Utilizing tubular retractors in colloid cyst resection: A single surgeon experience.

Background: Colloid cysts are intracranial lesions originating from abnormalities in the primitive neuroepithelium folding of the third ventricle. Various surgical approaches have been explored for the management of colloid cysts, each carrying its own set of advantages and limitations. Tubular retractors developed recently alleviate retraction pressure through radial distribution, potentially offering benefits for colloid cyst resection. This study aims to introduce and assess a modified microsurgical method utilizing the tubular retractor for addressing colloid cysts. Methods: The study included a retrospective assessment of patients who had colloid cysts and who were treated between 2015 and 2023 by one experienced surgeon. The demographic, clinical, radiological, histological, and surgical data regarding these patients were evaluated. The patients were assessed using the colloid cyst risk score, indicating a risk for obstructive hydrocephalus. Results: The minimally invasive microsurgical approach was successfully applied to all 22 identified patients. No postoperative surgical complications were reported. Gross total resection was achieved in 21 (95.5%) patients. The early complication rate was 22.7% (n = 5). There were no postoperative seizures, permanent neurological deficits, or venous injuries. The average hospital stay was 3 days. There was no evidence of recurrence at an average follow-up length of 25.9 months. Conclusion: The transtubular approach is an effective, safe method for treating colloid cysts. It achieves complete cyst removal with minimal complications, offering the benefits of less invasiveness, improved visualization, and reduced tissue disruption, strengthening its role in colloid cyst surgery.

Pneumatization types of the dorsum sellae: a computed tomography study.

PURPOSE: The present work aimed to classify the pneumatization of the dorsum sellae (DS) in subjects aged 1-90 years. METHODS: The study consisted of computed tomography images of 1080 subjects (582 males / 498 females), aged 1-90 years (mean age: 45.51 ± 26.06 years). Four different types regarding DS pneumatization were defined as follows: Type 0: no pneumatization, Type 1: pneumatization < 50%, Type 2: pneumatization > 50%, and Type 3: total pneumatization. RESULTS: DS pneumatization was identified in 354 (32.8%) subjects (189 males and 165 females). Its pneumatization was identified in 51 (21.2%) out of 241 children, and 303 (36.1%) out of 839 adults. The frequency of DS pneumatization types was found as follows: Type 0 (no pneumatization in 726 subjects, 67.2%) > Type 1 (pneumatization < 50% in 234 subjects, 21.6%) > Type 2 (pneumatization > 50% in 87 subjects, 8.1%) > Type 3 (total pneumatization in 33 subjects, 3.1%). DS pneumatization incidence was affected by ages (p < 0.001), but not sex (p = 0.818). The pneumatization degrees of DS (i.e., the distributions of Types 1-3) were not affected by ages (p = 0.637) or sex (p = 0.391). CONCLUSION: The pneumatization incidence of DS increased significantly with advancing adult ages (especially in elderly people). DS pneumatization should be taken into account by neurosurgeons and neuroradiologists to decrease the risk of complications such as cerebrospinal fluid fistula during surgeries such as posterior clinoidectomy.

Surgical Management of Brain Metastasis from Esophageal Cancer: A Systematic Review and Single-Center Experience.

BACKGROUND: Brain metastases from esophageal cancer (BMEC) are rare and aggressive, with limited literature on optimal treatment modalities and a standard of care yet to be established. The objective of this study was to systematically review existing literature and perform a retrospective analysis of our institution's patients to evaluate the influence of different treatment modalities on patient outcomes. METHODS: A systematic review of the literature following Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines and a retrospective review of our institutional experience with BMEC were both conducted. Data based on mean survival,histology, metastasis location, and treatment modality were abstracted. RESULTS: A total of 48 studies representing 136 patients with BMEC were identified, in addition to the 11 patients treated at our institution. There were a total of 100 males (12 unreported), with a median age of 62.2 at diagnosis in our systematic review, along with 8 males with a median age of 62 in our institutional review. Collectively, survival rates observed based on histology were not similar (squamous cell carcinoma: 9.2 months, adenocarcinoma: 13.4 months), however, based on treatment modalities (surgery: 11.6 months, radiation: 10.4 months, chemotherapy: 12.3 months), and metastasis location (supratentorial: 10.5 months, infratentorial: 9.9 months), the survival times were comparable. CONCLUSIONS: Our review suggests that causes of death were often independent of brain metastases highlighting the need for further studies on early detection and prevention of primary esophageal cancer, as well as improved treatment modalities for BMECs.

Antisense Oligonucleotides for Rapid Translation of Gene Therapy in Glioblastoma.

PURPOSE: The limited efficacy of current treatments for malignant brain tumors necessitates novel therapeutic strategies. This study aimed to assess the potential of antisense oligonucleotides (ASOs) as adjuvant therapy for high-grade gliomas, focusing on their CNS penetration and clinical translation prospects. METHODS: A comprehensive review of the existing literature was conducted to evaluate the implications of ASOs in neuro-oncology. Studies that investigated ASO therapy's efficacy, CNS penetration, and safety profile were analyzed to assess its potential as a therapeutic intervention for high-grade gliomas. RESULTS: ASOs present a promising avenue for enhancing targeted gene therapies in malignant gliomas. Their potent CNS penetration, in vivo durability, and efficient transduction offer advantages over conventional treatments. Preliminary in vivo and in vitro studies suggest ASOs as a viable adjuvant therapy for high-grade gliomas, warranting further exploration in clinical trials. CONCLUSIONS: ASOs hold significant promise as adjuvant therapy for high-grade gliomas, offering improved CNS penetration and durability compared with existing treatments. While preliminary studies are encouraging, additional research is needed to establish the safety and efficacy of ASO therapy in clinical settings. Further investigation and clinical trials are warranted to validate ASOs as a transformative approach in neuro-oncology.

Minimally invasive resection of intracranial lesions using tubular retractors: A single surgeon series.

OBJECTIVE: Tubular retractors are increasingly used due to their low complication rates, providing easier access to lesions while minimizing trauma from brain retraction. Our study presents the most extensive series of cases performed by a single surgeon aiming to assess the effectiveness and safety of a transcortical-transtubular approach for removing intracranial lesions. METHODS: We performed a retrospective review of patients who underwent resection of an intracranial lesion with the use of tubular retractors. Electronic medical records were reviewed for patient demographics, preoperative clinical deficits, diagnosis, preoperative and postoperative magnetic resonance imaging (MRI) scans, lesion characteristics including location, volume, extent of resection (EOR), postoperative complications, and postoperative deficits. RESULTS: 112 transtubular resections for intracranial lesions were performed. Patients presented with a diverse number of pathologies including metastasis (31.3 %), GBM (21.4 %), and colloid cysts (19.6 %) The mean pre-op lesion volume was 14.45 cm3. A gross total resection was achieved in 81 (71.7 %) cases. Seventeen (15.2 %) patients experienced early complications which included confusion, short-term memory difficulties, seizures, meningitis and motor and visual deficits. Four (3.6 %) patients had permanent complications, including one with aphasia and difficulty finding words, another with memory loss, a third with left-sided weakness, and one patient who developed new-onset long-term seizures. Mean post-operative hospitalization length was 3.8 days. CONCLUSION: Tubular retractors provide a minimally invasive approach for the extraction of intracranial lesions. They serve as an efficient tool in neurosurgery, facilitating the safe resection of deep-seated lesions with minimal complications.

Laser interstitial thermal therapy in neurosurgery: a single-surgeon experience of 313 patients.

OBJECTIVE: Real-time MRI-guided focused laser interstitial thermal therapy (LITT) is a minimally invasive surgical treatment choice for challenging intracranial lesions that are either resistant to conventional therapies or located in deep or critical areas of the brain. However, existing studies on LITT within surgical neuro-oncology are relatively small and have limited follow-up periods. The authors aimed to present a comprehensive analysis of their experiences with LITT in surgical neuro-oncology, with the intent to provide a clearer understanding of the safety and efficacy of this procedure. METHODS: This study was an exploratory cohort analysis encompassing all patients who underwent LITT for brain tumors at a single center between 2013 and 2023. The primary focus was extent of ablation (EOA), time to recurrence (TTR), and overall survival (OS). Secondary outcomes, including the rate of complications, were also evaluated. Comparative analyses were conducted based on lesion subtypes, and factors predicting outcomes were identified. RESULTS: Three hundred thirteen patients underwent LITT procedures. During a mean follow-up of 10.4 months, 66.8% of patients remained alive and 26.2% of the ablated lesions recurred. The mean age of the cohort was 60.4 ± 13.3 years (58.5% female). The lesion subtypes that were treated comprised metastases (30%), glioblastoma (GBM; 41.6%), low-grade glioma (9.1%), radiation necrosis (11.4%), and meningioma (2.2%). The permanent neurological deficit rate was 14% (n = 44), with 25 (8%) of them new-onset deficits and 19 deficits (6.1%) that were present preoperatively and did not resolve after LITT. The mean TTR and OS were 12.2 and 38.1 months, respectively. TTR and OS varied significantly by lesion subtype (p < 0.001, log-rank analysis). A high-grade lesion was identified as the single factor linked to tumor recurrence. Age, high-grade lesion, preoperative lesion volume, and readmission within 30 days were identified as factors significantly associated with OS in the multivariable Cox regression analysis. EOA > 100% predicted longer OS in metastases and GBM by log-rank analysis. CONCLUSIONS: LITT stands as a secure and feasible ablative treatment choice for intracranial lesions, potentially suitable for specific patient cases otherwise not amenable to surgical intervention. These findings further corroborate the safety of the procedure and its favorable outcomes, underscoring its potential significance in clinical practice.

Repeat endoscopic endonasal transsphenoidal surgery for residual or recurrent cushing's disease: safety, feasibility, and success.

PURPOSE: The success and outcomes of repeat endoscopic transsphenoidal surgery (ETS) for residual or recurrent Cushing's disease (CD) are underreported in the literature. This study aims to address this gap by assessing the safety, feasibility, and efficacy of repeat ETS in these patients. METHODS: A retrospective analysis was conducted on 56 patients who underwent a total of 65 repeat ETS performed by a single neurosurgeon between January 2006 and December 2020. Data including demographic, clinical, laboratory, radiological, and operative details were collected from electronic medical records. Logistic regression was utilized to identify potential predictors associated with sustained remission. RESULTS: Among the cases, 40 (61.5%) had previously undergone microscopic surgery, while 25 (38.5%) had prior endoscopic procedures. Remission was achieved in 47 (83.9%) patients after the first repeat ETS, with an additional 9 (16.1%) achieving remission after the second repeat procedure. During an average follow-up period of 97.25 months, the recurrence rate post repeat surgery was 6.38%. Sustained remission was achieved in 48 patients (85.7%), with 44 after the first repeat ETS and 4 following the second repeat ETS. Complications included transient diabetes insipidus (DI) in 5 (7.6%) patients, permanent (DI) in 2 (3%) patients, and one case (1.5%) of panhypopituitarism. Three patients (4.6%) experienced rhinorrhea necessitating reoperation. A serum cortisol level > 5 µg/dL on postoperative day 1 was associated with a reduced likelihood of sustained remission. CONCLUSION: Repeat ETS is a safe and effective treatment option for residual or recurrent CD with satisfactory remission rates and low rates of complications.

Quantitative assessment and objective improvement of the accuracy of neurosurgical planning through digital patient-specific 3D models.

Objective: Neurosurgical patient-specific 3D models have been shown to facilitate learning, enhance planning skills and improve surgical results. However, there is limited data on the objective validation of these models. Here, we aim to investigate their potential for improving the accuracy of surgical planning process of the neurosurgery residents and their usage as a surgical planning skill assessment tool. Methods: A patient-specific 3D digital model of parasagittal meningioma case was constructed. Participants were invited to plan the incision and craniotomy first after the conventional planning session with MRI, and then with 3D model. A feedback survey was performed at the end of the session. Quantitative metrics were used to assess the performance of the participants in a double-blind fashion. Results: A total of 38 neurosurgical residents and interns participated in this study. For estimated tumor projection on scalp, percent tumor coverage increased (66.4 ± 26.2%-77.2 ± 17.4%, p = 0.026), excess coverage decreased (2,232 ± 1,322 mm2-1,662 ± 956 mm2, p = 0.019); and craniotomy margin deviation from acceptable the standard was reduced (57.3 ± 24.0 mm-47.2 ± 19.8 mm, p = 0.024) after training with 3D model. For linear skin incision, deviation from tumor epicenter significantly reduced from 16.3 ± 9.6 mm-8.3 ± 7.9 mm after training with 3D model only in residents (p = 0.02). The participants scored realism, performance, usefulness, and practicality of the digital 3D models very highly. Conclusion: This study provides evidence that patient-specific digital 3D models can be used as educational materials to objectively improve the surgical planning accuracy of neurosurgical residents and to quantitatively assess their surgical planning skills through various surgical scenarios.

Machine learning applications in craniosynostosis diagnosis and treatment prediction: a systematic review.

Craniosynostosis refers to the premature fusion of one or more of the fibrous cranial sutures connecting the bones of the skull. Machine learning (ML) is an emerging technology and its application to craniosynostosis detection and management is underexplored. This systematic review aims to evaluate the application of ML techniques in the diagnosis, severity assessment, and predictive modeling of craniosynostosis. A comprehensive search was conducted on the PubMed and Google Scholar databases using predefined keywords related to craniosynostosis and ML. Inclusion criteria encompassed peer-reviewed studies in English that investigated ML algorithms in craniosynostosis diagnosis, severity assessment, or treatment outcome prediction. Three independent reviewers screened the search results, performed full-text assessments, and extracted data from selected studies using a standardized form. Thirteen studies met the inclusion criteria and were included in the review. Of the thirteen papers examined on the application of ML to the identification and treatment of craniosynostosis, two papers were dedicated to sagittal craniosynostosis, five papers utilized several different types of craniosynostosis in the training and testing of their ML models, and six papers were dedicated to metopic craniosynostosis. ML models demonstrated high accuracy in identifying different types of craniosynostosis and objectively quantifying severity using innovative metrics such as metopic severity score and cranial morphology deviation. The findings highlight the significant strides made in utilizing ML techniques for craniosynostosis diagnosis, severity assessment, and predictive modeling. Predictive modeling of treatment outcomes following surgical interventions showed promising results, aiding in personalized treatment strategies. Despite methodological diversities among studies, the collective evidence underscores ML's transformative potential in revolutionizing craniosynostosis management.

Creating a neuroanatomy education model with augmented reality and virtual reality simulations of white matter tracts.

OBJECTIVE: The utilization of digital technologies has experienced a notable surge, particularly in cases where access to cadavers is constrained, within the context of practical neuroanatomy training. This study evaluates augmented reality (AR)- and virtual reality (VR)-based educational models for neuroanatomy education. METHODS: Three-dimensional models were created using advanced photogrammetry. VR- and AR-based educational models were developed by arranging these 3D models to align with the learning objectives of neurosurgery residents and second-year medical students whose cadaveric training was disrupted due to an earthquake in Turkey. Participants engaged with and evaluated the VR- and AR-based educational models, followed by the completion of a 20-item graded user experience survey. A 10-question mini-test was given to assess the baseline knowledge level prior to training and to measure the achievement of learning objectives after training. RESULTS: Forty neurosurgery residents were trained with a VR-based educational model using VR headsets. An AR-based educational model was provided online to 200 second-year medical students for their practical neuroanatomy lesson. The average correct answer rates before the training were 7.5/10 for residents and 4.8/10 for students. These rates were significantly improved after the training to 9.7/10 for residents and to 8.7/10 for students (p < 0.001). Feedback from the users concurred that VR- and AR-based training could significantly enhance the learning experience in the field of neuroanatomy. CONCLUSIONS: VR/AR-based educational models have the potential to improve education. VR/AR-based training systems can serve as an auxiliary tool in neuroanatomy training, offering a realistic alternative to traditional learning tools.

Human Adapted Prosomeric Model: A Future for Brainstem Tumor Classification.

This study reevaluates the conventional understanding of midbrain anatomy and neuroanatomical nomenclature in the context of recent genetic and anatomical discoveries. The authors assert that the midbrain should be viewed as an integral part of the forebrain due to shared genetic determinants and evolutionary lineage. The isthmo-mesencephalic boundary is recognized as a significant organizer for both the caudal midbrain and the isthmo-cerebellar area. The article adopts the prosomeric model, redefining the whole brain as neuromeres, offering a more precise depiction of brain development, including processes like proliferation, neurogenesis, cell migration, and differentiation. This shift in understanding challenges traditional definitions of the midbrain based on external brain morphology. The study also delves into the historical context of neuroanatomical models, including the columnar model proposed by Herrick in 1910, which has influenced our understanding of brain structure. Furthermore, the study has clinical implications, affecting neuroanatomy, neurodevelopmental studies, and the diagnosis and treatment of brain disorders. It emphasizes the need to integrate molecular research into human neuroanatomical studies and advocates for updating neuroanatomical terminology to reflect modern genetic and molecular insights. The authors propose two key revisions. First, we suggest reclassifying the isthmo-cerebellar prepontine region as part of the hindbrain, due to its role in cerebellar development and distinct location caudal to the genetically-defined midbrain. Second, we recommend redefining the anterior boundary of the genetically-defined midbrain to align with genetic markers. In conclusion, the authors highlight the importance of harmonizing neuroanatomical nomenclature with current scientific knowledge, promoting a more precise and informed understanding of brain structure, which is crucial for both research and clinical applications related to the human brain.

Comparative analysis of bevacizumab and LITT for treating radiation necrosis in previously radiated CNS neoplasms: a systematic review and meta-analysis.

PURPOSE: Radiation necrosis (RN) is a local inflammatory reaction that arises in response to radiation injury and may cause significant morbidity. This study aims to evaluate and compare the efficacy of bevacizumab and laser interstitial thermal therapy (LITT) in treating RN in patients with previously radiated central nervous system (CNS) neoplasms. METHODS: PubMed, Cochrane, Scopus, and EMBASE databases were screened. Studies of patients with radiation necrosis from primary or secondary brain tumors were included. Indirect meta-analysis with random-effect modeling was performed to compare clinical and radiological outcomes. RESULTS: Twenty-four studies were included with 210 patients in the bevacizumab group and 337 patients in the LITT group. Bevacizumab demonstrated symptomatic improvement/stability in 87.7% of cases, radiological improvement/stability in 86.2%, and steroid wean-off in 45%. LITT exhibited symptomatic improvement/stability in 71.2%, radiological improvement/stability in 64.7%, and steroid wean-off in 62.4%. Comparative analysis revealed statistically significant differences favoring bevacizumab in symptomatic improvement/stability (p = 0.02), while no significant differences were observed in radiological improvement/stability (p = 0.27) or steroid wean-off (p = 0.90). The rates of adverse reactions were 11.2% for bevacizumab and 14.9% for LITT (p = 0.66), with the majority being grade 2 or lower (72.2% for bevacizumab and 62.5% for LITT). CONCLUSION: Both bevacizumab and LITT exhibited favorable clinical and radiological outcomes in managing RN. Bevacizumab was found to be associated with better symptomatic control compared to LITT. Patient-, diagnosis- and lesion-related factors should be considered when choosing the ideal treatment modality for RN to enhance overall patient outcomes.

Chat-GPT on brain tumors: An examination of Artificial Intelligence/Machine Learning's ability to provide diagnoses and treatment plans for example neuro-oncology cases.

OBJECTIVE: Assess the capabilities of ChatGPT-3.5 and 4 to provide accurate diagnoses, treatment options, and treatment plans for brain tumors in example neuro-oncology cases. METHODS: ChatGPT-3.5 and 4 were provided with twenty example neuro-oncology cases of brain tumors, all selected from medical textbooks. The artificial intelligence programs were asked to give a diagnosis, treatment option, and treatment plan for each of these twenty example cases. Team members first determined in which cases ChatGPT-3.5 and 4 provided the correct diagnosis or treatment plan. Twenty neurosurgeons from the researchers' institution then independently rated the diagnoses, treatment options, and treatment plans provided by both artificial intelligence programs for each of the twenty example cases, on a scale of one to ten, with ten being the highest score. To determine whether the difference between the scores of ChatGPT-3.5 and 4 was statistically significant, a paired t-test was conducted for the average scores given to the programs for each example case. RESULTS: In the initial analysis of correct responses, ChatGPT-4 had an accuracy of 85% for its diagnoses of example brain tumors and an accuracy of 75% for its provided treatment plans, while ChatGPT-3.5 only had an accuracy of 65% and 10%, respectively. The average scores given by the twenty independent neurosurgeons to ChatGPT-4 for its accuracy of diagnosis, provided treatment options, and provided treatment plan were 8.3, 8.4, and 8.5 out of 10, respectively, while ChatGPT-3.5's average scores for these categories of assessment were 5.9, 5.7, and 5.7. These differences in average score are statistically significant on a paired t-test, with a p-value of less than 0.001 for each difference. CONCLUSIONS: ChatGPT-4 demonstrates great promise as a diagnostic tool for brain tumors in neuro-oncology, as attested to by the program's performance in this study and its assessment by surveyed neurosurgeon reviewers.

A Novel Foley Catheter-Based Brain Retraction Method for the Interhemispheric Approach: Technical Considerations and an Illustrative Video.

BACKGROUND: Management of interhemispheric pathologies requires surgical intervention through a restricted anatomical corridor ensconced within critical cerebral structures. The use of retractors to facilitate operative access may cause damage to cerebral tissue. The development of an innovative retraction technique designed to alleviate cerebral damage in such cases is imperative. In this study, we present a novel and gentle retraction method to facilitate the interhemisferic approach. METHODS: We retrospectively examined data of 9 right-handed patients who underwent surgical resection of interhemispheric lesions between 2021 and 2022. All patients underwent surgery for the first time because of this pathology. All operative specimens were histologically confirmed. Clinical characteristics, operative details, and follow-up data were retrospectively analyzed. RESULTS: The new retraction technique was successfully applied to 8 tumor patients and 1 patient with an aneurysm. Eight patients had an anterior interhemispheric approach, and 1 patient had a posterior interhemispheric approach. Complete surgical excision was achieved in all patients with no postoperative complications. Postoperative Gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) showed no signs of ischemia or contusion. All patients exhibited significant improvements in their symptoms. An illustrative video that elucidates the removal of an interhemispheric epidermoid tumor, employing the anterior ipsilateral interhemispheric approach, featuring the novel retraction method. CONCLUSIONS: The ideal retraction technique during the interhemispheric approach is still a challenge. Our novel retraction technique may help minimize brain parenchymal damage during surgical resection of interhemispheric lesions.

Duraplasty with autologous cervical fascia in pediatric posterior fossa tumor surgery: a single-center experience with 214 cases.

PURPOSE: Posterior fossa surgeries for pediatric tumors pose challenges in achieving optimal dural repair and duraplasty is usually required. Autografts, allografts, xenografts, and synthetic substitutes can be used for duraplasty. Autologous cervical fascia can be a safe and reliable graft option for duraplasty after posterior fossa surgeries. This study aims to investigate the outcomes of duraplasty with autologous cervical fascial graft in children after posterior fossa surgery for pediatric brain tumors. METHODS: Pediatric patients with posterior fossa tumor who underwent surgery between March 2001 and August 2022 were retrospectively reviewed. Data on demographics, preoperative symptoms, diagnosis, tumor characteristics, hydrocephalus history, and postoperative complications, including cerebrospinal fluid (CSF) leakage, pseudomeningocele, and meningitis were collected. Logistic regression analysis was performed to explore risk factors for postoperative complications. RESULTS: Patient cohort included 214 patients. Autologous cervical fascia was used in all patients for duraplasty. Mean age was 7.9 ± 5.3 years. Fifty-seven patients (26.6%) had preoperative hydrocephalus and 14 patients (6.5%) received VPS or EVD perioperatively. Postoperative hydrocephalus was present in 31 patients (14.5%). Rates of CSF leak, pseudomeningocele, and meningitis were 4.2%, 2.8%, and 4.2% respectively. Logistic regression analysis revealed that postoperative EVD and VPS placement were the factors associated with postoperative complications. CONCLUSION: Autologous cervical fascia is a safe and reliable option for duraplasty with minimal risk of postoperative complications. The straightforward surgical technique and with no additional cost for harvesting the graft renders autologous cervical fascia a favorable alternative for resource-limited countries or surgical settings.

The Learning Curve and Clinical Outcomes With 250 Laser Ablations for Brain Tumors: A Pathway to Experience.

BACKGROUND AND OBJECTIVES: Laser interstitial thermal therapy (LITT) has gained popularity as a minimally invasive technique for treating brain tumors. Despite its proven safety profile, LITT is not yet widely available, and there is a lack of data on the learning curve required to achieve proficiency. This study analyzes a 250-patient cohort of laser-ablated tumors to describe changes in patient selection and clinical outcomes over time and experience, with the aim of providing insight into the learning curve for incorporating LITT into a neuro-oncology program and identifying a cutoff point that distinguishes novice from expert performance. METHODS: We retrospectively reviewed 250 patients with brain tumor who underwent LITT between 2013 and 2022. Demographic and clinical data were analyzed. Kaplan Meier curves were used for survival analysis. Operative time was evaluated using exponential curve-fit regression analysis to identify when consistent improvement began. RESULTS: The patients were divided into quartiles (Q) based on their date of surgery. Mean tumor volume increased over time (Q1 = 5.7 and Q4 = 11.9 cm3, P = .004), and newly diagnosed lesions were more frequently ablated (P = .0001). Mean operative time (Q1 v Q4 = 322.3 v 204.6 min, P < .0001) and neurosurgical readmission rate (Q1 v Q4 = 7.8% v 0%, P = .03) were reduced over time. The exponential curve-fit analysis showed a sustained decay in operative time after case #74. The extent of ablation (P = .69), the recurrence (P = .11), and the postoperative complication rate (P = .78) did not vary over time. CONCLUSION: After treating 74 patients, a downward trend in the operative time is observed. Patient selection is broadened as experience increases.

Intrathecal chemotherapy for leptomeningeal disease in high-grade gliomas: a systematic review.

BACKGROUND: Leptomeningeal disease (LMD) secondary to high grade glioma (HGG), such as glioblastoma (GBM), are characterized by the spread of tumor cells to the leptomeninges which further complicates treatment approaches. Intrathecal (IT) chemotherapy has surfaced as a potential strategy to bypass the blood-brain barrier and address the challenges posed by disseminated disease. Here, we present a review of the safety and efficacy of IT chemotherapy in the treatment of LMD secondary to HGG. METHODS: A systematic review following PRISMA guidelines was conducted searching PubMed and Embase from January 1995 to September 2022 using specified terms related to IT chemotherapy for LMD. Included articles involved patients diagnosed with LMD from HGG, treated with intrathecal chemotherapy, and provided survival data. Data, including demographics, tumor characteristics, treatment, and survival information, were collected and independently extracted. RESULTS: A total of 68 patients across 10 clinical studies were diagnosed with LMD from HGG and included in the review. Among these patients, the average age at diagnosis was 44.2 years. GBM was the most common tumor type (n = 58, 85.3%). A majority of the patients presented with recurrent disease (n = 29, 60.4%). The review encompassed various IT chemotherapy regimens, including mafosfamide, thio-TEPA, 5-fluoro-2'-deoxyuridine (FdUrd), methotrexate (MTX), and cytarabine; however, dosages and frequencies were inconsistently reported. The mean progression-free survival (PFS) and overall survival (OS) for this cohort were 7.5 months and 11.7 months, respectively. Common side effects of IT chemotherapy included headaches, nausea, and vomiting, with more severe complications such as myelotoxicity, disseminated intravascular coagulopathy, meningitis, and gastrointestinal toxicity reported in some cases. CONCLUSION: LMD continues to be an uncommon complication associated with HGG with a poor prognosis. This article provides an overview of the presently available literature on IT chemotherapy for LMD secondary to HGG, and their respective treatment protocols with overall survival attributes. Additional research is warranted to ascertain how to maximize the potential efficacy of IT chemotherapy as a treatment option.

Interactive microsurgical anatomy education using photogrammetry 3D models and an augmented reality cube.

OBJECTIVE: This study sought to assess the use of an augmented reality (AR) tool for neurosurgical anatomical education. METHODS: Three-dimensional models were created using advanced photogrammetry and registered onto a handheld AR foam cube imprinted with scannable quick response codes. A perspective analysis of the cube anatomical system was performed by loading a 3D photogrammetry model over a motorized turntable to analyze changes in the surgical window area according to the horizontal rotation. The use of the cube as an intraoperative reference guide for surgical trainees was tested during cadaveric dissection exercises. Neurosurgery trainees from international programs located in Ankara, Turkey; San Salvador, El Salvador; and Moshi, Tanzania, interacted with and assessed the 3D models and AR cube system and then completed a 17-item graded user experience survey. RESULTS: Seven photogrammetry 3D models were created and imported to the cube. Horizontal turntable rotation of the cube translated to measurable and realistic perspective changes in the surgical window area. The combined 3D models and cube system were used to engage trainees during cadaveric dissections, with satisfactory user experience. Thirty-five individuals (20 from Turkey, 10 from El Salvador, and 5 from Tanzania) agreed that the cube system could enhance the learning experience for neurosurgical anatomy. CONCLUSIONS: The AR cube combines tactile and visual sensations with high-resolution 3D models of cadaveric dissections. Inexpensive and lightweight, the cube can be effectively implemented to allow independent co-visualization of anatomical dissection and can potentially supplement neurosurgical education.

Defining the Temporal and Occipital Lobes: Cadaveric Study with Application to Neurosurgery of the Inferior Brain.

BACKGROUND: For surgical interventions, a precise understanding of the anatomical variations of the brain and defined anatomical landmarks to demarcate the regions of the temporal lobe is essential. Many anatomical studies have facilitated important surgical approaches to the temporobasal region. Because there is considerable sulcal variability, morphological analysis of the brain is imperative. The aim of this study was to define the boundaries of the temporal and occipital lobes and to define the variations in sulci and gyri in the inferior aspect. METHODS: In 110 cerebral hemispheres variations were identified and the major landmarks of the gyral-sulcal pattern at the inferior aspect of the brain were defined. RESULTS: The anatomy of the inferior aspect of the brain is defined in detail by morphological analysis of formalin-fixed hemispheres with a view to informing important surgical approaches. CONCLUSIONS: Since the literature defines no clear separation between the temporal and occipital lobes, certain landmarks such as the preoccipital notch and a basal temporo-occipital line were suggested as ways of making the distinction. The parahippocampal ramus is a constant structure that can be used as a reliable landmark for the posterior end of the hippocampus.