Risk Factor Assessment for the Development of Osteoradionecrosis

Surgical Factors and Progression of Osteoradionecrosis of Mandible: An Institutional Experience and Recommendations

The severe complication in oral cancer patients receiving radiation therapy is osteoradionecrosis. The reported incidence of ORN is highly variable, ranging from 0 to 37.5%. Diverse treatment protocols underscore the complexity of managing ORN. This study aims to address the surgical factors and their association with the formation of ORN in patients with oral squamous cell carcinoma undergoing surgery. Data of 17 patients who received definitive surgery and post-operative adjuvant radiotherapy (using the 3D CRT technique alone) to the head and neck from January 2016 to December 2023 presented with post-operative changes, which shows clinical evidence of ORN confirmed by radiographic investigations collected. Among 17 patients, 10 patients (58.8%) had posterior segmental mandibulectomy and seven patients (41.1%) had undergone marginal mandibulectomy with coronoidectomy respectively. Only two patients (11.7%) had regional flap reconstruction using PMMC flap, and for one patient (5.8%), surgical defect closed primarily; the remaining 14 (82.3%) patients underwent free flap reconstruction. Among free flaps, six patients (35.2%) had fibula and seven patients had radial forearm (41.1%) reconstruction. Only one patient (5.8%) underwent reconstruction using an anterolateral thigh flap. Along with consideration of radiation dose, dental extraction, oral hygiene, etc. do anticipate ORN and contemplate surgical risk factors during surgical planning in the management of head and neck cancer.

Prevention of osteoradionecrosis in patients with head and neck cancer treated with radiation therapy

BACKGROUND

Osteoradionecrosis is a long-term, serious side effect of head and neck radiation therapy and is associated with significant morbidity and quality of life issues.

METHODS

This paper sought to determine consensus on the prevention and management of osteoradionecrosis by an international panel of multidisciplinary professionals expert in the management of patients with head and neck cancer using a Delphi methodology. Unique to this work is our direct inclusion of the views of patients and carers in our findings.

RESULTS

This study reached consensus on the importance of pre and post oral health assessment and education for patients with head and neck cancer. This was also noted by the patients and carers who took part in the study.

CONCLUSIONS

This work highlights the need for a standardized oral health assessment tool and multidisciplinary care of patients to prevent and manage osteoradionecrosis.

An Unknown Foreign laryngeal Object: an exotic complication of skull base osteoradionecrosis

BACKGROUND

Osteoradionecrosis (ORN) of the skull base is a rare complication after head and neck radiation with a broad variety of subsequent complications.

METHODS

A 68-year-old woman with a complex oncological history (right-sided sphenoid meningioma; left-sided neck metastasis of a Cancer of Unknown Primary-CUP) was admitted with a right-sided epi-/ oropharyngeal mass and severe pain exacerbations for further evaluation. CT scan revealed an advanced ORN of the skull base with subsequent abruption of the ventral part of the clivus. This dislocated part of the clivus wedged in the oropharynx for 48 h and then moved towards the larynx, resulting in dyspnea and almost complete airway obstruction.

RESULTS

Due to the dangerous airway situation, an urgent exploration and removal of the dislocated clivus was necessary. After a potential cervical spine instability was ruled out, the patient's airway was initially secured with an awake tracheotomy and the clivus was removed transorally. The tracheostomy tube was removed during the ongoing inpatient stay, and the patient was discharged with significant pain relief.

CONCLUSIONS

The present case illustrates an orphan complication of skull base ORN resulting in a major airway emergency situation.

[Prevention, diagnosis and management of osteoradionecrosis: Where do we stand?]

Osteoradionecrosis (ORN) is a late secondary iatrogenic complication of external radiotherapy for cancers of the upper aero-digestive tract. Despite the systematization of intensity-modulated radiotherapy and its potential for preserving salivary secretion and limiting the dose delivered to the supporting bone, ORN remains a feared and frequent complication. The objective of this literature review was to provide an overview of the management of ORN and to determine the key points that would make it possible to improve patient care. The diagnosis of ORN requires to eliminate tumor recurrence then is based on clinical arguments and imaging by CT or Cone Beam evolving in a chronic mode (more than 3-6 months). The harmonization of its classifications aims to offer comprehensive and multidisciplinary care as early as possible. Primary prevention is based on pre-therapeutic oral and dental preparation, then associated with fluoroprophylaxis if salivary recovery is insufficient and requires supervision of invasive dental care and prosthetic rehabilitation. Semi-automatic contouring tools make it possible to identify doses delivered to dental sectors and guide dental care with personalized dosimetric mapping. Conservative medical treatment is offered at an early stage where innovative medical treatments, highlighted by early studies, could be of interest in the future. In the event of advanced ORN, a non-conservative treatment is then proposed and frequently consists of interruptive mandibulectomy associated with reconstruction by bony free flap, the conditions of implantation remaining to be defined with the support of prospective clinical trials.

Magneto-dynamic tool for full arch immediate loading in post-traumatic restoration with narrow implants: A case report

New surgical techniques using narrow, tilted implants positioned through a magneto-dynamic tool in guided surgery for a Toronto restoration. A 69-year-old woman wanted fixed rehabilitation to replace her removable complete dentures. A cone-beam computed tomography showed significant bone resorption in both the maxillary and mandibular regions. The plan was to load the entire upper arch with six implants immediately, while removable partial dentures were recommended for the lower jaw. The guided surgery project was aligned with the new dentures, and the laboratory created a printed cast with dental implant analogues in planned positions. A metal-reinforced denture was constructed, and surgery was performed to place six narrow implants using the magneto-dynamic instrument. The denture was directly screwed onto multi-unit abutments. Final rehabilitation was completed after 6 months. Narrow implants can be a good option for fixed, full-arch rehabilitations. Further research is needed to confirm these findings on a larger scale.

Osteoradionecrosis - an old problem with new consequences

PURPOSE OF REVIEW

Osteoradionecrosis (ORN) is a devasting complication of radiation therapy (RT), especially in head and neck cancers (HNC), and is still poorly understood. The aim of this review is to report its incidence and consider the risk factors associated with ORN to highlight prevention strategies to decrease its incidence.

RECENT FINDINGS

The average incidence of ORN is between 2% and 23%, with incidence decreasing in more recent years with the introduction of modern RT technology and better oral health care. Smoking, diabetes mellitus, oropharyngeal and oral cavity cancers, pre- and post-RT dental extractions and a total radiation dose of over 60 Gy were all identified as risk factors for ORN. In prevention, strategies were mainly structured around minimising risk factors or targeting possible mechanisms of ORN's pathophysiology.

SUMMARY

At present, the controversy surrounding the risk factors and pathogenesis of ORN makes it difficult to establish a set of prevention guidelines for its incidence. In order to achieve this, more research examining its aetiology must be conducted as well as a universal staging system within which ORN may be classified.

Tooth extraction within 2 weeks before radiotherapy and osteoradionecrosis: A nationwide cohort study

OBJECTIVES

The theory of at least 2-week waiting period between tooth extraction and head and neck radiotherapy could reduce osteoradionecrosis remains controversial. Thus, this study examined the theory and associated factors.

MATERIALS AND METHODS

Data were retrieved from the National Health Insurance Research Database, Taiwan Cancer Registry Database, and Cause of Death Statistics. We included 24,353 patients with head and neck cancer who received radiotherapy from 2011 to 2017 and were followed up until 2019. The patients were divided into three groups: those undergoing tooth removal 2-8 weeks before radiotherapy, those undergoing tooth removal within 2 weeks before radiotherapy, and others. Confounding factors were clinical information, physical conditions, and risky habits. We used the Cox regression model to assess osteoradionecrosis risk.

RESULTS

No significant difference in osteoradionecrosis risk was observed between those undergoing tooth extraction within 2 weeks before radiotherapy and the other groups. An irradiation dose of ≥60 Gy, chemotherapy, tumor excision, post-radiotherapy tooth extraction, mandibulectomy, hyperlipidemia, and oral cavity as the tumor subsite were significantly positively associated with osteoradionecrosis risk.

CONCLUSION

A waiting period of ≥2 weeks between tooth extraction and radiotherapy did not significantly reduce osteoradionecrosis risk.

An umbrella review exploring the effect of radiotherapy for head and neck cancer patients on the frequency of jaws osteoradionecrosis

OBJECTIVE

Efforts have been made to reduce epidemiological indicators of osteoradionecrosis in patients with head and neck cancer over recent years. This umbrella review aims to synthesize the information of the systematic reviews/meta-analyses investigating the effect of radiotherapy in patients with head and neck cancer on the frequency of osteoradionecrosis and to identify and analyze the gaps in current scientific literature.

MATERIAL AND METHODS

A systematic review of systematic reviews with and without meta-analysis of intervention studies was conducted. Qualitative analysis of the reviews and their quality evaluation were performed.

RESULTS

A total of 152 articles were obtained, and ten of them were selected for the final analysis, where six were systematic reviews and four were meta-analysis. According to the guide Assessing the Methodological Quality of Systematic Reviews (Amstar), eight articles included were of high quality and two of medium quality. These descriptive systematic reviews/meta-analyses included a total of 25 randomized clinical trials, showing that radiotherapy has positive effects on the frequency of osteoradionecrosis. Even though a reduction in the incidence of osteoradionecrosis was observed back in the history, in systematic reviews with meta-analysis, overall effect estimators were not significant.

CONCLUSIONS

Differential findings are not enough to demonstrate that there is a significant reduction in the frequency of osteoradionecrosis in patients with head and neck cancer treated by radiation. Possible explanations are related to factors such as the type of studies analyzed, indicator of irradiated complication considered, and specific variables included in the analysis. Many systematic reviews did not address publication bias and did identify gaps in knowledge that require further clarification.

Is Dose Volume a Better Predictor of Osteoradionecrosis Risk Than Total Dose for Patients Who Have Received Head and Neck Radiation?

PURPOSE

Oral and maxillofacial surgeons frequently encounter patients who require extractions following exposure to head and neck radiation, and they must assess the risk of extraction and consider alternatives such as deliberate root retention. The purpose of this study was to determine whether dose volume would be a better predictor for osteoradionecrosis (ORN) than total dose.

METHODS

This is a retrospective cohort study of patients diagnosed with ORN following head and neck radiation (administered between January 2006 and December 2018) and a comparison group selected based on site and dosage who did not develop ORN. The predictor variables were total radiation dose and mandibular dose volume, and the outcome variable was ORN occurrence. Covariates included age, sex, cancer stage and site, radiation therapy type, smoking status, alcohol use, adjuvant chemotherapy use, medical comorbidities, and concomitant tumor surgery. Logistic regression models were employed and area under receiver operating characteristic curve (AUROC) and model accuracy (Acc) were used to determine the better predictor.

RESULTS

A total of 56 patients were included in the study: 27 ORN positive (ORN+) and 29 matched controls who did not develop ORN (ORN-). Most patients were male (76.8%), considered smokers (78.6%), used alcohol (80.4%), were in stage IV (66.1%), received chemotherapy (75.0%), and received intensity modulated radiation therapy radiation (55.4%). The statistical models with V50 Gy (cc) and V65 Gy (cc) dosage variables exhibited greater predictability of ORN occurrence than total dose (AUROC: 0.90 vs 0.76 and model accuracy: 0.82 vs 0.75, respectively).

CONCLUSIONS

The results suggest that following head and neck radiation, dose volume may be a better predictor of ORN risk than total dose. This finding is significant, both for the oral and maxillofacial surgeon who is preoperatively assessing ORN risk following radiation exposure, and for the radiation oncologist striving to minimize the risk associated with their treatment.

Using Electronic Dental Records to Assess Osteoradionecrosis Risk in Irradiated Head and Neck Cancer

OBJECTIVE

Over the last 2 decades, investigations have demonstrated a decreased trend in the likelihood of osteoradionecrosis of the jaw (ORNJ) after extraction. The aim of this study was to explore the potential risk factors for ORNJ in irradiated head and neck cancer by using patients' electronic dental records (EDRs).

METHODS

Patients diagnosed with head and neck cancer who had irradiation between January 2010 and December 2020 were included in this retrospective cohort analysis. Patient charts showing evidence of "head and neck cancer," "oral cancer," "radiotherapy," "radiation," and "oral complication" were identified by an informatics analyst querying the EDR. Subsequently, the charts were manually reviewed, and data quality was assessed on 3 dimensions: completeness, accuracy, and consistency. The patient, tumor, systemic condition/drug, oral condition, treatment/trauma, and radiation were all categorized as potential risk factors.

RESULTS

A total of 359 patients were included. With the exception of radiation-related factors, we found that the data quality was generally sufficient to support the research. Multivariate logistic regression analysis demonstrated that the following factors were significant in predicting the occurrence of ORNJ development in irradiated head and neck cancer: smoking (odds ratio [OR], 9.0; 95% CI, 1.9 to 43.0; P = 0.006), steroid use (OR, 6.4; 95% CI, 1.3 to 30.8; P = 0.021), oral health status (OR, 23.7; 95% CI, 2.7 to 211.0; P = 0.005), and postirradiation extraction (OR, 3.8; 95% CI, 1.0 to 14.4; P = 0.050).

CONCLUSIONS

A 10-y retrospective analysis of data from an EDR revealed that smoking, steroid use, poor oral status, and postirradiation extraction are all factors linked to an increased risk of developing ORNJ. The quality of EDR data may be systematically assessed by determining the completeness, accuracy, and consistency of the underlying data. Radiation-related factors in particular were poorly documented, highlighting the need for collecting or incorporating this information into the EDR.

KNOWLEDGE TRANSFER STATEMENT

EDRs can be used to identify risk factors for developing ORNJ in irradiated head and neck cancer and can help clinicians with selecting treatments by incorporating risk and complication considerations.

Exposed bone in patients with head and neck cancer treated with radiation therapy: An analysis of the Observational Study of Dental Outcomes in Head and Neck Cancer Patients (OraRad)

BACKGROUND

Patients with head and neck cancer (HNC) treated with radiation therapy (RT) are at risk for jaw osteoradionecrosis (ORN), which is largely characterized by the presence of exposed necrotic bone. This report describes the incidence and clinical course of and risk factors for exposed intraoral bone in the multicenter Observational Study of Dental Outcomes in Head and Neck Cancer Patients (OraRad) cohort.

METHODS

Participants were evaluated before RT and at 6, 12, 18, and 24 months after RT. Exposed bone was characterized by location, sequestrum formation, and other associated features. The radiation dose to the affected area was determined, and the history of treatment for exposed bone was recorded.

RESULTS

The study enrolled 572 participants; 35 (6.1%) were diagnosed with incident exposed bone at 6 (47% of reports), 12 (24%), 18 (20%), and 24 months (8%), with 60% being sequestrum and with 7 cases (20%) persisting for >6 months. The average maximum RT dose to the affected area of exposed bone was 5456 cGy (SD, 1768 cGy); the most frequent associated primary RT sites were the oropharynx (42.9%) and oral cavity (31.4%), and 76% of episodes occurred in the mandible. The diagnosis of ORN was confirmed in 18 participants for an incidence rate of 3.1% (18 of 572). Risk factors included pre-RT extractions (P = .008), a higher RT dose (P = .039), and tobacco use (P = .048).

CONCLUSIONS

The 2-year incidence of exposed bone in the OraRad cohort was 6.1%; the incidence of confirmed ORN was 3.1%. Exposed bone after RT for HNC is relatively uncommon and, in most cases, is a short-term complication, not a recurring or persistent one.

Surgical Management of Skull Base Osteoradionecrosis in the Cancer Population - Treatment Outcomes and Predictors of Recurrence: A Case Series

BACKGROUND

Skull base osteoradionecrosis (ORN) is a challenging treatment-related complication sometimes seen in patients with cancer. Although ORN management strategies for other anatomic sites have been reported, there is a paucity of data guiding the management of skull base ORN.

OBJECTIVE

To report a single-center tertiary care series of skull base ORN and to better understand the factors affecting ORN recurrence after surgical management.

METHODS

We conducted a retrospective cohort study of patients with skull base ORN treated at our center between 2003 and 2017. Univariate and multivariate binary logistic regressions were performed to identify predictors of recurrence.

RESULTS

A total of 31 patients were included in this study. The median age at ORN diagnosis was 61.1 yr (range, 32.8-84.9 yr). Of these 31 patients, 15 (48.4%) patients were initially treated medically. All 31 patients underwent surgery. Three (14.3%) of 21 patients treated with a free flap and 4 (50.0%) of 8 patients who underwent primary closure experienced recurrence. Cox regression analysis revealed that reconstruction with local tissue closure (P = .044) and ongoing treatment for active primary cancer (P = .022) were significant predictors of recurrence. The median overall survival from index surgery for ORN treatment was 83.9 mo. At 12-mo follow-up, 78.5% of patients were alive.

CONCLUSION

In this study, we assess the outcomes of our treatment approach, surgical debridement with vascularized reconstruction, on recurrence-free survival in patients with skull base ORN. Further studies with larger cohorts are needed to assess current treatment paradigms.

[Predictive factors for mandibular osteoradionecrosis after irradiation of head and neck cancers]

The identification of the different risk factors for mandibular osteoradionecrosis (ORN) must be done before and after the management of patients with head and neck cancer. Various clinical criteria for this severe radiation-induced complication are related to the patient (intrinsic radiosensitivity, malnutrition associated with thin weight loss, active smoking intoxication, microcapillary involvement, precarious oral status, hyposalivation) and/or related to the disease (oral cavity, large tumor size, tumor mandibular invasion). Therapeutic risk factors are also associated with a higher risk of ORN (primary tumor surgery, concomitant radio-chemotherapy, post-irradiation dental avulsion, preventive non-observance with the absence of stomatological follow-up and daily installation of gutters fluoride and, non-observance curative healing treatments). Finally, various dosimetric studies have specified the parameters in order to target the dose values distributed in the mandible, which increases the risk of ORN. An mean mandibular dose greater than 48-54Gy and high percentages of mandibular volume receiving 40 to 60Gy appear to be discriminating in the risk of developing an ORN.

Partial and Total Flap Failure after Fibula Free Flap in Head and Neck Reconstructive Surgery: Retrospective Analysis of 180 Flaps over 19 Years

Fibula free flap (FFF) is widely used in head and neck reconstructive surgery and is considered as a standard and therapy of choice after ablative cancer surgery. The aim of this retrospective monocenter study was to determine the success rates of fibula free flaps for jaw reconstruction after ablative tumor surgery. The disease course of patients who underwent jaw reconstructive surgery with FFF from January 2002 to June 2020 was evaluated regarding the flap success rate. Flap failure was analyzed in detail and categorized into two groups: partial flap failure (PFF) and total flap failure (TFF). A total of 180 free fibular flaps were performed over the last 19 years and a total of 36 flap failures were recorded. TFF occurred in n = 20 (56.6%) and PFF in n = 16 cases (44.4%) cases. No statistically significant differences were found concerning patients' age at flap transfer, sex, BMI, ASA-Score, preoperative non-virtual or virtual surgical planning (non-VSP vs. VSP), and time of reconstruction (immediately vs. delayed). Duration of hospitalization shows statistically significant differences between both groups (p = 0.038), but no differences concerning operating time and duration on Intensive Care Unit (ICU). Partial flap failure appears to be underreported in literature. Sub- and complete failure of the skin paddle leads to clinical complaints like uncovered bone segments and plate exposure. Partial or complete FFF failure lead to infections on the recipient site and prolonged wound healing and therefore may cause a delay of the beginning of adjuvant radiation therapy (RT). PFF of hard tissue can be induced by RT.

Risk factors for osteoradionecrosis of the jaw in patients with head and neck squamous cell carcinoma

BACKGROUND

To evaluate factors associated with osteoradionecrosis of the jaw (ORNJ) in patients with head and neck squamous cell carcinoma (HNSCC), focusing on jaw-related dose-volume histogram (DVH) parameters.

METHODS

We retrospectively reviewed the medical records of 616 patients with HNSCC treated with curative-intent or postoperative radiation therapy (RT) during 2008-2018. Patient-related (age, sex, history of smoking or alcohol use, diabetes mellitus, performance status, pre-RT dental evaluation, pre- or post-RT tooth extraction), tumor-related (primary tumor site, T-stage, nodal status), and treatment-related (pre-RT surgery, pre-RT mandible surgery, induction or concurrent chemotherapy, RT technique) variables and DVH parameters (relative volumes of the jaw exposed to doses of 10 Gy-70 Gy [V10-70]) were investigated and compared between patients with and without ORNJ. The Mann-Whitney U test was used to compare RT dose parameters. Univariate and multivariate Cox regression analyses were used to assess factors associated with ORNJ development. Kaplan-Meier analyses were performed for cumulative ORNJ incidence estimation.

RESULTS

Forty-six patients (7.5%) developed ORNJ. The median follow-up duration was 40 (range 3-145) months. The median time to ORNJ development was 27 (range 2-127) months. DVH analysis revealed that V30-V70 values were significantly higher in patients with than in those without ORNJ. In univariate analyses, primary tumor site, pre-RT mandible surgery, post-RT tooth extraction, and V60 > 14% were identified as important factors. In multivariate analyses, V60 > 14% (p = 0.0065) and primary tumor site (p = 0.0059) remained significant. The 3-year cumulative ORNJ incidence rates were 2.5% and 8.6% in patients with V60 ≤ 14% and > 14%, respectively (p < 0.0001), and 9.3% and 1.4% in patients with oropharyngeal or oral cancer and other cancers, respectively (p < 0.0001).

CONCLUSIONS

V60 > 14% and oropharyngeal or oral cancer were found to be independent risk factors for ORNJ. These findings might be useful to minimize ORNJ incidence in HNSCC treated with curative RT.

Tumor subsites and risk of osteoradionecrosis of the jaw in patients with oral cavity cancer: a national-based cohort study

PURPOSE

The association between the tumor subsites of the oral cavity and the risk of osteoradionecrosis of the jaw (ORNJ) remains unclear. We study the correlation between oral cavity tumor subsites and the risk of ORNJ in a nationwide population-based database.

METHODS

We enrolled 16,701 adult patients with oral cavity cancers who were treated with radiotherapy between 2000 and 2013. The subsites of the oral tumor, treatments of oral cavity cancers, and the timing of tooth extraction were examined for their association with ORNJ in oral cancer patients.

RESULTS

903 patients (5.40%) developed ORNJ. Of the relevant variables, pre-RT mandible surgery, tooth extraction either before or after RT, and tumor sites were associated with the risk of ORNJ. The adjusted HRs for ORNJ in the mouth floor, gums, retromolar, and buccal cancer were 2.056 (1.490-2.837), 1.909 (1.552-2.349), 1.683 (1.105-2.562), and 1.303 (1.111-1.528), respectively, compared with the risk of tongue cancer. There was no significant difference in the risk of ORNJ between the pre-RT extraction group, the during-RT extraction group, and the post-RT extraction (less than 6 months) group; the post-RT extraction (more than 6 months) group had a significantly higher risk of ORNJ.

CONCLUSIONS

This study demonstrated that oral cavity tumor subsite is an independent risk factor of ORNJ after RT. Post-RT extraction (less than 6 months) group did not carry a significantly higher risk of ORNJ compared with pre-RT extraction group or during RT extraction group.

Osteoradionecrosis of the Maxilla: Conservative Management and Reconstructive Considerations

The implementation of radiotherapy in the multimodal treatment of advanced head and neck cancer has greatly improved survival rates. In some patients, however, this benefit comes at the potential expense of the tissue surrounding the primary site of malignancy. Osteoradionecrosis (ORN) of the facial bones, in particular the maxilla, is a debilitating complication of radiation therapy. Exposure to ionizing radiation results in devitalization of underlying bone with necrosis of adjacent soft tissue. Controversy surrounding appropriate early intervention in ORN persists and no consensus for clinical treatment has been established. In the present article, we review the pathophysiology of maxillary ORN and discuss the role of both conservative medical therapy and reconstruction.

Chinese expert group consensus on diagnosis and clinical management of osteoradionecrosis of the mandible

Osteoradionecrosis of the mandible (MORN) is one of the most devastating complications caused by radiation therapy in the head and neck region. It is characterized by infection and chronic necrosis of the mandible as the main manifestation. Clinically, MORN-related symptoms include swelling, pain, dysphagia, trismus, masticatory or speech disorders, refractory orocutaneous fistula, bone exposure, and even pathological fracture. MORN has become a challenging clinical problem for oral and maxillofacial surgeons to deal with, but thus far, this problem has not been solved due to the lack of widely accepted treatment algorithms or guidelines. Because of the nonexistence of standardized treatment criteria, most clinical treatment against MORN nowadays is largely based on controversial empirical understandings, while recommendations on post-therapeutic evaluations are scarce. Therefore, to further unify and standardize the diagnosis and treatment of MORN, to decrease the huge waste of medical resources, and ultimately, to improve the wellbeing of the patients, the Chinese Society of Oral and Maxillofacial Surgery (CSOMS) convened an expert panel specialized in MORN from 16 domestic medical colleges and affiliated hospitals to discuss the spectrum of diagnosis and and formulate treatment. In addition, consensus recommendations were also revised with a comprehensive literature review of the previous treatment experiences and research pearls. This 'expert consensus statement on diagnosis and clinical management of MORN' is for clinical reference.

Denture use and osteoradionecrosis following radiotherapy for head and neck cancer: A systematic review

BACKGROUND

It is strongly recommended to extract teeth with poor prognosis in head and neck cancer (HaNC) patients prior starting treatment with radiotherapy to avoid need for extraction post-radiotherapy and prevent development of osteoradionecrosis (ORN). Dental extraction means that patients are often left with insufficient teeth leading to psychological problems and reducing their quality of life post-radiotherapy. Some clinicians do not advocate the use of dentures in HaNC patients claiming that dentures might lead to soft tissue irritation followed by ORN when constructed on irradiated jaws.

AIMS

This systematic review aimed to investigate the existing evidence regarding the impact of denture use on the development of ORN in HaNC patients post-radiotherapy.

METHODS

This systematic review followed the Preferred Reporting Item for Systematic Review and Meta-analyses (PRISMA) guideline. Three database systems were used: Ovid Medline, EMBASE and PsycINFO. PROSPERO was searched for ongoing or recently completed systematic reviews. The https://ClinicalTrials.gov was searched for ongoing or recently completed trials. The Joanna Briggs Institute critical appraisal tools were used to assess quality of studies being reviewed.

RESULTS

Only three retrospective case-control studies were included. Numbers of participants included in the three studies are limited with incomparable types of mucosal dentures. None of the studies described the method of measurement of the exposure (denture use) in a standard, validated and reliable way.

CONCLUSION

The three included studies suggested no link between denture use and development of ORN. However, very little evidence exists and the robustness of the studies is questionable. Well-powered studies are needed.

Research Frontiers in Oral Toxicities of Cancer Therapies: Osteoradionecrosis of the Jaws

The deleterious effects of head and neck radiation on bone, with osteoradionecrosis (ORN) as the major disabling side effect of head and neck cancer treatment, are difficult to prevent and hard to treat. This review focuses on the current state of the science regarding the pathobiology, clinical impact, and management of ORN. With regard to the pathobiology underlying ORN, it is not yet confirmed whether the current radiation schedules by 3-dimensional conformal radiotherapy and intensity modified radiotherapy result in an unchanged, decreased, or increased risk of developing ORN when compared with conventional radiation treatment, the main risk factor being the total radiation dose delivered on any clinically significant surface of the mandible.

With regard to the prevention of ORN, a thorough, early pre-irradiation dental assessment is still considered the first step to reduce the hazard of developing ORN post-radiotherapy, and hyperbaric oxygen (HBO) treatment reduces the risk of developing ORN in case of dental surgery in an irradiated field.

With regard to the treatment of ORN, the focus is bidirectional: elimination of the necrotic bone and improving the vascularity of the normal tissues that were included in the radiation portal. The cure rate of limited ORN by conservative therapy is approximately 50%, and the cure rate of surgical approaches when conservative therapy has failed is approximately 40%.

Whether it is effective to support conservative or surgical treatment with HBO as an adjuvant is not set. HBO treatment is shown to increase the vascularity of hard and soft tissues and has been reported to be beneficial in selected cases. However, in randomized clinical trials comparing the preventive effect of HBO on developing ORN with, eg, antibiotic coverage in patients needing dental surgery, the preventive effect of HBO was not shown to surpass that of a more conservative approach.

More recently, pharmacologic management was introduced in the treatment of ORN with success, but its efficacy has to be confirmed in randomized clinical trials. The major problem of performing well-designed randomized clinical trials in ORN is having access to large numbers of patients with well-defined, comparable cases of ORN. Because many institutions will not have large numbers of such ORN cases, national and international scientific societies must be approached to join multicenter trials. Fortunately, the interest of funding organizations and the number researchers with an interest in healthy aging is growing. Research aimed at prevention and reduction of the morbidity of cancer treatment fits well within these programs.

Treatment of mandibular osteoradionecrosis by periosteal free flaps

Mandibular osteoradionecrosis (ORN) is one of the most serious complications of radiotherapy of the head and neck, and is characterised by hypoxia, hypovascularisation, and hypocellularity. Periosteal free flaps have intrinsic osteogenic, and extrinsic neoangiogenic, properties that are related to the periosteum. Our objective was to present our experience with the use of periosteal free flaps in the treatment of ORN (Notani class I or II) that are refractory to conservative management or have a large area of bone (≥2 cm) exposed. We organised a single-centre, retrospective study between 2003 and 2013 and describe the management of 11 patients (4 women and 7 men) who were being treated for refractory mandibular ORN. Thirteen periosteal free flaps were used: inner femoral condylar periosteum (n = 4), iliac crest (n = 1), external brachial with humeral periosteum (n = 1), and forearm with radial periosteum (n = 7). During follow-up we found three acute complications (haematoma, partial necrosis, and total vascular necrosis) that required immediate construction of a second periosteal free flap. There were also two chronic complications (fistula and post-traumatic fracture). With only one progressive lesion identified, the ORN was stopped in 11/12 patients. Two examples of osteoconduction were identified on postoperative images at six months and two years. Because of its osteoconductive and neoangiogenic capacities, the periosteal free flap seems to offer a real biological dimension to the treatment of ORN, and its efficiency favours its early revascularisation.

Role of Steroids in Preventing Osteoradionecrosis of the Head and Neck: A Systematic Review

Objective:

The aim of this study was to summarize the effectiveness of steroids in the prevention of osteoradionecrosis of the head and neck.

Data Sources:

PubMED, MEDLINE, Embase, Google Scholar, and Cochrane trial registries.

Methods:

A systematic review of these data sources was performed through September 2018 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included were English-language studies evaluating patients of all age groups diagnosed with head and neck cancer who underwent radiation therapy while receiving peritreatment steroids compared with those who did not receive steroids.

Results:

Two retrospective cohort studies were identified for qualitative review. On the basis of analysis of 25 328 participants (36-82 years of age) with head and neck cancer who underwent radiation therapy, the use of peritreatment steroids was associated with a significantly lower risk for osteoradionecrosis in both studies, with a hazard ratio of 0.74 (95% confidence interval, 0.59-0.94; P = .012) and a relative risk of 0.04 (95% confidence interval, 0.003-0.560; P = .017). Meta-analysis was precluded by clinical and statistical heterogeneity. Overall, the studies were of limited quality with high risk for bias and poor methodology.

Conclusions:

Limited retrospective data suggest that steroids are predictive of a reduced risk for osteoradionecrosis; however, no definitive conclusions can be made given the poor quality of the available literature. Well-designed, comparison-controlled trials are needed to clarify the promising role of steroids in the prevention of osteoradionecrosis of the head and neck.

Modern management of osteoradionecrosis

PURPOSE OF REVIEW

Despite recent advances in radiotherapy, osteoradionecrosis (ORN) remains a common and difficult complication of radiation therapy in head and neck cancer patients. Available treatment options are complementary to its complex pathophysiology and the currently available theories of ORN development. The efficacy of hyperbaric oxygen therapy has recently been questioned, and therapies targeting the fibroatrophic process have become a focus of ORN treatment. The objective of this review is to evaluate the literature regarding ORN of the mandible, with a focus on available treatment options.

RECENT FINDINGS

The recently proposed fibroatrophic theory has challenged the traditional hypovascular-hypoxic-hypocellular theory as the mechanism of ORN. Medical management targeting this fibroatrophic process offers promising results, but has yet to be confirmed with robust clinical trials. The routine use of hyperbaric oxygen therapy is not substantiated in the literature, but may be justified for select patients. Systemic steroids may also have a role, though data are limited.

SUMMARY

The fibroatrophic process has gained acceptance as a main mechanism of ORN. No gold standard treatment or consensus guidelines exist, though a combination of therapeutic strategies should be considered, taking into account the severity of disease and individual patient characteristics.

Osteoradionecrosis of the Zygoma

Osteoradionecrosis occurs in 4.74% to 37.5% of patients following radiation therapy for head and neck cancer. Osteoradionecrosis mostly happens in the mandible but seldom occurs in other maxillofacial bones. Here, the authors reported a rare case of zygomatic osteoradionecrosis which occurred after maxillectomy and then radiotherapy because of maxillary myoepithelial carcinoma. After resection of zygoma sequestrum, the defect was repaired with forehead flap and healed uneventfully.

Intensity-modulated proton therapy and osteoradionecrosis in oropharyngeal cancer

PURPOSE

We compared mandibular doses and osteoradionecrosis in patients with oropharyngeal cancer after intensity-modulated radiation therapy (IMRT) or intensity-modulated proton therapy (IMPT).

METHODS AND MATERIALS

We identified 584 patients who received definitive radiotherapy for oropharyngeal cancer from January 2011 through June 2014 at MD Anderson Cancer Center (534 IMRT and 50 IMPT). The dosimetric variables and osteoradionecrosis were compared with Chi-square test or Fisher's exact test.

RESULTS

Median follow-up time for all patients (534 IMRT and IMPT) was 33.8months (33.8months IMRT vs. 34.6months IMPT, P=0.854), and median time to osteoradionecrosis was 11.4months (range 6.74-16.1months). Mandibular doses were lower for patients treated with IMPT (minimum 0.8 vs. 7.3Gy; mean 25.6 vs. 41.2Gy; P<0.001), and osteoradionecrosis rates were lower as well: 2% IMPT (1 grade 1), 7.7% IMRT (12 grade 4, 5 grade 3, 1 grade 2 and 23 grade 1). Osteoradionecrosis location depended on the primary tumor site and high-dose field in the mandible.

CONCLUSIONS

Osteoradionecrosis events were significantly associated with higher dose irradiation to mandibular. Use of IMPT minimized excess irradiation of the mandible and consequently reduced the risk of osteoradionecrosis for oropharyngeal cancer.

Risk factors for osteonecrosis of the jaw in oral cancer patients after surgery and eventual adjuvant treatment: The potential role of chemotherapy

BACKGROUND AND PURPOSE

To identify the risk factors for osteonecrosis of the jaw (ONJ) in oral cancer patients after surgery with and without adjuvant therapy in a nationwide, population-based study.

MATERIAL AND METHODS

Using the Taiwan National Health Insurance Research Dataset, we recruited patients with newly diagnosed oral cancer between 1997 and 2011. All of them underwent primary surgery. Data regarding demographic characteristics; tooth extractions; medications; and cancer treatments, including types of mandibular surgery, radiotherapy and platinum-based chemotherapy, were collected for analysis.

RESULTS

We identified 25,858 patients who suffered 2802 ONJ events. The ONJ incidence rate was 3.45 per 100 person-years. Lip cancer was associated with the highest risk of ONJ, followed by buccal mucosa, gum, mouth floor and tongue cancer. Using a time-dependent Cox regression model, multivariable analysis demonstrated that mandibulotomy (hazard ratio (HR), 1.25; 95% confidence interval (CI), 1.01-1.55; p<0.001), radiotherapy (HR, 1.39; 95% CI, 1.26-1.54; p<0.001) and platinum-based chemotherapy (HR, 1.94; 95% CI, 1.56-2.41; p<0.001) were significant risk factors for ONJ. In the subgroup analysis of patients receiving radiotherapy and patients not receiving radiotherapy, platinum-based chemotherapy remained a risk factor for ONJ.

CONCLUSIONS

Mandibulotomy, radiotherapy and platinum-based chemotherapy were associated with an increased ONJ risk. Chemotherapy was a risk factor regardless of whether radiotherapy was administered.

Risk factors for and the role of dental extractions in osteoradionecrosis of the jaws: A national-based cohort study

BACKGROUND

The purpose of this study was to investigate the risk factors, especially the use of certain drugs and the dental procedures, for osteoradionecrosis of the jaw (ORNJ) in patients with head and neck cancer undergoing irradiation as their primary treatment.

METHODS

The cohort was composed of 23,527 patients with head and neck cancer. Cox proportional hazard models were used for risk factors analysis.

RESULTS

The overall incidence of ORNJ is 3.93 per 100 person-years. Buccal cancer carried the highest ORNJ risk. The use of steroids had a protective effect. Preradiotherapy extraction posed no excess risk, whereas postradiotherapy extraction was associated with gradually increased risk of ORNJ over time that peaked at 4 to 5 years.

CONCLUSION

ORNJ warrants life-long attention for head and neck cancer survivors. The present study strongly confirms the role of preirradiation dental extractions. Meanwhile, efforts should be made to prevent posttreatment extractions, especially in the first posttreatment 4 years. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1313-1321, 2017.

Dental Prophylaxis and Osteoradionecrosis: A Population-Based Study

The aim of this study was to investigate the association of different dental prophylactic modalities and osteoradionecrosis (ORN) and determine the risk of ORN under different timing periods of scaling, with the use chlorhexidine mouth rinse after surgery and with different strategies of fluoride gel application in head and neck cancer (HNC) participants. A cohort of 18,231 HNC participants, including 941 ORN patients and 17,290 matched control cases, were enrolled from a Longitudinal Health Insurance Database for Catastrophic Illness Patients (LHID-CIP) in Taiwan. Based on different dental prophylactic modalities before radiotherapy, including chlorhexidine mouth rinse, scaling, and fluoride gel, all HNC subjects were stratified into different groups. The Cox proportional hazard regression was used to compare ORN incidences under different dental prophylactic modalities. The results revealed that scaling and chlorhexidine mouth rinse were significantly related to ORN risk ( P = 0.004 and P < 0.0001). Chlorhexidine mouth rinse was highly correlated to ORN occurrence (hazard ratio [HR], 1.83–2.66), as exposure increased the risk by 2.43-fold among oral cancer patients, regardless of whether they had received major oral surgery or not. Oral cancer patients receiving scaling within 2 wk before radiotherapy increased their incidence of ORN by 1.28-fold compared with patients who had not undergone scaling within 6 mo. There is no significance of fluoride application for dental prophylaxis in increasing ORN occurrence. In conclusion, dental prophylaxis before radiotherapy is strongly correlated to ORN in HNC patients. Chlorhexidine exposure and dental scaling within 2 wk before radiotherapy is significantly related to ORN risk, especially in oral cancer patients. The use of 1.1% NaF topical application did not significantly increase the risk of ORN in HNC patients. An optimal dental prophylaxis protocol to reduce ORN should concern cancer location, cautious prescription of chlorhexidine mouth rinse, and proper timing of scaling.

Influence of genetic background and oxidative stress response on risk of mandibular osteoradionecrosis after radiotherapy of head and neck cancer

BACKGROUND

Osteoradionecrosis (ORN) of the mandible is a severe complication of head and neck radiotherapy (RT) treatment, where the impact of individual radiosensitivity has been a suggested explanation.

METHODS

A cohort of patients with stage II/III ORN was compared to matched controls. Blood was collected and irradiated in vitro to study the capacity to handle radiation-induced oxidative stress. Patients were also genotyped for 8 single-nucleotide polymorphisms (SNPs) in genes involved in the oxidative stress response.

RESULTS

A difference in 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) levels was found between the patient cohorts (p = 0.01). The SNP rs1695 in glutathione s-transferase p1 (GSTP1) was also found to be more frequent in the patients with ORN (p = .02). Multivariate analysis of the clinical and biological factors revealed concomitant brachytherapy plus the 2 biomarkers to be significant factors which influense risk of mandibular osteoradionecrosis after radiotherapy of head and neck cancer.

CONCLUSION

The current study indicates that oxidative stress response contributes to individual radiosensitivity and healthy tissue damage caused by RT and may be predicted by biomarker analysis.

Three-phase bone scintigraphy for imaging osteoradionecrosis of the jaw

This study evaluates the diagnostic utility of 3-phase bone scintigraphy for diagnosing osteoradionecrosis of the jaw (ORNJ).

METHODS

Thirty-two consecutive patients with a history of radiation to the head and neck region (range, 62-70 Gy; mean, 68 Gy; median, 69 Gy) due to squamous cell cancer and suspected ORNJ underwent 3-phase bone scans after injection of 520 to 750 MBq of Tc-MPD. In addition to planar scans, tomographic images (SPECT) were acquired in the second phase and SPECT/CT images during the third phase. Histopathologic findings (n = 18) and clinical follow-up (n = 14) served as reference standard for osteoradionecrosis.

RESULTS

The first, second, and third phases of planar images were rated positive in 18/32 patients (56.3%), 25/32 (78.1%), and 27/32 patients (84.4%), respectively. The late SPECT was positive in all patients (32/32, 100%), respectively. Histopathologic findings available in 18/32 patients (56.3%) confirmed ORNJ in all subjects. Acute inflammation was histologically proven in 18/18 specimens (100%) and additional chronic inflammation in 12/18 (66.7%). In 13/18 (72.2%) specimens, superinfection was evident histopathologically. A photopenic defect with surrounding hypermetabolism, a reported hallmark of ORJN, was found in less than 5%.

CONCLUSIONS

The predominant scintigraphic pattern of osteoradionecrosis includes increased bone mineralization phase in all patients. Central photopenia, reportedly a typical bone scan finding in bisphosphonate-induced osteonecrosis, was not characteristic for ORNJ. A differentiation of acute from chronic inflammatory processes was not possible.

Dental status, dental treatment procedures and radiotherapy as risk factors for infected osteoradionecrosis (IORN) in patients with oral cancer - a comparison of two 10 years' observation periods

Objectives

Dental status, dental treatment procedures and radiotherapy dosage as potential risk factors for an infected osteoradionecrosis (IORN) in patients with oral cancers: Retrospective evaluation of 204 patients treated in two observation periods of approximately ten years each.

Patients and methods

In group A, 90 patients were treated in the years 1993-2003, in group B 114 patients in the years 1983-1992 (data in brackets). All patients had histopathologically proven squamous cell cancers, mainly UICC stages III and IV. 70% (85%, n.s.) had undergone surgery before radiotherapy. All patients were referred to the oral and maxillofacial surgeon for dental rehabilitation before further treatment.

Radiotherapy was performed using a 3D-conformal technique with 4-6MV photons of a linear accelerator (Co-60 device up to 1987). The majority of patients were treated using conventional fractionation with total doses of 60-70 Gy in daily fractions of 2 Gy. Additionally, in group A, hyperfractionation was used applying a total dose of 72 Gy in fractions of 1.2 Gy twice daily (time interval > 6 hours). In group B, a similar schedule was used up to a total dose of 82.8 Gy (time interval 4-6 hours). 14 (0) patients had radiochemotherapy simultaneously. After therapy, the patients were seen regularly by the radiooncologist and – if necessary – by the oral and maxillofacial surgeon. The duration of follow-up was 3.64 years (5 years, p = 0.004).

Results

Before radiotherapy, the dental health status was very poor. On average, 21.5 (21.2, n.s.) teeth were missing. Further 2.04 teeth (2.33, n.s.) were carious, 1.4 (0.3, p = 0.002) destroyed.

Extractions were necessary in 3.6 teeth (5.8, p = 0.008), conserving treatment in 0.4 (0.1, p = 0.008) teeth. After dental treatment, 6.30 (4.8, n.s.) teeth remained.

IORN was diagnosed after conventionally fractionated radiotherapy in 15% (11%, n.s.), after hyperfractionation in 0% (34%, p = 0.01).

Conclusion

Within more than 20 years there was no improvement in dental status of oral cancer patients. Extensive dental treatment procedures remained necessary. There was an impressive reduction of the IORN frequency in patients treated in a hyperfractionated manner probably resulting from a dose reduction and an extension of the interfraction time.

Dental status, dental rehabilitation procedures, demographic and oncological data as potential risk factors for infected osteoradionecrosis of the lower jaw after radiotherapy for oral neoplasms: a retrospective evaluation

Purpose

Retrospective evaluation of the dental status of patients with oral cancer before radiotherapy, the extent of dental rehabilitation procedures, demographic and radiotherapy data as potential risk factors for development of infected osteoradionecrosis of the lower jaw.

Methods

A total of 90 patients who had undergone radiotherapy for oral cancer were included into this retrospective evaluation. None of them had distant metastases. After tumour surgery the patients were referred to an oral and maxillofacial surgeon for dental examination and the necessary dental rehabilitation procedures inclusive potential tooth extraction combined with primary soft tissue closure. Adjuvant radiotherapy was started after complete healing of the gingiva (> 7 days after potential extraction). The majority of patients (n = 74) was treated with conventionally fractionated radiotherapy with total doses ranging from 50-70Gy whereas further 16 patients received hyperfractionated radiotherapy up to 72Gy. The records of the clinical data were reviewed. Furthermore, questionnaires were mailed to the patients’ general practitioners and dentists in order to get more data concerning tumour status and osteoradionecrosis during follow-up.

Results

The patients’ dental status before radiotherapy was generally poor. On average 10 teeth were present, six of them were regarded to remain conservable. Extensive dental rehabilitation procedures included a mean of 3.7 tooth extractions. Chronic periodontitis with severe attachment loss was found in 40%, dental biofilm in 56%. An infected osteoradionecrosis (IORN) grade II according to (Schwartz et al., Am J Clin Oncol 25:168-171, 2002) was diagnosed in 11 of the 90 patients (12%), mostly within the first 4 years after radiotherapy. We could not find significant prognostic factors for the occurrence of IORN, but a trendwise correlation with impaired dental status, rehabilitation procedures, fraction size and tumour outcome.

Conclusion

The occurrence of IORN is an important long-term side effect of radiotherapy for oral cancers. From this data we only can conclude that a poor dental status, conventional fractionation and local tumour progression may enhance the risk of IORN which is in concordance with the literature.

Life-threatening cervical spine collapse as a result of postradiation osteonecrosis-case report and review of the literature

BACKGROUND

Mandibular osteoradionecrosis (ORN) is a well-known complication of head and neck radiotherapy; however, ORN of the cervical spine is rarely reported.

METHODS

Herein, we present a patient with a history of tonsillar carcinoma treated with chemoradiation who developed acute, severe progressive neck pain due to cervical spine collapse as a result of ORN. We also discuss diagnosis and treatment of cervical ORN based on a review of the literature.

RESULTS

The patient was successfully treated with antibiotics and surgical debridement and fixation.

CONCLUSION

Delayed diagnosis of cervical ORN can result in marked disability and pain due to spinal cord compression, as well as serious deformity and instability requiring surgical intervention, and even death. It is important for otolaryngologists who treat head and neck malignancies to be aware of this potential complication so that patients may be diagnosed as early as possible and treated with conservative measures.