Osteoradionecrosis: a new concept of its pathophysiology

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.

Molecular mechanisms of poor osseointegration in irradiated bone: In vivo study in a rat tibia model

AIM

Radiotherapy is associated with cell depletion and loss of blood supply, which are linked to compromised bone healing. However, the molecular events underlying these effects at the tissue-implant interface have not been fully elucidated. This study aimed to determine the major molecular mediators associated with compromised osseointegration due to previous exposure to radiation.

MATERIALS AND METHODS

Titanium implants were placed in rat tibiae with or without pre-exposure to 20 Gy irradiation. Histomorphometric, biomechanical, quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay analyses were performed at 1 and 4 weeks after implantation.

RESULTS

The detrimental effects of irradiation were characterized by reduced bone-implant contact and removal torque. Furthermore, pre-exposure to radiation induced different molecular dysfunctions such as (i) increased expression of pro-inflammatory (Tnf) and osteoclastic (Ctsk) genes and decreased expression of the bone formation (Alpl) gene in implant-adherent cells; (ii) increased expression of bone formation (Alpl and Bglap) genes in peri-implant bone; and (iii) increased expression of pro-inflammatory (Tnf) and pro-fibrotic (Tgfb1) genes in peri-implant soft tissue. The serum levels of pro-inflammatory, bone formation and bone resorption proteins were greater in the irradiated rats.

CONCLUSIONS

Irradiation causes the dysregulation of multiple biological activities, among which perturbed inflammation seems to play a common role in hindering osseointegration.

Prevalence of free flap failure in mandibular osteoradionecrosis reconstruction: a systematic review and meta-analysis

Our study aimed to estimate the prevalence of total free flap failure following free flap reconstruction for mandibular osteoradionecrosis (mORN) and assess the impact of potential moderators on this outcome. A comprehensive systematic literature search was independently conducted by two reviewers using the Medline, Scopus, Web of Science and Cochrane Library databases. Quality assessment of the selected studies was performed, and prevalence estimates with 95% confidence intervals (CI) were calculated. Outlier and influential analyses were conducted, and meta-regression analyses was employed to investigate the effects of continuous variables on the estimated prevalence. Ultimately, forty-six eligible studies (involving 1292 participants and 1344 free flaps) were included in our meta-analysis. The findings of our study revealed a prevalence of 3.1% (95% CI 1.3-5.4%) for total free flap failure after reconstruction for mORN. No study was identified as critically influential, and meta-regression analysis did not pinpoint any potential sources of heterogeneity. These findings provide valuable insights for researchers and serve as a foundation for future investigations into the management of mandibular osteoradionecrosis and the prevention of free flap failure in this context.

Osteoradionecrosis Rates After Head and Neck Radiation Therapy: Beyond the Numbers

PURPOSE

Osteoradionecrosis (ORN) is a severe late complication of head and neck radiation therapy shown to have profound negative effect on the quality of life of cancer survivors. Over the past few decades, improvements in radiation delivery techniques have resulted in a decrease in the incidence of ORN. However, even with modern radiation therapy techniques, ORN remains an important clinical concern. In recent literature, there is a wide range of reported ORN rates from 0% to as high as 20%. With such a high level of variability in the reported incidence of ORN, oncologists often encounter difficulties estimating the risk of this serious radiation therapy toxicity.

METHODS AND MATERIALS

In this review, the authors present a summary of the factors that contribute to the high level of variability in the reported incidence of ORN.

RESULTS

Variable definition, variable grading, and heterogeneity of both study inclusion criteria and treatment parameters can each significantly influence the reporting of ORN rates.

CONCLUSIONS

Given numerous factors can affect the reported incidence of ORN, a thorough understanding of the clinical context behind the reported ORN rates is needed to comprehend the true risk of this important radiation therapy toxicity.

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.

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.

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.

Favorable effects of open surgery on patients with extensive skull base osteoradionecrosis through a personalized sequential approach: A case series

The present study aimed to investigate outcomes following open surgery for extensive skull base ORN. Open surgery through a personalized sequential approach was employed to deal with five cases of extensive skull base ORN. Two patients with mild cases underwent regional debridement and sequestrectomy, and three patients with severe cases underwent extensive resection with reconstruction using free anterolateral thigh (ALT) flap. Biological glues and vascularized flaps were used for obturation of the skull base bony defect to prevent postoperative cerebrospinal fluid (CSF) leakage. The infections were controlled by antibiotic administrations which strictly followed the principles of antimicrobial stewardship (AMS). As results, both regional debridement plus sequestrectomy and extensive resection achieved satisfied outcomes in all patients. No severe complications and delayed hospitalization occurred. During the follow-up period (8-19 months), all patients were alive, pain free, without crusting or purulent discharge, and no sequestration or CSF leakage occurred. In conclusion, a personalized sequential approach including open surgery, pedicled/vascularized free flap reconstruction and AMS was advocated for patients with extensive skull base 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.

Radiation-Induced Myonecrosis: A Case Report of a Cervical Cancer Patient With a History of Systemic Lupus Erythematosus

Radiation-induced myonecrosis is a rare but serious complication of radiation therapy. We present a case of a 49-year-old woman with systemic lupus erythematosus who developed radiation-induced myonecrosis after concurrent chemoradiation for cervical cancer. She underwent external-beam radiation therapy, weekly cisplatin chemotherapy (40 mg/m2), and intracavitary brachytherapy. One month later, she received one cycle of nedaplatin (80 mg/m2) and irinotecan (60 mg/m2). Two months after treatment, she experienced pain in the left inguinal region. An MRI revealed a mass in the left obturator externus muscle and right pectineus muscle suggestive of myonecrosis. A biopsy confirmed the diagnosis. She received hyperbaric oxygen therapy, and her symptoms improved. The masses resolved completely.

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.

Mandibular Osteoradionecrosis: Defining the Microbial Milieu and Antimicrobial Resistance at the Time of Rescue Flap Surgery

OBJECTIVE

To report the microorganisms and their antibiotic sensitivity profile from tissue cultures and stains at the time of anterolateral thigh fascia lata (ALTFL) rescue flap for management of mandibular osteoradionecrosis (ORN).

METHODS

Retrospective chart review of patients who underwent ALTFL rescue flap for native mandibular ORN between 2011 and 2022.

RESULTS

Twenty-six cases comprising 24 patients (mean age 65.4 years, 65.4% male) with mandibular ORN from whom tissue cultures and gram stain were obtained at the time of ALTFL rescue flap. 57.7% grew bacterial species, while 34.6% grew fungal species. Multibacterial speciation was noted in 26.9% of cultures. A combination of bacterial and fungal growth was also seen in 15.4% of cases. All gram-positive cocci (GPC) were pansensitive to antibiotics except for one case of Staphylococcus aureus, which was resistant to levofloxacin. Gram-negative bacilli (GNB) species were isolated in 50.0% of cases. All fungal growth was due to Candida species. No growth was noted in 23.1% of cases. Multidrug resistance was noted in 53.8% of cases when GNB was isolated.

CONCLUSION

We report 76.9% of our cases of mandibular ORN had microbial growth from tissue cultures obtained at the time of the ALTFL rescue flap. Fungal growth was noted in a substantial number of cases and should be obtained as a specimen when pursuing culture-driven antibiotic therapy. Most GPCs were pansensitive to antibiotics, while GNBs were often the harbinger of multidrug resistant mandibular ORN.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:166-169, 2024.

Titanium Alloy Implants with Lattice Structures for Mandibular Reconstruction

In recent years, the field of mandibular reconstruction has made great strides in terms of hardware innovations and their clinical applications. There has been considerable interest in using computer-aided design, finite element modelling, and additive manufacturing techniques to build patient-specific surgical implants. Moreover, lattice implants can mimic mandibular bone's mechanical and structural properties. This article reviews current approaches for mandibular reconstruction, their applications, and their drawbacks. Then, we discuss the potential of mandibular devices with lattice structures, their development and applications, and the challenges for their use in clinical settings.

Rhino-oropharingeal osteoradionecrotic soft-tissue and bony defect reconstruction with submental artery island flap: a case report

BACKGROUND

The submental artery island flap is widely used in head and neck reconstruction, since it is easy and quick to harvest, and it can be successfully used for the coverage of perioral, intraoral and facial defects. We used this technique for the reconstruction of a complex soft-tissue and bony defect of rhino-oropharinx.

CASE REPORT

Osteoradionecrosis of rhino-oropharingeal posterior wall with C2 necrotic body exposure occurred in a 77-year-old woman. After the failure of reconstruction with a Hadad-Bassagasteguy flap, a submental island flap with cervical spine stabilization was planned to be performed in a one-stage operation. The anterior arc of C1 and odontoid process of C2 were removed and, according to the defect size, a submental island flap was designed in an elliptical fashion. The flap was rotated 180° and tunnelized under the left parapharingeal-prevertebral space, then it was positioned in the rhino-oropharinx and fixed with reabsorbable sutures. The donor site was closed primarily. No peri- or post-operative complications occurred, neither in the recipient nor in the donor-site. At the latest follow-up, 15 months postoperatively, the patient was able to speak without any impairment and started swallowing rehabilitation with good results and an aesthetically satisfactory outcome.

CONCLUSION

The submental island flap may be a reliable and versatile flap for reconstruction of head and neck defects, even though in the rhino-oropharingeal posterior wall.

Utility of pre-chemoradiotherapy Pan-Immune-Inflammation-Value for predicting the osteoradionecrosis rates in locally advanced nasopharyngeal cancers

PURPOSE

The aim of this retrospective study was to explore whether pretreatment Pan-Immune-Inflammation-Value (PIV) measurements might predict the risk of mandibular osteoradionecrosis (ORN) in patients receiving concurrent chemoradiotherapy (CCRT) for locally advanced nasopharyngeal cancer (LA-NPC).

METHODS

The platelet, monocyte, neutrophil, and lymphocyte counts acquired on the first day of CCRT were used to compute pretreatment PIV levels: PIV = (Platelets × Monocytes × Neutrophils) ÷ Lymphocytes. Receiver operating characteristic curve analysis was used to determine the association between ORN rates and PIV levels. Spearman correlation analysis was used to examine the probable intergroup correlations. The potential link between the pretreatment PIV levels and the post-treatment ORN rates was determined as the primary objective.

RESULTS

21 (10.0%) of 210 eligible patients were diagnosed with ORN. The optimal pre-CCRT PIV cutoff was 833, which separated patients into two PIV groups with divergent ORN prevalence estimates: Group 1: PIV < 833 (N = 153), and Group 2: PIV ≥ 833 (N = 57). The comparison analysis found that the PIV ≥ 833 cohort had significantly higher ORN rates than the PIV < 833 cohort (29.8% vs. 2.6%; P < 0.001). Other characteristics linked to significantly higher ORN rates were the patient's continuing smoking, the use of the Three-dimensional conformal radiation therapy technique, the mean mandibular dose of ≥ 58.1 Gy, the number of tooth extractions before CCRT ≥ 4, and the presence of tooth extractions after CCRT. The independent importance of all factors on higher ORN occurrence rates were retained in multivariate analysis (P < 0.05).

CONCLUSIONS

Our findings revealed a strong link between aggravated inflammatory response and ORN genesis, with high pretreatment PIV levels related to significantly higher ORN rates.

The role of hyperbaric oxygen in osteoradionecrosis-a prophylactic insight

BACKGROUND

Osteoradionecrosis (ORN) is an uncommon and debilitating consequence of head and neck radiotherapy and hyperbaric oxygen therapy (HBOT) has been advocated for prophylaxis prior to performing dentoalveolar procedures. The aim of this study was to evaluate a prophylactic HBOT protocol and describe the outcomes of susceptible individuals.

METHODS

A retrospective audit of adults who attended the Oral and Maxillofacial Surgery department at the Royal Adelaide Hospital (South Australia) who received dental extractions with a history of radiotherapy to the jaws from 2008 to 2020. Data including demographic information and outcomes of osteoradionecrosis and delayed healing was recorded.

RESULTS

A total of 121 individuals were eligible for case note review; 68.6% of individuals were male and 55.4% were aged over 67 years. Osteoradionecrosis occurred in 9.1% of individuals and delayed healing for 3.3%; fifteen individuals (12.4%) were unable to complete the HBOT protocol. The individuals who were diagnosed with ORN had a significant association with age (P = 0.006) and binary analysis showed alcohol consumption to be a significant predictor.

CONCLUSIONS

Prophylactic HBOT protocol had a lower proportion of individuals diagnosed with ORN and those who were diagnosed were more likely to be younger males and have current alcohol consumption.

Valero's host index is useful in predicting radiation-induced trismus and osteoradionecrosis of the jaw risks in locally advanced nasopharyngeal carcinoma patients

BACKGROUND

In the absence of previous research, we sought to assess the H-Index's predictive significance for radiation-induced trismus (RIT) and osteoradionecrosis of the jaw (ORNJ) in patients with locally advanced nasopharyngeal carcinoma (LA-NPC) receiving concurrent chemoradiotherapy (C-CRT).

PATIENTS AND METHODS

The research comprised 295 LA-NPC patients who had C-CRT and pre- and post-C-CRT oral exams between June 2010 and December 2021. The H-Index was calculated using neutrophils, monocytes, lymphocytes, hemoglobin, and albumin measurements obtained on the first day of C-CRT. Patients were divided into three and two H-index groups, respectively, based on previously established cutoff values (1.5 and 3.5) and the cutoff value determined by our receiver operating characteristic (ROC) curve analysis. The primary objective was the presence of any significant connections between pretreatment H-Index groups and post-C-CRT RIT and ORNJ rates.

RESULTS

RIT and ORNJ was diagnosed in 46 (15.6%) and 13 (7.8%) patients, respectively. The original H-Index grouping could only categorize RIT and ORNJ risks at a cutoff value of 3.5, with no significant differences in RIT and ORNJ rates between groups with H-Index 1.5 and 1.5 to 3.5 (P < 0.05 for each). The ideal H-Index cutoff for both RIT and ORNJ rates was found to be 5.5 in ROC curve analysis, which divided the entire research population into two groups: H-Index ≤ 5.5 (N = 195) and H-Index > 5.5 (N = 110). Intergroup comparisons revealed that patients in the H-Index > 5.5 group had significantly higher rates of either RIT (31.8% vs. 5.9%; P < 0.001) or ORNJ (17.3% vs. 2.2%; P < 0.001) than their H-Index ≤ 5.5 counterparts. The results of the multivariate analysis showed that H-Index > 5.5 was independently linked to significantly higher RIT (P < 0.001) and ORNJ (P < 0.001) rates.

CONCLUSION

Pre-C-CRT H-Index > 5.5 is associated with significantly increased RIT and ORNJ rates in LA-NPC patients receiving definitive C-CRT.

Dental considerations for head and neck cancer: A clinical review

Introduction

Radiotherapy is one of the treatment modalities for the treatment of head and neck cancer (HNC). However, it leads to the development of chronic and acute side effects. These side effects impact negatively on the patient's quality of life and oral functioning. This clinical review aims to provide basic information about HNC, understand the impact of radiotherapy on oral health, and explain the role of dental care providers for HNC patients during the pre-and post-radiotherapy time.

Materials and Methods

Electronic databases (i.e., PubMed, Scopus, and Google Scholar) were searched using defined keywords. The main inclusion criteria were any studies describing "dental management of patients with head and neck cancer" and "dental management of patients treated with radiotherapy."

Results

Thematic analysis was used to summaries the findings of the included studies (n = 102) into main headings and subheadings. All studies were published between 1970 and 2023.

Conclusion

The number of HNC patients is increasing. This necessitates the need for raising the awareness of dental care providers to the side-effects of HNC therapy which includes treatment with radiotherapy, chemotherapy, and/or surgery. Dental care providers should understand the common side-effects and their treatments besides their role in the pre- (i.e., dental extraction of teeth with poor prognosis and maintaining good oral hygiene) and post- (i.e., oral rehabilitation and post-HNC dental care) radiotherapy dental care.

Adipose-Derived Stem Cells Enhance Graft Incorporation and Mineralization in a Murine Model of Irradiated Mandibular Nonvascularized Bone Grafting

BACKGROUND

Nonvascularized bone grafting represents a practical method of mandibular reconstruction. However, the destructive effects of radiotherapy on native bone preclude the use of nonvascularized bone grafts in head and neck cancer patients. Adipose-derived stem cells have been shown to enhance bone healing and regeneration in numerous experimental models. The purpose of this study was to determine the impact of adipose-derived stem cells on nonvascularized bone graft incorporation in a murine model of irradiated mandibular reconstruction.

METHODS

Thirty isogenic rats were randomly divided into 3 groups: nonvascularized bone graft (control), radiation with nonvascularized bone graft (XRT), and radiation with nonvascularized bone graft and adipose-derived stem cells (ASC). Excluding the control group, all rats received a human-equivalent dose of radiation. All groups underwent mandibular reconstruction of a critical-sized defect with a nonvascularized bone graft from the contralateral hemimandible. After a 60-day recovery period, graft incorporation and bone mineralization were compared between groups.

RESULTS

Compared with the control group, the XRT group demonstrated significantly decreased graft incorporation (P = 0.011), bone mineral density (P = 0.005), and bone volume fraction (P = 0.001). Compared with the XRT group, the ASC group achieved a significantly increased graft incorporation (P = 0.006), bone mineral density (P = 0.005), and bone volume fraction (P = 0.013). No significant differences were identified between the control and ASC groups.

CONCLUSIONS

Adipose-derived stem cells enhance nonvascularized bone graft incorporation in the setting of human-equivalent radiation.

Evaluation of Anterolateral Thigh Fascia Lata Rescue Flap for Mandibular Osteoradionecrosis

Importance

Mandibular osteoradionecrosis (ORN) is a progressive disease that can be difficult to treat. Conservative measures often fail, while conventional definitive management requires a morbid segmental resection with osteocutaneous reconstruction. Evidence of the anterolateral thigh fascia lata (ALTFL) rescue flap technique's safety, effectiveness, and long-term outcomes is needed.

Objective

To determine the long-term outcomes of the ALTFL rescue flap procedure for treating patients with mandibular ORN.

Design, Settings, and Participants

This was a retrospective medical record review performed at a single tertiary-level academic health care institution with patients who were appropriate candidates for the ALTFL procedure to treat mandibular ORN from March 3, 2011, to December 31, 2022. Data analyses were performed from January 1 to March 26, 2023.

Main Outcomes and Measures

Patient characteristics, preoperative radiographic Notani staging, intraoperative defect size, length of stay, complication rates, and clinical and radiographic findings of progression-free intervals.

Results

The study population of 43 patients (mean [SD] age, 66.1 [47-80] years; 24 [55.8%] male individuals) included 52 cases of mandibular ORN. The preoperative Notani staging of the study population was known for 46 of the 52 total cases: 11 cases (23.9%) were stage I; 21 (45.7%), stage II; and 14 (30.4%), stage III. The mean defect area was 20.9 cm2. Successful arrest of ORN disease progression was noted in the clinical and radiographic findings of 50 of the 52 (96.2%) cases, with only 2 (3.8%) cases subsequently requiring fibular free flap reconstruction. The major complication rate was 1.9% (1 case). Clinical and radiographic progression-free intervals were assessed, and no statistically significant differences were noted between Notani staging groups (log-rank P = .43 and P = .43, respectively); ie, patients with stage III disease had no significant difference in risk of clinical (HR, 0.866; 95% CI, 0.054-13.853) or radiographic (HR, 0.959; 95% CI, 0.059-15.474) progression vs those with stage I disease. Weibull profiling revealed 96.9%, 94.6%, and 93.1% successful mandibular ORN arrest at 1, 3, and 5 years, respectively. The major complication rate was 1.9%. Mean (SD) length of stay was 2.7 (0.0-7.0) days. Mean (SD) radiographic follow-up was 29.3 (30.7) months.

Conclusions and Relevance

The findings of this large retrospective patient case series support the continued success of the ALTFL rescue flap technique, a safe and highly effective long-term treatment for mandibular ORN in carefully selected patients.

Oral microbiota may affect osteoradionecrosis following radiotherapy for head and neck cancer

BACKGROUND

Osteoradionecrosis (ORN) is a serious complication of radiotherapy for head and neck cancer (HNC). However, its etiology and pathogenesis have not been completely elucidated. Recent studies suggest the involvement of the oral microbiota in the development of ORN. The aim of this study was to assess the correlation between oral microbiota and the extent of bone resorption in ORN patients.

MATERIALS AND METHODS

Thirty patients who received high-dose radiotherapy for HNC were enrolled. Tissue specimens were collected from the unaffected and affected sides. The diversity, species differences and marker species of the oral microbial community were determined by 16 S rRNA sequencing and bioinformatics analysis.

RESULTS

The ORN group had greater microbial abundance and species diversity. The relative abundance of f_Prevotellaceaeand, f_Fusobacteriaceae, f_Porphyromonadaceae, f_Actinomycetaceae, f_Staphylococcaceae, g_Prevotella, g_Staphylococcus, s_Endodontalis and s_Intermedia were particular;y increased in ORN, suggesting a potential association between the oral microbiota and ORN. Furthermore, g_Prevotella, g_Streptococcus, s_parvula and s_mucilaginosa were identified as potential diagnostic and prognostic biomarkers of ORN. Association network analysis also suggested an overall imbalance in species diversity and ecological diversity in the oral microbiota of ORN patients. In addition, pathway analysis indicated that the dominant microbiota in ORN may disrupt bone regeneration by regulating specific metabolic pathways that increase osteoclastic activity.

CONCLUSION

Radiation-induced ORN is associated with significant changes in the oral microbiota, and the latter may play a potential role in the etiopathology of post-radiation ORN. The exact mechanisms through which the oral microbiota influence osteogenesis and osteoclastogenesis remain to be elucidated.

Osteonecrosis of the Jaws: An Update and Review of Literature

Aim

To provide a concise review on risk factors, stages, pathophysiology, prevention and possible treatment options for both MRONJ and ORN individually.

Methods

The review was conducted according to the 'Preferred Reporting Items for Systematic Reviews and Meta-Analyses' (PRISMA) guidelines. A comprehensive search of the PUBMED, Ebsco, SCOPUS, WEB OF SCIENCE and NDH for articles published up until 2021 was performed. After screening and full text analyses, 44 studies were included in this review. Definition, risk factors, etiology, symptoms, stages, pathophysiology, prevention and possible management options were explored and highlighted in this article.

Results

Three studies described osteonecrosis of jaw (ONJ) in general, 15 studies described ONJ associated with radiotherapy and 26 studies described ONJ associated with medications. Both the two conditions (ORN) and (MRONJ) have relatively similar clinical presentations clearing the fact that a resemblance in clinical presentations does not necessarily denote a similar pathophysiology.

Conclusion

However, various advancements have been made in the control and management of ONJ, but until and unless need for high tumoricidal doses exists, ONJ will certainly continue to remain as a clinical challenge demanding satisfactory treatment to improve the quality of life of the patient.

The dental management of patients irradiated for head and neck cancer

Patients undergoing radiotherapy for head and neck cancers are prone to a range of dental complications, including mucositis, trismus, xerostomia, radiation caries and osteoradionecrosis. Specific considerations include the preventive, restorative and rehabilitative management of such patients, and the prevention and treatment of complications. This article aims to highlight the current understanding and management of dental needs for patients who have had or will undergo radiotherapy.

The Role of Dental Practitioners in the Management of Oncology Patients: The Head and Neck Radiation Oncology Patient and the Medical Oncology Patient

This narrative review addresses the role of a dentist in the management of oncology patients, highlighting the oral complications that arise in head and neck radiation oncology patients and medical oncology patients. The prevention and management of these complications are discussed.

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

BACKGROUND

This retrospective study aimed to investigate whether the pretreatment hemoglobin-to-platelet ratio (HPR) could predict the risk of osteoradionecrosis (ORN) in patients receiving concurrent chemoradiotherapy (C-CRT) for locally advanced nasopharyngeal carcinoma (LA-NPC).

METHODS

ORN cases were reported from the records of LA-NPC patients who had oral examinations before and after C-CRT. The pretreatment HPR values were calculated on the first day of C-CRT. The connection between HPR values and ORN occurrences was determined using receiver operating characteristic curve analysis. The primary endpoint was the relationship between the pretreatment HPR values and post-C-CRT ORN incidence rates, while secondary endpoints included the identification of other putative ORN risk factors.

RESULTS

We distinguished 10.9% incidences of ORN during the post-C-CRT follow-up period among 193 LA-NPC patients. The optimal cutoff for pre-C-CRT HPR was 0.48 that grouped the patients into two HPR groups with fundamentally different post-C-CRT ORN incidence rates: Group 1: HPR ≤ 0.48 (N = 60), and Group 2: HPR > 0.48 (N = 133). The comparative analysis indicated a significantly higher ORN incidence in HPR ≤ 0.48 group (30%; P < 0.001). The other factors associated with meaningfully increased ORN rates included the presence of pre-C-CRT ≥ 5 teeth extractions, mandibular volume receiving ≥ 64 Gy, post-C-CRT tooth extractions, mean mandibular dose ≥ 50.6 Gy, and C-CRT to tooth extraction interval > 5.5 months.

CONCLUSION

Low pretreatment HPR levels were independently and unequivocally linked to significantly increased incidence of ORN post-C-CRT. Pre-C-CRT HPR levels may be used to estimate the incidence of ORN and be useful for taking preventive and therapeutic measures in these patients such as monitoring oral hygiene with strict follow-up, avoidance of unnecessary tooth extractions, particularly after C-CRT, and use of more rigorous mandibular RT dose limits.

Incidence and Risk Factors for Extremity Osteoradionecrosis after Limb-Sparing Surgery and Adjuvant Radiotherapy

Osteoradionecrosis (ORN) is a major complication after radiotherapy. Most studies on ORN have focused on patients with mandibular lesions, with few studies including patients with extremity soft tissue sarcoma (STS). We included 198 patients with extremity STS who underwent limb-sparing surgery and adjuvant radiotherapy between 2004 and 2017. The incidence rate of extremity ORN was 3.5% (7/198), with most lesions (6/7) located in the lower extremities. The mean follow-up time was 62 months. Clinical presentations included chronic ulcers, soft tissue necrosis, sinus discharge, bone nonunion, and pathological fractures. Compared with the non-ORN group, the ORN group had a significantly higher total radiation dose (68 Gy vs. 64 Gy, p = 0.048) and greater use of intraoperative periosteal stripping (p = 0.008). Repeat surgeries and subsequent soft tissue reconstruction or limb amputation were performed as treatments. The risk and management of ORN in patients with extremity STS was ignored previously. Because the disease is complex and affects both clinicians and patients, careful surveillance should be undertaken.

The Use of Hydrogel-Based Materials for Radioprotection

Major causes of the radiation-induced disease include nuclear accidents, war-related nuclear explosions, and clinical radiotherapy. While certain radioprotective drug or bioactive compounds have been utilized to protect against radiation-induced damage in preclinical and clinical settings, these strategies are hampered by poor efficacy and limited utilization. Hydrogel-based materials are effective carriers capable of enhancing the bioavailability of compounds loaded therein. As they exhibit tunable performance and excellent biocompatibility, hydrogels represent promising tools for the design of novel radioprotective therapeutic strategies. This review provides an overview of common approaches to radioprotective hydrogel preparation, followed by a discussion of the pathogenesis of radiation-induced disease and the current states of research focused on using hydrogels to protect against these diseases. These findings ultimately provide a foundation for discussions of the challenges and future prospects associated with the use of radioprotective hydrogels.

The Progress in Reconstruction of Mandibular Defect Caused by Osteoradionecrosis

Osteoradionecrosis (ORN) is described as a disease with exposed, nonviable bone that fails to heal spontaneously or by means of conservative treatment after radiotherapy in at least 3 months. Though traditional theories in the early stage including hypoxic-hypocellular-hypovascular and fibro-atrophic in addition to new findings such as ferroptosis were put forward to explain the mechanisms of the osteoradionecrosis, the etiology of ORN is still unclear. With the high rate of occurrence in the head and neck area, especially in the mandible, this disease can disrupt the shape and function of the irradiated area, leading to a clinical presentation ranging from stable small areas of asymptomatic exposed bone to severe progressive necrosis. In severe cases, patients may experience pain, xerostomia, dysphagia, facial fistulas, and even a jaw defect. Consequently, sequence therapy and sometimes extensive surgery and reconstructions are needed to manage these sequelae. Treatment options may include pain medication, antibiotics, the removal of sequesters, hyperbaric oxygen therapy, segmental resection of the mandible, and free flap reconstruction. Microanastomosed free-flaps are considered to be promising choice for ORN reconstruction in recent researches, and new methods including three-dimensional (3-D) printing, pentoxifylline, and amifostine are used nowadays in trying increase the success rates and improve quality of the reconstruction. This review summarizes the main research progress in osteoradionecrosis and reconstruction treatment of osteoradionecrosis with mandibular defect.

Early detection of mandible osteoradionecrosis risk in a high comorbidity veteran population

OBJECTIVE

Osteoradionecrosis (ORN) of the mandible is a devastating complication of external beam radiation therapy (EBRT) for head and neck squamous cell carcinoma (HNSCC). We sought to ascertain ORN risk in a Veteran HNSCC population treatment with definitive or adjuvant EBRT and followed prospectively.

STUDY DESIGN

Retrospective analysis of prospective cohort.

SETTING

Tertiary care Veterans Health Administration (VHA) medical center.

METHODS

Patients with HNSCC who initiated treatment at the Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC) are prospectively tracked for quality of care purposes through the end of the cancer surveillance period (5 years post treatment completion). We retrospectively analyzed this patient cohort and extracted clinical and pathologic data for 164 patients with SCC of the oral cavity, oropharynx, larynx, and hypopharynx who received definitive or adjuvant EBRT (2016-2020).

RESULTS

Most patients were dentate and 80 % underwent dental extractions prior to EBRT of which 16 (16 %) had complications. The rate of ORN was 3.7 % for oral cavity SCC patients and 8.1 % for oropharyngeal SCC patients. Median time to ORN development was 156 days and the earliest case was detected at 127 days post EBRT completion. All ORN patients were dentate and underwent extraction prior to EBRT start.

CONCLUSION

ORN development can occur early following EBRT in a Veteran population with significant comorbid conditions but overall rates are in line with the general population. Prospective tracking of HNSCC patients throughout the post-treatment surveillance period is critical to early detection of this devastating EBRT complication.

Free Tissue Transfer for Skull Base Osteoradionecrosis: A Novel Approach in the Endoscopic Era

OBJECTIVES

Osteoradionecrosis (ORN) of the skull base and craniovertebral junction is a challenging complication of radiation therapy (RT). Severe cases often require surgical intervention through a multi-modal approach. With the evolution in endoscopic surgery and advances in skull base reconstruction, there is an increasing role for microvascular free tissue transfer (MFTT). We describe an endoscopic-assisted approach for the management of ORN of the skull base using fascia lata for MFTT.

STUDY DESIGN

Retrospective case series.

METHODS

Between 2017 and 2021, a review of all cases in which fascia lata MFTT was utilized for skull base ORN was performed. Patient demographics, preoperative characteristics, and postoperative outcomes with long-term follow-up were reviewed.

RESULTS

Five patients were identified. Mean duration to onset of ORN was 17 months following RT. A trial of antibiotics, hyperbaric oxygen (HBO), and/or limited debridement was attempted without success. Refractory pain and progressive osteomyelitis were unifying symptoms. All patients underwent endoscopic debridement of the affected region of ORN prior to MFTT. Vascularized fascia lata was inset through a combined endonasal and transoral corridor. There was improvement in chronic pain in the postop setting with no patients requiring continued antibiotics or HBO therapy. Mean post-op follow-up was 23 months.

CONCLUSIONS

With continued evolution in endoscopic, minimally invasive approaches, there is an expanding indication for early surgical management in refractory ORN. Fascia lata MFTT is a novel and effective strategy for the management of ORN of the skull base and upper cervical spine with excellent postoperative outcomes and limited patient morbidity.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:562-568, 2023.

Pre-chemoradiotherapy low hemoglobin levels indicate increased osteoradionecrosis risk in locally advanced nasopharyngeal cancer patients

PURPOSE

We aimed to determine whether pretreatment hemoglobin (Hb) levels can predict the risk of osteoradionecrosis (ORN) in patients receiving concurrent chemoradiotherapy (CCRT) for locally advanced nasopharyngeal carcinoma (LA-NPC).

METHODS

ORN cases were identified from the records of LA-NPCs who had oral exams before and after CCRT. All Hb measurements were obtained on the first day of treatment. Receiving operating characteristic curve analysis was used to determine the relationship between Hb levels and ORN rates. The relationship between pretreatment Hb levels and ORN rates served as the primary endpoint, and secondary endpoints included the discovery of additional potential ORN risk factors.

RESULTS

Among the 263 eligible LA-NPCs, we identified 8.7% ORN cases. The ideal cutoff Hb before CCRT was 10.6 g/dL. It was revealed that HPR ≤ 10.6 group had a significantly higher ORN rate (32.5% vs. 1.5% for Hb > 10.6; P < 0.001). The mandibular V59.8 ≥ 36% Gy, pre-CCRT ≥ 4 tooth extractions, the presence of post-CCRT tooth extractions, and the time of post-CCRT tooth extractions > 8 months were the other factors associated with significantly increased ORN rates (P < 0.05 for each).

CONCLUSION

Low pre-CCRT Hb levels appeared to be independently linked to significantly higher ORN rates. Pretreatment Hb levels may be used to establish preventive measures and predict ORN.

National and international guidelines on the replacement of missing teeth with dentures for head and neck cancer patients post-radiotherapy: A rapid review

Background

Replacement of missing teeth is not a straightforward task in head and neck cancer (HNC) patients post-radiotherapy. There is debate regarding the best way to care for these patients as it has been reported that using dentures by HNC patients after receiving treatment with radiotherapy might initiate the development of osteoradionecrosis.

Aim

This rapid review aimed to collate and compare the national and international guidelines for the use of dentures following radiotherapy for HNC patients.

Materials and methods

Three steps were included in data collection of this rapid review (first step; identification of dental and relevant non-dental associations/societies, second step, identification of national and international guidelines regarding the dental management of HNC patients, and third step; identification of recommendations about the replacement of missing teeth in HNC patients).

Results

In the 193 countries recognized by the United Nations, there were 238 relevant societies found, from those 175 confirmed that they do not have clear guidelines. Only 32 associations/societies (all in either Europe and North America) recommend guidelines for their dentists (N = 12 guidelines) about the dental management of HNC patients and show their position regarding the use of dentures for HNC patients after receiving treatment with radiotherapy.

Conclusions

There are very few guidelines and those that do exist differ, lack detail, and rarely go beyond routine advice. Accordingly, clear, detailed, and evidence-based guidelines are required to inform the management of patients with missing teeth following radiotherapy for HNC patients.

Osteoradionecrosis of the Jaw Following Proton Radiation Therapy for Patients With Head and Neck Cancer

Importance

Proton radiation therapy (PRT) has reduced radiation-induced toxic effects, such as mucositis and xerostomia, over conventional photon radiation therapy, leading to significantly improved quality of life in patients with head and neck cancers. However, the prevalence of osteoradionecrosis (ORN) of the jaw following PRT in these patients is less clear.

Objective

To report the prevalence and clinical characteristics of ORN in patients with oral and oropharyngeal cancer (OOPC) treated with PRT.

Design, Setting, and Participants

This case series reports a single-institution experience (Memorial Sloan Kettering Cancer Center, New York, New York) between November 2013 and September 2019 and included 122 radiation therapy-naive patients with OOPC treated with PRT. Data were analyzed from 2013 to 2019.

Main Outcomes and Measures

Clinical parameters, including sex, age, comorbidities, tumor histology, concurrent chemotherapy, smoking, comorbidities, and preradiation dental evaluation, were obtained from the medical record. Patients with clinical or radiographic signs of ORN were identified and graded using the adopted modified Glanzmann and Grätz grading system. Characteristics of ORN, such as location, clinical presentation, initial stage at diagnosis, etiology, time to diagnosis, management, and clinical outcome at the last follow-up, were also collected.

Results

Of the 122 patients (mean [SD] age, 63 [13] years; 45 [36.9%] women and 77 [63.1%] men) included in this study, 13 (10.6%) developed ORN following PRT during a median (range) follow-up time of 40.6 (<1-101) months. All patients had spontaneous development of ORN. At the time of initial diagnosis, grade 0, grade 1, grade 2, and grade 3 ORN were seen in 2, 1, 9, and 1 patient, respectively. The posterior ipsilateral mandible within the radiation field that received the full planned PRT dose was the most involved ORN site. At a median (range) follow-up of 13.5 (0.2-58.0) months from the time of ORN diagnosis, complete resolution, stable condition, and progression of ORN were seen in 3, 6, and 4 patients, respectively. The 3-year rates of ORN and death in the total cohort were 5.2% and 21.5%, while the 5-year rates of ORN and death were 11.5% and 34.4%, respectively.

Conclusions and Relevance

In this case series, the prevalence of ORN following PRT was found to be 10.6%, indicating that ORN remains a clinical challenge even in the era of highly conformal PRT. Clinicians treating patients with OOPC with PRT should be mindful of this complication.

Risk factors for primary site necrosis after definitive concurrent chemoradiotherapy in head and neck cancer

OBJECTIVE

To identify risk factors of primary site necrosis (PSN) after definitive concurrent chemoradiation therapy (CCRT) in patients with nonoral cavity head and neck cancer (HNC).

METHODS

We retrospectively reviewed the records of 256 patients treated with CCRT for HNC during 2010-2018. Patient-related (age, sex, history of smoking, hypertension, diabetes mellitus, serum hemoglobin and albumin), tumor-related (tumor site, American Joint Committee on Cancer stage), and treatment-related (induction chemotherapy, maximum point dose and mean dose of planning target volume [PTV] of primary site, absolute volumes of the PTV receiving >50-75 Gy [V₅₀-V₇₅]) variables were analyzed. Critical dosimetric parameters of PSN were identified using receiver operating characteristic (ROC) curve analysis. Univariate and multivariate Cox regression analyses were used to select the significant variables for PSN development.

RESULTS

After median follow-up of 44 months (range, 5-127), 7 patients (2.7%) developed PSN with a median time to event of 10 months (range, 3-12). V₇₀ ⩾79.8 mL was the most critical dosimetric parameter for PSN (area under the ROC curve 0.873, sensitivity 0.857, specificity 0.747). In univariate analyses, pretreatment serum hemoglobin <11.0 g/dL and V₇₀ ⩾79.8 mL were significantly associated with higher risk of PSN occurrence. V₇₀ ⩾79.8 mL (hazard ratio 5.960, 95% confidence interval 1.289-27.548; p = 0.022) remained significant predictors of PSN in multivariate analyses.

CONCLUSIONS

V₇₀ ⩾79.8 mL is significantly related to the risk of developing PSN. These findings offer valuable clues for clinicians to minimize PSN incidence in HNC treated with curative CCRT.

Osteonecrosis of the Jaw

Osteonecrosis of the jaw is a condition in which bone cells die due to various causes. It is classified as drug-induced jaw osteonecrosis, osteoradionecrosis, traumatic, non-traumatic, and spontaneous osteonecrosis. Antiresorptive or antiangiogenic drugs cause drug-induced osteonecrosis. The combination of medications, microbial contamination, and local trauma induces this condition. Osteoradionecrosis is a severe radiation therapy side effect that can affect people with head and neck cancer. It is described as an exposed bone area that does not heal for longer than three months after the end of radiation treatment with the absence of any indications of an original tumor, recurrence, or metastasis. Trauma (tooth extraction), tumor site, radiation dose that the patient receives, the area of the bone which is irradiated, oral hygiene, and other factors are risk factors for the development of osteonecrosis. Less frequently, osteonecrosis can also be induced by non-traumatic and traumatic causes. Non-traumatic osteonecrosis is brought on by infections, acquired and congenital disorders, as well as the impact of chemicals. Traumatic osteonecrosis is brought on by thermal, mechanical, or chemical damage. The treatment of osteonecrosis can be conservative, which aims to be beneficial for the patient's quality of life, and surgical, which involves debridement of the necrotic bone.

Post radiation mucosal ulcer risk after a hypofractionated stereotactic boost and conventional fractionated radiotherapy for oropharyngeal carcinoma

BACKGROUND/PURPOSE

Post radiation mucosal ulcers (PRMU) after treatment for oropharyngeal squamous cell carcinoma (OPSCC) can have a huge negative impact on patients' quality of life, but little is known concerning risk factors and the impact of fraction size. Therefore, the goal of this study was to determine the pattern of PRMU development and to identify risk factors after a hypofractionated stereotactic body radiotherapy boost (SBRT) compared to conventionally fractionated radiotherapy for OPSCC.

MATERIAL AND METHODS

We performed a retrospective cohort study (N = 332) of OPSCC patients with ≥ 1-year disease-free survival, treated with 46 Gy Intensity Modulated Radiotherapy (IMRT) (2 Gy fractions) followed by either an SBRT boost of 16.5 Gy (5.5 Gy fractions) (N = 180), or 24 Gy IMRT (2 Gy fractions) (N = 152). PRMU (grade ≥ 2) was scored when observed > three months after the last radiotherapy (RT) fraction (CTCAE v5.0). Potential risk factors were analyzed with Cox regression models using death as competing risk. Dose at the PRMU site was calculated by projecting delineated PRMU on the planning CT.

RESULTS

All cases of PRMU (N = 64) occurred within 24 months; all were grade 2. The cumulative incidence at 2 years in the SBRT boost group was 26% (N = 46) vs. 12% (N = 18) for conventional fractionation (p = 0.003). Most PRMU developed within nine months (N = 48). PRMU occurring > nine months (N = 16) were mainly observed in the SBRT boost group (N = 15). Sex (p = 0.048), acute tube feeding (p = < 0.001), tumor subsite tonsil (p = 0.001), and N stage (p = 0.017) were associated with PRMU risk at multivariable regression in the hypofractionated SBRT boost group. All 25 delineated PRMU were located within the high dose regions.

CONCLUSION

The risk of PRMU should be included in the cost benefit analysis when considering future research using a hypofractionated SBRT boost for OPSCC patients.

Osseous Tissue Engineering in the Management of Mandibular Osteoradionecrosis - An Evaluative Study

Introduction

Osteoradionecrosis (ORN), a non-infectious, necrotic condition of the bone, occurs as a major complication of radiotherapy to the irradiated site. Simple irrigation of the involved bone to partial or complete resection of the involved bones is being employed in its conventional management. Osseous tissue engineering (OTE) provides a new strategy by regenerating bone cells along with biocompatible scaffolds and micromolecules to produce an engineered osseous tissue.

Materials and Methods

In this study, mandibular ORN following radiation secondary to oropharyngeal squamous cell carcinoma was included. OTE with composite engineered tissue containing a mixture of autologous culture expanded dental pulp stem cells (DPSCs), autologous uncultured bone marrow aspiration concentrate (BMAC) and autologous platelet-rich plasma (PRP) loaded in β-tricalcium phosphate (β-TCP) or hydroxyapatite (HA) sponge scaffold was used in the mandibular defect and the surrounding tissues. An assessment of clinical, radiological and functional attributes was done.

Results

A total of six cases with a mean age of 58.6 years were included in the study. We noted significant improvement in the mean post-operative score for pain and mouth opening; functional improvement in eating solid/liquid food, tongue movement, speech and deglutition were observed. The aesthetics was measured with Vancouver score and revealed a significance at P < 0.05; also lip competency and occlusion were noted in all the patients. No major complications were noticed until a mean follow-up of 28 months.

Discussion

Tissue engineering with a regenerative cocktail of autologous culture expanded DPSCs, autologous uncultured BMAC and autologous PRP loaded in HA or β-TCP utilised in the surgical reconstruction of the mandible is an effective treatment modality in the management of mandibular ORN following irradiation.

Osteoradionecrosis versus Cancer Recurrence: An Unresolved Clinical Dilemma

INTRODUCTION

Osteoradionecrosis is a rare and debilitating risk of definitive chemoradiotherapy for head and neck squamous cell carcinoma. It is difficult to distinguish between osteoradionecrosis and recurrent or progressive disease, as clinical and radiologic features may be similar. Our aim was to compare the clinical presentation and radiologic features of osteonecrosis with those of recurrent or progressive cancer.

METHODS

We conducted a single-center case series of 19 patients with head and neck squamous cell carcinoma diagnosed between 2011 and 2019 who subsequently developed clinical and/or radiological suspicion of osteoradionecrosis. The population was a referred sample from head and neck cancer physicians at Northwell Health Cancer Institute. Clinician notes and imaging reports were reviewed to assign a final diagnosis of either cancer, osteonecrosis, or indeterminate.

RESULTS

No differences were found in the clinical presentation or radiologic features between groups. Median time between treatment and development of symptoms was longer in patients with a final diagnosis of osteoradionecrosis than recurrent or progressive disease (5 vs. 3 months), but this difference was not statistically significant. Radiation dose and type were not associated with diagnosis. Mean standard uptake value maximums on positron emission tomography/computed tomography were significantly higher in the cancer group (median 14.8 vs. 9.1, p < 0.0152). At 1 year after first suspicion of osteoradionecrosis, 100% of osteoradionecrosis patients were alive, versus 28.6% of cancer patients.

DISCUSSION/CONCLUSION

There is significant overlap in clinical and radiologic features of osteoradionecrosis and cancer. Standard uptake maximums may be helpful in predicting diagnosis. Occurrence of symptoms within 6 months of completing chemoradiotherapy should raise the concern for malignancy.

Emerging role of mesenchymal stem cell-derived extracellular vesicles in oral and craniomaxillofacial tissue regenerative medicine

Mesenchymal stem cells (MSCs) are multipotent stem cells with differentiation potential and paracrine properties, drawing significant attention in the field of regenerative medicine. Extracellular vesicles (EVs), mainly including exosomes, microvesicles and apoptotic bodies (ABs), are predominantly endosomal in origin and contain bioactive molecules, such as miRNAs, mRNAs, and proteins, which are transferred from their original cells to target cells. Recently it has emerged that MSC-derived EVs (MSC-EVs) combine the advantages of MSCs and EVs, which may be used as a promising MSC-based therapy in tissue repair and regeneration. Oral and craniomaxillofacial diseases are clinically complications containing the soft and hard tissues in craniofacial and dental arches. These diseases are often induced by various factors, such as chemical, microbiological, physical factors, and systemic disorders. For decades, tissue repair and regeneration in oral and craniomaxillofacial regions provide substantial improvements in the prevention and treatment of some severe diseases. In this review we discuss MSC-EVs and their therapeutic potential in oral and craniomaxillofacial tissue regenerative medicine.

Bone Concentration of Ampicillin/Sulbactam: A Pilot Study in Patients with Osteonecrosis of the Jaw

Osteonecrosis of the jaw (ONJ) occurs typically after irradiation of the head and neck area or after the intake of antiresorptive agents. Both interventions can lead to compromised bone perfusion and can ultimately result in infection and necrosis. Treatment usually consists of surgical necrosectomy and prolonged antibiotic therapy, usually through beta-lactams such as ampicillin/sulbactam. The poor blood supply in particular raises the question as to whether this form of antibiosis can achieve sufficient concentrations in the bone. Therefore, we investigated the antibiotic concentration in plasma and bone samples in a prospective study. Bone samples were collected from the necrosis core and in the vital surrounding bone. The measured concentrations in plasma for ampicillin and sulbactam were 126.3 ± 77.6 and 60.2 ± 35.0 µg/mL, respectively. In vital bone and necrotic bone samples, the ampicillin/sulbactam concentrations were 6.3 ± 7.8/1.8 ± 2.0 µg/g and 4.9 ± 7.0/1.7 ± 1.7 µg/g, respectively. These concentrations are substantially lower than described in the literature. However, the concentration seems sufficient to kill most bacteria, such as Streptococci and Staphylococci, which are mostly present in the biofilm of ONJ. We, therefore, conclude that intravenous administration of ampicillin/sulbactam remains a valuable treatment in the therapy of ONJ. Nevertheless, increasing resistance of Escherichia coli towards beta-lactam antibiotics have been reported and should be considered.

Malnutrition, nutrition support and dietary intervention: the role of the dietitian supporting patients with head and neck cancer

Malnutrition is prevalent in patients with head and neck cancer (HNC) at diagnosis but can occur at any stage of the treatment pathway. The impact of disease burden and treatment side effects can lead to altered anatomy, compromised quality and quantity of saliva and impaired swallowing function, which can result in deleterious effects on nutritional status. Optimising nutrition status is critical, as malnutrition is adversely associated with treatment tolerance and outcomes, wound healing, morbidity, mortality, quality of life and survival. Dietitians are integral members of the HNC multidisciplinary team and are uniquely qualified in the assessment, management and optimisation of nutritional status across the care pathway. This includes providing informational counselling to patients and carers on the short- and long-term nutritional impact of planned treatments alongside multidisciplinary members. Dietitians lead on the recommendation, provision and monitoring of nutrition support, which can be via the oral, enteral or parenteral route. Oral nutrition support includes dietary counselling, nourishing dietary, food fortification advice and high energy/protein oral nutritional supplements. Enteral nutrition support, or tube feeding, can be required on a short- and/or long-term basis and dietitians support appropriate decision-making for the type of tube and timing of placement across the care pathway.

Combination of Advanced Platelet-Rich Fibrin and Pentoxifylline/Tocopherol as a Novel Preventive Option in Osteoradionecrosis: A Case Report

Osteoradionecrosis (ORN) of the jaws is an uncommon complication of radiation therapy that seriously affects the oral and maxillofacial region. Management of ORN is intrinsically difficult and treatment effects are unpredictable. ORN can be treated with pentoxifylline/tocopherol and autologous platelet concentrates to promote wound healing. Furthermore, the low speed of relative centrifugal forces platelet-rich fibrin (PRF + ) has been shown high efficacy for ORN. A 72-year-old male patient with history of radiation treatment for squamous cell carcinoma in the left side of the tongue. Six years after the treatment, his upper right first molar tooth (no. 16) was surgically extracted due to persistent pain. A few months following the extraction, intraoral examination showed gingival inflammation, and pain when palpation around the edentulous area of tooth no. 16. Radiological examination revealed retained root of 16 with radiolucent area and horizontal bone loss around upper right second molar tooth (no. 17). Pentoxifylline and tocopherol were given for a week before the surgical operation and were continued for 8 weeks after the operation. Retained roots of teeth no. 16 and 17 were removed and the sockets were debrided, the advanced PRF+ (A-PRF + ) membranes were placed followed by primary wound closure. Following 2 weeks of treatment, the mucosa healed and progressed to complete mucosal coverage at 2 months with no pathological findings or ORN progression. At 6-month follow-up, clinical and cone-beam computed tomography (CBCT) revealed no pathology. Our case demonstrates that the combination of pentoxifylline/tocopherol and the A-PRF+ surgical approach can be useful for wound healing and prevention of ORN.