The radiation-induced fibroatrophic process: therapeutic perspective via the antioxidant pathway

Skull base osteoradionecrosis: from pathogenesis to treatment

PURPOSE OF REVIEW

This review aims to provide a comprehensive analysis of skull base osteoradionecrosis (ORN), a severe and rare complication of radiotherapy for head and neck malignancies. It explores pathogenesis, clinical presentation, diagnostic strategies, and management approaches, emphasizing the importance of multidisciplinary care in addressing this challenging condition.

RECENT FINDINGS

Skull base ORN results from radiotherapy-induced tissue damage, characterized by hypovascularity, hypoxia, and necrosis, often compounded by secondary infections. Advances in radiotherapy techniques, such as intensity-modulated radiotherapy and heavy particles, have reduced ORN incidence, though cases persist, particularly in high-dose radiotherapy fields. Emerging treatments, including hyperbaric oxygen therapy and the pentoxifylline-tocopherol protocol, show promise but lack robust evidence for standardized use. Surgical interventions, especially those incorporating vascularized tissue reconstruction, have demonstrated favorable outcomes in refractory cases. Recent studies underscore the utility of multimodal imaging techniques, including MRI and PET/CT, for distinguishing ORN from tumor recurrence.

SUMMARY

Skull base ORN represents a complex and potentially life-threatening condition requiring tailored, multidisciplinary management. Although advancements in diagnostics and therapeutics have improved outcomes, significant challenges remain, particularly in developing standardized protocols. Further research is needed to refine treatment strategies and improve evidence-based practices for this entity.

Effects of ionizing radiation on osteoblastic cells: In vitro insights into the etiopathogenesis of osteoradionecrosis

OBJECTIVE

This in vitro study aimed to analyze the effects of ionizing radiation on immortalized human osteoblast-like cells (SaOS-2) and further assess their cellular response in co-culture with fibroblasts. These analyses, conducted in both monoculture and co-culture, are based on two theoretical models of osteoradionecrosis - the theory of hypoxia and cellular necrosis and the theory of the radiation-induced fibroatrophic process.

DESIGN

SaOS-2 cells were exposed to ionizing radiation and evaluated for cell viability, nitric oxide (NO) production, cellular morphology, wound healing, and gene expression related to the PI3K-AKT-mTOR pathway. SaOS-2 cells were co-cultured with human gingival fibroblasts using transwell membranes and subjected to the same irradiation. Subsequent evaluations included cell viability, NO levels, and gene expression analysis.

RESULTS

After 24 hours, a 16 Grays dose reduced cell viability by 40 % (p < 0.0001) and increased NO production by 14 % (p < 0.05). Additionally, the nuclear area was enlarged by 18 % (p < 0.01), and the nucleus-to-cytoplasm ratio in non-stimulated cells was around 33 %, but after radiation, this ratio increased to nearly 100 %. Also, there was a delay in wound closure of 6.6 % (p < 0.0001) post-irradiation and a trend toward down-regulation of genes related to the PI3K-AKT-mTOR pathway (p > 0.05). Under co-culture conditions, the dose of 16 Grays did not affect cell viability but increased NO production by 14 % (p < 0.001) and tended to up-regulate markers of the PI3K-AKT-mTOR pathway (p > 0.05).

CONCLUSIONS

The findings of this study demonstrate that an irradiation dose of 16 Grays induces a reduction in cell viability, an increase in NO production, and various other metabolic and morphologic effects on osteoblastic cells while emphasizing the impact of intercellular interaction in the etiopathogenesis.

Ru single-atom nanozymes targeting ROS-ferroptosis pathways for enhanced endometrial regeneration in intrauterine adhesion therapy

Intrauterine adhesion (IUA) presents a significant challenge in gynecology, characterized by excessive fibrosis and compromised reproductive function, leading to severe infertility. Although biocompatible hydrogels integrated with stem cells offer a promising approach for IUA therapy, clinical applications remain limited. Recent studies have highlighted the role of ferroptosis and reactive oxygen species (ROS) in IUA pathogenesis, yet strategies targeting ferroptosis through antioxidant stress are underexplored. This study investigates the therapeutic effects and mechanisms of a Ru-Single-Atom Nanozyme (Ru-SAN) incorporated into chitosan hydrogel for treating IUA. Ru-SAN, which mimics the enzyme activities of catalase, superoxide dismutase, and glutathione peroxidase, effectively clears excess ROS and shows promise in treating oxidative stress-induced diseases. The results demonstrate the superior antioxidative capabilities of Ru-SAN, significantly suppressing the ROS-ferroptosis cycle at the injury site. This creates a favorable microenvironment for post-injury repair by inhibiting inflammation, enhancing mesenchymal-to-epithelial transformation, promoting angiogenesis, and polarizing M2 macrophages. Importantly, it mitigates adverse repair outcomes from inflammation and excessive collagen fiber deposition, ultimately restoring uterine glandular structures and thickness, thereby achieving the ultimate goal of restoring fertility and live birth rates. In conclusion, our study delineates a pioneering therapeutic approach leveraging the antioxidant properties of Ru-SAN to target ferroptosis, thereby offering an efficacious treatment for IUA.

Establishment of an Osteoradionecrosis Model and its Mechanism Via Single Ionizing Radiation Exposure

INTRODUCTION AND AIMS

The aim of this study was to establish a reliable model of osteoradionecrosis of the mandible in New Zealand white rabbits and systematically examine the impacts of different radiation doses on mandibular tissue, as well as to appraise the inducing role of tooth extraction in the pathogenesis of the disease.

METHOD

In this research, 16 New Zealand white rabbits were randomly allocated to the control group, the 16Gy group, the 18Gy group, and the 20Gy group with a single high-dose radiation. Two weeks after radiotherapy, the teeth were extracted, and the animals were sacrificed four weeks later. Micro CT, scanning electron microscopy, HE staining, Masson staining, TRAP staining, TUNEL staining, and immunohistochemical staining were employed to verify the modelling status and damage mechanism.

RESULTS

Research findings show that, compared to the control group, rabbits exposed to 18Gy and 20Gy radiation doses exhibited significant bone necrosis after tooth extraction. Key observations included extensive bone tissue necrosis, increased osteoclasts (P < .05), reduced vascularization (P < .001), exacerbated fibrosis (P < .001), decreased bone density, disrupted trabecular structure, and damaged bone surface microstructure. In contrast, the 16Gy group showed some bone damage but did not meet bone necrosis criteria.

CONCLUSION

This study established an animal model appropriate for inducing ORNJ with a single large dose of radiation.

CLINICAL RELEVANCE

This work provides a solid experimental basis and a theoretical framework for further studies of ORNJ pathogenesis in particular to explore effective preventive and clinical treatment strategies.

Treatment approaches in cases of mandibular osteoradionecrosis: A systematic meta-analysis

BACKGROUND

Osteoradionecrosis (ORN) refers to necrotic bone that remains unhealed for a minimum of 3 months following radiotherapy in an irradiated region. The aim of this systematic meta-analysis was to evaluate the efficacy of hyperbaric oxygen therapy and surgery alone or in combination in the treatment of patients with ORN.

METHODS

A systematic review and analysis of literature were performed to ascertain the role of surgery and HBO in the treatment of ORN. In May 2024 we updated the searches of the Cochrane Central Register of Controlled Trials (CENTRAL), (The Cochrane Library, Issue 1), MEDLINE, EMBASE, DORCTIHM and reference lists of articles.

RESULTS

Among patients who underwent both HBO and surgery, the success rate of the treatment was 69 % (95 % Confidence Interval [CI]: 0.47-0.85, df = 9). Patients who solely received HBO had a success rate of 38 % (CI: 0.20-0.61, df = 4), while those who only had surgery had a success rate of 36 % (CI: 0.19-0.58, df = 3). The statistical analysis showed no significant difference in the results between patients who received only hyperbaric oxygen therapy or surgical treatment (z=0.139, p=0.889). The analysis indicated significant disparities in treatment success rates among patients receiving a combination of HBO and surgery compared to those treated solely with HBO or surgery alone (z = 2.428, p = 0.015 for HBO vs HBO+surgery, z = 2.655, p = 0.008 for surgery vs HBO+surgery).

CONCLUSION

The findings of this study indicate that the combination of HBO and surgery is a more effective approach for managing ORN, with better results observed when treatments are combined rather than used individually.

Mechanism of skull base osteoradionecrosis explored through laboratory assessment with propensity score-matched analysis

Skull base osteoradionecrosis (sbORN) is a severe complication of radiotherapy (RT) in patients with nasopharyngeal carcinoma (NPC) that can severely affect quality of life (QOL) and may even be life-threatening. The etiology and pathogenesis of sbORN remain largely unknown or uncertain. Therefore, this study aimed to identify potential risk factors for sbORN by analyzing the laboratory assessments of patients to enable early clinical interventions. This retrospective case-control study reviewed NPC patients who were pathologically diagnosed with sbORN after primary radical radiotherapy. These patients were matched 1:1 with propensity scores for patients without sbORN at our center. The impact of laboratory examination indexes on sbORN occurrence was assessed using both univariate and multivariate logistic regression analyses. We reviewed 1,200 NPC patients who were followed up in our department from 2010 to 2020; a total of 57 patients met the inclusion criteria. Each patient underwent endoscopic and pathological examinations, which confirmed the diagnosis. In addition, 98 patients without sbORN were also collected and matched 1:1 by propensity score matching, resulting in the inclusion of 38 patients. Univariate logistic regression analysis revealed statistically significant differences in hemorrhage (HB), erythrocytes (RBC), albumin (Alb), platelets (PLT), indirect bilirubin (IBil), globulin (Glo), aspartate aminotransferase (AST), and fibrinogen (Fg) between the two groups (p < 0.05). Multivariate logistic regression analysis revealed statistically significant differences only for Fg (p < 0.05). Receiver operating characteristic (ROC) curve analysis further demonstrated the diagnostic utility of Fg, yielding an area under the curve (AUC) of 0.829, with specificity and sensitivity values of 0.842 and 0.711, respectively. The occurrence of sbORN was closely associated with elevated plasma Fg levels, suggesting that high plasma Fg may be a potential risk factor for sbORN. Plasma Fg has a certain diagnostic value for sbORN and can be used as a supplementary diagnostic method.

Association between microvascular free-flap arterial anastomosis caliber and risk for development of osteoradionecrosis

OBJECTIVES

Osteoradionecrosis (ORN) following radiation therapy (RT) is a serious complication for patients undergoing head and neck cancer treatment. Recent literature has found an association between ipsilateral external carotid artery (ECA) diameter and the development of ORN. This study evaluates microvascular free-flap arterial anastomosis diameter and the development of ORN.

MATERIALS AND METHODS

Sixty-six patients underwent fibular free-flap reconstruction followed by RT between 2012-2019 at the University of Florida. Anastomosis and ECA diameters pre- and post-RT were measured from computed tomography images. Multivariate regression analysis identified significant factors in the development of ORN.

RESULTS

Incidence of ORN was 33.3 % (N = 22/66). Mean post-RT anastomosis diameters were 2.3 and 2.2 for the ORN group and no-ORN group, respectively (p = 0.548). Mean post-RT ipsilateral ECA diameters were 4.7 and 4.2 for the ORN group and no-ORN groups, respectively (p = 0.040). The change in pre-RT versus post-RT ipsilateral ECA diameters was different in patients with RT dose above and below 55 Gy (p = 0.041). Neither post-RT anastomosis (OR = 1.78, 95% CI: 0.43, 8.65, p = 0.434), nor ECA (OR = 1.44, 95% CI: 0.78, 2.83, p = 0.250) diameters were associated with development of ORN while controlling RT dose (OR = 1.15, 95% CI: 1.04, 1.28, p = 0.006), post-operative fistula (OR = 9.11, 95% CI: 1.65, 93.7, p = 0.010), and post-operative infection (OR = 3.48. 95% CI = 1.01, 12.7, p = 0.048), and CCI (OR = 0.61, 95 % CI: 0.36, 0.96, p = 0.031).

CONCLUSION

A higher degree of narrowing in ipsilateral ECA following RT may be linked to development of ORN. RT doses ≥ 55 Gy were associated with a high risk of ORN.

Managing Mandibular Osteoradionecrosis

OBJECTIVE

Mandibular osteoradionecrosis (MORN) is a morbid complication of head and neck radiation therapy. Recent advances in surgical and medical therapies underscore the need for a shift in traditional treatment paradigms and a disease grading system that can guide appropriate management.

DATA SOURCES

Pubmed/MEDLINE.

REVIEW METHODS

We conducted a detailed review of publications related to MORN, specifically focusing on its staging and management techniques. Articles meeting inclusion criteria were synthesized into a final narrative review.

CONCLUSION

There has been a paradigm shift away from hyperbaric oxygen therapy in the management of MORN. Growing evidence for the efficacy of pentoxifylline and tocopherol in early-stage disease and novel surgical techniques to manage moderate and late-stage disease warrant an updated staging stratification which is proposed.

IMPLICATIONS FOR PRACTICE

This review summarizes the clinical efficacy of established and novel therapeutic modalities currently available in treating MORN, emphasizing the significant advances achieved over the last decade. It introduces a contemporary staging and treatment algorithm which incorporates traditional, evidence-supported surgical and medical management with effective early intervention strategies.

Complications in Deep Circumflex Iliac Artery-Related Vascularized Free Iliac Flap

BACKGROUND

Since its first application in 1978, the vascularized free iliac flap (VFIF) has gradually become a mainstay for tissue defect reconstruction. However, the complications associated with harvesting the bone flap and its corresponding reconstruction surgery cannot be overlooked.

METHODS

We conducted a narrative review through literature search to identify the types, incidence, influencing factors, measurement methods, and treatment approaches of complications related to DCIA-related VFIF.

RESULTS

We propose the "LIP" rule (Loss, Injury, Postoperative) for classifying donor site complications. For the four most common recipient sites, mandible, maxilla, extremities, and hip joint, we list the common and rare complications that may occur. Additionally, we provide a summary of the methods and advances in preventing these complications.

CONCLUSIONS

We comprehensively describe the complications observed in the application of DCIA-related VFIF and introduce the "LIP" principle and other strategies to minimize or avoid adverse outcomes.

Development of a Preclinical Double Model of Mandibular Irradiated Bone and Osteoradionecrosis in New Zealand Rabbits

PURPOSE

Radiotherapy (RT) plays a crucial role in head and neck (HN) cancer treatment. Nevertheless, it can lead to serious and challenging adverse events such as osteoradionecrosis (ORN). A preclinical rabbit model of irradiated bone and ORN is herein proposed, with the aim to develop a viable model to be exploited for investigating new therapeutic approaches.

METHODS

Nine New Zealand white rabbits were irradiated using a single beam positioned to the left of the mandible and directed perpendicular to the left mandible. A 10 × 10 mm2 region of interest (ROI) located below the first molar tooth on the left side was identified and irradiated with 7 Gy each fraction, once every 2 days, for five fractions. Dose distributions demonstrated that the corresponding ROI on the contralateral (right) mandibular side received approximately 5 Gy each fraction, thus bilateral irradiation of the mandible was achieved. ROIs were categorized as ROIH on the left side receiving the high dose and ROIL on the right side receiving the low dose. Rabbits were followed up clinically and imaged monthly. After 4 months, the irradiated bone was excised, and histological examination of ROIs was performed.

RESULTS

Radiological signs suggestive for ORN were detected in the entire population (100%) 16 weeks after irradiation on ROIH, which consisted of cortical erosion and loss of trabeculae. ROIL did not show any radiological evidence of bone damage. Histologically, both sides showed comparable signs of injury, with marked reduction in osteocyte count and increase in empty lacunae count.

CONCLUSIONS

A preclinical double model was successfully developed. The side receiving the higher dose showed radiological and histological signs of bone damage, resulting in an ORN model. Whereas the contralateral side, receiving the lower dose, presented with histological damage only and a normal radiological appearance. This work describes the creation of a double model, an ORN and irradiated bone model, for further study using this animal species.

Antiresorptive therapy in combination with radiation results in enhanced risk for necrosis and associated complicatifions

OBJECTIVE

Patients exposed to a combination of antiresorptive medication and radiotherapy of the head and neck area developing necrosis of the jaw in the course of treatment are extremely rare. Therefore, the aim of this study was to identify the outcome and complications in this highly vulnerable patient cohort.

STUDY DESIGN

Seventeen patients who received both antiresorptive treatment and radiotherapy (medication-related osteonecrosis of the jaw/osteoradionecrosis = the [MRONJ/ORN] group) in the head and neck area were enrolled in this study. Included patients were treated in our department between 2005 and 2022. Four hundred twenty-four patients with MRONJ (the MRONJ group) and 138 patients with ORN of the jaw were enrolled as two control groups (the ORN group). Demographic data, lesion localization, date of primary diagnosis, clinical symptoms, type of therapy (surgical or non-surgical), details on antiresorptive treatment, outcome, and complications were recorded.

RESULTS

Pathological fractures, continuity resection, and recurrence appear more often in patients who receive a combination of antiresorptive treatment and radiotherapy in the head and neck area compared with patients undergoing only one of these treatments. There was a statistically significant difference (P < .001) between the MRONJ/ORN group and the MRONJ group and the MRONJ/ORN group and the ORN group considering recurrence, fracture, and continuity resection. Patients with ORN combined with MRONJ have a 4-times higher risk for developing recurrence compared with patients with MRONJ and a 1.5-times higher risk for recurrence compared with patients with ORN. Jaw fracture and continuity resection appear more often in patients with MRONJ/ORN.

CONCLUSIONS

Patients under antiresorptive therapy in combination with radiation therapy in the head and neck area have a higher risk for developing complications in case of osteonecrosis of the jaw. Therefore, a strict follow-up care schedule is highly recommended.

Fractal Analysis of Mandible in Panoramic Radiographs of Patients Received Radiotherapy for Nasopharyngeal Carcinoma

PURPOSE

This study aimed to assess the impact of radiotherapy on the internal structure complexity of mandibular cortical and trabecular bone and to determine the duration required for a return to healthy values post-radiotherapy.

MATERIALS AND METHODS

Panoramic radiographs from patients undergoing radiotherapy for nasopharyngeal carcinoma were analyzed before and after treatment. Four groups were formed based on post-radiotherapy radiography timing (0-6 months, 6-12 months, 12-24 months, and 24-36 months), comprising a total of 59 cases and 118 radiographs. Fractal analysis was conducted on four bilateral regions (ROI) in both trabecular and cortical bone on each radiograph. Additionally, measurements of inferior alveolar canal width and mandibular cortical width were performed. Mean and maximum radiation dose values to the mandible were measured, and their correlation with changes in fractal dimension, inferior alveolar canal width, and mandibular cortical width values was assessed.

RESULTS

Fractal dimension values in regions over trabecular bone showed a statistically significant decrease in all groups, although no significant difference was observed among the four groups. In ROI-4 from cortical bone, a significant fractal dimension decrease was noted in all groups except the 0-6 month group. The magnitude of fractal dimension decrease was higher in the 12-24 and 24-36 month groups compared to the 0-6 month group. inferior alveolar canal width and mandibular cortical width values significantly decreased post-radiotherapy in all groups, with a consistent decrease across the groups.

CONCLUSIONS

Radiotherapy induces a reduction in the internal complexity of trabecular and cortical bone structures in the mandible. Osteoradionecrosis risk persists even three years post-radiotherapy, suggesting a cautious approach to interventional procedures on the bone.

Hypofractionated accelerated radiation dose-painting (HARD) improves outcomes in unresected soft-tissue sarcoma

Soft tissue sarcomas (STS) are radioresistant with a low α/β, which may have a biologic benefit with hypofractionation. For unresectable STS, the dose escalation required to achieve durable control is often limited by long-term toxicity risk. We sought to compare an isotoxic approach utilizing hypofractionated accelerated radiation dose-painting (HARD) versus standard fractionated radiation therapy (SFT) in patients with unresected STS. We conducted a retrospective analysis of patients with unresected STS who received either HARD (n = 49) or SFT (n = 43) with photon-based therapy between 1990 and 2022. The 2 HARD regimens each use 3 dose levels based on risk of disease burden. The gross disease, intermediate risk, and low-risk clinical target volumes were treated with either 20-22 fractions of 3/2.5/2-2.2 Gy or 28 fractions of 2.5/2.2/1.8 Gy. SFT included patients treated with definitive intent, receiving ≥ 50 Gy in 1.8-2 Gy per fraction. Clinical endpoints included 3-year local control (LC), overall survival (OS), and progression-free survival (PFS), along with treatment-related toxicity. With a median age of 67 and tumor size of 7 cm, most patients were stage IV (37 %), grade 3 (67 %), had no concurrent systemic therapy (70 %), and were lower extremity tumors (24 %). HARD cohort consisted of higher age, stage, recurrent disease, and median BED4 (p < 0.05), when compared to SFT. With a median follow-up of 35.9 months, HARD demonstrated significant improvement in 3-year LC (96.4 % vs. 48.4 %, p < 0.001), compared to SFT overall, with a median PFS benefit (16 vs. 10 months, p = 0.037) for non-distantly metastatic patients at baseline. On multivariate analysis, HARD was significantly associated with improved LC (HR 0.058, 95 % CI 0.005-0.682, p = 0.024). The HARD regimen found no significant increase in toxicity, with limited acute grade 3 (24 %, all dermatitis) and late grade 3 toxicity (6 %) observed, with no grade 4 or 5 events. HARD regimen significantly improves LC for unresectable STS without a significant increase in toxicity, when compared to a standard fractionated approach, supporting further prospective investigation of this treatment approach.

Outcomes of free flap reconstruction for mandibular ORN: Systematic review and meta-analysis

OBJECTIVE

This study aims to evaluate the success rates and complications associated with different free flap donor sites used in surgical reconstruction for mandibular osteoradionecrosis, providing insights to aid clinical decision-making.

DATA SOURCES

MEDLINE, Embase, Cochrane, and Web of Science.

REVIEW METHODS

Comprehensive database searches were conducted up to October 2023. Three independent reviewers screened articles per PRISMA guidelines. This review is registered with PROSPERO (CRD42023456929). Meta-analysis, using inverse variance statistical method and a random effects model, was performed with OpenMeta software (Version 10.12, Brown University, USA). Study quality was assessed via the methodological index for non-randomized studies (MINORS).

RESULTS

Nineteen full-text articles met inclusion criteria, encompassing 397 patients and 424 free flap procedures. Patients averaged 54.8 years old; 27.5 % were female. Squamous cell carcinoma was the main radiation indication (83.1 %). Flap types included fibula (63 %), iliac crest (36 %), scapula (3.7 %), and radial forearm (3.5 %). Symptoms of osteoradionecrosis appeared on average four years post-radiation therapy, with a mean dose of 6346 cGy. Pooled postoperative complication rate was 22.5 % (95 % CI 0.165-0.284, I2:48%). Radial forearm flaps had the lowest complication rate (13.5 %, 95 % CI 0.026-0.295, I2:0%), while scapula flaps had the highest (34.9 %, 95 % CI 0.039-0.66, I2:40.3 %). Fibula flaps had the lowest failure rate (3.3 %, 95 % CI 0.003-0.025, I2:0%), while iliac crest flaps had the highest (11.9 %, 95 % CI 0.022-0.260, I2:60.4 %).

CONCLUSION

The fibula is the preferred flap for mandibular reconstruction due to its low failure rate. Radial forearm flaps show the fewest complications. More robust, multi-institutional prospective studies are needed.

A Retrospective Study Evaluating the Outcomes of Conventionally Fractionated Radiation Therapy as a Treatment for Infiltrative Lipomas in Twenty-One Dogs

Infiltrative lipomas represent a subcategorisation of rarer, potentially more aggressive, lipoma-related neoplasms. Twenty-one dogs treated with conventionally fractionated radiotherapy (CFRT) for infiltrative lipomas were included in this retrospective study. One patient had no prior surgical excision, 11 patients had one prior surgery and 9 patients had two or more surgeries prior to CFRT. Five patients (24%) had microscopic disease and 16 patients (76%) had macroscopic disease prior to treatment. A complete response or no regrowth was seen in 10 patients (48%), stable disease in 6 patients (29%) and progressive disease or regrowth in 5 patients (24%). Response to treatment of macroscopic tumours was significantly different between dogs that had one prior surgery versus two or more (p = 0.01). Dogs with a single surgery were most likely to result in stable disease compared with dogs with two or more surgeries resulting in a complete response. The dog without surgery developed progressive disease at 211 days, dogs with one surgery had a median progression or recurrence at 1369 days and dogs with two or more surgeries developed progression or recurrence at 826 days (p = 0.04). Twelve dogs were alive at the time of analysis. Overall median survival time (MST) was 1694 days. The prior number of surgeries did not significantly affect MST. While survival time is comparable to previous reports, the number of patients with progressive disease or recurrence of previous microscopic disease requires more investigation into the most appropriate protocol, dose and treated field size.

Incidence and Factors Associated With the Development of Calvarial Osteoradionecrosis in Patients Treated for Cutaneous Malignancies

Study Design

Retrospective cohort study.

Objective

Calvarial osteoradionecrosis (ORN) is a rare but devastating complication of radiotherapy. The aim of this study was to describe the cumulative incidence of Calvarial ORN in patients in patients treated for cutaneous malignancy of the scalp.

Methods

Data was compiled from patient records of a large tertiary hospital Plastic Surgery department and radiotherapy records of an affiliated cancer Center. We included all patients that were treated for cutaneous malignancies of the scalp that received radiotherapy. Patient demographics, cancer stage, treatment modalities, intraoperative details, and patient outcome data were recorded. Patients with incomplete radiotherapy data were excluded.

Results

We analyzed 105 radiotherapy treatments to the scalp administered to 84 patients and recorded 7 cases of calvarial ORN resulting in a gross incidence of 6.67% per radiotherapy treatment. The parietal bone was the most frequently targeted site of radiotherapy and accordingly the most common site of ORN (85.7%). Median time from radiotherapy dose to the development of ORN was 846 days. Higher number of radiotherapy fractionation (P = .038), cumulative radiotherapy dose (P = .035), prolonged radiotherapy duration (P = .022) and skin grafting (P = .003) were associated with the development of ORN.

Conclusions

Our findings suggest radiotherapy variables, such as prolonged radiotherapy duration, increased cumulative dose and higher radiotherapy fractions were strongly associated with the development of ORN. In addition, skin grafting following surgical resection was associated with the development of ORN. Further studies with larger sample sizes are required to further explore this relationship.

Predictive potential of pan-immune-inflammation value / hemoglobin index as biomarker for osteoradionecrosis risk in locally advanced nasopharyngeal carcinomas

OBJECTIVE

We aimed to investigate whether the Pan-Immune-Inflammation-Value/Hemoglobin (PIV/Hb) index could predict the risk of osteoradionecrosis (ORN) in patients receiving concurrent chemoradiotherapy (CCRT) for locally advanced nasopharyngeal cancer (LA-NPC).

MATERIALS AND METHODS

This retrospective analysis included LA-NPC patients who underwent CCRT and pre-CCRT oral exams at our institution's Departments of Radiation Oncology and Dentistry between January 2010 and December 2022. The relationship between ORN rates and PIV-Hb levels was explored using receiver operating characteristic curve analysis. The primary objective was to establish a correlation between pre-CCRT PIV-Hb levels and ORN rates, while the secondary objective was to identify other risk factors for ORN.

RESULTS

Of 249 eligible patients, 21 (8.4 %) were diagnosed with ORN. The optimal pre-CCRT PIV/Hb cutoff was 73.8, which divided patients into two subgroups with distinctive ORN risk estimates: Group 1: PIV/Hb < 73.8 (N = 206), and Group 2: PIV/Hb ≥ 73.8 (N = 43). The results of the comparative analysis indicated that the cohort with PIV/Hb ≥ 73.8 exhibited substantially higher rates of ORN than the PIV/Hb < 73.8 cohort (44.2 % vs. 1.0 %; P < 0.001). The multivariate logistic regression analysis indicated that the pretreatment PIV/Hb ≥ 73.8 was independently associated with higher ORN rates (P < 0.001).

CONCLUSION

The results of our current investigation indicate that higher levels of pretreatment PIV/Hb were associated with a significant independent increase in ORN rates in LA-NPC patients who received CCRT.

Diagnostic and Therapeutic Approaches to Jaw Osteoradionecrosis

Jaw osteoradionecrosis (ORN) is a major complication of head and neck cancer radiotherapy. Treatment complications account for most of the poor outcomes for head and neck cancers and the associated racial health disparities in cancer survivorship. The global incidence of jaw ORN is improving due to pre-radiotherapy patient preparations and improved head and neck cancer radiotherapy protocols. The diagnosis and management of jaw ORN are based on the patient's history and clinical presentation combined with radiological and histopathological tests. Evidence-based jaw ORN therapies focus on preventive, palliative, and surgical principles. However, new and innovative therapeutic approaches based on the cellular and molecular pathophysiological processes of jaw ORN and the jawbone's susceptibility to radiation bone damage are limited. The rationale for this narrative review is to highlight the current diagnostic approaches to jaw ORN and the pathophysiological basis for new therapeutic options for ORN.

The initial implementation of the transverse bone transport technique in the post-radiation region of the mandible. A pre-clinical in vivo study

BACKGROUND

To link the treatment of radiation injury with angiogenesis, and to design and seek a new therapeutic technique for the prevention and treatment of radiation injury.

METHODS

The transverse bone transport device for rabbit mandible was designed and manufactured. Eighteen New Zealand white rabbits were randomly divided into a radiotherapy group and a normal group. The radiotherapy group received 18 Gy of radiation, and the device was implanted two weeks later. After a 7-day incubation period, transverse transportation was performed at a speed of 0.5 circles (0.4 mm) per day, with an 8-day cycle and a total traction distance of 3.2 mm. CBCT, Micro CT, and histological staining were employed to assess the dynamics of movement, osteogenesis, and angiogenesis.

RESULTS

The transverse bone transport model of rabbit mandible was successfully established. CBCT revealed that the transport height in the normal and radiotherapy groups were 3.24 ± 0.17 mm and 3.22 ± 0.19 mm respectively. Micro CT analysis showed an increase in BV/TV and Tb.N over time, while Tb.Sp decreased; differences in BV/TV existed at 2 weeks but disappeared thereafter; differences in Tb.N and Tb.Sp persisted at 2 and 4 weeks. Histological staining using HE, Masson, and IHC demonstrated good bone maturity accompanied by rich neovascularization, and this was also confirmed by ImageJ software analysis.

CONCLUSIONS

The transverse bone transport was employed for the first time in the radiation-induced mandibular damage, thereby establishing a basis for further investigation into its clinical efficacy, application value, and underlying mechanisms. This breakthrough offers novel prospects for clinical interventions.

Relationship between bone union and degree of bone marrow fibrosis at resection margins of advanced mandibular ORN

BACKGROUND

The pathological evaluation of cancellous bone at resection margins of mandibular osteoradionecrosis (ORN) has not been well elucidated. Here, we developed a unique classification system for evaluating the degree of bone marrow fibrosis, one of most common pathological features, in patients with mandibular ORN, based on which we investigated its relationship with treatment outcome.

METHODS

This study included 15 patients who underwent mandibulectomy and free fibula osteocutaneous flap reconstruction. The extent of mandibulectomy was determined, with safety margins of approximately 10 mm from the apparent osteolytic areas on preoperative computed tomography image. Special staining was performed on thin sections from center of the osteolytic areas (medial area) and bilateral resection margins, and the degree of bone marrow fibrosis was evaluated and investigated its relationship with presence of bone union as a treatment outcome.

RESULTS

The degree of bone marrow fibrosis of medial area was significantly higher than those of resection margins. Although most resection margins had collagen fibers which indicate severe fibrosis, all transferred fibula flaps achieved bone union.

CONCLUSION

When mandibulectomy is performed with safety margins of approximately 10 mm from the apparent osteolytic areas, all transferred fibula flaps achieved bone union regardless of the degree of bone marrow fibrosis at resection margin. In other words, the association between severe bone marrow fibrosis at resection margins and treatment outcome was not seen.

CLINICAL RELEVANCE

Setting safety margins of approximately 10 mm may achieve bone union, but further study is needed.

Microvascular reconstruction of midface osteoradionecrosis

BACKGROUND

Head and neck osteoradionecrosis (ORN) of the midface requiring free flap (FF) reconstruction is uncommon. This multi-institutional study was designed to review outcomes for this rare patient population.

METHODS

Retrospective multi-institutional review of FF reconstruction for midface ORN (2005-2022; n = 54).

RESULTS

The FF survival rate was 87% (n = 54). Patients were less likely to be tolerating a regular diet at 3 months postoperative if they had a preoperative history of prior head and surgery (80% vs. 95%; p = 0.02), a pathologic fracture (50% vs. 90%; p = 0.04), exposed bone intraorally (43% vs. 94%; p = 0.002), or a fistula (67% vs. 96%; p = 0.03). Mean albumin was higher in patients whose FF survived (3.6 ± 0.5 vs. 2.7 ± 1.4; p = 0.03). Patients with low prealbumin were more likely to undergo a hematoma evacuation (27% vs. 0%; p = 0.02).

CONCLUSION

In this series of midface ORN requiring FF reconstruction preoperative nutritional status impacted postoperative complications. Preoperative occurrence of a fistula, pathologic fracture, and intraoral bone exposure correlated with decreased tolerance of a regular diet following reconstruction.

Bone complications of cancer treatment

With the advancements in conventional treatment modalities such as radiation, chemotherapy, and surgery, as well as the emergence of immunotherapy, the overall cure rate for solid tumor malignancies has experienced a significant increase. However, it is unfortunate that exposure to cancer treatments can have detrimental effects on the function of osteoblasts and osteoclasts, disturbing bone metabolic homeostasis in patients, as well as causing damage to bone marrow cells and other bone tissues. Consequently, certain tumor treatment options may pose a risk for subsequent bone diseases. Common bone disorders associated with cancer treatment include osteonecrosis, bone loss, and secondary bone tumors. (1)Cancer treatment-related osteonecrosis is primarily linked to the use of radiation therapy and certain chemicals, such as bisphosphonates, denosumab, antiangiogenic agents, and immunomodulators. It has been observed that high-dose radiation therapy is more likely to result in osteonecrosis. (2)Chemicals and hormones, particularly sex hormones, glucocorticoids, and thyroid hormones or thyrotropic hormones, are among the factors that can contribute to cancer treatment-related bone loss. (3)Secondary bone tumors differ from metastases originating from primary tumors, and radiotherapy plays a significant role in their development, while chemotherapy may also exert some influence. Radiogenic secondary bone tumors are predominantly malignant, with osteosarcoma being the most common type. Chemotherapy may be a risk factor for the relatively rare occurrence of secondary Ewing sarcoma of the bone. These treatment-related bone disorders have a considerable adverse impact on the prognosis of cancer patients. Hence, it is imperative to prioritize the bone health of patients undergoing cancer treatment and give it further attention.

The Role of Surgery in the Management of Radiation-Induced Brachial Plexopathy

Radiation-induced brachial plexopathy (RIBP) is a rare long-term complication of radiation therapy often causing pain, motor deficit, and overall quality of life reduction for affected patients. While a standard treatment for RIBP is yet to be established, management consists mostly of symptom management through the use of medications and physical therapy. There is a lack of evidence regarding the efficacy of surgical treatment. Omentoplasties and other vascularized flaps are commonly discussed options for eliminating neuropathic pain associated with RIBP. However, these approaches show no meaningful improvement in motor function. While limited, current literature suggests that nerve transfers may be an option for relief of neuropathic pain as well as restoration of motor function. This review of literature explores the options available to those affected by RIBP with a focus on the role of surgery.

Tissue expansion mitigates radiation-induced skin fibrosis in a porcine model

Tissue expansion (TE) is the primary method for breast reconstruction after mastectomy. In many cases, mastectomy patients undergo radiation treatment (XR). Radiation is known to induce skin fibrosis and is one of the main causes for complications during post-mastectomy breast reconstruction. TE, on the other hand, induces a pro-regenerative response that culminates in growth of new skin. However, the combined effect of XR and TE on skin mechanics is unknown. Here we used the porcine model of TE to study the effect of radiation on skin fibrosis through biaxial testing, histological analysis, and kinematic analysis of skin deformation over time. We found that XR leads to stiffening of skin compared to control based on a shift in the transition stretch (transition between a low stiffness and an exponential stress-strain region characteristic of collagenous tissue) and an increase in the high modulus (modulus computed with stress-stretch data past the transition point). The change in transition stretch can be explained by thicker, more aligned collagen fiber bundles measured in histology images. Skin subjected to both XR+TE showed similar microstructure to controls as well as similar biaxial response, suggesting that physiological remodeling of collagen induced by TE partially counteracts pro-fibrotic XR effects. Skin growth was indirectly assessed with a kinematic approach that quantified increase in permanent area changes without reduction in thickness, suggesting production of new tissue driven by TE even in the presence of radiation treatment. Future work will focus on the detailed biological mechanisms by which TE counteracts radiation induced fibrosis. STATEMENT OF SIGNIFICANCE: Breast cancer is the most prevalent in women and its treatment often results in total breast removal (mastectomy), followed by reconstruction using tissue expanders. Radiation, which is used in about a third of breast reconstruction cases, can lead to significant complications. The timing of radiation treatment remains controversial. Radiation is known to cause immediate skin damage and long-term fibrosis. Tissue expansion leads to a pro-regenerative response involving collagen remodeling. Here we show that tissue expansion immediately prior to radiation can reduce the level of radiation-induced fibrosis. Thus, we anticipate that this new evidence will open up new avenues of investigation into how the collagen remodeling and pro-regenerative effects of tissue expansion can be leverage to prevent radiation-induced fibrosis.

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

AIMS

To evaluate osteoradionecrosis (ORN) incidence in a cohort of patients undergoing tooth extraction (TE) before radiotherapy (RT) for head and neck cancers.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

External validation of a multimodality deep-learning normal tissue complication probability model for mandibular osteoradionecrosis trained on 3D radiation distribution maps and clinical variables

Background and purpose

While the inclusion of spatial dose information in deep learning (DL)-based normal-tissue complication probability (NTCP) models has been the focus of recent research studies, external validation is still lacking. This study aimed to externally validate a DL-based NTCP model for mandibular osteoradionecrosis (ORN) trained on 3D radiation dose distribution maps and clinical variables.

Methods and materials

A 3D DenseNet-40 convolutional neural network (3D-mDN40) was trained on clinical and radiation dose distribution maps on a retrospective class-balanced matched cohort of 184 subjects. A second model (3D-DN40) was trained on dose maps only and both DL models were compared to a logistic regression (LR) model trained on DVH metrics and clinical variables. All models were externally validated by means of their discriminative ability and calibration on an independent dataset of 82 subjects.

Results

No significant difference in performance was observed between models. In internal validation, these exhibited similar Brier scores around 0.2, Log Loss values of 0.6-0.7 and ROC AUC values around 0.7 (internal) and 0.6 (external). Differences in clinical variable distributions and their effect sizes were observed between internal and external cohorts, such as smoking status (0.6 vs. 0.1) and chemotherapy (0.1 vs. -0.5), respectively.

Conclusion

To our knowledge, this is the first study to externally validate a multimodality DL-based ORN NTCP model. Utilising mandible dose distribution maps, these models show promise for enhancing spatial risk assessment and guiding dental and oncological decision-making, though further research is essential to address overfitting and domain shift for reliable clinical use.

Efficacy of adjunctive modalities during tooth extraction for the prevention of osteoradionecrosis: A systematic review and meta-analysis

BACKGROUND

Jaw osteoradionecrosis (ORN) is a complication in patients with previous head and neck radiotherapy. Its incidence increases with dental extractions. Hence, this review aimed to evaluate the efficacy of adjunctive treatment modalities undertaken at the time of extraction in previous head and neck radiotherapy patients in preventing ORN.

METHODS

A systematic review was conducted, where studies with data on ORN incidence after extraction with or without adjunctive interventions were included. Meta-analyses were conducted to estimate the pooled prevalence of ORN per intervention and the pooled odds ratio for incidence of ORN between interventions.

RESULTS

In total, 1520 patients in 29 studies were included. Interventions identified were hyperbaric oxygen (HBO), pentoxifylline-tocopherol (PENTO), antibiotics (ABX), platelet-rich fibrin and photobiomodulation. The pooled prevalence of ORN for HBO (4.6%), PENTO (3.4%) and ABX (3.8%) was significantly lower than the Control (17.6%). For studies with direct comparisons between groups, HBO had lower but not significant odds of developing ORN than the Control (OR 0.27) and ABX (OR 0.57).

CONCLUSIONS

HBO, PENTO and ABX may reduce the incidence of ORN compared to no intervention. Given that all three have similar incidences of ORN, ABX may be the most cost-effective and accessible adjunctive modality.

Effect of Statins on Patients With Osteoradionecrosis of the Jaw

BACKGROUND

Osteoradionecrosis of the jaw (ORN) is a late complication of radiation therapy. Radiation-induced fibrosis is the most likely mechanism for developing ORN, and statins are effective against radiation-induced fibrosis. However, no reports have indicated the direct effectiveness of statins in treating ORN.

PURPOSE

This study aimed to measure the association between statin exposure and ORN disease resolution.

STUDY DESIGN, SETTING, SAMPLE

This retrospective cohort study included patients with ORN diagnosed between January 2008 and December 2020 at the Hospital's Department of Oral and Maxillofacial Surgery. Patients who were immunocompromised or followed up for < 6 months were excluded.

PREDICTOR VARIABLE

The predictor variable was statin exposure, which was defined as the use of statins for dyslipidemia.

MAIN OUTCOME VARIABLE

The main outcome variable was ORN disease progression status (good prognosis). Patients who showed full recovery and improvement were included in the good prognosis group, and those who showed invariance and deterioration were included in the poor prognosis group.

COVARIATES

We analyzed the clinicodemographic including the age of onset, sex, history of smoking, alcohol consumption, history of chemotherapy, tumor site, association with dental treatment, location (maxilla or mandible), the time to ORN onset from radiation therapy, and stage of ORN, and treatment characteristics including hyperbaric oxygen therapy, long-term macrolide administration, and sequestrectomy.

ANALYSES

We analyzed the association between statin exposure or covariates and time to ORN improvement using bivariate and multivariate Cox regression. The significance level was set at P = .05.

RESULTS

We analyzed 102 patients, and the improvement rate was 32.4%. The favorable prognostic factors were statin exposure (adjusted hazard ratio [HR], 3.71; 95% confidence interval [CI], 1.62 to 8.50; P = .002), onset in the maxilla (HR, 2.15; 95% CI, 1.02 to 4.55; P = .045), and stage 1 of ORN (HR, 2.65; 95% CI, 1.20 to 5.83; P = .016).

CONCLUSION AND RELEVANCE

In this study, statin exposure, onset in the maxilla, and stage 1 of Lyons's classification were favorable prognostic factors for ORN. Although this study's findings were insufficient to recommend statin use for ORN, statins may be a novel and effective treatment for ORN.

Extracorporeal Membrane Oxygenation (ECMO)-Assisted Tracheostomy in a Patient with a "Woody Neck" Due to Radiation Therapy and Complicated by Bilateral Internal Jugular Vein Occlusion: A Case Report

Radiation for head and neck cancer (HNC) can lead to neck fibrosis, commonly known as "woody neck", limiting neck mobility. We report the case of a 46-year-old male with a history of tonsillar squamous cell carcinoma, with a "woody neck" following multiple radiation treatments. Facial swelling and impending airway loss prompted emergent intubation. Despite nasotracheal tube placement, bilateral internal jugular vein occlusion led to a difficult tracheostomy. An airway exchange catheter (AEC) facilitated multiple attempts at tracheal cannulation, but due to challenging anatomy, prolonged nasotracheal intubation was maintained. Tracheostomy was attempted again with extracorporeal membrane oxygenation (ECMO) support, which resulted in successful tracheal cannulation.

Radiation-induced fibrosis: Mechanisms and therapeutic strategies from an immune microenvironment perspective

Radiation-induced fibrosis (RIF) is a severe chronic complication of radiotherapy (RT) manifested by excessive extracellular matrix (ECM) components deposition within the irradiated area. The lung, heart, skin, jaw, pelvic organs and so on may be affected by RIF, which hampers body functions and quality of life. There is accumulating evidence suggesting that the immune microenvironment may play a key regulatory role in RIF. This article discussed the synergetic or antagonistic effects of immune cells and mediators in regulating RIF's development. Several potential preventative and therapeutic strategies for RIF were proposed based on the immunological mechanisms to provide clinicians with improved cognition and clinical treatment guidance.

Microvascular reconstruction of medication related osteonecrosis of the head and neck

BACKGROUND

Medication related osteonecrosis of the jaw (MRONJ) requiring free flap (FF) reconstruction is uncommon with limited reported findings.

METHODS

Multicenter, retrospective case series of 49 consecutive adult patients presenting with advanced MRONJ requiring FF reconstruction from 2010 to 2022. Perioperative complications and outcomes were analyzed.

RESULTS

Eighty-two percent (n = 40) of cases were of the mandible and 18% (n = 9) were of the maxilla. The mean follow-up was 15 months (±19.6). The majority of FF survived (96%, n = 47). FF reconstructions of the maxilla were more likely to require postoperative debridement (56%, 95% CI [27, 81%] vs. 15%, 95% CI [7, 25%], p = 0.008) or develop intraoral bone exposure (56%, 95% CI [27, 81%] vs. 18%, 95% CI [9, 27%], p = 0.02). Most patients (71%, n = 35) received preoperative antibiotics which was associated with a higher rate of FF survival (100% vs. 86%, 95% CI [60, 96%], p = 0.02) and fewer complications.

CONCLUSIONS

Patients undergoing FF reconstruction for MRONJ do well with high rates of FF success. MRONJ of the maxilla have a higher rate of some complications. Preoperative antibiotics correlated with higher FF survival and fewer postoperative complications.

Role of Photodynamic Therapy in Osteonecrosis and Osteoradionecrosis of the Jaws: A Systematic Review

Aim

Photodynamic therapy (PDT) is a minimally invasive treatment modality that has been used clinically for early stage and inoperable cancers. Successful use of this atraumatic therapy in osteoradionecrosis (ORN) and osteonecrosis of the jaws (ONJ) has been documented in the literature. The aim of this review was to systematically evaluate the role of photodynamic therapy in ORN and ONJ.

Methods

Two independent reviewers conducted an elaborate search in PubMed, Google Scholar and Cochrane's CENTRAL database for studies published on PDT as stand-alone or adjuvant therapy in ORN/ONJ until June 2022. The present study was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Demographic data, type and stage of necrosis of the jaws, site, PDT protocol, time to heal and follow-up were evaluated. Eighteen articles were included totally based on the inclusion and exclusion criteria for final analysis.

Results

A total of 94 patients were included in the present review out of which 36 were males and 58 were females. Five studies reported the use of PDT as an adjuvant therapy in ORN. Thirteen studies reported successful outcomes with PDT in ONJ. Complete epithelialization was achieved with PDT ± other adjuvants in 86/94 (91.48%) patients. The time taken for regression of the lesion ranged between 4 days and 12 months with PDT in the present study.

Conclusion

The reviewed studies demonstrate the effectiveness of PDT, as an adjuvant therapy, in managing various stages of ORN and ONJ.

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

BACKGROUND AND PURPOSES

To 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 METHODS

Review 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.

RESULTS

ORN 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).

CONCLUSION

This 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.

The incidence of osteoradionecrosis of the jaws in oral cavity cancer patients treated with intensity-modulated radiotherapy: a systematic review and meta-analysis

OBJECTIVE

A systematic review with meta-analysis was conducted to define the incidence of osteoradionecrosis (ORN) in patients with oral cavity cancer (OCC) treated with intensity-modulated radiotherapy (IMRT), and to identify the risk factors influencing its development.

STUDY DESIGN

Six databases were searched systematically. A meta-analysis was performed to determine overall, spontaneous, and dental extraction-attributed incidences of ORN. The Grading of Recommendations Assessment, Development, and Evaluation tool evaluated evidence certainty.

RESULTS

Out of 11 eligible studies, 6 underwent meta-analysis for the overall aggregated ORN incidence in OCC patients receiving IMRT, resulting in an incidence rate of 8% (95% CI: 6%-11%). Regarding development reasons, 2 studies were assessed, revealing an incidence of 36% (95% CI: 1%-98%) for spontaneous ORN, and 17% (95% CI: 5%-44%) ensued from dental extraction exclusively pre-RT. All rates had very low certainty of evidence. Factors significantly correlated with ORN development included postoperative RT use (78%), employment of therapeutic doses above 50 Gy, and mandibular involvement (80.5%).

CONCLUSION

The findings suggest that IMRT alone is not sufficient to decrease ORN rates in OCC patients, underscoring the importance of precisely identifying the involved risk factors. However, further detailed primary studies will be necessary.

Medial Femoral Condyle Periosteal Free Flap for Bone Coverage Following Debridement of Intermediate-Stage Osteoradionecrosis of the Jaw

STUDY DESIGN

Case report. Osteoradionecrosis (ORN) of the jaw is a potentially devastating consequence of head and neck irradiation. The progression of ORN can lead to loss of bone, teeth, soft tissue necrosis, pathologic fracture, and oro-cutaneous fistula. Reconstructive surgery has mostly been reserved for late-stage disease where segmental resections are frequently necessary. Evidence is emerging to support earlier treatment in the form of debridement in combination with soft tissue free flaps for intermediate-stage ORN. The authors present a case of a 76-year-old male with persistent Notani 2 ORN of the mandible, treated with surgical removal of all remaining mandibular teeth, transoral debridement of all necrotic mandibular bone, and bone coverage with a left medial femoral condyle (MFC) periosteal free flap based on the descending genicular artery. Treatment was uneventful both intraoperatively and postoperatively. Since surgery (15 mo) the patient has remained free from clinical and radiologic signs of ORN. The MFP periosteal free flap provided an excellent result with minimal surgical complexity and morbidity in this case. Such treatment at an intermediate stage likely results in a reduction in segmental resections, less donor site morbidity, less operative time, less overall treatment time, and possibly fewer postoperative complications compared with the status quo.

Osteoradionecrosis treatment in head and neck cancer patients: An overview of systematic reviews

AIMS

Evaluate the existing evidence of osteoradionecrosis (ORN) treatment in adults with head and neck cancer, the methodological quality and the evidence grade within systematic reviews (SRs).

METHODS

An extensive systematic literature search of SRs that addressed ORN in head and neck cancer patients was conducted with screening of eligible studies, data extraction, methodological (AMSTAR 2) and evidence quality assessment (GRADE) of the SRs by independent and calibrated authors.

RESULTS

A total of six SRs were enrolled. Based primarily on studies from the 1990s, there is critically low- or moderate-quality evidence that hyperbaric oxygen therapy (HBO) improves ORN healing. From 2005 onward, evidence has been discovered in relation to treatment with pentoxifylline and tocopherol (PENTO). The SRs indicate that the management of ORN with PENTO appears to be promising. The greatest rates of healing are seen in mild and moderate stages of ORN. However, the quality of evidence regarding PENTO, surgery and other treatments remains critically low.

CONCLUSION

There is no standardized protocol to treat ORN. PENTO appears to be the most promising conservative treatment; however, the current level of evidence regarding PENTO is still critically low. More robust clinical studies are needed to establish the best treatment for ORN.

Mechanisms and protective measures for radiation-induced brachial plexus nerve injury

Radiation therapy is a common treatment modality for patients with malignant tumors of the head and neck, chest and axilla. However, radiotherapy inevitably causes damage to normal tissues at the irradiated site, among which damage to the brachial plexus nerve(BP) is a serious adverse effect in patients receiving radiation therapy in the scapular or axillary regions, with clinical manifestations including abnormal sensation, neuropathic pain, and dyskinesia, etc. These adverse effects seriously reduce the living quality of patients and pose obstacles to their prognosis. Therefore, it is important to elucidate the mechanism of radiation induced brachial plexus injury (RIBP) which remains unclear. Current studies have shown that the pathways of radiation-induced BP injury can be divided into two categories: direct injury and indirect injury, and the indirect injury is closely related to the inflammatory response, microvascular damage, cytokine production and other factors causing radiation-induced fibrosis. In this review, we summarize the underlying mechanisms of RIBP occurrence and possible effective methods to prevent and treat RIBP.

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.

The clinical manifestations and molecular pathogenesis of radiation fibrosis

Advances in radiation techniques have enabled the precise delivery of higher doses of radiotherapy to tumours, while sparing surrounding healthy tissues. Consequently, the incidence of radiation toxicities has declined, and will likely continue to improve as radiotherapy further evolves. Nonetheless, ionizing radiation elicits tissue-specific toxicities that gradually develop into radiation-induced fibrosis, a common long-term side-effect of radiotherapy. Radiation fibrosis is characterized by an aberrant wound repair process, which promotes the deposition of extensive scar tissue, clinically manifesting as a loss of elasticity, tissue thickening, and organ-specific functional consequences. In addition to improving the existing technologies and guidelines directing the administration of radiotherapy, understanding the pathogenesis underlying radiation fibrosis is essential for the success of cancer treatments. This review integrates the principles for radiotherapy dosimetry to minimize off-target effects, the tissue-specific clinical manifestations, the key cellular and molecular drivers of radiation fibrosis, and emerging therapeutic opportunities for both prevention and treatment.

The role of surgery in the management of radiation-induced brachial plexopathy: a systematic review

This systematic literature review of the clinical characteristics of radiation-induced brachial plexopathy and outcomes after intervention includes 30 trials with 611 patients. The mean radiation dose to the brachial plexus was 56 Gy, and the mean duration of radiation was 4 weeks. The mean time from radiation to the onset of symptoms was 35 months. The most commonly reported symptom was sensory loss (n = 323, 62%), followed by motor deficits (n = 294, 56%) and neuropathic pain (n = 284, 54%). In total, 65 (56%) patients had panplexus involvement and 51 (44%) patients had partial plexus involvement. The most common surgical procedure was neurolysis with flap coverage (n = 108, 6%), followed by neurolysis alone (n = 71, 30%). Of the 237 patients who underwent surgery, 125 (53%) reported an improvement in pain. Motor and sensory deficits were improved in 46 (19%) and 39 (16%) patients, respectively, suggesting that surgery is beneficial in relieving pain, but not as beneficial in restoring motor and sensory function.

M2 macrophage-derived exosomes carry miR-142-3p to restore the differentiation balance of irradiated BMMSCs by targeting TGF-β1

Radiotherapy is essential to cancer treatment, while it inevitably injures surrounding normal tissues, and bone tissue is one of the most common sites prone to irradiation. Bone marrow mesenchymal stem cells (BMMSCs) are sensitive to irradiation and the irradiated dysfunction of BMMSCs may be closely related to irradiation-induced bone damage. Macropahges play important role in regulating stem cell function, bone metabolic balance and irradiation response, but the effects of macrophages on irradiated BMMSCs are still unclear. This study aimed to investigate the role of macrophages and macrophage-derived exosomes in restoring irradiated BMMSCs function. The effects of macrophage conditioned medium (CM) and macrophage-derived exosomes on osteogenic and fibrogenic differentiation capacities of irradiated BMMSCs were detected. The key microribonucleic acids (miRNAs) and targeted proteins in exosomes were also determined. The results showed that irradiation significantly inhibited the proliferation of BMMSCs, and caused differentiation imbalance of BMMSCs, with decreased osteogenic differentiation and increased fibrogenic differentiation. M2 macrophage-derived exosomes (M2D-exos) inhibited the fibrogenic differentiation and promoted the osteogenic differentiation of irradiated BMMSCs. We identified that miR-142-3p was significantly overexpressed in M2D-exos and irradiated BMMSCs treated with M2D-exos. After inhibition of miR-142-3p in M2 macrophage, the effects of M2D-exos on irradiated BMMSCs differentiation were eliminated. Furthermore, transforming growth factor beta 1 (TGF-β1), as a direct target of miR-142-3p, was significantly decreased in irradiated BMMSCs treated with M2D-exos. This study indicated that M2D-exos could carry miR-142-3p to restore the differentiation balance of irradiated BMMSCs by targeting TGF-β1. These findings pave a new way for promising and cell-free method to treat irradiation-induced bone damage.

Sacral-Nerve-Sparing Planning Strategy in Pelvic Sarcomas/Chordomas Treated with Carbon-Ion Radiotherapy

To minimize radiation-induced lumbosacral neuropathy (RILSN), we employed sacral-nerve-sparing optimized carbon-ion therapy strategy (SNSo-CIRT) in treating 35 patients with pelvic sarcomas/chordomas. Plans were optimized using Local Effect Model-I (LEM-I), prescribed DRBE|LEM-I|D50% (median dose to HD-PTV) = 73.6 (70.4-76.8) Gy (RBE)/16 fractions. Sacral nerves were contoured between L5-S3 levels. DRBE|LEM-I to 5% of sacral nerves-to-spare (outside HD-CTV) (DRBE|LEM-I|D5%) were restricted to <69 Gy (RBE). The median follow-up was 25 months (range of 2-53). Three patients (9%) developed late RILSN (≥G3) after an average period of 8 months post-CIRT. The RILSN-free survival at 2 years was 91% (CI, 81-100). With SNSo-CIRT, DRBE|LEM-I|D5% for sacral nerves-to-spare = 66.9 ± 1.9 Gy (RBE), maintaining DRBE|LEM-I to 98% of HD-CTV (DRBE|LEM-I|D98%) = 70 ± 3.6 Gy (RBE). Two-year OS and LC were 100% and 93% (CI, 84-100), respectively. LETd and DRBE with modified-microdosimetric kinetic model (mMKM) were recomputed retrospectively. DRBE|LEM-I and DRBE|mMKM were similar, but DRBE-filtered-LETd was higher in sacral nerves-to-spare in patients with RILSN than those without. At DRBE|LEM-I cutoff = 64 Gy (RBE), 2-year RILSN-free survival was 100% in patients with <12% of sacral nerves-to-spare voxels receiving LETd > 55 keV/µm than 75% (CI, 54-100) in those with ≥12% of voxels (p < 0.05). DRBE-filtered-LETd holds promise for the SNSo-CIRT strategy but requires longer follow-up for validation.

Prophylactic Use of Pentoxifylline and Tocopherol for Prevention of Osteoradionecrosis of the Jaw after Dental Extraction in Post-Radiated Oral and Oropharyngeal Cancer Patients: An Initial Case Series

Osteoradionecrosis of the jaw is a morbid complication of radiotherapy in patients with oral and oropharyngeal cancers that may be precipitated by dental extractions. Pentoxifylline and tocopherol (PENTO) has been utilized in the management of osteoradionecrosis and as prophylaxis for post-radiated head and neck oncology patients requiring an invasive dental procedure. This observational study aims to report the outcome of the prophylactic use of PENTO in the prevention of osteoradionecrosis of the jaw after dental extractions in post-radiated oral and oropharyngeal cancer patients and to review the current literature on this topic. Four post-radiated oral and oropharyngeal oncology patients were referred to the dental oncology clinic of the University Dental Practice, University of Tennessee Health Sciences Center for dental extractions. All four patients were prescribed pentoxifylline 400 mg BID (twice a day) and tocopherol 400 IU BID (oral tablets) for 2 weeks before extraction(s) and for 6 weeks after extraction(s). All patients were followed up every week after the second week post-extraction if feasible until the extraction site(s) healed (covered by mucosa). The assessment endpoint was defined as 6 weeks post-extraction with the outcomes assessed as using four categories determined by the area of exposed bone: complete healing (complete mucosal coverage of extraction site); partial healing (reduction in size of extraction site); no change; and progression (increase in size of the extraction site). At the assessment endpoint, all patients had complete healing of all extraction sites. The ORN rate at the patient level (0/4) and individual tooth level (0/8) was 0%. All patients tolerated the PENTO medications and no adverse effects from the use of these medications were reported. This limited study in addition to the other reviewed studies estimates the rate of ORN at the patient level as 3.2% (14/436) for post-radiated head and neck oncology patients after dental extractions/invasive oral procedures. In conclusion, this PENTO regimen can reduce/prevent the incidence of ORN in post-radiated head and neck oncology patients. This safe and cost-effective protocol (PENTO regimen) should be further evaluated as prophylaxis for post-radiated head and neck oncology patients requiring an invasive dental procedure. We recommend large prospective studies to be carried out to further validate these findings.

Medication-related osteonecrosis of the jaw: evolving research for multimodality medical management

PURPOSE

Medication-related osteonecrosis of the jaw (MRONJ) is a debilitating side effect of antiresorptive and antiangiogenic agents that can lead to progressive bone destruction in the maxillofacial region. Dental surgery, including tooth extractions, commonly trigger the onset of MRONJ. While guidelines suggest avoiding extraction when possible, complete avoidance is not always feasible, as necrosis can develop from dental and periodontal disease without dental procedures. The goal of this article is to provide an update review of current preventive and therapeutic approaches for MRONJ.

METHODS

A comprehensive electronic search was conducted on PubMed/MEDLINE, Embase, and Scopus databases. All English articles encompassing randomized controlled trials, systematic reviews, observational studies, and case studies were reviewed. The current medical treatments and adjuvant therapies for managing MRONJ patients were critically assessed and summarized.

RESULTS

Pentoxifylline and alpha tocopherol (PENT-E), teriparatide, photobiomodulation (PBM), photodynamic therapy (PDT), and the use of growth factors have shown to enhance healing in MRONJ patients. Implementing these methods alone or in conjunction with surgical treatment has been linked to reduced discomfort and improved wound healing and increased new bone formation.

DISCUSSION

While several adjuvant treatment modalities exhibit promising results in facilitating the healing process, current clinical practice guidelines predominantly recommend antibiotic therapy as a non-surgical approach, primarily addressing secondary infections in necrotic areas. However, this mainly addresses the potential infectious complication of MRONJ. Medical approaches including PENT-E, teriparatide, PBM, and PDT can result in successful management and should be considered prior to taking a surgical approach. Combined medical management for both preventing and managing MRONJ holds potential for achieving optimal clinical outcomes and avoiding surgical intervention, requiring further validation through larger studies and controlled trials.

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.

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.

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.

A Case of Radiation-Induced Brachial Plexopathy Below the Tolerance Dose

This case report details a rare instance of radiation-induced brachial plexopathy (RIBP) occurring below the typical tolerance dose in a 55-year-old woman following chemoradiotherapy for apical non-small cell lung carcinoma. Despite receiving a radiation dose considered safe (47-48 Gray in 25 fractions), she developed sensory abnormalities and motor weakness in the right upper limb. The diagnostic distinction between RIBP and tumor recurrence was achieved using MRI, which showed characteristic features of radiation-induced damage. The patient's medical history included smoking and rheumatoid arthritis, highlighting the role of patient-specific factors in the development of RIBP. The case underscores the importance of recognizing RIBP as a potential diagnosis in patients with new-onset brachial plexopathy post-radiation therapy, even when radiation exposure is within conventional safety limits. This report contributes to the literature by demonstrating that RIBP can occur at lower-than-expected radiation doses, especially in the presence of contributing factors like neurotoxic chemotherapy and individual patient risks. It emphasizes the need for careful assessment and management in such cases to distinguish between RIBP and cancer recurrence.