the study. Epithelial cells were obtained from the maxillary anterior gingiva and buccal mucosa by gentle scraping with a wooden spatula immediately before exposure and again 10 days after exposure. Cytologic preparations were made according to the Papanicolaou staining method and analyzed under a light microscope for micronucleus count.

RESULTS

The mean ± SD micronucleus count of gingival epithelial cells was 1.08 ± 0.76 before radiographic exposure and 1.6 ± 0.93 after exposure. This increase was statistically significant (P < .05). Similarly, there was an increase in the postexposure micronucleus count in the buccal mucosa, but this increase was not significant (P > .05). A significant correlation was observed between the age of subjects and micronucleus count, although no such correlation was found between sex and micronucleus count.

CONCLUSION

Although radiation-related effects from panoramic radiography were reduced compared with full-mouth intraoral periapical radiographs or radiotherapy, the results of this study show that genotoxic effects do take place. Thus, radiographs should be taken with adequate protection measures and only when the potential benefit outweighs the potential risk.

Effects of curcumin and capsaicin irradiated with visible light on murine oral mucosa

The purpose of this study was to evaluate the histopathological effects of curcumin and capsaicin, with or without visible light (VL) irradiation for 5 min, on the oral mucous membrane in mice. Capsaicin-treated, but not curcumin-treated, buccal epithelium exhibited slight tissue damage; VL irradiation caused excessive tissue damage, particularly when combined with the former treatment. The TdT-mediated dUTP-biotin nick end-labeling (TUNEL) method demonstrated that both capsaicin and curcumin induced apoptosis, with the apoptotic effect of capsaicin appearing at an early stage of application. VL irradiation increased the number of apoptotic cells, particularly those upon in the capsaicin-treated area. Capsaicin and curcumin acted as photosensitizers exposure to VL, in the presence of oxygen. Curcumin and capsaicin with VL irradiation could thus be used for photodynamic therapy in the clinical setting, especially in precancerous oral diseases.

Acute mucosal radiation reactions in patients with head and neck cancer. Patterns of mucosal healing on the basis of daily examinations

PURPOSE

The goal of this research was to evaluate the healing processes of acute mucosal radiation reactions (AMRR) in patients with head and neck cancer.

MATERIALS AND METHODS

In 46 patients with oral and oropharyngeal cancer patients irradiated with conventional (n = 25) and accelerated (n = 21) dose fractionation AMRR was evaluated daily during and after radiotherapy. Complex of morphological and functional symptoms according to the Dische score were collected daily until complete healing.

RESULTS

Duration of healing after the end of radiotherapy ranged widely (12-70 days). It was on the average 8 days longer for accelerated than for conventional radiotherapy (p = 0.016). Duration of dysphagia was also longer for accelerated irradiation (11 days, p = 0.027). Three types of morphological symptoms were observed as the last symptom at the end of AMRR healing: spotted and confluent mucositis, erythema, and edema. Only a slight correlation between healing duration and area of irradiation fields (r = 0.23) was noted. In patients with confluent mucositis, two morphological forms of mucosal healing were observed, i.e., marginal and spotted. The spotted form was noted in 71% of patients undergoing conventional radiotherapy and in 38% of patients undergoing accelerated radiotherapy. The symptoms of mucosal healing were observed in 40% patients during radiotherapy.

CONCLUSION

The wide range of AMRR healing reflects individual potential of mucosa recovery with longer duration for accelerated radiotherapy. Two morphological forms of confluent mucositis healing were present: marginal and spotted. Healing of AMRR during radiotherapy can be observed in a significant proportion of patients.

Micronuclei and other nuclear anomalies in buccal mucosa following exposure to X-ray radiation

OBJECTIVE

To evaluate DNA damage and cellular death in exfoliated buccal mucosa cells from healthy individuals following dental X-ray exposure, to compare effects of different types of radiographic techniques using the buccal cytome assay and to standardize the staining procedure.

STUDY DESIGN

This study comprised 90 patients, categorized into 3 groups subjected to intraoral periapical radiography, conventional orthopantomogram and digital orthopantomogram X-ray exposure. Exfoliated oral mucosa cells were collected immediately before the X-ray and 10 days later and stained using DNA-specific stains and nonspecific DNA stains.

RESULTS

The results indicated no statistically significant differences in micronucleated cells before and after dental X-ray exposure. On the other hand, X-ray exposure did increase other nuclear alterations closely related to cytotoxicity, such as karyorrhexis, pyknosis and karyolysis.

CONCLUSION

These data indicate that dental radiography may not induce chromosomal damage, but it is able to promote cytotoxicity.

Oral mucosa response to laser patterned microcoagulation (LPM) treatment. An animal study

In this study a minimally invasive microsurgical approach was used for laser patterned microcoagulation (LPM) to initiate gingival and oral mucosal tissue regeneration. We performed a feasibility assessment and histological examination of laser damage and regeneration in the gingiva and oral mucosa using an animal model. The study animals comprised 18 healthy rabbits which were treated in vivo with single pulses from a diode laser at a wavelength of 980 nm and a power of up to 20 W applied to the gingival and oral mucosa at multiple time points. Biopsies were stained with hematoxylin and eosin, nitroblue tetrazolium chloride and picrosirius red, and evaluated by two pathologists blinded to the parameters and date of laser exposure. Histological analysis revealed that the continuity of the epithelial basal cell layer had been reestablished by 1-2 days after LPM, and complete epithelial regeneration had occurred by 7-12 days. A pronounced reactive inflammation developed in the column area 1 day after treatment. High activity of fibroblasts producing new collagen participated in the formation of a network of new thin-wall blood vessel. By the 28th day the tissue structure was almost completely restored with a similar increase of vascularity, and there were no signs of scarring. By the 90th day, tissue structure was completely restored, indicating complete healing. A single LPM treatment induces a wound healing response in the oral mucosa, showing the potential of LPM for the initiation of oral mucosa and gingival regeneration. Complete healing observed in 3 months after treatment with no keratinization change or scar tissue formation.

Use of laser phototherapy on a delayed wound healing of oral mucosa previously submitted to radiotherapy: case report

Radiotherapy produces both acute and delayed effects on mucosal tissues, disturbing their healing. This report shows a successful treatment with laser phototherapy (LPT) on a delayed wound healing in oral mucosa previously submitted to radiotherapy with a follow up of 3 years. A 47-year-old patient treated 6 months earlier for tongue squamous cell carcinoma by surgery and radiotherapy presented with a mass in the operated area. Biopsy showed chronic inflammatory infiltrate around a residual polyglactin suture. After 2 months there was a painful mucosal dehiscence on the biopsy site. LPT was performed using a semiconductor laser with 660-nm wavelength (InGaAlP) and spot size of 0·04 cm(2) . The parameters applied were 40 mW, 4 Jcm(2) /point, 0·16 J/point, 2·4 J/session. The irradiation was performed punctually, through contact mode in 15 points (4 seconds/point), on top of and around the lesion, during ten sessions. The wound healed completely after ten sessions. This treatment proved to be conservative and effective, inducing healing of a chronic wound in a tissue previously submitted to radiotherapy.

Effect of low-level laser therapy on experimental wounds of hard palate mucosa in mice

Under general anesthesia and sterile conditions, incision wound was induced in the hard palate mucosa of adult male mice. The wounds of groups 1 and 2 were irradiated daily with He-Ne laser at 3 and 7.5 J/cm2 for 120 and 300 s, respectively, while the incision wound of group 3 not exposed served as controls. On day 3 of injury, the laser-treated wounds contained significantly lower neutrophils than the wounds in the control group. By day 7 after injury, the laser-treated wounds contained significantly more fibroblasts and at the same time contained significantly fewer macrophages. In conclusion, an acceleration of the wound healing process of experimental wounds in the hard palate mucosa of mice at low-level laser therapy with a He-Ne laser at energy densities of 3 and 7.5 J/cm2 was observed.

Effect of CO2 laser irradiation on hormesis induction in cultured oral cells

BACKGROUND

Many drugs (including toxicants) and radiation therapy have been reported to exert bi-phasic hormetic effects on cultured cells, but only when both the concentration and treatment time were optimal. Most previous studies have been carried out with multiple laser modalities other than CO(2) laser, and there has been no comparison of the hormetic response between normal and tumor cells. We investigated here whether CO(2) laser treatment induces hormesis in human gingival fibroblast (HGF) and oral squamous cell carcinoma (HSC-2) cells.

MATERIALS AND METHODS

Cells were cultured for 24, 48 or 72 hours after exposure to various irradiation powers, and the viable cell number was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method.

RESULTS

CO(2) laser irradiation stimulated cell growth at low and inhibited it at high irradiation power. Among three dispatch modes, super pulse (SP)2 most effectively induced growth stimulation in HGF, at an irradiation dose slightly lower than that which induced cytotoxicity. Higher irradiation doses were comparably cytotoxic against both normal (HGF) and tumor (HSC-2) cells, reaching a plateau of cytotoxicity within 24 hours.

CONCLUSION

Since both the range and magnitude of hormetic response in HGF cells were very narrow and small, it is crucial to establish the optimal conditions for hormesis induction for clinical application in dentistry.

[Er:YAG laser: tissue interaction and histomorphological characterization]

Authors describe Er:YAG laser interaction with tissues, in particular their histomorphological characteristics to identify a specific clinic area for laser application through the examination of different clinical international trials. This study includes experimental trials about pig and rat skin laser application to know laser Er: YAG capability and limits; investigation is extended to laser application in human soft tissues as mucosa, periosteum and bones, its utility in cutaneous pathologies and in antiageing treatments.

Results of multidisciplinary therapy of squamous cell carcinoma of the buccal mucosa at Srinagarind Hospital, Thailand

OBJECTIVE

Review the clinical presentation and treatment of buccal carcinoma and compare it to the results of treatment as per survival rate.

MATERIAL AND METHOD

The authors reviewed the medical records of newly diagnosed seen between 1995 and 2005 at the Division of Plastic Surgery and the Department of Radiotherapy, Srinagarind Hospital, Faculty of Medicine, Khon Kaen University Patients previously treated elsewhere or those whose lesions secondarily involved the buccal mucosa were excluded.

RESULTS

The authors reviewed the medical records of 107 buccal carcinoma patients (94 females and 13 males) averaging 67 years of age. The 5-year survival rates of patients with Stage I (5.6%), 11 (6.5%), III (12.1%), and IVa (75.7%) were 67%, 43%, 47%, and 26%, respectively. A combined modality treatment (surgery and radiation or chemotherapy) was used to treat the advanced stage (III and IV) patients. The rate of incomplete therapy was high (47.78%). In the group that completed the protocol (i.e., neoadjuvant, surgery, and post operative radiation), there were five patients for whom the 5-year survival seemed higher than the patients who followed the standard treatment of surgery and post-operative radiation but it was not statistically significant.

CONCLUSION

The treatment of buccal carcinoma requires a multidisciplinary team approach because most of the patients are elderly and present with an advanced stage. If treatment continues through to completion of the protocol, the survival rate would increase.

Oral mucositis

Mucosal damage is one of the most common adverse effects of radiotherapy and of cytotoxic therapy for cancer. With prevalence between 10% and 100%, depending of the cytotoxic regimen and patient-associated variables, this morbid condition represents a significant problem in oncology. In this paper we address oral mucositis and discuss its pathobiology, risk factors, impact and management in view of the most recent evidence. Despite of clear progress and the development of clinical guidelines, what we currently have to offer to patients to manage mucositis and oropharyngeal pain is still inadequate. Expansion of the knowledge of the pathogenesis of mucositis as well as a better insight into individual risk factors will provide opportunities to improve management strategies.

[Associated risk factors in developing oral manifestations in patients with blood dyscrasia]

The oral and dental complications arising in cancer patients can be attributable to the malignant disease itself and to the various modalities of cancer therapy. Up to 37.2% of all patients receiving cancer chemotherapy develop acute oral complications and up to 31.1% of all patients receiving cancer radiotherapy develop acute oral manifestations. Oral complications may result in significant morbidity, impaired nutrition, treatment delays, and dose reductions which are affecting the prognosis of the primary disease.

MATERIAL AND METHOD

We investigated 312 cases of blood dyscrasia which 296 cases had oral manifestations (86.2%). They had a mean age of 40,6 years (range from 7 to 86 years). The male to female ratio was 1.0:0.75 (178/134). Data were statistically analyzed by t test, chi-square, Wilcoxon, Kruskal-Wallis and two-tailed exact Fischer, using the SPSS program, at a significance level of 5%.

RESULTS

Oral complications are frequently encountered in patients receiving anticancer therapy and these complications may result in significant morbidity, treatment delays, dose reductions, and nutritional deficiencies. The acute effects of anticancer chemotherapy upon the oral cavity include mucositis, infection, hemorrhage, xerostomia and nutritional deficiencies. Patients which undergo radiotherapy, specific in head and neck carcinomas, display a 30-60% incidence of the oral manifestations. The antineoplastic therapy will interfere with the turnover of the epithelial cells, followed by mucosal injury, later by infections, due to indirect invasion of Gram-negative bacteria and fungal species, as most of the anti-cancer drugs cause immunological changes.

CONCLUSIONS

The mucosal surface that is the oral cavity may provide insight into the immune function of the patient. Differential diagnosis is important as many disorders may manifest themselves similarly in the buccal area.

Development of an in vitro model for radiation-induced effects on oral keratinocytes

Changes in epithelial cell activity and the production of pro-inflammatory cytokines were examined utilizing an organotypic culture system as an in vitro model to study the effects of radiation on oral keratinocytes to simulate what is thought to occur in radiation-induced oral mucositis. Monolayer cultures of oral keratinocyte were irradiated by varying the dose. Cell injury was assessed using a colony forming efficiency (CFE) assay. Third passage oral keratinocytes were seeded onto AlloDerm to form a 3D construct of an ex vivo produced oral mucosa equivalent (EVPOME) which was irradiated with 0, 1, 3 and 8Gy. Formalin-fixed sections of the EVPOME were used for histology and immunohistochemistry to examine proliferative capacity. Epithelial cell viability of EVPOME was measured by MTT assay. Spent culture medium was used to determine post-radiation pro-inflammatory cytokine production. Basal cells became more swollen and pyknotic as radiation increased, implying loss of cell viability also determined by MTT assay. The number of Ki-67 immunopositive cells and CFE showed negative correlation with radiation, indicating loss of cell proliferative capacity. The production of pro-inflammatory cytokines, IL-1alpha and IL-8, tended to increase in a radiation dose dependent manner. The EVPOME lacking submucosal cellular components was a useful model.