Unique presentation of an endemic opportunistic fungal infection: Disseminated coccidioidomycosis mimicking metastatic lung cancer with endotracheal and endobronchial involvement.

Coccidioidomycosis is a fungal infection primarily Endemic in the Southwest United States. Disseminated Coccidioidomycosis is a life-threatening variant that mainly occurs in an immunocompromised host. This report describes an unusual presentation of disseminated Coccidioidomycosis in an immunocompetent individual. The patient was admitted with a subacute cough, progressively worsening shortness of breath, significant weight loss, nodular skin lesions in upper extremities, and acute hypoxemic respiratory failure. Chest imaging revealed extensive nodularity and mass-like lesions. What sets this case apart is the significant endotracheal and endobronchial involvement, which mimicked metastatic lung cancer. The diagnosis was confirmed through serology and bronchoscopy biopsy. This case underscores the critical importance of considering detailed travel history and maintaining a high index of suspicion for fungal infections in patients with endobronchial lesions, particularly in regions where Coccidioidomycosis is endemic.

The Metaverse, Religious Practice and Wellbeing: A Narrative Review.

The metaverse is touted as the next phase in the evolution of the Internet. This emerging digital ecosystem is widely conceptualized as a persistent matrix of interconnected multiuser, massively scaled online environments optimally experienced through immersive digital technologies such as virtual reality (VR). Much of the prognostication about the social implications of the metaverse center on secular activities. For example, retail, entertainment (gaming/concerts), and social networking. Little attention has been given to how the metaverse might impact religion. This narrative review explores contemporary research into online religious practice and the use of immersive digital technologies for religious purposes. This focus informs a discussion about how the metaverse, an online and immersive technology, might impact religion/religious practices. For billions worldwide, religion is an essential aspect of social identity and a cornerstone of psychological wellbeing. The emergence of the metaverse may represent a new way of connecting with an ancient source of human flourishing.

Antibody Drug Clearance: An Underexplored Marker of Outcomes with Checkpoint Inhibitors.

Immune-checkpoint inhibitor (ICI) therapy has dramatically changed the clinical landscape for several cancers, and ICI use continues to expand across many cancer types. Low baseline clearance (CL) and/or a large reduction of CL during treatment correlates with better clinical response and longer survival. Similar phenomena have also been reported with other monoclonal antibodies (mAb) in cancer and other diseases, highlighting a characteristic of mAb clinical pharmacology that is potentially shared among various mAbs and diseases. Though tempting to attribute poor outcomes to low drug exposure and arguably low target engagement due to high CL, such speculation is not supported by the relatively flat exposure-response relationship of most ICIs, where a higher dose or exposure is not likely to provide additional benefit. Instead, an elevated and/or increasing CL could be a surrogate marker of the inherent resistant phenotype that cannot be reversed by maximizing drug exposure. The mechanisms connecting ICI clearance, therapeutic efficacy, and resistance are unclear and likely to be multifactorial. Therefore, to explore the potential of ICI CL as an early marker for efficacy, this review highlights the similarities and differences of CL characteristics and CL-response relationships for all FDA-approved ICIs, and we compare and contrast these to selected non-ICI mAbs. We also discuss underlying mechanisms that potentially link mAb CL with efficacy and highlight existing knowledge gaps and future directions where more clinical and preclinical investigations are warranted to clearly understand the value of baseline and/or time-varying CL in predicting response to ICI-based therapeutics.

Religious coping and levels of posttraumatic stress disorder symptomatology after the Beirut explosion.

OBJECTIVE: Religious coping has implications for the development of psychopathology in the aftermath of traumatic events. This study explored the relationship between religious coping (positive and negative) and posttraumatic stress disorder (PTSD) symptomology among survivors of a large industrial explosion that devastated parts of Beirut in August of 2020. METHOD: Three months after the disaster, 996 residents of Beirut and Lebanon completed validated measures of religious coping (RCOPE) and PTSD symptomatology (Impact of Events Scale-Revised) in either English or Arabic. The majority of participants were young adults aged between 18 and 25 years. RESULTS: Results indicated that higher levels of negative religious coping were a significant predictor of higher levels of PTSD symptomatology and were associated with a two-fold risk of meeting the criteria for probable PTSD. Other significant predictors included female gender, being a resident of Beirut at the time of the explosion, having personally sustained an injury, or knowing a person injured in the explosion. Effects sizes ranged from .34 to .68. CONCLUSIONS: Higher scores on measures of negative religious coping were associated with higher levels of PTSD symptomatology. However, negative religious coping may be better construed as a set of religious-based appraisals of event causality and may represent a form of peritraumatic appraisal in the wake of traumatic events. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Decoupling FcRn and tumor contributions to elevated immune checkpoint inhibitor clearance in cancer cachexia.

High baseline clearance of immune checkpoint inhibitors (ICIs), independent of dose or systemic exposure, is associated with cachexia and poor outcomes in cancer patients. Mechanisms linking ICI clearance, cachexia and ICI therapy failure are unknown. Here, we evaluate in four murine models and across multiple antibodies whether altered baseline catabolic clearance of administered antibody requires a tumor and/or cachexia and whether medical reversal of cachexia phenotype can alleviate altered clearance. Key findings include mild cachexia phenotype and lack of elevated pembrolizumab clearance in the MC38 tumor-bearing model. We also observed severe cachexia and decreased, instead of increased, baseline pembrolizumab clearance in the tumor-free cisplatin-induced cachexia model. Liver Fcgrt expression correlated with altered baseline catabolic clearance, though elevated clearance was still observed with antibodies having no (human IgA) or reduced (human H310Q IgG1) FcRn binding. We conclude cachexia phenotype coincides with altered antibody clearance, though tumor presence is neither sufficient nor necessary for altered clearance in immunocompetent mice. Magnitude and direction of clearance alteration correlated with hepatic Fcgrt, suggesting changes in FcRn expression and/or recycling function may be partially responsible, though factors beyond FcRn also contribute to altered clearance in cachexia.

The spectrum of cerebrospinal fluid findings in tuberculous meningitis and their relation to severity, radiological features, and outcome.

Objectives: The aim of the study was to evaluate cerebrospinal fluid (CSF) findings in tuberculous meningitis (TBM) and correlate it with severity, radiological features, and outcome of TBM. Materials and Methods: In a retrospective study, data from admitted TBM patients were analyzed, and findings of CSF examinations were recorded. The CSF was categorized as typical (protein 50-500 mg/dL, cells 50-500/mm3, and glucose 50% or lower of blood sugar); those above and below these values were categorized as increased or decreased, respectively. The CSF findings were correlated with stage of TBM, and 3-month outcome and radiological features. Paradoxical response was also noted. Results: There were 111 patients with TBM (definite 34, highly probable 77). On admission, 20 patients were in Stage I, 63 in Stage II, and 28 in Stage III TBM. CSF cells were in typical range in 73, low in 27 and increased in 11 patients. Protein was in typical range in 92 patients decreased in 11 patients and increased in eight patients. Sugar was normal in 41 and reduced in 70 patients. CSF cells, glucose, and protein did not correlate with the severity of meningitis. Fifteen patients had normal initial magnetic resonance imaging (MRI). Tuberculomas were present in 53 patients, hydrocephalus in 43 patients, basal exudates in 43 patients, and infarction in 44 patients. Mixed findings were present in 65 patients. The MRI features did not correlate with CSF. Second CSF was available after a median duration of 26 (13-276) days in 50 patients. The CSF cells were decreased in 20 and increased in 30 patients, protein increased in 30 and sugars decreased in 16 patients. Paradoxical worsening occurred in 27 patients. Fifty-one patients recovered completely, 41 partially, 15 had poor, three patients were lost to follow-up, and one died. CSF parameters did not correlate with 3-month outcome or paradoxical worsening. CSF parameters do not differ significantly between baseline and 1 month CSF, but cells and lymphocytes changed significantly between 1st month and 3rd month CSF. Conclusion: Typical CSF findings were present in 66% and did not correlate severity of TBM, radiological features paradoxical worsening or 3-month outcome. CSF cell count decreased within 3 months of treatment.

Hydrogen bonding in duplex DNA probed by DNP enhanced solid-state NMR N-H bond length measurements.

Numerous biological processes and mechanisms depend on details of base pairing and hydrogen bonding in DNA. Hydrogen bonds are challenging to quantify by X-ray crystallography and cryo-EM due to difficulty of visualizing hydrogen atom locations but can be probed with site specificity by NMR spectroscopy in solution and the solid state with the latter particularly suited to large, slowly tumbling DNA complexes. Recently, we showed that low-temperature dynamic nuclear polarization (DNP) enhanced solid-state NMR is a valuable tool for distinguishing Hoogsteen base pairs (bps) from canonical Watson-Crick bps in various DNA systems under native-like conditions. Here, using a model 12-mer DNA duplex containing two central adenine-thymine (A-T) bps in either Watson-Crick or Hoogsteen confirmation, we demonstrate DNP solid-state NMR measurements of thymine N3-H3 bond lengths, which are sensitive to details of N-H···N hydrogen bonding and permit hydrogen bonds for the two bp conformers to be systematically compared within the same DNA sequence context. For this DNA duplex, effectively identical TN3-H3 bond lengths of 1.055 ± 0.011 Å and 1.060 ± 0.011 Å were found for Watson-Crick A-T and Hoogsteen A (syn)-T base pairs, respectively, relative to a reference amide bond length of 1.015 ± 0.010 Å determined for N-acetyl-valine under comparable experimental conditions. Considering that prior quantum chemical calculations which account for zero-point motions predict a somewhat longer effective peptide N-H bond length of 1.041 Å, in agreement with solution and solid-state NMR studies of peptides and proteins at ambient temperature, to facilitate direct comparisons with these earlier studies TN3-H3 bond lengths for the DNA samples can be readily scaled appropriately to yield 1.083 Å and 1.087 Å for Watson-Crick A-T and Hoogsteen A (syn)-T bps, respectively, relative to the 1.041 Å reference peptide N-H bond length. Remarkably, in the context of the model DNA duplex, these results indicate that there are no significant differences in N-H···N A-T hydrogen bonds between Watson-Crick and Hoogsteen bp conformers. More generally, high precision measurements of N-H bond lengths by low-temperature DNP solid-state NMR based methods are expected to facilitate detailed comparative analysis of hydrogen bonding for a range of DNA complexes and base pairing environments.

Treating black patients as "knowers".

Recent trends in healthcare policy from high-volume service models to "high-value" delivery systems have refocused the need for patient-centered approaches to quality care. However, benchmarks of how to define and evaluate successful patient-centeredness have not been sufficiently established. Such ill-defined evaluation criteria can further exacerbate systemic inequities in maximum quality health care delivery, especially based on the intersectional diversity of various patient populations. In this context, applying a phenomenology of medicine framework or perspective-driven analysis is useful in defining cross-cultural patient-centeredness. This reframing from a naturalistic or objective/biological viewpoint to a phenomenological viewpoint may aid in placing greater epistemic or knowledge authority in the hands of vulnerable and/or marginalized patients- allowing these patients to become key "knowers" in the clinical interaction. Moreover, treating Black patients as "knowers" emphasizes the prioritization of patient values at the core of providing valuable healthcare. Such an academic, policy, and clinical approach to medicine agrees with well-established principles of medical ethics. In addition, the framework of a phenomenology of medicine can better facilitate physician-patient communication and interaction by delineating often muddled hermeneutics.

Now you see me, now you don't: New approaches to sparing nonmalignant cells from CAR T cell therapies.

While new immunotherapies have revolutionized the field of oncology, they have been limited by their inability to distinguish between cancerous cells and healthy HSPCs. Work by Casirati et al.1 and Wellhausen et al.2 in epitope editing antigens commonly expressed on AML and HSPCs has unlocked several new targets for immunotherapies.

Sepsis as the Grand Mimic of Secondary Hemophagocytic Lymphohistiocytosis: Serratia marcescens Bacteremia with Concomitant Decompensated Cirrhotic Liver Disease.

Secondary hemophagocytic lymphohistiocytosis (HLH) is an elusive entity with sequelae that may be confused with sepsis. We discuss a 45-year-old man with decompensated liver cirrhosis with sepsis treated with broad-spectrum intravenous antibiotics. Further work-up initially supported sepsis-HLH overlap syndrome (SHLHOS) and corticosteroids were added. Ongoing refractory hypotension ensued, and the patient passed within 31 hours of presentation. Based on the patient's overwhelming immune activation and clinical course likely unsalvageable by cytotoxic immunosuppressive agents, the patient was diagnosed with sepsis with acute end organ dysfunction. This case report illustrates both the diagnostic challenge of sepsis versus HLH, which both require very different treatments, and the potential for rapid clinical decline without swift recognition and management of the true pathology.

Nanotopography by chromatic confocal microscopy of the endothelium in Fuchs endothelial corneal dystrophy, pseudophakic bullous keratopathy and healthy corneas.

AIM: To investigate the interest of chromatic confocal microscopy (CCM) to characterise guttae in Fuchs endothelial corneal dystrophy (FECD). METHODS: Descemet's membranes (DM) were obtained during endothelial keratoplasty in patients with FECD and pseudophakic bullous keratopathy (PBK). They were compared with healthy samples obtained from body donation to science. Samples were fixed in 0.5% paraformaldehyde and flat mounted. Surface roughness of DMs was quantified using CCM and the AltiMap software that provided the maximum peak (Sp) and valley (Sv) heights, the mean square roughness (Rq) and the asymmetry coefficient (Ssk). RESULTS: The physiological roughness of healthy samples was characterised by an Rq of 0.12±0.05 µm, which was two times rougher than in PBK (Rq=0.06±0.03 µm), but both were still flat with a symmetrical distribution between peaks and valleys (Ssk close to 0, npeaks=nvalleys), smaller than 1 µm. In FECD, the maximum peak height was 5.10±2.40 µm, up to 5.8 and 8.3 times higher than the control and PBK, respectively. The maximum valley depth was half than the peak (2.28±0.89 µm). The surface with guttae was very rough (Rq=0.45±0.14 µm) and the Ssk=1.84± 0.43 µm, greater than 0, confirms an asymmetric surface with high peaks and low valleys (npeaks>nvalleys). Moreover, the CCM provided quantitative parameters allowing to distinguish different types of guttae from different patients. CONCLUSIONS: CCM is an innovative approach to describe and quantify different morphologies of guttae. It could be useful to analyse the different stages of FECD and define subgroups of patients.

Modelling the impact of forest management and CO2-fertilisation on growth and demography in a Sitka spruce plantation.

Afforestation and reforestation to meet 'Net Zero' emissions targets are considered a necessary policy by many countries. Their potential benefits are usually assessed through forest carbon and growth models. The implementation of vegetation demography gives scope to represent forest management and other size-dependent processes within land surface models (LSMs). In this paper, we evaluate the impact of including management within an LSM that represents demography, using both in-situ and reanalysis climate drivers at a mature, upland Sitka spruce plantation in Northumberland, UK. We compare historical simulations with fixed and variable CO2 concentrations, and with and without tree thinning implemented. Simulations are evaluated against the observed vegetation structure and carbon fluxes. Including thinning and the impact of increasing CO2 concentration ('CO2 fertilisation') gave more realistic estimates of stand-structure and physical characteristics. Historical CO2 fertilisation had a noticeable effect on the Gross Primary Productivity seasonal-diurnal cycle and contributed to approximately 7% higher stand biomass by 2018. The net effect of both processes resulted in a decrease of tree density and biomass, but an increase in tree height and leaf area index.

CD90-targeted lentiviral vectors for HSC gene therapy.

Hematopoietic stem cell (HSC) gene therapy is currently performed on CD34+ hematopoietic stem and progenitor cells containing less than 1% true HSCs and requiring a highly specialized infrastructure for cell manufacturing and transplantation. We have previously identified the CD34+CD90+ subset to be exclusively responsible for short- and long-term engraftment. However, purification and enrichment of this subset is laborious and expensive. HSC-specific delivery agents for the direct modification of rare HSCs are currently lacking. Here, we developed novel targeted viral vectors to specifically transduce CD90-expressing HSCs. Anti-CD90 single chain variable fragments (scFvs) were engineered onto measles- and VSV-G-pseudotyped lentiviral vectors that were knocked out for native targeting. We further developed a custom hydrodynamic titration methodology to assess the loading of surface-engineered capsids, measure antigen recognition of the scFv, and predict the performance on cells. Engineered vectors formed with minimal impairment in the functional titer, maintained their ability to fuse with the target cells, and showed highly specific recognition of CD90 on cells ex vivo. Most important, targeted vectors selectively transduced human HSCs with secondary colony-forming potential. Our novel HSC-targeted viral vectors have the potential to significantly enhance the feasibility of ex vivo gene therapy and pave the way for future in vivo applications.

Investigating the Role of TGF-ß Signaling Pathways in Human Corneal Endothelial Cell Primary Culture.

Corneal endothelial diseases are the leading cause of corneal transplantation. The global shortage of donor corneas has resulted in the investigation of alternative methods, such as cell therapy and tissue-engineered endothelial keratoplasty (TEEK), using primary cultures of human corneal endothelial cells (hCECs). The main challenge is optimizing the hCEC culture process to increase the endothelial cell density (ECD) and overall yield while preventing endothelial-mesenchymal transition (EndMT). Fetal bovine serum (FBS) is necessary for hCEC expansion but contains TGF-ßs, which have been shown to be detrimental to hCECs. Therefore, we investigated various TGF-ß signaling pathways using inhibitors to improve hCEC culture. Initially, we confirmed that TGF-ß1, 2, and 3 induced EndMT on confluent hCECs without FBS. Using this TGF-ß-induced EndMT model, we validated NCAM as a reliable biomarker to assess EndMT. We then demonstrated that, in a culture medium containing 8% FBS for hCEC expansion, TGF-ß1 and 3, but not 2, significantly reduced the ECD and caused EndMT. TGF-ß receptor inhibition had an anti-EndMT effect. Inhibition of the ROCK pathway, notably that of the P38 MAPK pathway, increased the ECD, while inhibition of the ERK pathway decreased the ECD. In conclusion, the presence of TGF-ß1 and 3 in 8% FBS leads to a reduction in ECD and induces EndMT. The use of SB431542 or LY2109761 may prevent EndMT, while Y27632 or Ripasudil, and SB203580 or SB202190, can increase the ECD.

Technique of flat-mount immunostaining for mapping the olfactory epithelium and counting the olfactory sensory neurons.

The pathophysiology underlying olfactory dysfunction is still poorly understood, and more efficient biomolecular tools are necessary to explore this aspect. Immunohistochemistry (IHC) on cross sections is one of the major tools to study the olfactory epithelium (OE), but does not allow reliable counting of olfactory sensory neurons (OSNs) or cartography of the OE. In this study, we want to present an easy immunostaining technique to compensate for these defects of IHC. Using the rat model, we first validated and pre-screened the key OSN markers by IHC on cross sections of the OE. Tuj-1, OMP, DCX, PGP9.5, and N-cadherin were selected for immunostaining on flat-mounted OE because of their staining of OSN dendrites. A simple technique for immunostaining on flat-mounted septal OE was developed: fixation of the isolated septum mucosa in 0.5% paraformaldehyde (PFA) preceded by pretreatment of the rat head in 1% PFA for 1 hour. This technique allowed us to correctly reveal the olfactory areas using all the 5 selected markers on septum mucosa. By combining the mature OSN marker (OMP) and an immature OSN marker (Tuj-1), we quantified the mature (OMP+, Tuj-1-), immature (OMP-, Tuj-1+), transitory (OMP+, Tuj-1+) and total OSN density on septal OE. They were respectively 42080 ± 11820, 49384 ± 7134, 14448 ± 5865 and 105912 ± 13899 cells per mm2 (mean ± SD). Finally, the same immunostaining technique described above was performed with Tuj-1 for OE cartography on ethmoid turbinates without flat-mount.

Impact of a subcutaneous casirivimab and imdevimab clinic in outpatients with symptomatic COVID-19: A single-center, propensity-matched cohort study.

PURPOSE: To evaluate the success of a clinic for subcutaneous administration of casirivmab and imdevimab (REGEN-COV; Regeneron) for treatment of patients with symptomatic mild to moderate coronavirus disease 2019 (COVID-19) in terms of preventing disease progression and healthcare utilization. METHODS: This retrospective single-center, propensity-matched cohort study examined healthcare utilization outcomes for patients who received subcutaneous casirivimab and imdevimab at a pharmacist-led clinic of an academic health system. Eligible patients were treated between August 1, 2021, and January 5, 2022, and were at high risk for COVID-19 disease progression. Treatment patients were propensity matched with high-risk control patients with a diagnosis of COVID-19 in the same timeframe who did not receive casirivimab and imdevimab. Patients were followed for 30 days for collection of data on inpatient admissions, emergency department visits, and mortality. Risk of a 30-day healthcare utilization event was assessed and tested for statistical significance utilizing McNemar's test. RESULTS: A total of 585 patients who received treatment with subcutaneous casirivimab and imdevimab were matched with 585 patients who did not receive casirivimab and imdevimab therapy. Patients who received casirivimab and imdevimab had significantly lower risk of a 30-day all-cause inpatient admission event than untreated patients (relative risk reduction, 62.4%; P < 0.0001). Treated patients also had a significantly lower risk of 30-day all-cause emergency department visit than untreated subjects (relative risk reduction, 36.5%; P = 0.0021). There were 6 mortality events in the untreated group and no mortality events in the treatment group. CONCLUSION: This study provides evidence for the effectiveness of a subcutaneous casirivimab and imdevimab clinic in preventing progression of symptomatic mild to moderate COVID-19.

Associations between Dietary Intake of Vitamin D, Sun Exposure, and Generalized Anxiety among College Women.

Vitamin D insufficiency impacts about half of the population worldwide. Almost one billion individuals across all ages and ethnicities suffer from vitamin D deficiency. Hypovitaminosis D is mainly related to lifestyle choices and habits, such as outdoor activities and food intake. Several studies have demonstrated a correlation between vitamin D status and anxiety symptoms. The main purpose of this study was to investigate the correlation between anxiety and factors including age, vitamin D deficiency, citizens, dietary and supplementary vitamin D intake, along with sun exposure, among a sample of female college students in the United Arab Emirates. A descriptive questionnaire, including a short version of the generalized anxiety disorder scale, food frequency questionnaire, and sun avoidance inventory, was used to assess the relationship between the dietary intake of vitamin D-rich foods and supplements, along with sun avoidance/exposure and generalized anxiety, among a total of 386 female participants aged 18 and above. The findings showed clear evidence that sun avoidance behaviors are strongly associated with an elevated risk of generalized anxiety disorder among adult females in the United Arab Emirates.

Predictors of follow-up non-compliance after definitive radiotherapy for locally advanced cervical cancer at a community cancer center.

Introduction: Non-compliance to post-treatment cancer surveillance can lead to late detection of recurrence. This study aims to identify patients at high risk for loss of follow-up after radiotherapy for locally advanced cervical cancer. Methods: Consecutive patients with locally advanced cervical cancer treated with definitive chemoradiotherapy (2013-2020) at a community cancer center were retrospectively reviewed. The main outcome was overall follow-up compliance rate over time. Additionally, specialist-specific follow-up times, reasons for discontinuation and predictors of loss of follow-up events were evaluated. Results: The median age of the 154 patients included was 46.5 years (range: 26-84). The 6-month, 1-, 3-, and 5-year overall loss of follow-up rates were: 5.3%, 15.3%, 33.6%, and 48.2%, respectively. After a median overall follow-up time of 21.0 months, the median specialist-specific surveillance times were 17 months and 6 months with gynecologic and radiation oncologists, respectively (p < 0.01). Overall, the most common reasons for loss of follow-up were financial (21.7%) and relocation to another city (28.3%). By specialty, the most common reasons were relocation of care (56.5%, gynecologic oncologist) and disease progression (31.3%, radiation oncologist). In the multivariable analysis, older age (continuous, OR: 0.96; p < 0.01) and Hispanic ethnicity (OR: 0.39; p < 0.01) were protective against loss of follow-up, while increased number of gestations (continuous, OR: 1.23, p = 0.01) and living farther from the cancer center (continuous, OR: 1.002; p = 0.03) increased the chance of loss of follow-up. Conclusion: Younger, non-Hispanic, multiparous women that live far from the community cancer center have an increased chance of follow-up discontinuity, which are attributed to financial reasons in more than 20% of the cases.

Three-dimensional (3D) anatomic location, extension, and timing of severe osteoradionecrosis of the mandible.

Background: The purpose of this study was to describe the topography, extension (volume), and timing of severe osteoradionecrosis (ORN) that required mandible resection in patients previously treated for head and neck cancer at a high-volume Veterans Affairs Medical Center. Materials and methods: The records from a reference hyperbaric oxygen clinic were retrospectively analyzed (n = 50, 2018-2021). Inclusion criteria were: I) severe ORN defined as progressive ORN that required resection; II) pathologic confirmation of ORN; and III) availability of pre-operative CT-imaging. Using a radiotherapy (RT) imaging software, we performed a detailed volumetric (3D) analysis of the bone involvement by ORN. Time intervals from RT to surgery for ORN and from surgery to the last follow-up were calculated. Results: All patients that met inclusion criteria (n = 10) were male with significant smoking history (median 47.5 pack-years) and a median age of 57 years old at the time of RT. The primary tumors were: oropharynx (n = 6), oral cavity (n = 3) and nasopharynx (n = 1). The median time from RT to ORN surgery was 8 years. The most common ORN location was the posterior lateral body (molar) and six patients had associated fractures. The mean ORN volume was 3.6 cc (range: 0.6-8.3), corresponding to a mean 6.3% (range: 0.7-14) of the total mandibular volume. After a median follow-up of 13.5 months, no recurrence of ORN occurred. Three patients died of non-cancer and non-ORN-recurrence related causes (1 y OS 77.1%). Conclusion: Severe ORN occurred after a median of 8 years from the previous RT and usually affected the posterior lateral body. Surgical resection achieved excellent ORN control.