Tension pneumocephalus related to nasopharyngeal carcinoma: A case report.

Tension pneumocephalus associated with nasopharyngeal carcinoma is an exceptionally rare but potentially fatal condition. We report a case of tension pneumocephalus associated with nasopharyngeal carcinoma treated by radiochemotherapy. Three-month follow-up computed tomography (CT) and positron emission tomography-computed tomography (PET-CT) showed significant tumor regression but moderate intracranial pneumocephalus. Four days later, the patient was found in a comatose state and emergency brain CT showed extensive pneumocephalus with transtentorial descending and right temporal herniations. The patient died 5 days later. A summary of tension pneumocephalus is presented and the mechanism of fistula formation is discussed. This case enlightens tension pneumocephalus as a possible early complication of nasopharyngeal carcinoma treatment.

Neuroanatomical photogrammetric models using smartphones: a comparison of apps.

OBJECTIVES: A deep knowledge of the surgical anatomy of the target area is mandatory for a successful operative procedure. For this purpose, over the years, many teaching and learning methods have been described, from the most ancient cadaveric dissection to the most recent virtual reality, each with their respective pros and cons. Photogrammetry, an emergent technique, allows for the creation of three-dimensional (3D) models and reconstructions. Thanks to the spreading of photogrammetry nowadays it is possible to generate these models using professional software or even smartphone apps. This study aims to compare the neuroanatomical photogrammetric models generated by the two most utilized smartphone applications in this domain, Metascan and 3D-Scanner, through quantitative analysis. METHODS: Two human head specimens (four sides) were examined. Anatomical dissection was segmented into five stages to systematically expose well-defined structures. After each stage, a photogrammetric model was generated using two prominent smartphone applications. These models were then subjected to both quantitative and qualitative analysis, with a specific focus on comparing the mesh density as a measure of model resolution and accuracy. Appropriate consent was obtained for the publication of the cadaver's image. RESULTS: The quantitative analysis revealed that the models generated by Metascan app consistently demonstrated superior mesh density compared to those from 3D-Scanner, indicating a higher level of detail and potential for precise anatomical representation. CONCLUSION: Enabling depth perception, capturing high-quality images, offering flexibility in viewpoints: photogrammetry provides researchers with unprecedented opportunities to explore and understand the intricate and magnificent structure of the brain. However, it is of paramount importance to develop and apply rigorous quality control systems to ensure data integrity and reliability of findings in neurological research. This study has demonstrated the superiority of Metascan in processing photogrammetric models for neuroanatomical studies.

Clinical characteristics and therapeutic outcomes after endoscopic endonasal surgery for craniopharyngioma in the elderly.

OBJECTIVE: Craniopharyngiomas (CPs) in adults are rare benign epithelial tumors, and few contemporary studies have explored outcomes after surgical treatment in elderly patients, especially with regard to endoscopic endonasal surgery (EES). METHODS: A retrospective cohort study was conducted on patients aged ≥ 18 years with CP who were treated with EES from 2013 to 2022. The cohort was divided into nonelderly (18-64 years) and elderly (≥ 65 years) groups based on age. Various parameters, including patient and tumor characteristics, surgical outcomes, complications, and follow-up, were compared between the two age groups. RESULTS: A total of 193 patients met the inclusion criteria, with 161 (83.4%) patients in the nonelderly group and 32 (16.6%) patients in the elderly group. Preoperatively, older patients were more likely to have memory impairment (4.3% vs 18.8%, p = 0.010), fatigue or decreased energy (9.3% vs 34.4%, p = 0.001), hypopituitarism (68.7% vs 90.6%, p = 0.012), or hydrocephalus (18% vs 40.6%, p = 0.005), and they were more likely asymptomatic (1.2% vs 9.4%, p = 0.033) and less likely to experience headache (57.8% vs 31.3%, p = 0.006). Patients in the elderly group had a longer symptom duration (median [IQR] 5 [10] months vs 9.5 [13] months, p = 0.001) and higher comorbidity scores (p < 0.001). Postoperatively, gross-total resection was achieved in 145 (90.1%) and 28 (87.5%) patients in the nonelderly and elderly groups, respectively. Older patients were more likely to develop pneumonia (5% vs 21.9%, p = 0.004). There were no significant differences in the extent of resection (p = 0.541), pathological subtypes (88.2% vs 75.0% adamantinomatous, p = 0.089), operation time (mean ± SD 307.8 ± 68.3 minutes vs 323.5 ± 86.0 minutes, p = 0.257), estimated blood loss (median [IQR] 300 [200] ml vs 300 [238] ml, p = 0.594), length of stay (median [IQR] 15 [8] days vs 15 [22] days, p = 0.964), perioperative mortality (2.5% vs 3.1%, p > 0.99), or postoperative severe hypothalamic dysfunction (37.9% vs 50.0%, p = 0.237) between the groups. Multivariate Cox regression analysis demonstrated that tumor calcification (HR 3.406, 95% CI 1.859-27.233, p = 0.038) and preoperative hydrocephalus (HR 3.688, 95% CI 1.310-10.386, p = 0.013) were independently associated with decreased survival. The median follow-up period in the elderly group was shorter (71 months vs 44 months, p = 0.001), and no recurrence was observed (7.1% vs 0%, p = 0.132). CONCLUSIONS: This study demonstrates that EES is a viable treatment option for older CP patients. With appropriate perioperative management, EES does not significantly increase mortality and, in selected populations, is well tolerated by patients.

Acute peritumoral brainstem hemorrhage of a clival chondrosarcoma successfully treated via endoscopic endonasal surgery: illustrative case.

BACKGROUND: Chondrosarcoma is typically a slow-growing tumor, and intratumoral hemorrhage is rare. Acute brainstem hemorrhage due to chondrosarcoma has rarely been reported. OBSERVATIONS: A 77-year-old man presented with the sudden onset of headache and vomiting followed by a declining level of consciousness, progressive right hemiparesis, and left ophthalmoplegia. Magnetic resonance imaging showed pontine hemorrhage and a mass in the retroclival space compressing the brainstem. Emergency endoscopic endonasal surgery was performed. Intraoperative observation revealed that a hematoma was located in the pons and subdural space around the tumor mass, suggesting that the hematoma had likely been caused by the rupture of small vessels around the pons, not by intratumoral hemorrhage. The pathological diagnosis was chondrosarcoma. The patient recovered well and underwent radiotherapy. LESSONS: This report describes a case of sudden neurological deterioration due to hemorrhage in a patient with chondrosarcoma of the skull base. An emergency endoscopic endonasal approach for mass reduction and hematoma removal was effective in the acute setting. This approach revealed the suspected etiology of peritumoral hemorrhage, not intratumoral hemorrhage. https://thejns.org/doi/10.3171/CASE2460.

A novel technique for skull base reconstruction in craniofacial fibrous dysplasia surgery using three-dimensional printing and a dental alginate mold: illustrative case.

BACKGROUND: Fibrous dysplasia is a rare and benign skeletal lesion characterized by fibrous tissue proliferation due to an abnormal osteogenesis replacing normal bone. OBSERVATIONS: An 18-year-old male with fibrous dysplasia of the left sphenoid, ethmoid, orbit, and frontal bones was managed with excision and skull base reconstruction. After complete removal of the tumor, skull base reconstruction was commenced by making a reverse temporalis flap and placing it over the opened paranasal sinuses for a robust vascularized graft, followed by an abdominal fat graft, and then a pedicled pericranal flap was added to complete the multilayer onlay graft. To recreate the skull base, a mirror image of the contralateral skull base was constructed using three-dimensional (3D) printing, and the 3D-printed model was sterilized prior to the surgery. Intraoperatively, the model was then pressed onto dental alginate gel to make a negative mold. This was used to make the definitive flap using polymethylmethacrylate. Temporoplasty was also performed using polymethylmethacrylate to fill the defect left by the temporalis graft. The patient recovered well following the procedure. LESSONS: Appropriate, personalized skull base reconstruction techniques can be successfully done with 3D printing using alternative low-cost materials and implements, especially following resection of cases like craniofacial fibrous dysplasia. https://thejns.org/doi/10.3171/CASE24262.

Assessing The Feasibility of Selective Piezoelectric Osteotomy in Transorbital Approach to The Middle Cranial Fossa: Anatomical and Quantitative Study and Surgical Implications.

OBJECTIVES: To verify the feasibility and to discuss advantages and disadvantages of a piezoelectric orbitotomy (PO) during Superior Eyelid Endoscopic Transorbital Approach (SETOA). METHODS: Five adult specimens underwent exoscopic/endoscopic SETOA to middle cranial fossa. The surgical corridor was created via piezoelectric orbitotomy by performing three selective and safe micrometric bone cuts providing a one-piece trapezoid bone flap which was repositioned and secured at the end of procedure. A 3D scan of the bone flap allowed us to reconstruct a 3D model and calculate its volume. An illustrative case demonstrating the application of this novel technique was also presented. RESULTS: Anatomical-morphometric quantitative analysis showed a mean bony-volume gain of 1,574.26 mm3 by using PO. PO yielded concrete surgical advantages and theoretical benefits in terms of functional and esthetic outcomes. All osteotomies were micrometric clear-cut and precise, resulting in a very thin bony gap; a complete sparing of soft tissues and neurovascular structures in- and around the orbit was observed. Lateral orbital wall reconstruction by replacing the bone flap aims to mitigate the risk of enophthalmos, proptosis, CSF leakage, pseudomeningocele and pulsatile headache, which represent significant challenges in the relevant literature. CONCLUSION: PO may offer a viable, selective, effective, safe alternative to high-speed drilling during SETOA, especially for patients affected by intra-axial pathologies in which a watertight closure is mandatory. This procedure could prevent/decrease the risk of some of the main postoperative complications associated to the standard SETOA, resulting potentially in better functional and esthetic outcome.

Proton-Based Radiation Therapy for Skull Base Chondrosarcomas in Children and Adolescents: 40-year experience from a single institution.

BACKGROUND: The literature on skull base chondrosarcoma (CHS) is scarce. We report outcomes for pediatric and young patients ≤ 22 years with base of skull (BOS) CHSs treated with proton-based radiotherapy (PBRT). METHODS: We retrospectively reviewed all patients treated with PBRT between 1981 and 2023. Primary endpoints were overall survival (OS), chondrosarcoma-specific survival (CSS), progression-free survival (PFS), local control (LC), and distal control (DC). RESULTS: Eighty-four patients were identified. Median age at diagnosis was 19 years (range, 6 - 22). Most patients (n=79, 94%) had conventional CHS while 5 (6%) had mesenchymal CHS. Nine patients (11%) underwent gross total resection (GTR), 64 (76%) subtotal resection (STR) and 11 patients (13%) underwent biopsy. Twenty-four (29%) patients progressed prior to radiotherapy (RT). The median prescription dose was 70 Gy (RBE) (range, 50 - 79.7). At a median follow-up of 18.0 years [interquartile range (IQR),), 9.2 -26.2] from diagnosis, 11 patients recurred (7 local, 4 distant). Six patients died of disease. Five patients died of other causes. Ten-year OS, CSS and PFS rates for all patients were 93.3%, 94.7% and 88%, respectively. Twenty-year OS, CSS and PFS rates for conventional CHS (n=79) were 93.1%, 97.1% and 89.2%, respectively. Mesenchymal histology was significantly associated with worse OS and PFS. Pre-RT tumor progression portended worse OS and CSS. Eight patients (9.9 %) experienced a late toxicity grade 3 or greater. CONCLUSIONS: This is the largest cohort of pediatric BOS CHSs in literature to date. High-dose PBRT following surgical resection achieves excellent disease control with minimal toxicity.

Comparative overall survival analysis of chordomas of the base of the skull from the Surveillance, Epidemiology, and End Results (SEER) program between 2000 and 2020.

Chordomas of the skull base are rare, slow growing, locally invasive cancers with limited long-term survival analysis reported in the literature. We seek to provide comparative survival analysis of patients on a long-term (20-year) basis using population-level data. The Surveillance, Epidemiology, and End Results (SEER) program was queried for cases of chordoma relegated to the base of the skull, diagnosed between 2000 and 2020. Demographic, disease, and treatment information were analyzed using Cox proportional hazards and log-rank comparisons. 630 patients with chordoma of the skull base were identified. Age ≤ 49 years at diagnosis was associated with increased five-, 10-, and 20-year overall survival (hazard ratio (HR) = 0.39, 0.33, and 0.30, respectively; p < 0.001 for all). Treatment with surgery and adjuvant radiotherapy was associated with increased five-, 10-, and 20-year survival (HR = 0.71, 0.79, and 0.79, respectively; p < 0.001 for all). On univariate analysis, widowed patients had decreased survival (20-year overall survival = 34.8% [15.3%-34.8%] compared to married patients (74.4% [68.1%-80.8%]. Surgery remains the primary treatment associated with increased survival among patients with chordoma of the skull base, with adjuvant radiotherapy serving a complimentary role. Demographic factors such as marital status are also associated with changes in survival.

Medicare Reimbursement and Utilization Trends Within Skull Base Surgery.

BACKGROUND: Medicare reimbursements for otolaryngology and neurosurgery procedures have generally declined since 2000. We explore Medicare reimbursement trends for anterior (ACF), middle (MCF), posterior cranial fossa (PCF), pituitary surgery (PS), and skull base reconstruction (SBR) surgery from 2000-2022. METHODS: Cross-sectional analysis of the Centers for Medicare and Medicaid Services (CMS) Physician Fee Schedule was performed from 2000-2022 on approach, resection, and repair of the skull base (CPTs 31290-31291, 61546, 61548, 61575-61619, 62165). Reimbursement data was adjusted for inflation to 2022 US dollars, and annual and total changes calculated. The CMS Part B National Summary Data File was analyzed for trends in Medicare procedure volume and total payment. RESULTS: Adjusted for inflation since 2000, reimbursements for ACF, MCF, PCF, PS, and SBR codes had an overall decrease of 22.85%, 32.43%, 28.09%, 44.22%, and 38.65%, respectively. Simultaneously, procedure volume increased at an average annual rate of 63.99%, 128.57%, 19.75%, 36.11%, and 12.79%, respectively. CONCLUSIONS: While nominal per-service Medicare reimbursement has increased for skull base surgery codes, there has been a downward trend in inflation-adjusted procedural reimbursement. This parallels findings in other otolaryngology and neurosurgery procedures. Despite this, surgical volume in all skull base surgery subfields has increased, indicating increased utility and adoption of these techniques.

Fluorescence guidance in skull base surgery: Applications and limitations - A systematic review.

Introduction: Intraoperative fluorescence guidance is a well-established surgical adjunct in high-grade glioma surgery. In contrast, the clinical use of such dyes and technology has been scarcely reported in skull base surgery. Research question: We aimed to systematically review the clinical applications of different fluorophores in both open and endonasal skull base surgery. Material and methods: We performed a systematic review and discussed the current literature on fluorescence guidance in skull base surgery. Results: After a comprehensive literature search, 77 articles on skull base fluorescence guidance were evaluated. A qualitative analysis of the articles is presented, discussing clinical indications and current controversies. The use of intrathecal fluorescein was the most frequently reported in the literature. Beyond that, 5-ALA and ICG were two other fluorescent dyes most extensively discussed, with some experimental fluorophore applications in skull base surgery. Discussion and conclusion: Intraoperative fluorescence imaging can serve as an adjunct technology in skull base surgery. The scope of initial indications of these fluorophores has expanded beyond malignant glioma resection alone. We discuss current use and controversies and present an extensive overview of additional indications for fluorescence imaging in skull base pathologies. Further quantitative studies will be needed in the future, focusing on tissue selectivity and time-dependency of the different fluorophores currently commercially available, as well as the development of new compounds to expand applications and facilitate skull base surgeries.

Risk factors associated with postoperative cerebrospinal fluid leak after endoscopic endonasal skull base surgery: Two-center retrospective cohort study.

Background: Over the past two decades, endoscopic endonasal skull base surgery (EESBS) has revolutionized the treatment of skull base tumors by enabling minimal access to resect significant pathologies such as meningiomas, pituitary adenomas, and chordomas. Despite its efficacy, complications such as cerebrospinal fluid (CSF) leak pose significant challenges, with an average incidence of 8.9% following EESBS. Therefore, our study aims to investigate the risk factors associated with postoperative CSF leak after employing an endoscopic endonasal approach for skull base surgery, focusing on patients treated at King Abdul-Aziz Medical City in Jeddah and King Abdullah Medical City in Makkah, Saudi Arabia. Methods: A retrospective review of patients who underwent an endoscopic endonasal approach for the resection of intradural skull base pathology between January 2016 and December 2022 was performed with a total of 51 patients. Basic demographic data were collected, along with patient comorbidities, presenting symptoms, tumor pathology, tumor site, the extent of resection, and outcomes. Results: 51 participants were analyzed, with a mean age of 43.41. Male participants comprised (58.8%), while headaches were the most common symptom (74.5%), followed by visual disturbances (51.0%). Nonsecretory tumors predominated, primarily located in the sellar and suprasellar regions (58.8%). Gross total resection was performed in the majority (56.9%), with a 9.8% incidence of postoperative CSF leak. Notably, all four patients with CSF leak experienced preoperative headaches. Hypertension was prevalent in Cases 1 and 4, with Case 4 having a history of neurological disease and radiation therapy. Anterior skull base tumors were most frequent in Cases 3 and 4. Conclusion: The incidence of CSF leakage after surgery in this study was similar to that previously reported. It is worth noting that repeated surgeries may increase the risk of postoperative CSF leakage. Therefore, it is important to carefully evaluate the surgical approach for tumor removal and skull base reconstruction, considering the tumor characteristics and the patient's overall condition.

Successful treatment of recurrent extracranial hypoglossal schwannoma using the neuroendoscopic transnasal far-medial approach.

Background: Extracranial hypoglossal schwannomas are rare, and transcranial skull base surgery can be challenging due to their proximity to the lower cranial nerves, jugular vein, vertebral artery, and carotid artery. The application of neuroendoscopic surgery for extracranial hypoglossal schwannomas has rarely been reported. Case Description: A 53-year-old woman previously underwent lateral suboccipital surgery for a hypoglossal schwannoma when she was 25 years old. The patient had experienced aggravated dysphagia over the past month. Radiological examination revealed a recurrent extracranial hypoglossal schwannoma invading the left side of the clivus. The neuroendoscopic transnasal far-medial approach was performed, and the recurrent schwannoma was completely removed without any significant perioperative complications or recurrence for 3 years. Conclusion: Our report highlights the usefulness of the neuroendoscopic transnasal far-medial approach for the removal of recurrent extracranial hypoglossal schwannomas. The neuroendoscopic approach offers a viable and less invasive alternative to traditional transcranial skull-base surgery, especially in complex cases involving critical anatomical structures. The reported case study underscores the potential of neuroendoscopic surgery as a valuable tool in managing challenging skull-base tumors.

Modified colored three-dimensional posterior and temporal cranial fossa model with mobility of the joint between C1 and occipital condyle.

BACKGROUND: Skull base surgery requires anatomical knowledge and appropriate surgical technique in bone drilling. We developed a newly modified three-dimensional (3D) model of the posterior cranial fossa as a learning tool that improves knowledge of skull base anatomy and surgical approaches, including skull base drilling techniques. METHODS: This bone model of the posterior cranial fossa was created based on computed tomography data using a 3D printer, and incorporates artificial cranial nerves, cerebral vessels, bony structures, dura mater, and cerebellar tentorial dura. These anatomical components are differentiated with various colors. In addition, the atlanto-occipital junction can be mobilized to fully expose the surface of the cartilage between the C1 condyle and occipital condyle to allow drilling to open the hypoglossal canal under a wide surgical field. The usefulness of the model for practicing skull base surgical approaches was evaluated. RESULTS: Experience of bone drilling, dural dissection, and 3D positioning of important structures, including cranial nerves and blood vessels, was identical to that in actual surgery. CONCLUSIONS: This model is designed to facilitate teaching anatomical knowledge and essential epidural procedure-related skills, and is useful for teaching the essential elements of posterior skull base surgery.

Reconstruction of Anterior Skull Base After Cleaver Trauma: Combined Use of Fascia Lata and Middle Turbinate Flap in a Patient with Concha Bullosa.

This video article presents a 47-year-old male patient who presented to the emergency department after a cleaver bounced off the grinding wheel and lodged between his eyebrows. The patient complained of clear nasal drainage since the trauma. Computed tomography showed a comminuted displaced fracture starting from the right frontonasal recess and extending along the right ethmoid roof. The patient underwent surgery. The skull base defect was reconstructed with a free fascia lata graft in the first operation. In the second session, the reconstruction of the skull base was reinforced with a flap that was prepared from the middle turbinate with the concha bullosa. The patient was followed for eight months. The patient's symptoms resolved completely and there was no evidence of rhinorrhoea or any other complication at the control examination. No complications were seen on control magnetic resonance imaging.

Outcomes of Endoscopic Endonasal Surgery for Tuberculum Sellae and Planum Sphenoidale Meningiomas: A Retrospective Study.

BACKGROUND: To evaluate clinical outcomes and volumetric changes following endoscopic endonasal approach (EEA) for tuberculum sellae (TS) and planum sphenoidale (PS) meningiomas. Key objectives included evaluating pre- and postoperative tumor volumes, visual assessments and EEA-related complications. METHODS: A single-center retrospective study was conducted at Foothills Medical Centre, University of Calgary, Canada, from 2009 to 2022 including 24 patients meeting inclusion criteria for midline skull base tumors, confirmed as WHO Grade I or II meningiomas with optic canal extension. RESULTS: EEA achieved gross total resection in 87.5% of cases, with a mean tumor volume reduction of 92.24%. Postoperatively, 91.67% exhibited visual improvement or stability. Cerebrospinal fluid leaks occurred in 12.5% of cases, necessitating revision surgery in one case. Persistent postoperative endocrine dysfunction affected 4.17%. Preoperative tumor volume did not demonstrate a correlation with complications. CONCLUSIONS: This study delivers reproducible data for pre- and postoperative tumor volume following the EEA after TS or PS meningiomas. The EEA demonstrated favorable radiographic and clinical outcomes in TS and PS meningiomas, achieving gross total resection with minimal morbidity.

Skull Base Osteomyelitis Due to Staphylococcus epidermidis in the Absence of Indwelling Medical Devices Presenting With Bilateral Internal Carotid Artery Thrombosis.

Skull base osteomyelitis (SBO) is a severe and uncommon infection that typically affects the skull base and may arise from undiagnosed otogenic or sinonasal infection. This case describes a rare presentation of SBO, accompanied by thrombosis of the bilateral internal carotid artery with neurological deficits in a resource-limited environment, illustrating diagnostic and management dilemmas. A male patient aged 40 years with poorly controlled type 2 diabetes presented with sudden onset loss of consciousness and worsening right-sided weakness. MRI studies revealed SBO with cerebral involvement with thrombosis in major cerebral arteries and multiple brain infarcts. After receiving broad-spectrum antibiotics and supportive care shortly after admission, the patient developed septic shock and died two days after admission. The fast course of the disease in this case shows how severe SBO and its complications may be, calling for early diagnosis and intensive management of SBO, especially in diabetic patients. The fact that Staphylococcus epidermidis was established as a causative agent of disease in the absence of artificial heart valves or joints, it is becoming clear that there is a need to increase awareness of such rare pathogens, and probably new strategies for handling such infections should be developed. Additional research is required to elucidate the precise role of the pathogen and refine treatment approaches, especially for low-resource healthcare systems.

Case report of large solitary skull base metastasis from renal cell carcinoma as initial clinical presentation: Radiological findings and differentials.

A 58-year-old male with good past health presented with headache and visual disturbance for 1 month. Computed tomography (CT) and magnetic resonance imaging (MRI) were performed, showing a large aggressive midline mass with epicenter at the skull base and sellar-suprasellar region. There was marked heterogenous enhancement and intratumoral calcifications. It demonstrated clivus erosion, sphenoid sinus invasion, cavernous sinus invasion and optic chiasm compression. The imaging features were considered to be consistent with clival chordoma and the patent underwent emergent endoscopic transsphenoidal surgical excision. The difficult operation found an unexpected highly vascularized tumor and histopathology of the excision showed clear cell renal cell carcinoma metastasis. Subsequent work up of the patient with positron emission tomography-computed tomography (PET-CT) confirmed suspicion of the primary tumor, arising from left kidney. This case demonstrates an underestimated differential diagnosis of a large aggressive skull base mass as the first initial clinical presentation of metastatic disease.

Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) combined with conventional MRI for the detection of skull-base invasion in nasopharyngeal carcinoma: comparison with 18F-sodium fluoride (18F-NaF) positron emission tomography/computed tomography (PET/CT).

Background: The extent of skull base invasion (SBI) in nasopharyngeal carcinoma (NPC) directly impacts tumor staging, treatment strategies, and prognosis assessment for NPC patients, emphasizing the critical need for prompt diagnosis and precise assessment of invasion. Thus, we aimed to integrate the advantages of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and conventional magnetic resonance imaging (cMRI), and assess their combined diagnostic efficacy versus that of 18F-sodium fluoride (18F-NaF) positron emission tomography/computed tomography (PET/CT) for detecting SBI in NPC patients. Methods: The study prospectively and randomly recruited 62 patients newly diagnosed with NPC by pathological biopsy at the Cancer Center of Affiliated Hospital of Guangdong Medical University from January 2021 to September 2022. All patients underwent baseline cMRI, IVIM-DWI, and PET/CT scans. The IVIM-DWI analysis included 3 primary parameters: true diffusion coefficient (D), pseudodiffusion coefficient (D*), and pseudodiffusion fraction (f). SBI was defined as the involvement of any substructure confirmed by follow-up MRI and clinical symptoms. Inter-observer agreement was evaluated utilizing the intraclass correlation coefficients (ICC) and kappa coefficients. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic performance of cMRI, IVIM-DWI plus cMRI, and PET/CT. DeLong test was used to compare the areas under the curve (AUC) of the 3 modalities. Results: Excellent inter-observer reliability was observed (range, 0.841-0.946). Among the IVIM-DWI parameters, D* + f demonstrated comparable accuracy to D + D* + f (AUC 0.906 vs. 0.904; sensitivity 88.9% vs. 89.8%; specificity 92.3% vs. 91.0%). IVIM-DWI plus cMRI yielded an overall AUC of 0.947, sensitivity of 92.6%, and specificity of 96.8%, surpassing cMRI alone with an AUC of 0.914 (P=0.025), sensitivity of 91.2%, and specificity of 91.7%, as well as 18F-NaF PET/CT with an AUC of 0.852 (P<0.001), sensitivity of 80.1%, and specificity of 90.4%. In detecting substructures of SBI, IVIM-DWI plus cMRI showed superior performance compared to 18F-NaF PET/CT within the petrous part of the temporal bone (AUC 0.968 vs. 0.871, P=0.011; sensitivity 93.5% vs. 87.1%, specificity 100% vs. 87.1%), pterygopalatine fossa (AUC 0.935 vs. 0.831, P=0.032; sensitivity 93.9% vs. 69.7%, specificity 93.1% vs. 96.6%), and foramen ovale (AUC 0.885 vs. 0.710, P=0.019; sensitivity 76.9% vs. 61.5%, specificity 100% vs. 80.6%). Conclusions: IVIM-DWI plus cMRI can accurately detect SBI and the substructures in NPC, providing a valuable reference for personalized treatment strategies and precise prognosis assessment.

Microbial spectrum, management challenges, and outcome in patients with otogenic skull base osteomyelitis.

Objectives: The study aimed to explore the spectrum and trend of causative microbial agents and to identify management challenges and the risk factors for poor outcomes in patients with confirmed otogenic skull base osteomyelitis. Methods: A retrospective observational study was conducted at a tertiary-care academic center from 1999 through 2019 and included 28 adult patients with confirmed otogenic skull base osteomyelitis. Relevant data was extracted from electronic and hard patient medical files. The microbial spectrum of involved microbes was identified and correlated to management options. Deterioration risk factors were investigated using suitable statistical analysis tests. Results: Twenty-eight patients with confirmed skull base osteomyelitis were included; most were males (78.6%) and Saudis (78.6%). All patients were ≥50 years of age (mean ± SD is 69.0±10.2.4). Of 41 identified microbial isolates, 56% were bacterial, 44% were fungal. 32.1% of patients had polymicrobial infections, most patients (92.8%) had received ≥2 systemic antibiotics, 57.1% received systemic antibiotic combinations, and 32.1% underwent surgical interventions. The mean antibiotic and antifungal therapy duration was 58.3 and 45.8 days, respectively. The identified risk factors of deterioration were advanced age and concomitant cardiac failure, with P-values of .006 and .034, respectively. Conclusions: The study findings highlight the microbiological spectrum and trend of otogenic skull base osteomyelitis-causative microbes over two decades, present the management challenges, identify deterioration risk factors, and suggest tissue biopsy as the golden standard for accurately identifying causative microbes.