Monte Carlo based dosimetry of extraoral photobiomodulation for prevention of oral mucositis.

Photobiomodulation therapy (PBMT) is recommended for prevention and treatment of oral mucositis, a painful condition that occurs in cancer patients. Intraoral PBMT is limited to treating distal oral mucosa and oropharynx. Extraoral PBMT may provide a more efficient intervention. The goal of this study was to develop a clinically viable protocol for extraoral PBMT. Monte Carlo modeling was used to predict the distribution of 850 nm light for four treatment sites, using anatomical data obtained from MRI and optical properties from the literature. Simulated incident light power density was limited to 399 mW/cm2 to ensure treatment safety and to prevent tissue temperature increase. The results reveal that total tissue thickness determines fluence rate at the oral mucosa, whereas the thickness of individual tissue layers and melanin content are of minor importance. Due to anatomical differences, the fluence rate varied greatly among patients. Despite these variations, a universal protocol was established using a median treatment time methodology. The determined median treatment times required to deliver efficacious dose between 1 and 6 J/cm2 were within 15 min. The developed PBMT protocol can be further refined using the combination of pretreatment imaging and the Monte Carlo simulation approach implemented in this study.

Oral lichen planus: comparative efficacy and treatment costs-a systematic review.

OBJECTIVE: To compare the reported efficacy and costs of available interventions used for the management of oral lichen planus (OLP). MATERIALS AND METHODS: A systematic literature search was performed from database inception until March 2021 in MEDLINE via PubMed and the Cochrane library following PRISMA guidelines. Only randomized controlled trials (RCT) comparing an active intervention with placebo or different active interventions for OLP management were considered. RESULTS: Seventy (70) RCTs were included. The majority of evidence suggested efficacy of topical steroids (dexamethasone, clobetasol, fluocinonide, triamcinolone), topical calcineurin inhibitors (tacrolimus, pimecrolimus, cyclosporine), topical retinoids, intra-lesional triamcinolone, aloe-vera gel, photodynamic therapy, and low-level laser therapies for OLP management. Based on the estimated cost per month and evidence for efficacy and side-effects, topical steroids (fluocinonide > dexamethasone > clobetasol > triamcinolone) appear to be more cost-effective than topical calcineurin inhibitors (tacrolimus > pimecrolimus > cyclosporine) followed by intra-lesional triamcinolone. CONCLUSION: Of common treatment regimens for OLP, topical steroids appear to be the most economical and efficacious option followed by topical calcineurin inhibitors. Large-scale multi-modality, prospective trials in which head-to-head comparisons interventions are compared are required to definitely assess the cost-effectiveness of OLP treatments.

Validation of a Monte Carlo Modelling Based Dosimetry of Extraoral Photobiomodulation.

An in vivo validation study was performed to confirm the accuracy of extraoral photobiomodulation therapy (PBMT) dosimetry determined by modelling. The Monte Carlo technique was utilized to calculate the fluence rate and absorbed power of light delivered through multi-layered tissue. Optical properties used during Monte Carlo simulations were taken from the literature. Morphological data of four study volunteers were acquired using magnetic resonance imaging (MRI) scans. Light emitting diode (LED) coupled to a power meter were utilized to measure transmitted power through each volunteer's cheek, in vivo. The transmitted power determined by Monte Carlo modelling was compared to the in vivo measurements to determine the accuracy of the simulations. Experimental and simulation results were in good agreement for all four subjects. The difference between the mean values of the measured transmission was within 12% from the respective transmission obtained using Monte Carlo simulations. The results of the study indicate that Monte Carlo modelling is a robust and reliable method for light dosimetry.

Superoxide Dismutase as an Intervention for Radiation Therapy-Associated Toxicities: Review and Profile of Avasopasem Manganese as a Treatment Option for Radiation-Induced Mucositis.

Toxicities associated with radiation therapy are common, symptomatically devastating, and costly. The best chance to effectively mitigate radiation-associated normal tissue side effects are interventions aimed at disrupting the biological cascade, which is the basis for toxicity development, while simultaneously not reducing the beneficial impact of radiation on tumor. Oxidative stress is a key initiator of radiation-associated normal tissue injury as physiologic antioxidant mechanisms are overwhelmed by the accumulation of effects produced by fractionated treatment regimens. And fundamental to this is the generation of superoxide, which is normally removed by superoxide dismutases (SODs). Attempts to supplement the activity of endogenous SOD to prevent radiation-induced normal tissue injury have included the administration of bovine-derived SOD and increasing SOD production using gene transfer, neither of which has resulted in a clinically acceptable therapy. A third approach has been to develop synthetic small molecule dismutase mimetics. This approach has led to the creation and development of avasopasem manganese, a unique and specific dismutase mimetic that, in clinical trials, has shown promising potential to reduce the incidence, severity and duration of severe oral mucositis amongst patients being treated with concomitant chemoradiation for cancers of the head and neck. Further, avasopasem and related analogues have demonstrated mechanism-related antitumor synergy in combination with high dose per fraction radiotherapy, an observation that is also being tested in clinical trials. An ongoing Phase 3 trial seeks to confirm avasopasem manganese as an effective intervention for severe oral mucositis associated with chemoradiation in head and neck cancer patients.

The Path to an Evidence-Based Treatment Protocol for Extraoral Photobiomodulation Therapy for the Prevention of Oral Mucositis.

Oral mucositis is a painful complication of hematopoietic stem cell transplantation for which photobiomodulation therapy (PBMT) is a safe and effective intervention. Extraoral delivery of PBMT has clinical advantages over intraoral delivery but requires additional dosimetric considerations due to the external tissue layers through which the light must propagate before reaching the oral mucosa. Additionally, to date there has been no dose modeling study, a task essential to developing a justified treatment protocol. We review here some of the complexities surrounding extraoral photobiomodulation therapy and offer that may help guide researchers toward an evidence-based treatment protocol for the prevention of oral mucositis.

Phase IIb, Randomized, Double-Blind Trial of GC4419 Versus Placebo to Reduce Severe Oral Mucositis Due to Concurrent Radiotherapy and Cisplatin For Head and Neck Cancer.

PURPOSE: Oral mucositis (OM) remains a common, debilitating toxicity of radiation therapy (RT) for head and neck cancer. The goal of this phase IIb, multi-institutional, randomized, double-blind trial was to compare the efficacy and safety of GC4419, a superoxide dismutase mimetic, with placebo to reduce the duration, incidence, and severity of severe OM (SOM). PATIENTS AND METHODS: A total of 223 patients (from 44 institutions) with locally advanced oral cavity or oropharynx cancer planned to be treated with definitive or postoperative intensity-modulated RT (IMRT; 60 to 72 Gy [≥ 50 Gy to two or more oral sites]) plus cisplatin (weekly or every 3 weeks) were randomly assigned to receive 30 mg (n = 73) or 90 mg (n = 76) of GC4419 or to receive placebo (n = 74) by 60-minute intravenous administration before each IMRT fraction. WHO grade of OM was assessed biweekly during IMRT and then weekly for up to 8 weeks after IMRT. The primary endpoint was duration of SOM tested for each active dose level versus placebo (intent-to-treat population, two-sided α of .05). The National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.03, was used for adverse event grading. RESULTS: Baseline patient and tumor characteristics as well as treatment delivery were balanced. With 90 mg GC4419 versus placebo, SOM duration was significantly reduced (P = .024; median, 1.5 v 19 days). SOM incidence (43% v 65%; P = .009) and severity (grade 4 incidence, 16% v 30%; P = .045) also were improved. Intermediate improvements were seen with the 30-mg dose. Safety was comparable across arms, with no significant GC4419-specific toxicity nor increase of known toxicities of IMRT plus cisplatin. The 2-year follow-up for tumor outcomes is ongoing. CONCLUSION: GC4419 at a dose of 90 mg produced a significant, clinically meaningful reduction of SOM duration, incidence, and severity with acceptable safety. A phase III trial (ROMAN; ClinicalTrials.gov identifier: NCT03689712) has begun.

The Use of Hyperbaric Oxygen for the Prevention and Management of Osteoradionecrosis of the Jaw: A Dana-Farber/Brigham and Women's Cancer Center Multidisciplinary Guideline.

BACKGROUND: Osteoradionecrosis of the jaw (ORN) is an infrequent yet potentially devastating complication of radiation therapy to the head and neck region. Treatment options include antimicrobial therapy, local sequestrectomy, resection, and the use of hyperbaric oxygen (HBO). Published data on ORN are difficult to compare because of the lack of a universally accepted classification and staging system, and the literature on the use of HBO to either prevent or successfully manage ORN is controversial and inconclusive. Therefore, we aimed to establish a standard approach for using HBO at our institution. MATERIALS AND METHODS: A literature search was conducted of articles published in the English language between January 1980 and January 2016. Retrieved articles were evaluated by two independent reviewers. Isolated case reports, abstracts, case series, review articles, and cohort studies without a control group were excluded; summary data were extracted from the remaining studies. A panel of experts from Head and Neck Oncology and Oral Medicine from the Dana-Farber Cancer Institute and Brigham and Women's Hospital reviewed the summary data and established multidisciplinary guidelines on the use of HBO for the prevention and management of ORN. RESULTS: Seven studies were evaluated and reviewed by the multidisciplinary panel. There was no consistent evidence in support of HBO for either the prevention or management of ORN. CONCLUSION: Based on the available evidence and expert opinion, routine use of HBO for the prevention or management of ORN is not recommended and is rarely used at our institution. The Oncologist 2017;22:343-350 IMPLICATIONS FOR PRACTICE: The Division of Head and Neck Oncology of Dana-Farber/Brigham and Women's Cancer Center does not recommend the routine use of HBO for the prevention or management of ORN. Adjunctive HBO may be considered for use on a case-by-case basis in patients considered to be at exceptionally high risk who have failed conservative therapy and subsequent surgical resection.

Dusquetide: A novel innate defense regulator demonstrating a significant and consistent reduction in the duration of oral mucositis in preclinical data and a randomized, placebo-controlled phase 2a clinical study.

Dusquetide, a novel Innate Defense Regulator, modulates the innate immune system at a key convergence point in intracellular signaling pathways and has demonstrated activity in both reducing inflammation and increasing clearance of bacterial infection. Innate immunity has also been implicated in the pathogenesis of oral mucositis (OM), a universal toxicity of chemoradiation therapy (CRT). Testing the hypothesis that dusquetide can mitigate the development and duration of OM, preclinical studies have been completed and correlated with interim results from a Phase 2 clinical study in patients undergoing CRT for head and neck cancer. Dusquetide reduced the duration of OM in mouse and hamster models by approximately 50%, which was recapitulated by the 50% reduction of severe OM (SOM) in the Phase 2 trial. A reduction in the clinical rate of infection was also observed, consistent with previously reported preclinical studies. In aggregate, these results not only demonstrate the safety and efficacy of dusquetide in addressing this unmet medical need, but also provide proof of concept for the translation of dusquetide action between animal models and the human clinical setting, and further support the contention that innate immunity is an important driver for the initiation and continued impact of OM.

Low level laser therapy/photobiomodulation in the management of side effects of chemoradiation therapy in head and neck cancer: part 1: mechanisms of action, dosimetric, and safety considerations.

PURPOSE: There is a large body of evidence supporting the efficacy of low level laser therapy (LLLT), more recently termed photobiomodulation (PBM), for the management of oral mucositis (OM) in patients undergoing radiotherapy for head and neck cancer (HNC). Recent advances in PBM technology, together with a better understanding of mechanisms involved, may expand the applications for PBM in the management of other complications associated with HNC treatment. This article (part 1) describes PBM mechanisms of action, dosimetry, and safety aspects and, in doing so, provides a basis for a companion paper (part 2) which describes the potential breadth of potential applications of PBM in the management of side-effects of (chemo)radiation therapy in patients being treated for HNC and proposes PBM parameters. METHODS: This study is a narrative non-systematic review. RESULTS: We review PBM mechanisms of action and dosimetric considerations. Virtually, all conditions modulated by PBM (e.g., ulceration, inflammation, lymphedema, pain, fibrosis, neurological and muscular injury) are thought to be involved in the pathogenesis of (chemo)radiation therapy-induced complications in patients treated for HNC. The impact of PBM on tumor behavior and tumor response to treatment has been insufficiently studied. In vitro studies assessing the effect of PBM on tumor cells report conflicting results, perhaps attributable to inconsistencies of PBM power and dose. Nonetheless, the biological bases for the broad clinical activities ascribed to PBM have also been noted to be similar to those activities and pathways associated with negative tumor behaviors and impeded response to treatment. While there are no anecdotal descriptions of poor tumor outcomes in patients treated with PBM, confirming its neutrality with respect to cancer responsiveness is a critical priority. CONCLUSION: Based on its therapeutic effects, PBM may have utility in a broad range of oral, oropharyngeal, facial, and neck complications of HNC treatment. Although evidence suggests that PBM using LLLT is safe in HNC patients, more research is imperative and vigilance remains warranted to detect any potential adverse effects of PBM on cancer treatment outcomes and survival.

Could the biological robustness of low level laser therapy (Photobiomodulation) impact its use in the management of mucositis in head and neck cancer patients.

Low level laser therapy (LLLT) has been noted to be effective in mitigating the development of oral mucositis among patients being treated with chemoradiation for cancers of the head and neck. To explain the biological basis for this observation we performed a comprehensive literature search. Our investigation identified a substantial number of LLLT-activated pathways that have been strongly associated with negative tumor outcomes including proliferation, invasion, angiogenesis, metastases and cancer-treatment resistance. In light of these findings, we suggest an investigational strategy to assure that LLLT's anti-mucositis efficacy is independent of its possible potential to enhance threatening tumor behaviors. Included are appropriate pre-clinical modeling, short- and long-term follow-up of LLLT-treated patients, and the requirement for consistency of LLLT parameters.

Risk and outcomes of chemotherapy-induced diarrhea (CID) among patients with colorectal cancer receiving multi-cycle chemotherapy.

BACKGROUND: Diarrhea is a common toxicity of chemotherapy, but the practice of reporting only severe grades (≥ 3) in clinical trials results in misleading conclusions of significance. Epidemiology remains poorly described, and effects of multi-cycle regimens have not been investigated. To better understand the risks, symptom burden and consequences of CID, we studied patients receiving chemotherapy for colorectal cancer (CRC). METHODS: One hundred and fourteen patients receiving FOLFOX (95 patients, 530 cycles), FOLFOX + monoclonal antibodies (10 patients, 49 cycles) or FOLFIRI (9 patients, 50 cycles) were enrolled. CID was identified from diaries at baseline and daily during up to 8 chemotherapy cycles using supplemental questions on the Oral Mucositis Daily Questionnaire, a valid tool for collecting patient-reported outcomes of regimen-related mucosal injury. Patients scored CID severity from 0 "none" to 10 "worst possible," and quantity from "little" to "severe" on a 5-point scale. Quality of life was measured using the FACT-G, and fatigue using the FACIT fatigue scale. RESULTS: CID occurred in 89% of patients on FOLFIRI, 50% on FOLFOX + monoclonal antibodies and 56% on FOLFOX alone. The risk of a first episode was highest during Cycle 1 (35 %) and dropped to <10% during Cycles 3-5. Patients with CID reported poorer quality of life scores than those without CID (77.1 vs 80.7). CONCLUSIONS: Diarrhea occurs more commonly than typically appreciated during chemotherapy for CRC. Risk is highest during first exposure, suggesting variable susceptibility. Identification of this high-risk subgroup for prophylaxis could improve the quality of life.

MASCC/ISOO clinical practice guidelines for the management of mucositis secondary to cancer therapy.

BACKGROUND: Mucositis is a highly significant, and sometimes dose-limiting, toxicity of cancer therapy. The goal of this systematic review was to update the Multinational Association of Supportive Care in Cancer and International Society of Oral Oncology (MASCC/ISOO) Clinical Practice Guidelines for mucositis. METHODS: A literature search was conducted to identify eligible published articles, based on predefined inclusion/exclusion criteria. Each article was independently reviewed by 2 reviewers. Studies were rated according to the presence of major and minor flaws as per previously published criteria. The body of evidence for each intervention, in each treatment setting, was assigned a level of evidence, based on previously published criteria. Guidelines were developed based on the level of evidence, with 3 possible guideline determinations: recommendation, suggestion, or no guideline possible. RESULTS: The literature search identified 8279 papers, 1032 of which were retrieved for detailed evaluation based on titles and abstracts. Of these, 570 qualified for final inclusion in the systematic reviews. Sixteen new guidelines were developed for or against the use of various interventions in specific treatment settings. In total, the MASCC/ISOO Mucositis Guidelines now include 32 guidelines: 22 for oral mucositis and 10 for gastrointestinal mucositis. This article describes these updated guidelines. CONCLUSIONS: The updated MASCC/ISOO Clinical Practice Guidelines for mucositis will help clinicians provide evidence-based management of mucositis secondary to cancer therapy.

A novel Peptide to treat oral mucositis blocks endothelial and epithelial cell apoptosis.

PURPOSE: No effective agents currently exist to treat oral mucositis (OM) in patients receiving chemoradiation for the treatment of head-and-neck cancer. We identified a novel 21-amino acid peptide derived from antrum mucosal protein-18 that is cytoprotective, mitogenic, and motogenic in tissue culture and animal models of gastrointestinal epithelial cell injury. We examined whether administration of antrum mucosal protein peptide (AMP-p) could protect against and/or speed recovery from OM. METHODS AND MATERIALS: OM was induced in established hamster models by a single dose of radiation, fractionated radiation, or fractionated radiation together with cisplatin to simulate conventional treatments of head-and-neck cancer. RESULTS: Daily subcutaneous administration of AMP-p reduced the occurrence of ulceration and accelerated mucosal recovery in all three models. A delay in the onset of erythema after irradiation was observed, suggesting that a protective effect exists even before injury to mucosal epithelial cells occurs. To test this hypothesis, the effects of AMP-p on tumor necrosis factor-α-induced apoptosis were studied in an endothelial cell line (human dermal microvascular endothelial cells) as well as an epithelial cell line (human adult low-calcium, high-temperature keratinocytes; HaCaT) used to model the oral mucosa. AMP-p treatment, either before or after cell monolayers were exposed to tumor necrosis factor-α, protected against development of apoptosis in both cell types when assessed by annexin V and propidium iodide staining followed by flow cytometry or ligase-mediated polymerase chain reaction. CONCLUSIONS: These observations suggest that the ability of AMP-p to attenuate radiation-induced OM could be attributable, at least in part, to its antiapoptotic activity.

Role of the cyclooxygenase pathway in chemotherapy-induced oral mucositis: a pilot study.

GOALS: Oral mucositis can be a significant and dose-limiting complication of high-dose cancer therapy. Mucositis is a particularly severe problem in patients receiving myeloablative chemotherapy prior to bone marrow or hematopoetic stem cell transplant (HSCT). The cyclooxygenase (COX) pathway mediates tissue injury and pain through upregulation of pro-inflammatory prostaglandins, including prostaglandin E2 (PGE2) and prostacyclin (PGI2). The objective of this small (n = 3) pilot study was to examine the role of the COX pathway in causing mucosal injury and pain in chemotherapy-induced oral mucositis. MATERIALS AND METHODS: We collected blood, saliva, and oral mucosal biopsy specimens from three autologous HSCT patients at the following time-points before and after administration of conditioning chemotherapy: Day -10, +10, +28, and +100, where day 0 is day of transplant. RNA extracted from full-thickness tissue samples was measured by RT-PCR for the following: COX-1, COX-2, microsomal prostaglandin E synthase (mPGES), IL-1beta, and TNF-alpha. Blood and saliva samples were measured by ELISA for PGE2 and PGI2, which are markers of COX activity. Severity of oral mucositis was determined using the Oral Mucositis Index. Severity of pain due to oral mucositis was measured using a Visual Analog Scale. Relationships between the different variables were examined using Spearman rank correlation coefficients. MAIN RESULTS: Mean mucositis and pain scores increased significantly after administration of chemotherapy and then gradually declined. The correlation between changes in mucositis and pain scores was strong and statistically significant. The following additional correlations were statistically significant: between tissue COX-1 and pain; between tissue mPGES and pain; between salivary PGE1 and pain; between salivary PGI2 and pain. Other relationships were not statistically significant. CONCLUSIONS: Our finding of significant associations of pain scores with tissue COX-1 and mPGES, as well as salivary prostaglandins, is suggestive of a role for the cyclooxygenase pathway in mucositis, possibly via upregulation of pro-inflammatory prostaglandins. However, our small sample size may have contributed to the lack of significant associations between COX-2 and other inflammatory mediators with mucosal injury and pain. Thus, additional studies with larger numbers of subjects are warranted to confirm the involvement of the cyclooxygenase pathway in chemotherapy-induced mucositis.