Incidence Of Osteoradionecrosis Research Articles

Predicting osteoradionecrosis risk in patients with locoregionally advanced nasopharyngeal carcinoma undergoing concurrent chemoradiotherapy: The value of the CARWL index.

Osteoradionecrosis (ORN) is a severe complication that can arise in patients with nasopharyngeal carcinoma due to the aggressive nature of chemoradiotherapy treatment. The purpose of our study was to assess the utility of the recently introduced CARWL index, which integrates the C-reactive protein-to-albumin ratio (CAR) and significant weight loss (SWL), in predicting the risk of ORN in patients with locoregionally advanced nasopharyngeal cancer (LA-NPC) undergoing concurrent chemoradiotherapy (CCRT). We conducted a retrospective cohort analysis on 304 patients with LA-NPC treated with CCRT. Patients were categorized into CARWL index groups based on CAR (cut-off: 3.0) and SWL (weight loss > 5% over the past six months): CARWL-0 (CAR < 3.0, SWL ≤ 5%), CARWL-1 (CAR < 3.0 with SWL > 5% or CAR ≥ 3.0 with SWL ≤ 5%), and CARWL-2 (CAR ≥ 3.0 and SWL > 5%). The primary endpoint was the incidence of ORN in each CARWL index group. At a median follow-up of 67.2 months, 28 patients (9.2%) developed ORN. The incidence of ORN was 2.1%, 9.4%, and 16.3% in the CARWL-0, CARWL-1, and CARWL-2 groups, respectively (P < 0.001). Multivariate analysis identified smoking status (HR: 2.58, P = 0.034), N-stage (HR: 1.96, P = 0.008), T-stage (HR: 1.84, P = 0.017), pre-CCRT tooth extraction status (HR: 5.81, P < 0.001), post-CCRT tooth extraction status (HR: 6.82, P < 0.001), mandibular V55.8 Gy (HR: 6.12, P < 0.001), and CARWL score (HR: 5.67, P = 0.002) as significant predictors of ORN. The CARWL index is a reliable predictive tool for evaluating the risk of ORN in LA-NPC patients undergoing CCRT. If further validated, its use in clinical settings could aid in the early identification of high-risk patients and enable the implementation of personalized preventive strategies.

Risk factors associated with the development of osteoradionecrosis (ORN) in Head and Neck cancer patients in Ireland: A 10-year retrospective review

Background and PurposesTo assess osteoradionecrosis (ORN) incidence in a population of Irish Head and Neck cancer (HNC) patients, and assess precipitating factors that may contribute to ORN development to aid prevention. Materials and MethodsReview of 1050 HNC patients attending the Dental Oncology Clinic, CUDSH between 2010 and 2021 identified 47 cases of ORN. Medical, dental and radiotherapy records of these forty-seven patients were retrospectively reviewed. Patient-, tumour-, and treatment-related variables were investigated in association with osteoradionecrosis development. Analysis conducted using SPSS, Pearson’s Chi-square test (p < 0.05), and ordinal regression model. ResultsORN incidence was 4.4 %. Median time from radiotherapy (RT) to ORN development was 9.5 months (range 1–98.5 months). ORN development within the mandibular surgical site was significant (p <.001), presenting at a higher Notani grade (p =.002), in mid-mandibular body region (p =.028), at radiation doses ≥ 60 Gy (p =.035), due to induced causes (p =.029), and without resolution (p =.019). ConclusionThis is the first retrospective study of ORN in HNC patients in Ireland over 10-year period. ORN incidence was extremely low (4.4%). As patients reported high smoking/alcohol use and poor dental attendance pre-diagnosis, this suggests intensive dental intervention pre/post-diagnosis contributed to low ORN rates. Mandibular surgery pre-RT increased risk of developing ORN at the surgical site. Therefore, we recommend future treatment planning should contour the surgical site, designating it an organ at risk (OAR), assigning a dose constraint, where oncologically possible, with emphasis on reducing the hot-spot to this region; findings reinforce importance of life-long expert dental care to reduce ORN incidence.

Osteoradionecrosis incidence in pre-radiation teeth extractions: A prospective study.

To evaluate osteoradionecrosis (ORN) incidence in a cohort of patients undergoing tooth extraction (TE) before radiotherapy (RT) for head and neck cancers. The study protocol was approved by the Ethics Committee of Università Cattolica del Sacro Cuore (ID-2132) and registered at clinicaltrials.gov (ID: NCT04009161). TE was performed in case of signs of pericoronitis, periapical lesions, restorative impossibility, severe periodontitis. ORN was defined as exposed bone at an unhealed post-extraction socket in the absence of oncological recurrence. The RT plans were reviewed, and each post-extractive socket was contoured to calculate the received radiation dose. In total, 156 patients with 610 TE were enrolled. The mean follow-up was 567 days. ORN was diagnosed in four patients (2.6% of patients and 0.7% of TE). Need for osteotomy and radiation dose at the extraction site were associated with ORN (OR for osteotomy: 21.9, 95% CI: 2.17-222.2, p = 0.009; OR for RT dose: 1.1, 95% CI: 1-1.15, p = 0.05). TE appears to be a significant risk factor for ORN, particularly when osteotomy is required, and post-extraction sockets receive a high RT dosage. This study proposes a decision-making algorithm for TE and outlines a straightforward surgical protocol.

Cluster-Based Toxicity Estimation of Osteoradionecrosis Via Unsupervised Machine Learning: Moving Beyond Single Dose-Parameter Normal Tissue Complication Probability by Using Whole Dose-Volume Histograms for Cohort Risk Stratification

PurposeGiven the limitations of extant models for normal tissue complication probability estimation for osteoradionecrosis (ORN) of the mandible, the purpose of this study was to enrich statistical inference by exploiting structural properties of data and provide a clinically reliable model for ORN risk evaluation through an unsupervised-learning analysis that incorporates the whole radiation dose distribution on the mandible. Materials and MethodsThe analysis was conducted on retrospective data of 1,259 head and neck cancer (HNC) patients treated at XXX between 2005 and 2015. During a minimum 12-month post-therapy follow-up period, 173 patients in this cohort (13.7%) developed ORN (grades I to IV). The (structural) clusters of mandibular dose-volume histograms (DVHs) for these patients were identified using the K-means clustering method. A soft-margin support vector machine (SVM) was used to determine the cluster borders and partition the dose-volume space. The risk of ORN for each dose-volume region was calculated based on incidence rates and other clinical risk factors. ResultsThe K-means clustering method identified six clusters among the DVHs. Based on the first five clusters, the dose-volume space was partitioned by the soft-margin SVM into distinct regions with different risk indices. The sixth cluster entirely overlapped with the others; the region of this cluster was determined by its envelopes. For each region, the ORN incidence rate per pre-radiation dental extraction status (a statistically significant, non-dose related risk factor for ORN) was reported as the corresponding risk index. ConclusionThis study presents an unsupervised-learning analysis of a large-scale data set to evaluate the risk of mandibular ORN among HNC patients. The results provide a visual risk-assessment tool for ORN (based on the whole DVH and pre-radiation dental extraction status) as well as a range of constraints for dose optimization under different risk levels.

Interpretability of a Deep Learning-Based Prediction Model for Mandibular Osteoradionecrosis.

The development of radiation-induced toxicities is a multifactorial process. Existing DVH-based prediction models use traditional multivariate analysis to combine all the potential risk factors. Recently, deep learning (DL) has been proposed for predicting mandibular osteoradionecrosis (ORN) directly from 3D dose distribution maps [1]. However, with this approach, incorporating non-imaging data such as potential risk factors presents challenges. We investigate the use of DL-based multimodality fusion for the purpose of radiation-induced ORN toxicity prediction. This study explores early and late fusion strategies for combining 3D radiation dose distribution maps and clinical and demographic variables in the prediction of mandibular ORN incidence in head and neck cancer patients treated with radiotherapy. The results are compared to single-modality predictions with a random forest (RF) trained only on clinical variables and a 3D DenseNet40 trained on dose maps alone. We investigate two different fusion approaches. In the first, the image features extracted from the radiation dose maps using a 3D DenseNet40 were concatenated with the clinical variables into one single vector using a type II early fusion strategy. The combined feature vector was input into a fully connected layer for classification of ORN vs. controls. A final softmax activation layer was added to obtain the class predicted probabilities. The second approach used a late fusion strategy, in which the outputs from the 3D DenseNet40 and the RF model were combined by averaging the predicted classification probabilities for each of the two classes (ORN and no ORN) to obtain the final class decision on a case-by-case basis. The AUROC values obtained for the late and early fusion models and the single-modality 3D DenseNet40 and RF models were 0.70, 0.68, 0.69 and 0.60, respectively. The highest AUC ROC was observed with the late fusion approach, which was statistically significantly different to that of the RF single-modality model with a significance level of 0.05. However, after Bonferroni correction (Altman 1999) for multiple comparisons was applied, resulting in a corrected significance level of 0.05/6 = 0.008 for each comparison, no statistically significant difference was observed between any of the models' AUROC values. This is most likely due to the lack of discriminative contribution observed from clinical variables, which on their own resulted in a poorly predictive RF model. To our knowledge, no previous work has been published on the use of multimodal fusion DL methods to combine dose distribution maps and clinical variables in the prediction of mandibular ORN. Although non-conclusive results were obtained, this study demonstrates the potential of DL in the prediction of the multifactorial side effects resulting from radiotherapy treatments. [1] Humbert-Vidan L et al. Prediction of Mandibular ORN Incidence from 3D Radiation Dose Distribution Maps Using DL (2022).

Review of the Pathogenesis, Diagnosis, and Management of Osteoradionecrosis of the Femoral Head.

Osteoradionecrosis (ORN) of the femoral head is an important issue for orthopedists and radiologists in clinical practice. With the rapid development of technological advances in radiation therapy and the improvement in cancer survival rates, the incidence of ORN is rising, and there is an unmet need for basic and clinical research. The pathogenesis of ORN is complex, and includes vascular injury, mesenchymal stem cell injury, bone loss, reactive oxygen species, radiation-induced fibrosis, and cell senescence. The diagnosis of ORN is challenging and requires multiple considerations, including exposure to ionizing radiation, clinical manifestations, and findings on physical examination and imaging. Differential diagnosis is essential, as clinical symptoms of ORN of the femoral head can resemble many other hip conditions. Hyperbaric oxygen therapy, total hip arthroplasty, and Girdlestone resection arthroplasty are effective treatments, each with their own advantages and disadvantages. The literature on ORN of the femoral head is incomplete and there is no criterion standard or clear consensus on management. Clinicians should gain a better and more comprehensive understanding on this disease to facilitate its early and better prevention, diagnosis, and treatment. This article aims to review the pathogenesis, diagnosis, and management of osteoradionecrosis of the femoral head.

The predictive value of pretreatment hemoglobin-to-platelet ratio on osteoradionecrosis incidence rates of locally advanced nasopharyngeal cancer patients managed with concurrent chemoradiotherapy

BackgroundThis retrospective study aimed to investigate whether the pretreatment hemoglobin-to-platelet ratio (HPR) could predict the risk of osteoradionecrosis (ORN) in patients receiving concurrent chemoradiotherapy (C-CRT) for locally advanced nasopharyngeal carcinoma (LA-NPC).MethodsORN cases were reported from the records of LA-NPC patients who had oral examinations before and after C-CRT. The pretreatment HPR values were calculated on the first day of C-CRT. The connection between HPR values and ORN occurrences was determined using receiver operating characteristic curve analysis. The primary endpoint was the relationship between the pretreatment HPR values and post-C-CRT ORN incidence rates, while secondary endpoints included the identification of other putative ORN risk factors.ResultsWe distinguished 10.9% incidences of ORN during the post-C-CRT follow-up period among 193 LA-NPC patients. The optimal cutoff for pre-C-CRT HPR was 0.48 that grouped the patients into two HPR groups with fundamentally different post-C-CRT ORN incidence rates: Group 1: HPR ≤ 0.48 (N = 60), and Group 2: HPR > 0.48 (N = 133). The comparative analysis indicated a significantly higher ORN incidence in HPR ≤ 0.48 group (30%; P < 0.001). The other factors associated with meaningfully increased ORN rates included the presence of pre-C-CRT ≥ 5 teeth extractions, mandibular volume receiving ≥ 64 Gy, post-C-CRT tooth extractions, mean mandibular dose ≥ 50.6 Gy, and C-CRT to tooth extraction interval > 5.5 months.ConclusionLow pretreatment HPR levels were independently and unequivocally linked to significantly increased incidence of ORN post-C-CRT. Pre-C-CRT HPR levels may be used to estimate the incidence of ORN and be useful for taking preventive and therapeutic measures in these patients such as monitoring oral hygiene with strict follow-up, avoidance of unnecessary tooth extractions, particularly after C-CRT, and use of more rigorous mandibular RT dose limits.

Time required for prophylactic oral care in head and neck cancer patients scheduled for radiotherapy: A single center, prospective cohort study.

Prophylactic oral care (POC) before radiotherapy (RT) is an adjunct but an integral process toward preparing patients for RT, however, time to be invested in POC remains unexplored. Prospective treatment records were maintained in head and neck cancer patients, who received POC following a standardized protocol with definite timelines. Data collected for oral treatment time (OTT), interruption in RT due to oro-dental issues, future extraction(s), and incidence of osteoradionecrosis (ORN) up to 18 months after treatment were analyzed. Three hundred thirty-three patients, 275 males and 58 females, mean age 52.45 ± 11.2 years were included. Mean OTT was 21.0 ± 6.2 days and was influenced significantly with the number of extractions (p < 0.00). There was no interruption in RT schedule due to oro-dental issues. Five patients were diagnosed with ORN. Performing POC as demonstrated aid in timely removal of nidus of infection(s), perform RT as scheduled, and maintain satisfactory oral health through the survivorship of patients.

Empirical Relative Biological Effectiveness (RBE) for Mandible Osteoradionecrosis (ORN) in Head and Neck Cancer Patients Treated with Pencil-Beam-Scanning Proton Therapy (PBSPT): A Retrospective, Case-Matched Cohort Study

<h3>Purpose/Objective(s)</h3> To retrospectively investigate empirical relative biological effectiveness (RBE) for mandible osteoradionecrosis (ORN) in head and neck (H&N) cancer patients treated with pencil-beam-scanning proton therapy (PBSPT). <h3>Materials/Methods</h3> We included 1,266 H&N cancer patients, of which, 931 patients were treated with volumetric-modulated arc therapy (VMAT) and 335 were treated with PBSPT. Among them, 26 VMAT and 9 PBSPT patients experienced mandible ORN (ORN group), while all others were included in the control group. To minimize the impact of the possible imbalance in clinical factors between VMAT and PBSPT patients in the dosimetric comparison between these two modalities and the resulting RBE quantification, we formed a 1:1 case-matched patient cohort (335 VMAT patients and 335 PBSPT patients including both the ORN and control groups) using the greedy nearest neighbor matching of propensity scores. Mandible dosimetric metrics were extracted from the case-matched patient cohort and statistically tested to evaluate the association with mandibular ORN to derive dose volume constraints (DVCs) for VMAT and PBSPT, respectively. We sought the equivalent constraint doses for VMAT so that the critical volumes of VMAT were equal to those of PBSPT at different physical doses. Empirical RBEs of PBSPT for ORN were obtained by calculating the ratio between the derived equivalent constraint doses and physical doses of PBSPT. Bootstrapping was further used to get the confidence intervals. <h3>Results</h3> Clinical variables of age, gender, tumor stage, prescription dose, chemotherapy, hypertension or diabetes, dental extraction, smoking history, or current smoker were not statistically related to the incidence of ORN in the overall patient cohort. Smoking history was found to be significantly associated with the ORN incidence in PBSPT patients only. V40 Gy[RBE], V50 Gy[RBE], and V60 Gy[RBE] were statistically different (<i>p</i> < 0.05) between the ORN and control group for VMAT and PBSPT. Empirical RBEs of 1.58 (95% CI: 1.34-1.64), 1.34 (95% CI: 1.23-1.40), and 1.24 (95% CI: 1.15-1.26) were obtained for proton dose at 40 Gy[RBE=1.1], 50 Gy[RBE = 1.1] and 60 Gy[RBE = 1.1], respectively (Table). <h3>Conclusion</h3> Our study suggested that RBEs were larger than 1.1 at moderate doses (between 40 and 60 Gy[RBE=1.1]) with high LET for mandible ORN. RBEs are underestimated in current clinical practice in PBSPT. The derived DVCs can be used for PBSPT plan evaluation and optimization to minimize the incidence rate of mandible ORN.

Empirical Relative Biological Effectiveness (RBE) for Mandible Osteoradionecrosis (ORN) in Head and Neck Cancer Patients Treated With Pencil-Beam-Scanning Proton Therapy (PBSPT): A Retrospective, Case-Matched Cohort Study.

PurposeTo retrospectively investigate empirical relative biological effectiveness (RBE) for mandible osteoradionecrosis (ORN) in head and neck (H&N) cancer patients treated with pencil-beam-scanning proton therapy (PBSPT).MethodsWe included 1,266 H&N cancer patients, of which, 931 patients were treated with volumetric-modulated arc therapy (VMAT) and 335 were treated with PBSPT. Among them, 26 VMAT and 9 PBSPT patients experienced mandible ORN (ORN group), while all others were included in the control group. To minimize the impact of the possible imbalance in clinical factors between VMAT and PBSPT patients in the dosimetric comparison between these two modalities and the resulting RBE quantification, we formed a 1:1 case-matched patient cohort (335 VMAT patients and 335 PBSPT patients including both the ORN and control groups) using the greedy nearest neighbor matching of propensity scores. Mandible dosimetric metrics were extracted from the case-matched patient cohort and statistically tested to evaluate the association with mandibular ORN to derive dose volume constraints (DVCs) for VMAT and PBSPT, respectively. We sought the equivalent constraint doses for VMAT so that the critical volumes of VMAT were equal to those of PBSPT at different physical doses. Empirical RBEs of PBSPT for ORN were obtained by calculating the ratio between the derived equivalent constraint doses and physical doses of PBSPT. Bootstrapping was further used to get the confidence intervals.ResultsClinical variables of age, gender, tumor stage, prescription dose, chemotherapy, hypertension or diabetes, dental extraction, smoking history, or current smoker were not statistically related to the incidence of ORN in the overall patient cohort. Smoking history was found to be significantly associated with the ORN incidence in PBSPT patients only. V40Gy[RBE], V50Gy[RBE], and V60Gy[RBE] were statistically different (p<0.05) between the ORN and control group for VMAT and PBSPT. Empirical RBEs of 1.58(95%CI: 1.34-1.64), 1.34(95%CI: 1.23-1.40), and 1.24(95%: 1.15-1.26) were obtained for proton dose at 40 Gy[RBE=1.1], 50 Gy[RBE=1.1] and 60 Gy[RBE=1.1], respectively.ConclusionsOur study suggested that RBEs were larger than 1.1 at moderate doses (between 40 and 60 Gy[RBE=1.1]) with high LET for mandible ORN. RBEs are underestimated in current clinical practice in PBSPT. The derived DVCs can be used for PBSPT plan evaluation and optimization to minimize the incidence rate of mandible ORN.

Dosimetric and Clinical Risk Factors for the Development of Maxillary Osteoradionecrosis in Adenoid Cystic Carcinoma (ACC) Patients Treated With Carbon Ion Radiotherapy.

BackgroundThe present study aims to evaluate dosimetric and clinical risk factors for the development of maxillary osteoradionecrosis (ORN) in head and neck adenoid cystic carcinoma (ACC) patients treated with carbon ion radiotherapy (CIRT).MethodsClinical data and treatment plans of ACC patients, consecutively treated from January 2013 to September 2016 within the phase II clinical trial CNAO S9/2012/C, were retrospectively reviewed. ORN and other treatment-related toxicity were graded according to the Common Terminology Criteria for Adverse Events (CTACE), version 4.0. The maxillary bone was contoured on the planning CT, and only patients receiving more than 10% of the prescription dose at their maxilla were considered for the analysis (67 patients). The volumes of maxilla receiving doses from 10 Gy (RBE) to 60 Gy (RBE) (VD), with an increment of 10 Gy (RBE), and additional clinical factors were correlated to the incidence of ORN with univariate analysis (Chi-square test). The logistic regression model was subsequently applied for multivariate analysis. Treatment plans calculated with a local effect model (LEM)-based optimization were recalculated with the modified microdosimetric kinetic model (MKM), and compared with literature data from the Japanese experience.ResultsThe median time interval from the start of CIRT to ORN appearance was 24 months (range, 8–54 months). Maxillary ORN was observed in 11 patients (16.4%). Grade 1 ORN was observed in 2 patients (18.1%), G2 in 4 (36.3%), G3 in 4 (36.3%) and G4 in 1 (9.3%). From univariate analysis, the site of the tumor, the presence of teeth within the PTV and acute mucositis correlated with the development of maxillary ORN. VD were significantly higher for all the dose levels tested in patients with maxillary ORN than patients without necrosis, according to both radiobiological models. The multivariate analysis showed that V60 significantly correlated with ORN risk.ConclusionThe volume of maxilla irradiated with high dose values was relevant for ORN development in our cohort of ACC patients. These results are in line with previously published data obtained with a different radiobiological model. Our findings might be helpful to prevent the risk of ORN in patients receiving CIRT.

Advances and Controversies in the Management of Osteoradionecrosis After Head and Neck Cancer Treatment: A Narrative Review.

Osteoradionecrosis (ORN) is a painful and debilitating serious late complication following treatment for head and neck cancer (HNC) often requiring surgical resection of the jaw and complex multidisciplinary management. An important aggravating factor for mandibular ORN is surgical trauma, commonly dental extractions or implant placement following head and neck radiotherapy. The evidence on the treatment protocols ranges from conservative management to more radical surgical strategies including the use of hyperbaric oxygen therapy. The available evidence on the preventive approaches for ORN includes prophylactic dental care prior to radiotherapy, the use of hyperbaric oxygen (HBO) treatment and prophylactic antibiotics for post-radiotherapy extractions. However, the efficacy of hyperbaric oxygen therapy has been questioned recently signifying poor understanding of the pathophysiology of the condition and therapies targeting the fibroatrophic process have become a focus of ORN treatment. Implementing recent IMRT radiation techniques has also shown evidence to reduce the incidence of ORN. This review provides an insight into the variations in definition and classification of the ORN, the controversies in its pathophysiology and the advances in the prevention and management.

Osteoradionecrosis of the Jaws Due to Teeth Extractions during and after Radiotherapy: A Systematic Review.

Simple SummaryTeeth extractions before or after radiotherapy (RT) could be procedures at high risk for osteoradionecrosis (ORN) onset. This systematic review was performed to investigate the ORN incidence following teeth extractions during and after RT for head and neck (H&N) cancer and to evaluate any other possible risk factor. The results highlight how post-RT teeth extractions are a major risk factor for ORN onset (ORN incidence of 5.8%), especially in the mandible, with a diminishing trend in the last years.Teeth extractions before or after radiotherapy (RT) could be procedures at high risk for osteoradionecrosis (ORN) onset. This systematic review was performed to investigate the ORN incidence following teeth extractions during and after RT for head and neck (H&N) cancer and to evaluate any other possible risk factor. Methods: This systematic review was conducted according to PRISMA protocol, and the PROSPERO registration number was CRD42018079986. An electronic search was performed on the following search engines: PubMed, Scopus, and Web of Science. A cumulative meta-analysis was performed. Results: Two thousand two hundred and eighty-one records were screened, and nine were finally included. This systematic review revealed an ORN incidence of 5.8% (41 patients out of 462, 95% CI = 2.3–9.4); 3 ORN developed in the maxilla. No other clinical risk factors were detected. Conclusion: Post-RT teeth extractions represent a major risk factor for ORN development, especially in the mandible, with a diminishing trend in the last years. Further research on other possible risk factors might improve this evidence.

Clinical and X-ray Characteristics of Osteoradionecrosis of the Jaws and Related Factors

This retrospective cohort study was conducted on 73 patients diagnosed with Osteoradionecrosis of the Jaws (ORNJ), treated in the Department of Maxillofacial Surgery of the National Hospital of Odonto – Stomatology to describe some criteria including clinical symptoms, radiographic images and related factors of ORNJ in these patients by consulting medical records and interviewing patients. The study results show that the majority of lesions presented in the mandible, particularly in the angle region. The prominent symptoms were deep pain, fistula, exposed necrotic bone, tingling and numbness in the lips and cheeks, and trimus. Radiographic feature was ill-defined cortical destruction without sequestration. The patients’ major oral health problems were poor dental hygiene and periodontitis. The related factors were tooth extraction, non-standard dental prosthesis and even root canal treatment.&#x0D; Keywords: Osteoradionecrosis of the jaws, clinical symptoms, radiography images, related factors.&#x0D; References&#x0D; [1] N. M. H. McLeod, M. C. Bater, P. A. Brennan, Management of Patients at Risk of Osteoradionecrosis: Results of Survey of Dentists and Oral &amp; Maxillofacial Surgery Units in The United Kingdom, and Suggestions for Best Practice, British Journal of Oral and Maxillofacial Surgery, Vol. 48, No. 4, 2010, pp. 301-304, https://doi.org/10.1016/j.bjoms.2009.06.128.[2] S. Beaumont, N. Bhatia, L. McDowell et al., Timing of Dental Extractions in Patients Undergoing Radiotherapy and the Incidence of Osteoradionecrosis: A Systematic Review and Meta-analysis, British Journal of Oral and Maxillofacial Surgery, Vol. 59, No. 5, 2021, pp. 511-523, https://doi.org/10.1016/j.bjoms.2020.10.006.[3] A. Chronopoulos, T. Zarra, M. Ehrenfeld, S. Otto, Osteoradionecrosis of the Jaws: Definition, Epidemiology, Staging and Clinical and Radiological Findings. A Concise Review, International Dental Journal, Vol. 68, No. 1, 2018, pp. 22-30, https://doi.org/10.1111/idj.12318.[4] T. Reuther, T. Schuster, U. Mende, A. Kübler, Osteoradionecrosis of the Jaws as a Side Effect of Radiotherapy of Head and Neck Tumour Patients – A Report of a Thirty Year Retrospective Review, International Journal of Oral &amp; Maxillofacial Surgery, Vol. 32, No. 3, 2003, pp. 289-295, https://doi.org/10.1054/ijom.2002.0332.[5] J. Silvestre-Rangil, F. J. Silvestre, Clinico-therapeutic Management of Osteoradionecrosis: A Literature Review and Update, Medicina Oral Patologia Oral y Cirugia Bucal, Vol. 16, No. 7, 2011, pp. e900-904, https://doi.org/10.4317/medoral.17257.[6] S. M. Mallya, S. Tetradis, Imaging of Radiation- and Medication-Related Osteonecrosis, Radiologic Clinics of North America, Vol. 56, No. 1, 2018, pp. 77-89, https://doi.org/10.1016/j.rcl.2017.08.006.[7] B. R. Goldwaser, S. K. Chuang, L. B. Kaban, M. August, Rick Factor Assessment for the Development of Osteoradionecrosis, Journal of Oral and Maxillofacial Surgery, Vol. 65, No. 11, 2007, pp. 2311-2316, https://doi.org/10.1016/j.joms.2007.05.021.[8] J. J. Thorn, H. S. Hansen, L. Specht, L. Bastholt, Osteoradionecrosis of the Jaws: Clinical Characteristics and Relation to the Field of Irradiation, Journal of Oral and Maxillofacial Surgery, Vol. 58, No. 10, 2000, pp. 1088-1093, https://doi.org/10.1053/joms.2000.9562.[9] I. J. Lee, W. S. Koom, C. G. Lee et al., Risk Factors and Dose-effect Relationship for Mandibular Osteoradionecrosis in Oral and Oropharyngeal Cancer Patients, International Journal of Radiation Oncology - Biology - Physics, Vol. 75, No. 4, 2009, pp. 1084-1091, https://doi.org/10.1016/j.ijrobp.2008.12.052.[10] B. S. Raggio, R. Winters, Modern Management of Osteoradionecrosis, Current Opinion in Otolaryngology &amp; Head and Neck Surgery, Vol. 26, No. 4, 2018, pp. 254-259, https://doi.org/10.1097/MOO.0000000000000459.[11] K. Katsura, K. Sasai, K. Sato et al., Relationship Between Oral Health Status and Development of Osteoradionecrosis of the Mandible: a Retrospective Longitudinal Study, Oral Surgery Oral Medicine Oral Pathology Oral Radiology, Vol. 105, No. 6, 2008, pp. 731-738, https://doi.org/10.1016/j.tripleo.2007.10.011.[12] H. Abed, M. Burke, S. Scambler et al., Denture Use and Osteoradionecrosis Following Radiotherapy for Head and Neck Cancer: A Systematic Review, Gerodontology, Vol. 37, No. 2, 2020, pp. 102-109, https://doi.org/10.1111/ger.12456.&#x0D; &#x0D; &#x0D;

Osteomyocutaneous Free Fibula Flap Prevents Osteoradionecrosis and Osteomyelitis in Head and Neck Cancer Reconstruction.

Osteoradionecrosis (ORN) is one of the most severe complications of free fibula reconstruction after radiotherapy. The gold standard treatment of osteomyelitis involves extensive debridement, antibiotics, and sufficiently vascularized muscle flap coverage for better circulation. Therefore, we hypothesized that free fibula flap with muscle could decrease the risk of ORN. This study consisted of 85 patients who underwent reconstruction with free fibula flap in head and neck cancer by a single reconstructive surgeon at Kaohsiung Veterans General Hospital over a period of 19 years (1998-2016). Patients with postoperative adjuvant radiotherapy were included in the study and were grouped by either free fibula osteocutaneous flap or free fibula osteomyocutaneous flap (with flexor hallucis longus muscle), and the incidence of ORN was compared. Of the 85 patients, 15 were reconstructed with osteocutaneous fibula flap and 70 were with osteomyocutaneous fibula flap. The rate of ORN or osteomyelitis was significantly lower in the muscle group (18.6%, n = 13/70 vs. 46.7%, n = 7/15, p = 0.020, Chi-square test). Vascularized muscle transfer increases perfusion of surrounding tissues and the bone flap, thereby decreasing the incidence of osteomyelitis or osteonecrosis.

Proactive Customized Protocol for Oral Management in Head and Neck Cancer Patients Planned for Radiotherapy

Osteoradionecrosis (ORN) is a nemesis of radiotherapy which adversely affects the life of an individual. It is more often seen with conventional external beam radiotherapy using telecobalt machine. Newer radiotherapy techniques are being used in developed nations to circumvent its inherent disadvantages. A higher incidence of ORN is seen in dentate jaws because of extractions done for odontogenic infections in the post radiation period. Systematic evaluation of oral tissues and instituting appropriate therapeutic and prophylactic measures before, during and after completion of radiotherapy is mandatory. In our hospital since we use telecobalt radiotherapy it was deemed necessary to design our own protocol to reduce the incidence of this debilitating complication. Our protocol is based on recommended guidelines and which has been customized to our patient strata. We present the findings of a retrospective study on patients undergoing radiotherapy in whom this oral management protocol was used. This protocol has been effective in reducing the frequency of osteoradionecrosis at our tertiary care hospital.

Hypomagnesemia and incidence of osteoradionecrosis in patients with head and neck cancers.

We aimed to determine whether hypomagnesemia predicts osteoradionecrosis development in patients with squamous cell carcinoma of the oropharynx and oral cavity who received platinum-based concurrent chemoradiation with or without induction therapy. We reviewed data from patients with head and neck cancers who had undergone chemoradiation with weekly cisplatin/carboplatin between January 1, 2010 and December 31, 2014 at our institution. Pathologic features, laboratory test results, disease stage, and social histories were recorded. The association between hypomagnesemia and osteoradionecrosis was analyzed controlling for known confounding factors. Hypomagnesemia during cancer treatment was associated with osteoradionecrosis development (HR = 2.72, P = .037) independent of total radiation dose (HR = 1.07, P = .260) and smoking history (HR = 2.05, P = .056) among the patients who received platinum-based induction chemotherapy followed by concurrent chemoradiation. Hypomagnesemia was predictive of the development of osteoradionecrosis in patients with cancers of the oropharynx and oral cavity receiving platinum-based induction followed by concurrent chemoradiation.

Analysis of the critical dose of radiation therapy in the incidence of Osteoradionecrosis in head and neck cancer patients: a case series

IntroductionOsteoradionecrosis (ORN) is a dramatic complication following radiation therapy (RT) for head and neck tumours. Symptoms include pain, trismus, and malodour. ORN can present with exposed necrotic bone, an orocutaneous fistula, and/ or a pathological fracture.AimsTo analyse the RT dose responsible for the pathogenesis of ORN and its associated risk factors.MethodsThe data of 17 patients from 2005 to 2017 were retrospectively reviewed from the Pinnacle(3), WebPublication, and Electronic patient records (EPR) provided by Christie Hospital and Pennine Acute NHS Trust.ResultsThe mean RT dose that ORN sites received was 57.3 Gy. The mean onset duration for ORN after RT was 640.6 days. six patients (35.2%) developed ORN following post-RT dental extractions.ConclusionRT dosages of >57.3 Gy significantly increase the likelihood of developing ORN. Mandibular surgery, post-RT dental extraction, concurrent smoking, and alcohol abuse all amplify the risk of developing ORN.

Oropharyngeal cancer and osteoradionecrosis in a novel radiation era: a single institution analysis

AbstractAimThis study investigates the incidence of osteoradionecrosis (ORN) in patients with oropharyngeal cancer (OPC) since the use of intensity‐modulating radiation therapy (IMRT).Materials and methodsThe multi‐disciplinary log for head and neck cancer (HNC) at Guys &amp; St Thomas’ NHS Foundation Trust was used to identify and collect data on all patients with OPC and treated with a curative intent. Basic and oncology‐related demographic data were collected retrospectively. The presence and absence of ORN along with the causative factor was recorded.ResultsA total of 361 patients were available for analysis 1‐year post‐IMRT with the number decreasing to 129 patients at ≥5 years post‐IMRT. Thirty‐eight cases of ORN were identified from which 29 patients had necrotic areas in the region of pre‐RT dental extractions. The occurrence of spontaneous ORN was most evident within the first 2 years following RT while induced causes appear a steady lifelong threat particularly in the human papilloma virus (HPV)‐positive OPC group.ConclusionsThe introduction of novel targeted IMRT has not seen a significant reduction in the incidence of ORN with the condition of concern particularly evident in the HPV‐positive OPC group. These patients present with a relatively intact dentition receiving RT doses above the threshold for development of ORN. Additionally, the favourable long‐term survival of the HPV‐positve OPC population is likely to be contributory to the rise of cases seen which provides a clinical challenge the dental sector will have to proactively manage.

ORN - could it have been avoided? A retrospective audit of pre-radiotherapy dental assessments and consequent effect on the incidence of osteoradionecrosis

ORN - could it have been avoided? A retrospective audit of pre-radiotherapy dental assessments and consequent effect on the incidence of osteoradionecrosis