ABSTRACT Background Olfactory neuroblastoma (ONB) exhibits variable recurrence patterns, with significant late recurrences occurring years after treatment. We investigated cutoff periods to define late recurrence and identified predictors that distinguish patients at risk of late recurrence from those considered cured. Methods From a multi‐institutional cohort of 219 ONB patients treated at nine centers, we analyzed 77 patients with documented recurrence. Using a 48‐month cutoff to define early (< 48 months) versus late (≥ 48 months) recurrence, we evaluated 35 clinical, anatomic, and treatment variables using Firth penalized logistic regression across three comparisons: (1) late versus early recurrence timing, (2) late recurrence versus no recurrence, and (3) early recurrence versus no recurrence. Results Thirty‐four of the 77 (44.2%) recurrences were classified as late. Among the 77 patients who recurred, smaller tumor volume (OR 0.243, p = 0.035) and lower novel Dulguerov staging (OR 0.802, p = 0.038) were associated with late, rather than early recurrence. When patients with late recurrence were compared to those who remained disease‐free, radiographic skull base bone involvement was the strongest independent predictor (OR 2.90, 95% CI 1.14–8.64, p = 0.025), and this effect strengthened after adjusting for tumor volume (OR 3.80, p = 0.029). Pathologic dural invasion (OR 3.29, p = 0.013), Kadish stage (OR 2.02, p = 0.026), and T‐stage (OR 1.32, p = 0.040) were also significant. Conclusions A 48‐month cutoff effectively stratifies ONB recurrence risk. Skull base bone involvement independently predicts recurrence when compared to nonrecurrent cases and uniquely persists as a risk factor for late recurrence. These findings establish skull base bone involvement as a novel biomarker for risk‐stratified surveillance protocols.
Relations of the Anterior Cavernous Sinus and Internal Carotid Artery in an Endoscopic Perspective; Anatomical and Surgical Implications
Abstract Objective: Reading is a complex cognitive process requiring the integration of orthographic, phonological, and semantic information. The visual word form area, located in the ventral occipitotemporal cortex, is critically involved in orthographic decoding, and damage to this region is known to cause alexia. In contrast, the contributions of white matter pathways supporting reading are less well understood. Method: We present a unique neurosurgical case undergoing awake brain surgery for resection of a metastasis in the left occipitotemporal cortex. A tubular retractor was used to access the lesion and during the insertion of the retractor the patient underwent careful, continuous neuropsychological testing, including evaluation of reading. fMRI language mapping and diffusion MRI were performed preoperatively. Postoperative neuropsychological testing was completed two weeks after surgery to assess cognitive outcome. Results: The patient developed an alexia with letter-by-letter reading in real time during insertion of the tubular retractor. Stealth imaging enabled localization of the tubular retractor at the exact onset of the alexia and, by correlating this with tractography, showed that the tubular retractor was in the vertical occipital fasciculus (VOF). Conclusions: We present the first detailed case report linking the VOF to the acute onset of alexia observed intraoperatively during awake brain surgery. We discuss the connectomics of reading and possible contributions of the VOF in reading.
Proton Beam vs Intensity-Modulated Radiotherapy in Olfactory Neuroblastoma
Importance Adjuvant radiotherapy can improve locoregional control and survival in patients with olfactory neuroblastoma (ONB), particularly with advanced-stage and histologic-grade disease. Standard radiotherapy treatment is with intensity-modulated radiotherapy (IMRT). Proton beam radiotherapy (PBRT) provides theoretical advantages in greater sparing of dose to uninvolved organs at risk. Objective To investigate if there are differences in the effectiveness and radiation treatment–related adverse events (RTAEs) between adjuvant IMRT and PBRT for patients with ONB. Design, Setting, and Participants This propensity score–matched cohort study included patients with ONB treated between February 2005 and April 2021 with either IMRT or PBRT at 9 academic tertiary care centers in North America. Patients were matched 1:2 based on age, modified Kadish stage, and Hyams grade. Data were analyzed from July 2024 to January 2025. Exposure Adjuvant IMRT or adjuvant PBRT. Main Outcomes and Measures Local recurrence-free survival (RFS), any RFS, and overall survival (OS). RTAEs, ie, grade 2 events or higher based on Common Terminology Criteria for Adverse Events, were recorded for both modalities. Results Of 54 included patients, 27 (50%) were female, and the mean (SD) age was 46.2 (15.4) years. A total of 18 were treated with PBRT and 36 were treated with IMRT. Most patients had modified Kadish stage C disease (33 of 54 [61%]), and 24 patients (44%) had Hyams grade III or IV disease. The RTAE rate was 20% (8 of 40); IMRT had a rate of 21% (6 of 29), and PBRT had a rate of 18% (2 of 11). The difference in the point estimates for 10-year RFS showed a potential clinical benefit favoring IMRT, although the wide confidence interval indicates uncertainty (10-year RFS: IMRT, 63.3%; 95% CI, 44.6-89.8; PBRT, 37.8%; 95% CI, 14.2-100; difference, 25.5 percentage points; 95% CI, −17.6 to 68.6). There were no clinically meaningful differences in 10-year local RFS (IMRT, 75.6%; 95% CI, 59.8-95.4; PBRT, 72.7%; 95% CI, 45.2-100; difference, 2.9 percentage points; 95% CI, −35.9 to 41.7) or 10-year OS (IMRT, 61.8%; 95% CI, 42.8-89.1; PBRT, 57.1%; 95% CI, 24.3-100; difference, 4.7 percentage points; 95% CI, −49.2 to 58.6), although wide confidence intervals indicate considerable uncertainty. Conclusions and Relevance Due to the imprecision of estimates, no definitive conclusions can be made regarding the comparative effectiveness of IMRT vs PBRT for patients with ONB. These preliminary data may inform the design of appropriately powered prospective studies evaluating the efficacy of PBRT vs IMRT in this population.
Surgical Management of a Painful Temporal Bone En Plaque Meningioma: A Case Report and Review of the Literature
AbstractTemporal bone en plaque meningiomas can present management challenges, particularly when accompanied by severe pain. We report the case of a 42-year-old woman who was initially diagnosed with chronic otitis media but was later found to have a painful left temporal bone en plaque meningioma. Despite conservative therapy, her pain progressed, prompting the decision to undergo surgical resection, which resulted in considerable pain relief. This report illustrates the influence of pain on surgical decision-making for temporal bone en plaque meningiomas and reviews the literature on their variable presentations and management strategies.
Applicability of a Dexterity-Enhancing Handheld Robot for 360° Endoscopic Skull Base Approaches: An Exploratory Cadaver Study
BACKGROUND AND OBJECTIVES: Endoscopic skull base surgery aims to reduce surgical morbidity by minimizing tissue manipulation and exposure. However, the anatomic constraints posed by the narrow surgical corridors and constrained operative workspace present technical challenges due to reduced dexterity. This study evaluates the applicability of a novel dexterity-enhancing handheld robot for endoscopic skull base approaches. METHODS: The robotic system is comprised of interchangeable articulated end-effectors coupled to a handheld controller. Two attending skull base neurosurgeons and 2 neurosurgery residents performed 8 skull base approaches on cadaveric specimens, spanning anterior, anterolateral, lateral, posterolateral, and posterior approaches. Conventional instruments were used to expose anatomic landmarks, followed by intraoperative tasks using the handheld robot. Participants were interviewed during the procedures to assess the robot's feasibility (ability to safely reach and perform its objective of manipulating tissue at the operative site) and usefulness (ability to perform desired objectives well). RESULTS: The handheld robotic system was tested across 8 endoscopic skull base approaches, achieving feasibility in all cases. Superior workspace reach compared with standard instruments was demonstrated in 6 of 8 approaches. Tissue manipulation was satisfactory in all approaches. All surgeons reported that the current or a future device prototype could be useful across all 8 approaches. The most frequently cited advantage was the expanded dextrous workspace reach provided by the articulated end-effectors, particularly in approaches with long working channels, such as the endonasal approach. However, the robot encountered difficulties in transcranial approaches (trans-sylvian and subtemporal) due to the lack of shorter, curved shafts, which impaired visualization. CONCLUSION: The handheld robotic system demonstrated applicability across various endoscopic skull base approaches, offering increased dextrous workspace and effective tissue manipulation capabilities. Overall, this study supports the potential of handheld robots in endoscopic skull base surgery while highlighting the need for iterative development to optimize instrument design and functionality.
Exploring the Feasibility of a Handheld Robot for 360-Degree Skull Base Surgical Approaches: A Cadaver Study
“From above and Below”: The Surgical Anatomy of Interhemispheric Transtentorial and Supracerebellar Infratentorial Approaches to Access the Pineal Region—A Cadaveric Dissection