Osteoradionecrosis in a Torus Mandibularis Treated by Antimicrobial Photodynamic Therapy: A Case Report.

Background: Osteoradionecrosis (ORN) of the jaws is a late complication after radiotherapy to head and neck cancer. Objective: To describe a rare case of ORN of the torus mandibularis that was successfully managed exclusively with antimicrobial photodynamic therapy (aPDT). Case report: A 72-year-old man presented an exposed necrotic bone observed in the torus mandibularis, extending to the lingual alveolar ridge with no edema nor suppuration. The treatment provided a noninvasive treatment leading to spontaneous sequestrectomy of the torus in 2 weeks with complete mucosal repair in 5 weeks and absence of lesion signs and/or symptoms even after 6 months of follow-up. Conclusions: The aPDT indicated to be a satisfactory treatment for ORN affecting torus mandibularis, a region with surgical limitations, avoiding surgery.

[Prevention, diagnosis and management of osteoradionecrosis: Where do we stand?] / Prévention, diagnostic et prise en charge de l'ostéoradionécrose : où en est-on ?

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.

[Issues and implementation of postoperative radiotherapy after flap reconstructive surgery in head and neck cancers]. / Enjeux et mise en œuvre de radiothérapie postopératoire après chirurgie reconstructrice avec lambeau dans les cancers de la tête et du cou.

The management of head and neck cancers is multidisciplinary, often relying on the use of combined treatments to maximize the chances of cure. Combined treatments are however also responsible for cumulative side effects. The aim of reconstructive surgery with a flap is to restore a function lost with the loss of substance from the tumor resection. However, changes in reconstructive surgery have impact of postoperative radiotherapy planning. The optimization of imaging protocols for radiotherapy planning should make it possible to identify postoperative changes and to distinguish flaps from surrounding native tissues to delineate the flaps and document the spontaneous evolution of these flaps or dose-effect relationships in case of radiotherapy. Such changes include atrophy, fibrosis of soft tissue flaps and osteoradionecrosis of bone flaps. Radiotherapy optimization also involves standardization of the definition of target volumes in situations where a flap is present, a situation that is increasingly common in routine care. This evolution of practice, beyond the essential multidisciplinary consultation meetings defining treatment indications, requires a close radio surgical collaboration with respect to technical aspects of the two disciplines. Doing so, anticipation of relapse and toxicity profiles could possibly lead to propose strategies for personalized de-escalation of multimodal treatments through interdisciplinary trials.

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.

Investigation of clindamycin concentrations in human plasma and jawbone tissue in patients with osteonecrosis of the jaw: A prospective trial.

The aim of this study was to investigate the jawbone concentration of clindamycin (CLI) in patients with an osteonecrosis of the jaw (ONJ). Patients with medication-related ONJ (MRONJ) and osteoradionecrosis (ORN) with an antibiotic treatment with CLI were included. Plasma, vital and necrotic bone samples were collected. Plasma and jawbone samples were analyzed by liquid chromatography-tandem mass spectrometry. Patients with MRONJ exhibited a mean plasma CLI concentration of 9.6 µg/mL (SD ± 3.6 µg/mL) and mean concentrations of 2.3 µg/g CLI (SD ± 1.4 µg/g) and 2.1 µg/g CLI (SD ± 2.4 µg/g) in vital and necrotic bone samples, without statistical significance (p = 0.79). In patients with ORN, mean concentration in plasma was 12.0 µg/mL (SD ± 2.6 µg/mL), in vital bone 2.1 µg/g (SD ± 1.5 µg/g), and in necrotic bone 1.7 µg/g (SD ± 1.2 µg/g). Vital and necrotic bone concentrations did not differ significantly (p = 0.88). The results demonstrate that CLI concentrations are considerably lower than in plasma, but sufficient for most bacteria present in ONJ. Within the limitations of the study, it seems that CLI is a relevant alternative to other antibiotics in the treatment of ONJ because it reaches adequate concentrations in jawbone.

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.

A systematic review and meta-analysis of osteoradionecrosis following proton therapy in patients with head and neck cancer.

INTRODUCTION: Head and neck cancer ranks as the seventh most common cancer worldwide. Proton therapy is widely used in head and neck cancer. Osteoradionecrosis(ORN) is currently a commonly investigated side effect of proton therapy. A meta-analysis is needed to investigate this topic. MATERIAL/METHODS: Two authors searched three databases, including PubMed, Embase, and Cochrane Library; the search period was from inception to June 2023. The search keyword was set to be ((("osteoradionecrosis") OR ("osteonecrosis")) AND ("proton")). RESULTS: We initially collected 410 articles, and after article selections, 22 articles remained in our systematic reviews. Due to the overlapping of patient populations, 17 studies were finally included in our meta-analysis. The pooled grade 3 or more ORN rate is 0.01(95 % CI = 0.01-0.03). Subgroup analysis showed that IMPT didn't reduce grade 3 or more ORN compared with 3DCPT (p = 0.15). CONCLUSIONS: Our meta-analysis showed that severe ORN rarely occurred in proton therapy for head and neck cancer patients.

Long-term follow-up of osteoradionecrosis of the mandible.

AIM: Investigating the prevalence of mandibular ORN in a single Swedish Oncology Center. METHODS: A total of 450 patients, treated with radiotherapy for squamous cell carcinoma in the oropharynx between 2004 and 2014 were included. Three different techniques of radiotherapy were studied. ORN diagnosis was set when clinical signs according to Marx were observed, or if radiological signs were staged according to Schwartz and Kagan. RESULTS: Using the staging system, 90 patients (20%) were diagnosed with ORN. The mean age of the ORN patients was 56.6 years, the older the patient the lower the risk of developing ORN (p = .01). The risk of developing ORN for patients receiving Intensity Modulated Radiotherapy was lower compared to patients treated with the other techniques in the multivariable analysis. Brachytherapy significantly increases the risk of ORN. The risk of ORN increased by 8% each year after radiation (p = .04). The mean time to the ORN diagnosis was 3.9 years. In the multivariate analysis, the risk of ORN increased by 13% each year after radiation (p = .0013). CONCLUSION: The mean radiation dose was of greater importance for the risk of ORN than the maximum dose. Elderly people with oropharyngeal cancer were less prone to develop ORN.

Retrospective analysis of tooth extraction and osteoradionecrosis after low-dose rate brachytherapy for patients with tongue cancer.

OBJECTIVES: This study aimed to investigate the incidence of osteonecrosis of the jawbones (ORN) after tooth extraction in patients undergoing low-dose rate brachytherapy (LDR-BT) and assess its safety. METHODS: This study retrospectively analyzed 145 patients with tongue cancer treated at Hiroshima University Hospital from 2007 to 2021 with LDR-BT using 192Ir or 198Au alone, LDR-BT and external beam radiotherapy (EBRT) with or without chemotherapy, and LDR-BT with chemotherapy. Patients' mandible and maxilla were protected with spacers. Forty-seven patients underwent tooth extraction, and the incidence, site, and relationship of ORN with tooth extraction were recorded. A subgroup of 26 patients received additional EBRT to the neck after dissection for late cervical lymph node metastases. RESULTS: Of 145 patients, six (4.1%) developed ORN on the same side of the mandible as LDR-BT, and EBRT was performed before and/or after LDR-BT on the sites where ORNs developed. Five of 47 (10.6%) patients who underwent tooth extraction after LDR-BT developed ORN. ORN incidence was 1.8% (2/109) in the LDR-BT and/or chemotherapy group and 11.1% (4/36) in the combination LDR-BT and EBRT and/or chemotherapy group for primary tongue cancer. Different irradiation methods (LDR-BT and/or chemotherapy and combination LDR-BT and EBRT and/or chemotherapy) and the presence or absence of tooth extraction showed significant differences (p = 0.0335 and p = 0.0139, respectively) with or without ORN. CONCLUSIONS: Mandibular tooth extraction should be avoided on the side of LDR-BT in combined EBRT cases. However, tooth extraction is feasible using a spacer in LDR-BT and/or chemotherapy.

Microstructural changes in the irradiated and osteoradionecrotic bone: a SEM study.

Radiation exposure is a major health concern due to bone involvement including mandible, causing deleterious effects on bone metabolism, and healing with an increasing risk of infection and osteoradionecrosis. This study aims to investigate the radiotherapy-induced microstructural changes in the human mandible by scanning electron microscopy (SEM). Mandibular cortical bone biopsies were obtained from control, irradiated, and patients with osteoradionecrosis (ORN). Bone samples were prepared for light microscopy and SEM. The SEM images were analyzed for the number of osteons, number of Haversian canal (HC), diameter of osteon (D.O), the diameter of HC (D.HC), osteonal wall thickness (O.W.Th), number of osteocytes, and number of osteocytic dendrites. The number of osteons, D.O, D.HC, O.W.Th, the number of osteocytes, and osteocytic dendrites were significantly decreased in both irradiated and ORN compared to controls (p < .05). The number of HCs decreased in irradiated and ORN bone compared to the control group. However, this was statistically not significant. The deleterious effect of radiation continues gradually altering the bone quality, structure, cellularity, and vascularity in the long term (>5 years mean radiation biopsy interval). The underlying microscopic damage in bone increases its susceptibility and contributes further to radiation-induced bone changes or even ORN.