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.

Incidence of tethered cord syndrome in neurofibromatosis types 1 and 2 pediatric patients: a population-level analysis.

PURPOSE: Tethered spinal cord syndrome (TCS) is characterized by cutaneous attachments on the filum terminale that stretch the spinal cord, leading to musculoskeletal and urogenital sequelae. While the neurocutaneous associations with TCS remain undefined, a recent study reports a high incidence of TCS among a pediatric neurofibromatosis (NF) cohort. This present study utilizes a population-level database to estimate TCS incidence among pediatric patients with neurofibromatosis types 1 and 2 (NF1, NF2). METHODS: The TriNetX Research Network was queried to identify patients diagnosed with NF and/or TCS before the age of 21. Symptomatic TCS requiring surgical intervention was identified using corresponding procedural codes within 12 months following TCS diagnosis. Odds ratios (OR) were calculated to measure the associations of NF1/NF2 with TCS. RESULTS: 19,426 pediatric NF patients were evaluated (NF1: 18,383, NF2: 1042). The average ages of TCS diagnosis among NF1, NF2, and non-NF patients were 12, 16, and 9 years, respectively. The incidence of TCS was 1.2% in NF1 patients and 7.3% in NF2 patients, compared to 0.074% in the general population. The associations of NF incidence with TCS were significantly increased in both NF1 (OR 16.42; 14.38-18.76) and NF2 (OR 105.58; 83.56-133.40) patients compared to the general population. Symptomatic TCS requiring surgical intervention was not significantly associated with NF1/NF2 patients compared to the general TCS population. CONCLUSION: This analysis demonstrates a high incidence of TCS but delayed intervention in pediatric NF patients. Considering TCS counseling, spinal MRI, and earlier intervention may be warranted for NF patients experiencing musculoskeletal symptomatology.

Outcomes of HSV-1 encephalitis infection in glioblastoma: An integrated systematic analysis.

INTRODUCTION: Herpes Simplex Virus-1 (HSV-1) is a neurotropic DNA virus with neural latency and stereotypic viral encephalitis. It has been reported to conceal underlying glioblastoma (GBM) due to similar radiographic imaging and clinical presentation. Limited data exist on the co-occurrence of GBM and HSV-1. To better describe the pathophysiology of HSV-1 superinfections in GBM, we performed a comprehensive review of GBM cases with superimposed HSV-1. METHODS: A comprehensive literature search of six electronic databases with apriori search criteria was performed to identify eligible cases of GBM with HSV-1. Relevant clinic-radiographic data were collected, Kaplan-Meier estimates, Fisher's exact test, and logistic regression analyses were used. RESULTS: We identified 20 cases of HSE in GBM with an overall survival (OS) of 8.0 months. The median age of presentation was 63 years (range: 24-78 years) and the median interval between GBM or HSE diagnosis was 2 months (range: 0.05-25 months). HSE diagnosis before GBM diagnosis was a predictor for improved survival (HR: 0.06; 95% CI: [0.01-0.54]; p < 0.01). There is a significant reduction in OS in patients with concomitant HSE and GBM compared to the cancer genome atlas (TCGA) cohort (median OS: 8 months vs. 14.2 months; p < 0.05). Finally, HSV does not directly infect GBM cells but indirectly activates a local immune response in the tumor microenvironment. CONCLUSIONS: Superimposed HSE in GBM may contribute to a significant reduction in OS compared to uninfected controls, potentially activating proto-oncogenes during active infection and latency. Preoperative HSE may induce an antiviral immune response, which may serve as a positive prognostic factor. Prompt antiviral treatment upon co-occurrence is necessary.

Towards the definition of progressive disease in brain metastasis treated with laser ablation: an evidence-based study.

PURPOSE: The postoperative period after laser interstitial thermal therapy (LITT) is marked by a temporary increase in volume, which can impact the accuracy of radiographic assessment. The current criteria for progressive disease (PD) suggest that a 20% increase in size of brain metastasis (BM) assessed in 6-12 weeks intervals should be considered as local progression (LP). However, there is no agreement on how LP should be defined in this context. In this study, we aimed to statistically analyze which tumor volume variations were associated with LP. METHODS: We analyzed 40 BM that underwent LITT between 2013 and 2022. For this study, LP was defined following radiographic features. A ROC curve was generated to evaluate volume change as a predictor of LP and find the optimal cutoff point. A logistic regression analysis and Kaplan Meier curves were performed to assess the impact of various clinical variables on LP. RESULTS: Out of 40 lesions, 12 (30%) had LP. An increase in volume of 25.6% from baseline within 120-180 days after LITT presented a 70% sensitivity and 88.9% specificity for predicting LP (AUC: 0.78, p = 0.041). The multivariate analysis showed a 25% increase in volume between 120 and 180 days as a negative predictive factor (p = 0.02). Volumetric changes within 60-90 days after LITT did not predict LP (AUC: 0.57; p = 0.61). CONCLUSION: Volume changes within the first 120 days after the procedure are not independent indicators of LP of metastatic brain lesions treated with LITT.

Pregnancy in spina bifida patients: a comparative analysis of peripartum procedures and complications.

PURPOSE: Spina bifida (SB) is caused by a failure in neural tube closure that can present with lower extremity sensory deficits, paralysis, and hydrocephalus. Medical advances have allowed increased pregnancies among SB patients, but management and pregnancy-associated complications have not been thoroughly investigated. The objective is to delineate peripartum procedures and complications in patients with SB. METHODS: A national de-identified database, TriNetX, was retrospectively queried to evaluate pregnant SB patients and the general population. Procedures and complications were investigated using corresponding ICD-10 and CPT codes within 1 year of pregnancy diagnosis. RESULTS: 11,405 SB patients were identified and compared to 9,269,084 non-SB patients. SB patients were significantly more likely to undergo cesarean delivery (1.200; 95% CI [1.133-1.271]) and less likely to receive neuraxial analgesia (0.406; 95% CI [0.383-0.431]). Additionally, patients with SB had an increased risk of seizures (3.922; 95% CI [3.529-4.360]) and venous thromboembolism (VTE) (3.490; 95% CI [3.070-3.969]). Risks of preeclampsia and hemorrhage were comparable. SB patients with hydrocephalus and Chiari malformation type 1 (CM-1) or type 2 (CM-2) were compared to patients without these comorbid conditions. This sub-group analysis showed a significantly increased risk of having cesarean deliveries (SB with hydrocephalus: 12.55%, S.B. with CM-1 or CM-2: 12.81% vs. SB without hydrocephalus or CM, 6.16%) and VTE (3.74%, 2.43% vs. 0.81%). There were also increased risks of hemorrhage and seizures and decreased use of neuraxial analgesia, but the sample size was insufficient. CONCLUSION: SB patients were more likely to undergo cesarean section and exhibit peripartum complications compared to those without SB.

Two-stage radiosurgery for large brain metastases: a systematic review and meta-analysis of clinical outcomes.

OBJECTIVE: Brain metastases (BMs) are the most common intracranial tumors. In several cases, they present as large masses, which are related to a worse prognosis and more complex therapeutic alternatives. Staged radiosurgery is reported to achieve local control with minimal radiation-related adverse events in BMs. However, no methodological consensus has been achieved in its use for large brain metastases (LBMs; > 2 cm). Therefore, the authors aimed to determine the effectiveness and safety of 2-stage Gamma Knife radiosurgery (GKRS) for LBMs, in order to optimize patients' postoperative course. METHODS: A systematic review of available literature was run in PubMed/MEDLINE, Scopus, Web of Science, Cochrane (OvidSP), and Google Scholar for works published up to December 14, 2022. Nonrandomized clinical trials, case series, and cohort studies were included. The risk of bias was assessed using the Risk of Bias in Nonrandomized Studies-of Interventions (ROBINS-I) and Joanna Briggs Institute tools. Pooled mean difference and rates estimates were calculated by a random-effects model meta-analysis. The degree of heterogeneity was expressed using the I2 statistic. A subgroup analysis was performed. Ultimately, the certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessment. RESULTS: Fourteen studies met the eligibility criteria (cohorts, case series, and nonrandomized clinical trials), including 958 patients. A total pooled mean volume reduction of 6.27 cm3 (95% CI 5.67-6.88 cm3) and 54.36% (95% CI 39.92%-68.79%) after 2-stage GKRS was reported. Pooled rates of complete response (44.63%; 95% CI 26.50%-64.31%), neurological mortality (16.19%; 95% CI 7.68%-30.98%), and all-cause mortality (47.92%; 95% CI 28.04%-68.49%) were calculated. Overall certainty of evidence ranged from very low to moderate. CONCLUSIONS: Two-stage GKRS is an effective and safe approach for the treatment of LBMs. Nevertheless, the lack of available literature and the weak methodological approaches used determine a low to very low certainty of evidence and cannot provide robust evidence to recommend this intervention. Therefore, it is necessary to conduct higher-quality primary studies.

Surgical management of brain metastasis from ovarian cancer: a systematic review and case series.

OBJECTIVE: Ovarian cancer is a rare origin of brain metastasis (BM), with an incidence of only 1%-3%. Consequently, the literature is sparse, and no treatment consensus guideline is available for ovarian BM. The authors conducted a systematic review of ovarian BM and performed a combined pooled cohort survival analysis with their case series. METHODS: A systematic review of PubMed, Scopus, and Web of Science consistent with PRISMA guidelines along with an institutional retrospective chart review was conducted. Inclusion criteria for the systematic review included patients with confirmed BM and primary ovarian cancer, reported perioperative complications and outcomes, differentiated histology, and explicitly reported individual patient data. Reviews, commentaries, technical notes, and articles without English-language translations were excluded. The Newcastle-Ottawa Quality Assessment Scale was used independently by the first and second authors to assess the quality of each article. The authors performed univariate and multivariate analyses of several survival prognostic factors. Kaplan-Meier curves were generated for significant prognostic factors in the univariate analysis. RESULTS: A total of 48 patients with individual data across 34 studies and 8 patients from the authors' institution were included. All patients (n = 56) underwent resection for BM; 83.9% received adjuvant radiotherapy following surgery and 41.1% of patients received adjuvant chemotherapy. The median progression-free survival was 12 months (range 2-43 months). The median overall survival was 9 months (range 1-49 months). On univariate analysis, a single BM and no extracranial metastasis conferred a survival benefit, while clear cell carcinoma as the primary histology corresponded to worsened OS. Multivariable analysis showed that age > 50 years (p = 0.002) and > 1 BM (p < 0.001) were risk factors for poor prognosis. Protective factors included the addition of the following multimodal adjuvant therapy with surgery: radiotherapy (p = 0.002), chemotherapy and radiotherapy (p = 0.005), and stereotactic radiosurgery (p = 0.002). CONCLUSIONS: Although the scarcity of published individual patient data hinders the determination of optimal management, the authors' analysis highlights that multimodal therapies, a single cranial lesion, and age < 50 years are associated with increased survival for patients with ovarian BMs.

Same-day discharge after craniotomy for brain tumor resection: enhancing patient selection through a prognostic scoring system.

OBJECTIVE: Neurosurgery, among other surgical fields, is amid a shift in patient management with enhanced recovery and same-day discharge (SDD) protocols slowly becoming more popular and feasible. While such protocols reduce the risk of nosocomial complications and improve patient satisfaction, appropriate patient selection remains an area of debate. The authors aimed to better quantify selection criteria through a prospective follow-up study of patients undergoing brain tumor resection with SDD. METHODS: Three arms of analysis were carried out. First, clinical data of SDD patients were prospectively collected between August 2021 and August 2022. In parallel, a retrospective analysis of patients who qualified for SDD but were excluded at surgeon clinical discretion over the same period was performed. Third, a comparative analysis of the pilot and follow-up studies was done from which a clinical scoring system for patient selection was derived. RESULTS: Over the duration of the study, 31 of 334 patients were selected for SDD while 59 qualified for SDD by previously defined criteria but were not selected at the surgeon's discretion. There was no difference in outcomes between the two groups, and there were no postoperative complications among the SDD group within 30 days of surgery. Preoperative clinical characteristics found to be significantly different between the two cohorts (left-sided lesion, extra-axial pathology, prior treatment of brain tumor, and tumor volume ≤ 11.75 cm3) were included in a predictive scoring system for successful SDD. The scoring system was found to significantly predict high or low likelihood for successful SDD when tested on the mixed prospective cohort. CONCLUSIONS: This study provides a straightforward clinical scoring system for appropriate selection of candidates for SDD after craniotomy for brain tumor resection. This clinical tool aims to aid clinicians in appropriate admission course selection and builds on the growing literature surrounding same-day and outpatient cranial neurosurgery.

Stereotactic radiosurgery for Koos grade IV vestibular schwannoma in patients ≥ 65 years old: a multi-institutional retrospective study.

BACKGROUND: Surgery is the preferred treatment for large vestibular schwannomas (VS). Good tumor control and cranial nerve outcomes were described in selected Koos IV VS after single-session stereotactic radiosurgery (SRS), but outcomes in elderly patients have never been specifically studied. The aim of this study is to report clinical and radiological outcomes after single-session SRS for Koos IV VS in patients ≥ 65 years old. METHOD: This multicenter, retrospective study included patients ≥ 65 years old, treated with primary, single-session SRS for a Koos IV VS, and at least 12 months of follow-up. Patients with life-threatening or incapacitating symptoms were excluded. Tumor control rate, hearing, trigeminal, and facial nerve function were studied at last follow-up. RESULTS: One-hundred and fifty patients (median age of 71.0 (IQR 9.0) years old with a median tumor volume of 8.3 cc (IQR 4.4)) were included. The median prescription dose was 12.0 Gy (IQR 1.4). The local tumor control rate was 96.0% and 86.2% at 5 and 10 years, respectively. Early tumor expansion occurred in 6.7% and was symptomatic in 40% of cases. A serviceable hearing was present in 16.1% prior to SRS and in 7.4% at a last follow-up of 46.5 months (IQR 55.8). The actuarial serviceable hearing preservation rate was 69.3% and 50.9% at 5 and 10 years, respectively. Facial nerve function preservation or improvement rates at 5 and 10 years were 98.7% and 91.0%, respectively. At last follow-up, the trigeminal nerve function was improved in 14.0%, stable in 80.7%, and worsened in 5.3% of the patients. ARE were noted in 12.7%. New hydrocephalus was seen in 8.0% of patients. CONCLUSION: SRS can be a safe alternative to surgery for selected Koos IV VS in patients ≥ 65 years old. Further follow-up is warranted.

Stereotactic radiosurgery for Koos grade IV vestibular schwannoma in young patients: a multi-institutional study.

PURPOSE: Surgery is the treatment of choice for large vestibular schwannomas (VS). Stereotactic radiosurgery (SRS) has been suggested as an alternative to resection in selected patients. However, the safety and efficacy of SRS in Koos grade IV patients ≤ 45 years old has not been evaluated. The aim of this study is to describe the clinical and radiological outcomes of Koos grade IV in young patient managed with a single-session SRS. METHODS: This retrospective, multicenter analysis included SRS-treated patients, ≤ 45 years old presenting with non-life threatening or incapacitating symptoms due to a Koos Grade IV VS and with follow-up ≥ 12 months. Tumor control and neurological outcomes were evaluated. RESULTS: 176 patients [median age of 36.0 (IQR 9) and median tumor volume of 9.3 cm3 (IQR 4.7)] were included. The median prescription dose was 12 Gy (IQR 0.5). Median follow-up period was 37.5 (IQR 53.5) months. The 5- and 10-year progression-free survival was 90.9% and 86.7%. Early tumor enlargement occurred in 10.9% of cases and was associated with tumor progression at the last follow-up. The probability of serviceable hearing preservation at 5- and 10-years was 56.8% and 45.2%, respectively. The probability of improvement or preservation of facial nerve function was 95.7% at 5 and 10-years. Adverse radiation effects were noted in 19.9%. New-onset hydrocephalus occurred in 4.0%. CONCLUSION: Single-session SRS is a safe and effective alternative to surgical resection in selected patients ≤ 45 years old particularly those with medical co-morbidities and those who decline resection. Longer term follow up is warranted.

Mental health disorders in newly diagnosed non-functional pitutary adenoma under initial observation: an observational cohort study using the nationwide MarketScan database.

PURPOSE: Nonfunctioning pituitary adenomas account for 15-30% of pituitary tumors. Studies exploring the role of an intracranial tumor diagnosis, specifically nonfunctioning pituitary adenomas, on mental health disorders (MHDs) in patients have been limited. We characterize the incidence and factors affecting the development of MHDs in untreated pituitary adenomas. METHODS: Utilizing a large-scale private payor database, MarketScan, we performed a retrospective study of patients with an untreated pituitary adenomas and corresponding MHD. RESULTS: We found that in patients diagnosed with an untreated pituitary adenomas, approximately 15% were newly diagnosed with a MHD within 1 year of the pituitary adenoma diagnosis. Independent risk factors included female gender and substance abuse. Headaches, visual symptoms, and higher Charlson Co-morbidity indexes were also independently associated with a subsequent diagnosis of MHD. On multivariable analysis, patients in the pituitary tumor cohort were more likely to be diagnosed with a MHD than those in the matched cohort (aOR: 1.31, CI: 1.19-1.44). CONCLUSION: By identifying risk factors, advanced screening can focus on non-operative pituitary adenoma patients at high-risk for the development of MHD.

The Supraorbital Approach via an Eyebrow Incision: Analysis of Cosmetic Outcomes Using the Scar Cosmesis Assessment Rating Scale.

ABSTRACT: The supraorbital craniotomy through an eyebrow incision, referred to as the suprabrow approach, may be used to access intracranial lesions. Though offering good surgical exposure for anterior base cranial lesions, the suprabrow approach has a paucity of studies on its cosmetic outcomes. In this study, we aimed to assess the cosmetic outcomes of suprabrow approach using validated Scar Cosmesis Assessment Rating (SCAR) scale for the first time. Three patients underwent a suprabrow approach for resection of a suprasellar or frontal mass. Their postoperative courses were followed, with specific attention to the cosmetic outcome of their procedures. The SCAR scale was used to determine the cosmetic success of the approach. We found that all 3 patients scored ≤ 5 on the SCAR scale. All 3 resections were successful with no major postoperative complications. The only minor complication was transient hypoesthesia of the ipsilateral forehead that was noted in all 3 patients.This study quantified the positive cosmetic outcomes of a minimally invasive suprabrow approach. The suprabrow approach provides acceptable surgical exposure and access in an appropriately selected patient with anterior cranial base lesions and results in favorable cosmesis. Although transient hypoesthesia in the distribution of the ophthalmic branch of the trigeminal nerve occurs, the overall benefits of the approach and desirable cosmetic outcomes make the suprabrow approach a good technique to access intracranial lesions in appropriate cases.

Repeat Gamma Knife Radiosurgery for Recurrent Glossopharyngeal Neuralgia: A Systematic Review and Our Initial Experience.

BACKGROUND: Glossopharyngeal neuralgia (GPN) is a rare facial pain syndrome with debilitating symptoms. For medication-resistant GPN, stereotactic radiosurgery (SRS) is an emerging treatment option with a promising role; however, recurrence rates after SRS are fairly high. We present a patient who underwent repeat SRS for recurrent GPN and subsequently maintained over 3 years of complete pain relief. For the first time, we present a systematic review of repeat SRS for recurrent GPN. SUMMARY: Twelve cases of repeat SRS for GPN have previously been reported in the literature (13 studies including ours). Among patients with follow-up, initial pain relief was achieved in 83% (n = 10) of cases a median of 5 weeks after repeat SRS; 2 patients failed to obtain any pain relief. A favorable pain response (BNI I-IIIb) was achieved in 67 and 58% of cases at 6 and 12 months, respectively. All 13 were targeted to the glossopharyngeal meatus. Three patients (23%) experienced adverse radiation effects. Five patients (50%) experienced recurrence a median of 14 months after repeat SRS. Two patients (17%) required additional surgical intervention. At the final follow-up, 75% (n = 9) of the patients had a favorable pain outcome. Key Messages: Repeat SRS may be a viable alternative to open surgery for the treatment of recurrent GPN, albeit with an increased risk of adverse radiation effects. Though limited by a small cohort of patients, the best predictors of an effective second treatment may be a response to initial SRS for >5 months, a maximum dose >75 Gy, and a target at the glossopharyngeal meatus. Larger prospective studies are needed to better define its role.

Regression of Multiple Intracranial Meningiomas With Cessation of Progesterone Agonist Therapy: A Case Report.

In this case report, we discuss a patient who experienced spontaneous regression of multiple intracranial meningiomas that were treated conservatively for 5 years after cessation of megestrol acetate, an exogenous progestin. In addition, we discuss the previous literature describing the relationship between exogenous progesterone medications and meningioma growth. This case, along with others reported, implies that cessation of progesterone therapy, when feasible, may alter the natural history of meningioma growth and thus impact treatment decisions.

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.

Infrasellar Nasopharyngeal Craniopharyngiomas: An Individual Participant Data Meta-Analysis and Review of the Literature.

BACKGROUND: Craniopharyngiomas are benign tumors of the anterior skull base arising from epithelial remnants of Rathke pouch. They mainly occur in the suprasellar space, can be incredibly debilitating, and remain difficult to resect as they frequently involve critical neurovascular structures. Although it is embryologically possible for craniopharyngiomas to arise extracranially along the entire migrational path of Rathke pouch, these remain exceedingly rare, especially among adults, and can be mistaken for nasopharyngeal cancer. As such, minimal data exist evaluating the management and outcomes of such lesions. We evaluated our institutional experience with purely infrasellar nasopharyngeal craniopharyngiomas and obtained individual patient data reported in the contemporary literature to better characterize the demographics, presentation, surgical management, and long-term outcomes of these lesions. METHODS: A systematic review of the literature was performed to identify previously published cases of purely infrasellar nasopharyngeal craniopharyngioma in 3 electronic databases: MEDLINE (PubMed), Embase, and Scopus. Search terms were "infrasellar craniopharyngioma" and "nasopharyngeal craniopharyngioma." RESULTS: We identified 25 cases, in which 72% of patients presented with symptoms of nasal obstruction, epistaxis, or headache. An endoscopic approach was performed in 40% of cases; 83.3% of all patients had gross total resection, with 60% having no recurrence at a median follow-up of 13 months. No postoperative complications were reported. Tumor location involving the cavernous sinus was associated with incomplete resection (100%) compared with tumors not involving the cavernous sinus (87%) (P = 0.033). CONCLUSIONS: While uncommon, infrasellar nasopharyngeal craniopharyngiomas appear to have better perioperative and long-term surgical outcomes than their suprasellar counterparts.

Exploring the Landscape of Machine Learning Applications in Neurosurgery: A Bibliometric Analysis and Narrative Review of Trends and Future Directions.

BACKGROUND: The field of neurosurgery has consistently represented an area of innovation and integration of technology since its inception. As such, machine learning (ML) has found its way into applications within neurosurgery relatively rapidly. Through this bibliometric review and cluster analysis, we seek to identify trends and emerging applications of ML within neurosurgery. METHODS: A bibliometric analysis was carried out in the Web of Science database on publications from January 2000 to March 2023. The full data set of the 200 most cited publications including title, author information, journal, citation count, keywords, and abstracts for each publication was evaluated in CiteSpace. CiteSpace was used to elucidate publication characteristics, trends, and topic clusters via collaborate network analysis using the Kamada-Kawai algorithm. RESULTS: The 25 most cited titles were included in our analysis. Harvard University and its affiliates represented the top institution, contributing nearly 25% of publications in the literature. WORLD NEUROSURGERY was the journal with the highest net citation count of 747 (29%). Collaborative network analysis generated 12 unique clusters, the largest of which was machine learning, followed by feature importance and deep brain stimulation. CONCLUSION: This review highlights the most impactful articles pertaining to ML in the field of neurosurgery. ML has been applied into several sub-specialties within neurosurgery to optimize patient care, with special attention to outcome predictors, patient selection, and surgical decision making.

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.

Minimally invasive keyhole approach for supramaximal frontal glioma resections: technical note.

OBJECTIVE: The authors aimed to review the frontal lobe's surgical anatomy, describe their keyhole frontal lobectomy technique, and analyze the surgical results. METHODS: Patients with newly diagnosed frontal gliomas treated using a keyhole approach with supramaximal resection (SMR) from 2016 to 2022 were retrospectively reviewed. Surgeries were performed on patients asleep and awake. A human donor head was dissected to demonstrate the surgical anatomy. Kaplan-Meier curves were used for survival analysis. RESULTS: Of the 790 craniotomies performed during the study period, those in 47 patients met our inclusion criteria. The minimally invasive approach involved four steps: 1) debulking the frontal pole; 2) subpial dissection identifying the sphenoid ridge, olfactory nerve, and optic nerve; 3) medial dissection to expose the falx cerebri and interhemispheric structures; and 4) posterior dissection guided by motor mapping, avoiding crossing the inferior plane defined by the corpus callosum. A fifth step could be added for nondominant lesions by resecting the inferior frontal gyrus. Perioperative complications were recorded in 5 cases (10.6%). The average hospital length of stay was 3.3 days. High-grade gliomas had a median progression-free survival of 14.8 months and overall survival of 23.9 months. CONCLUSIONS: Keyhole approaches enabled successful SMR of frontal gliomas without added risks. Robust anatomical knowledge and meticulous surgical technique are paramount for obtaining successful resections.