Explore the vast range of titles available.

Purpose This study assesses the reliability of deep learning models based on planar whole-body bone scintigraphy for diagnosing Skull base invasion (SBI) in nasopharyngeal carcinoma (NPC) patients. Methods In this multicenter study, a deep learning model was developed using data from one center with a 7:3 allocation to training and internal test sets, to diagnose SBI in patients newly diagnosed with NPC using planar whole-body bone scintigraphy. Patients were diagnosed based on a composite reference standard incorporating radiologic and follow-up data. Ten different convolutional neural network (CNN) models were applied to both whole-image and partial-image input modes to determine the optimal model for each analysis. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), calibration, decision curve analysis (DCA), and compared with expert assessments by two nuclear medicine physicians. Results The best-performing model using partial-body input achieved AUCs of 0.80 (95% CI: 0.73, 0.86) in the internal test set, 0.84 (95% CI: 0.77, 0.91) in the external cohort, and 0.78 (95% CI: 0.73, 0.83) in the treatment test cohort. Calibration curves and DCA confirmed the models’ excellent discrimination, calibration, and potential clinical utility across internal and external datasets. The AUCs of both nuclear medicine physicians were lower than those of the best-performing deep learning model in external test set (AUC: 0.75 vs. 0.77 vs. 0.84). Conclusion Deep learning models utilizing partial-body input from planar whole-body bone scintigraphy demonstrate high discriminatory power for diagnosing SBI in NPC patients, surpassing experienced nuclear medicine physicians.

Abstract There are a myriad of head and neck pathologies that extend from the extracranial to the intracranial compartment, traversing the skull base, and knowledge of the imaging appearance of this pathology is critical to practicing neurosurgeons. This article reviews some of the important inflammatory or acquired head and neck pathology along the skull base, neoplastic skull base lesions, and the intracranial extension of head and neck malignancy. Focus will be on the relevant anatomy, appropriate imaging protocols to evaluate these processes, as well as the differentiating imaging findings on computed tomography and magnetic resonance imaging.

Abstract Chordomas are rare tumors of the axial skeleton that are refractory to conventional therapy. Few studies have compared the morphological and molecular characteristics of chordomas according to the skull base and sacral locations. Histopathological data and changes revealed by array comparative genomic hybridization (CGH) and next-generation sequencing (NGS) of cell cycle regulation genes were analyzed for 28 skull base (SBCs) and 15 sacral (SC) chordomas. All cases were conventional chordomas. SBCs were significantly more frequent in patients aged <40 years and SCs predominated in patients aged >60 years. Mitotic indices ≥2 mitoses/10 high-power fields were correlated with high degrees of nuclear atypia and Ki67 labeling indices ≥6%. We identified 321 genomic positions, and copy number variation losses were more frequent than gain. Moreover, we report a panel of 85 genetic variants of cell cycle genes and the presence of molecular clusters for chordoma as well in CGH as in NGS. These new data strengthen the view that the chordoma should not be considered as a single molecular entity.

Objective This is a case report of a dermoid cyst located in the infratemporal fossa and its surgical removal using infratemporal fossa type B approach. Case report A 15-year-old male was referred from a local clinic after an incidental finding of a mass lesion in the skull base area on computed tomography (CT). Pre-operative magnetic resonance imaging showed a large cystic mass lesion, expanding to the foramen ovale with fat component in the right infratemporal fossa region. The lesion was completely excised using an infratemporal fossa type B approach. Conclusion An extremely rare case of dermoid cysts of the infratemporal fossa was managed with infratemporal fossa type B approach without severe complication.

PurposeNon-vestibular schwannomas (NVSs) of the skull base occur in several sites, and few previous studies have evaluated the usefulness of the endoscopic endonasal transmaxillary-pterygoid approach (EETMPA) to resect these lesions. We aimed to evaluate the characteristics and clinical outcomes of patients who underwent EETMPA for skull-base NVSs and to investigate the efficacy, safety, and indications for the procedure.MethodsWe retrospectively reviewed the clinical data of 10 consecutive patients (mean age, 45 ± 17) who underwent EETMPA for skull-base NVSs at the University of Tsukuba hospital between 2013 and 2020. We also calculated the total tumor volume and the size of the corridor to the tumor for EEA (SCEEA) in nine patients who underwent EEA for NVSs adjacent to the Meckel’s cave or cavernous sinus.ResultsNine patients (9/10), including five women (5/10), underwent primary surgery. Gross total resection and subtotal resection were achieved in five patients each (5/10). Postoperatively, one patient showed a new and mild cranial nerve V sensory deficit and one patient showed slight worsening of abducens nerve palsy. The greater palatine nerve was amputated in two patients; however, permanent perception loss in the soft palate was observed in one patient. The Vidian nerve was sacrificed in four patients, and new dry eye occurred in one patient. None of the patients experienced postoperative tumor recurrence or regrowth during the follow-up period of 40 ± 28 months.ConclusionEETMPA is safe and effective for excising skull-base NVSs which are not eligible for radiosurgery leading to a high rate of successful resection and a high rate of but mild neurological sequela. The EEA is appropriate when the tumor extends to the paranasal sinus with sufficient SCEEA.

Modulation of tumor microenvironment is an emerging frontier for new therapeutics. However in meningiomas, the most frequent adult brain tumor, the correlation of microenvironment with tumor phenotype is scarcely studied. We applied a variety of systems biology approaches to bulk tumor transcriptomics to explore the immune environments of both skull base and convexity (hemispheric) meningiomas. We hypothesized that the more benign biology of skull base meningiomas parallels the relative composition and activity of immune cells that oppose tumor growth and/or survival. We firstly applied gene co-expression networks to tumor bulk transcriptomics from 107 meningiomas (derived from 3 independent studies) and found immune processes to be the sole biological mechanism correlated with anatomical location while correcting for tumour grade. We then derived tumor immune cell fractions from bulk transcriptomics data and examined the immune cell-cytokine interactions using a network-based approach. We demonstrate that oncolytic Gamma-Delta T cells dominate skull base meningiomas while mast cells and neutrophils, known to play a role in oncogenesis, show greater activity in convexity tumors. Our results are the first to suggest the importance of tumor microenvironment in meningioma biology in the context of anatomic location and immune landscape. These findings may help better inform surgical decision making and yield location-specific therapies through modulation of immune microenvironment.

The management of cerebrospinal fluid (CSF) fistulae after anterior cranial base fracture remains a surgical challenge. We reviewed our results in the repair of CSF fistulae complicating multiple anterior cranial base fractures via a combined intracranial extradural and intradural approach and describe a treatment algorithm derived from this experience. We retrospectively reviewed the files of 209 patients with an anterior cranial base fracture complicated by a CSF fistula who were admitted between 1980 and 2003 to Liège State University Hospital. Among those patients, 109 had a persistent CSF leak or radiological signs of an unhealed dural tear. All underwent the same surgical procedure, with combined extradural and intradural closure of the dural tear. Of the 109 patients, 98 patients (90%) were cured after the first operation. Persistent postoperative CSF rhinorrhea occurred in 11 patients (10%), necessitating an early complementary surgery via a transsphenoidal approach (7 patients) or a second-look intracranial approach (4 patients). No postoperative neurological deterioration attributable to increasing frontocerebral edema occurred. During the mean follow-up period of 36 months, recurrence of CSF fistula was observed in five patients and required an additional surgical repair procedure. The closure of CSF fistulae after an anterior cranial base fracture via a combined intracranial extradural and intradural approach, which allows the visualization and repair of the entire anterior base, is safe and effective. It is essentially indicated for patients with extensive bone defects in the cranial base, multiple fractures of the ethmoid bone and the posterior wall of the frontal sinus, cranial nerve involvement, associated lesions necessitating surgery such as intracranial hematomas, and post-traumatic intracranial infection. Rhinorrhea caused by a precisely located small tear may be treated with endoscopy.

Abstract BACKGROUND: Gamma knife radiosurgery (GKRS) is well established in the management of inaccessible, recurrent, or residual benign skull base meningiomas. Most series report clinical outcome parameters and complications in the short intermediate period after radiosurgery. Reports of long-term tumor control and neurological status are still lacking. OBJECTIVE: To report the presentation, treatment, and long-term outcome of skull base meningiomas after GKRS. METHODS: From a prospectively collected institutional review board-approved database, we selected patients with a World Health Organization grade I skull base meningioma treated with a single-session GKRS and a minimum of 60 months follow-up. One hundred thirty-five patients, 54.1% males (n = 73), form the cohort. Median age was 54 years (19–80). Median tumor volume was 4.7 cm3 (0.5–23). Median margin dose was 15 Gy (7.5–36). Median follow-up was 102.5 months (60.1–235.4). Patient and tumor characteristics were assessed to determine the predictors of neurological function and tumor progression. RESULTS: At last follow-up, tumor volume control was achieved in 88.1% (n = 119). Post-GKRS clinical improvement or stability was reported in 61.5%. The 5-, 10-, and 15-year actuarial progression-free survival rates were 100%, 95.4%, and 68.8%, respectively. Favorable outcome (both tumor control and clinical preservation/improvement) was attained in 60.8% (n = 79). Pre-GKRS performance status (Karnofsky Performance Scale) was shown to influence tumor progression (P = .001) and post-GKRS clinical improvement/preservation (P = .003). CONCLUSION: GKRS offers a highly durable rate of tumor control for World Health Organization grade I skull base meningiomas, with an acceptably low incidence of neurological deficits. The Karnofsky Performance Scale at the time of radiosurgery serves as a reliable long-term predictor of overall outcome.

Trigeminal schwannomas make up 0.8% to 8% of all intracranial schwannomas. To analyze our surgical experience with trigeminal schwannomas. We performed 107 operations on 105 patients harboring trigeminal schwannomas over the past 30 years. We classified the tumors as peripheral, ganglion cavernous, posterior fossa root, and dumbbell types according to the portion of the nerve that gave rise to the tumor. Fourteen were peripheral-type tumors (13.1%), 39 (36.4%) were ganglion cavernous type, 22 (20.6%) were posterior fossa root type, and 32 (30.0%) were dumbbell type. Sixty-five tumors were solid, 35 were mixed, and only 7 were cystic. Among solid tumors, 14 were vascular, fibrous, and adherent to adjacent structures. Total or near-total removal was performed in 86 cases (81.9%), and subtotal removal was achieved in 18 (17.1%). The most common symptom was facial hypesthesia, occurring in 69 patients. This symptom improved in 11 patients, persisted in 50 patients, and worsened in 8 patients after surgery. New postoperative hypesthesia was observed in 8 patients. The second most common symptom was facial pain, observed in 24 patients. Facial pain subsided in 22 and persisted in 2 patients after surgery. Diplopia was observed in 21 patients. This symptom improved postoperatively in 14 patients, persisted in 6 patients, and worsened in 1 patient. The present series demonstrates acceptable results using microsurgical treatment to remove trigeminal schwannomas. Pain and diplopia may be relieved after surgery; however, hypesthesia frequently remains or may be worsened by surgery.

Purpose Although reconstruction techniques after endoscopic skull base surgery have been improved, there are difficulties in reconstructing the skull base with a nasoseptal flap (NSF), especially in the case of high-flow cerebrospinal fluid (CSF) leak. The aim of this study was to analyze risk factors for the development of postoperative CSF leaks in terms of less experienced surgeon practices. Methods Retrospective review of medical records was performed for 125 patients who underwent endoscopic skull base surgery for intradural pathology with intraoperative high-flow CSF leakage between Oct 2012 and Apr 2017. Basic demographic data were collected, including body mass index (BMI), tumor pathology, comorbidities, and outcomes. To assess the learning curve effect, patients were divided into early cohort ( n  = 30) and late cohort ( n  = 95) groups. Results Overall postoperative CSF leakage was 10.4% (13/125) in this series. There were no significant risk factors for postoperative CSF leakage among the demographic data including BMI, comorbidities, or radiation history. Postoperative CSF leakage was most prevalent in the transclival approach than in other approaches, but the difference was not statistically significant (20.8%, p  = 0.351). When dividing the results by timetable, the patients who underwent skull base reconstruction in the early cohort experienced more postoperative CSF leakage (23.3%, 7 cases out of 30) than in the late cohort (6.3%, 6 cases out of 95, p  = 0.014). The learning curve was steeper in the early cohort (30 early cases 23.3%, 31–60 10%, 61–90 6.7%, 91–125 2.9%). Conclusions To improve the success rate of endoscopic skull base reconstruction, surgeons have to keep the basic technical details in mind to reduce the learning curve.