Intraventricular meningioma resection and visual outcomes

OBJECTIVE

Intraventricular meningiomas (IVMs) of the lateral ventricle are rare tumors that present surgical challenges because of their deep location. Visual field deficits (VFDs) are one risk associated with these tumors and their treatment. VFDs may be present preoperatively due to the tumor and mass effect (tumor VFDs) or may develop postoperatively due to the surgical approach (surgical VFDs). This institutional series aimed to review surgical outcomes following resection of IVMs, with a focus on VFDs.

METHODS

Patients who received IVM resection at one academic institution between the years 1996 and 2021 were retrospectively reviewed. Diffusion tensor imaging (DTI) reconstructions of the optic radiations around the tumor were performed from preoperative IVM imaging. The VFD course and resolution were documented.

RESULTS

Thirty-two adult patients underwent IVM resection, with gross-total resection in 30 patients (93.8%). Preoperatively, tumor VFDs were present in 6 patients, resolving after surgery in 5 patients. Five other patients (without preoperative VFD) had new persistent surgical VFDs postoperatively (5/32, 15.6%) that persisted to the most recent follow-up. Of the 5 patients with persistent surgical VFDs, 4 received a transtemporal approach and 1 received a transparietal approach, and all these deficits occurred prior to regular use of DTI in preoperative imaging.

CONCLUSIONS

New surgical VFDs are a common neurological deficit after IVM resection. Preoperative DTI may demonstrate distortion of the optic radiations around the tumor, thus revealing safe operative corridors to prevent surgical VFDs.

Socioeconomic differences between medically and surgically treated prolactinomas: a retrospective review of 598 patients

OBJECTIVE

Socioeconomic status (SES) is known to affect presentations and outcomes in pituitary neuroendocrine tumor resections, but there is a paucity of literature examining its impact specifically on patients with prolactinomas, who may be treated medically or surgically. The authors sought to determine whether SES was associated with differences in treatment choice or outcomes for prolactinoma patients.

METHODS

The authors retrospectively reviewed patient records at a high-volume academic pituitary center for prolactinoma diagnoses. Patients were split into medically and surgically treated cohorts. Race, ethnicity, insurance status, primary care physician (PCP) status, and zip code-based income data were collected and examined as socioeconomic covariates. Outcomes of interest included pretreatment likelihood of surgical cure, medical versus surgical treatment allocation, and posttreatment remission rates.

RESULTS

The authors analyzed 568 prolactinoma patients (351 medically treated and 217 surgically treated). Patients receiving surgery were more likely to have Medicaid or private insurance (p < 0.001) and have lower incomes (p < 0.001) than medically treated patients. Lower-income surgical patients were more likely to require surgical intervention for an indication such as tumor decompression than higher-income patients (p = 0.023). Surgical patients with a PCP had a higher estimated likelihood of surgical cure (p = 0.008), while no SES-based differences in surgical remission likelihood existed in the medical cohort. After surgery, surgical patients who achieved remission had significantly higher income than those who did not (p < 0.001). Other SES factors were not associated with surgical remission, and among medically treated patients, remission rates were not affected by any SES factor. Income was inversely related to prolactinoma size in both cohorts (surgical, p < 0.001; medical, p = 0.005) but was associated more prominently in surgical patients (surgical, -0.65 mm per $10,000; medical, -0.37 mm per $10,000).

CONCLUSIONS

While surgical prolactinoma patients were prone to income and PCP-related disparities, no SES disparities were found among medically treated patients. Income had a more pronounced association with tumor size in the surgical cohort and likely contributed to the increased need for surgical intervention seen in low-income surgical patients. Addressing socioeconomic healthcare disparities is needed among surgical prolactinoma patients to increase rates of early presentation and improve the outcomes of low-SES populations.

Analysis of upfront resection or stereotactic radiosurgery for local control of solid and cystic cerebellar hemangioblastomas

OBJECTIVE

The purpose of this study was to identify rates of and risk factors for local tumor progression in patients who had undergone surgery or radiosurgery for the management of cerebellar hemangioblastoma and to describe treatments pursued following tumor progression.

METHODS

The authors conducted a retrospective single-center review of patients who had undergone treatment of a cerebellar hemangioblastoma with either surgery or stereotactic radiosurgery (SRS) between 1996 and 2019. Univariate and multivariate regression analyses were performed to examine factors associated with local tumor control.

RESULTS

One hundred nine patients met the study inclusion criteria. Overall, these patients had a total of 577 hemangioblastomas, 229 of which were located in the cerebellum. The surgical and SRS cohorts consisted of 106 and 123 cerebellar hemangioblastomas, respectively. For patients undergoing surgery, tumors were treated with subtotal resection and gross-total resection in 5.7% and 94.3% of cases, respectively. For patients receiving SRS, the mean target volume was 0.71 cm3 and the mean margin dose was 18.0 Gy. Five-year freedom from lesion progression for the surgical and SRS groups was 99% and 82%, respectively. The surgical and SRS cohorts contained 32% versus 97% von Hippel-Lindau tumors, 78% versus 7% cystic hemangioblastomas, and 12.8- versus 0.56-cm3 mean tumor volumes, respectively. On multivariate analysis, factors associated with local tumor progression in the SRS group included older patient age (HR 1.06, 95% CI 1.03-1.09, p < 0.001) and a cystic component (HR 9.0, 95% CI 2.03-32.0, p = 0.001). Repeat SRS as salvage therapy was used more often for smaller tumor recurrences, and no tumor recurrences of < 1.0 cm3 required additional salvage surgery following repeat SRS.

CONCLUSIONS

Both surgery and SRS achieve high rates of local control of hemangioblastomas. Age and cystic features are associated with local progression after SRS treatment for cerebellar hemangioblastomas. In cases of local tumor recurrence, salvage surgery and repeat SRS are valid forms of treatment to achieve local tumor control, although resection may be preferable for larger recurrences.

Genomic alterations associated with postoperative nodular leptomeningeal disease after resection of brain metastases

OBJECTIVE

The relationship between brain metastasis resection and risk of nodular leptomeningeal disease (nLMD) is unclear. This study examined genomic alterations found in brain metastases with the aim of identifying alterations associated with postoperative nLMD in the context of clinical and treatment factors.

METHODS

A retrospective, single-center study was conducted on patients who underwent resection of brain metastases between 2014 and 2022 and had clinical and genomic data available. Postoperative nLMD was the primary endpoint of interest. Targeted next-generation sequencing of > 500 oncogenes was performed in brain metastases. Cox proportional hazards analyses were performed to identify clinical features and genomic alterations associated with nLMD.

RESULTS

The cohort comprised 101 patients with tumors originating from multiple cancer types. There were 15 patients with nLMD (14.9% of the cohort) with a median time from surgery to nLMD diagnosis of 8.2 months. Two supervised machine learning algorithms consistently identified CDKN2A/B codeletion and ERBB2 amplification as the top predictors associated with postoperative nLMD across all cancer types. In a multivariate Cox proportional hazards analysis including clinical factors and genomic alterations observed in the cohort, tumor volume (× 10 cm3; HR 1.2, 95% CI 1.01-1.5; p = 0.04), CDKN2A/B codeletion (HR 5.3, 95% CI 1.7-16.9; p = 0.004), and ERBB2 amplification (HR 3.9, 95% CI 1.1-14.4; p = 0.04) were associated with a decreased time to postoperative nLMD.

CONCLUSIONS

In addition to increased resected tumor volume, ERBB2 amplification and CDKN2A/B deletion were independently associated with an increased risk of postoperative nLMD across multiple cancer types. Additional work is needed to determine if targeted therapy decreases this risk in the postoperative setting.

The importance of considering competing risks in recurrence analysis of intracranial meningioma

BACKGROUND

The risk of recurrence is overestimated by the Kaplan-Meier method when competing events, such as death without recurrence, are present. Such overestimation can be avoided by using the Aalen-Johansen method, which is a direct extension of Kaplan-Meier that accounts for competing events. Meningiomas commonly occur in older individuals and have slow-growing properties, thereby warranting competing risk analysis. The extent to which competing events are considered in meningioma literature is unknown, and the consequences of using incorrect methodologies in meningioma recurrence risk analysis have not been investigated.

METHODS

We surveyed articles indexed on PubMed since 2020 to assess the usage of competing risk analysis in recent meningioma literature. To compare recurrence risk estimates obtained through Kaplan-Meier and Aalen-Johansen methods, we applied our international database comprising ~ 8,000 patients with a primary meningioma collected from 42 institutions.

RESULTS

Of 513 articles, 169 were eligible for full-text screening. There were 6,537 eligible cases from our PERNS database. The discrepancy between the results obtained by Kaplan-Meier and Aalen-Johansen was negligible among low-grade lesions and younger individuals. The discrepancy increased substantially in the patient groups associated with higher rates of competing events (older patients with high-grade lesions).

CONCLUSION

The importance of considering competing events in recurrence risk analysis is poorly recognized as only 6% of the studies we surveyed employed Aalen-Johansen analyses. Consequently, most of the previous literature has overestimated the risk of recurrence. The overestimation was negligible for studies involving low-grade lesions in younger individuals; however, overestimation might have been substantial for studies on high-grade lesions.

Epigenetic reprogramming shapes the cellular landscape of schwannoma

Mechanisms specifying cancer cell states and response to therapy are incompletely understood. Here we show epigenetic reprogramming shapes the cellular landscape of schwannomas, the most common tumors of the peripheral nervous system. We find schwannomas are comprised of 2 molecular groups that are distinguished by activation of neural crest or nerve injury pathways that specify tumor cell states and the architecture of the tumor immune microenvironment. Moreover, we find radiotherapy is sufficient for interconversion of neural crest schwannomas to immune-enriched schwannomas through epigenetic and metabolic reprogramming. To define mechanisms underlying schwannoma groups, we develop a technique for simultaneous interrogation of chromatin accessibility and gene expression coupled with genetic and therapeutic perturbations in single-nuclei. Our results elucidate a framework for understanding epigenetic drivers of tumor evolution and establish a paradigm of epigenetic and metabolic reprograming of cancer cells that shapes the immune microenvironment in response to radiotherapy.

Epidemiology, Genetics, and DNA Methylation Grouping of Hyperostotic Meningiomas

BACKGROUND AND OBJECTIVES

Meningiomas are the most common primary intracranial tumors and are among the only tumors that can form lamellar, hyperostotic bone in the tumor microenvironment. Little is known about the epidemiology or molecular features of hyperostotic meningiomas.

METHODS

Using a retrospective database of 342 meningiomas treated with surgery at a single institution, we correlated clinical, tumor-related, targeted next-generation DNA sequencing (n = 39 total, 16 meningioma-induced hyperostosis [MIH]), and surgical variables with the presence of MIH using generalized linear models. Meningioma DNA methylation grouping was analyzed on a separate population of patients from the same institution with preoperative imaging studies sufficient for identification of MIH (n = 200).

RESULTS

MIH was significantly correlated with anterior fossa (44.3% of MIH vs 17.5% of non-MIH were in the anterior fossa P < .001, c2) or skull base location (62.5% vs 38.3%, P < .001, c2) and lower MIB-1 labeling index. Gross total resection was accomplished in 27.3% of tumors with MIH and 45.5% of nonhyperostotic meningiomas (P < .05, t test). There was no association between MIH and histological World Health Organization grade (P = .32, c2). MIH was significantly more frequent in meningiomas from the Merlin-intact DNA methylation group (P < .05). Somatic missense mutations in the WD-repeat-containing domain of the TRAF7 gene were the most common genetic alteration associated with MIH (n = 12 of 15, 80%, P < .01, c2).

CONCLUSION

In this article, we show that MIH has a predilection for the anterior skull base and affected tumors are less amenable to gross total resection. We find no association between MIH and histological World Health Organization grade, but show that MIH is more common in the Merlin-intact DNA methylation group and is significantly associated with TRAF7 somatic missense mutations. These data provide a framework for future investigation of biological mechanisms underlying MIH.

Does waiting for surgery matter? How time from diagnostic MRI to resection affects outcomes in newly diagnosed glioblastoma

OBJECTIVE

Maximal safe resection is the standard of care for patients presenting with lesions concerning for glioblastoma (GBM) on magnetic resonance imaging (MRI). Currently, there is no consensus on surgical urgency for patients with an excellent performance status, which complicates patient counseling and may increase patient anxiety. This study aims to assess the impact of time to surgery (TTS) on clinical and survival outcomes in patients with GBM.

METHODS

This is a retrospective study of 145 consecutive patients with newly diagnosed IDH-wild-type GBM who underwent initial resection at the University of California, San Francisco, between 2014 and 2016. Patients were grouped according to the time from diagnostic MRI to surgery (i.e., TTS): ≤ 7, > 7-21, and > 21 days. Contrast-enhancing tumor volumes (CETVs) were measured using software. Initial CETV (CETV1) and preoperative CETV (CETV2) were used to evaluate tumor growth represented as percent change (ΔCETV) and specific growth rate (SPGR; % growth/day). Overall survival (OS) and progression-free survival (PFS) were measured from the date of resection and were analyzed using the Kaplan-Meier method and Cox regression analyses.

RESULTS

Of the 145 patients (median TTS 10 days), 56 (39%), 53 (37%), and 36 (25%) underwent surgery ≤ 7, > 7-21, and > 21 days from initial imaging, respectively. Median OS and PFS among the study cohort were 15.5 and 10.3 months, respectively, and did not differ among the TTS groups (p = 0.81 and 0.17, respectively). Median CETV1 was 35.9, 15.7, and 10.2 cm3 across the TTS groups, respectively (p < 0.001). Preoperative biopsy and presenting to an outside hospital emergency department were associated with an average 12.79-day increase and 9.09-day decrease in TTS, respectively. Distance from the treating facility (median 57.19 miles) did not affect TTS. In the growth cohort, TTS was associated with an average 2.21% increase in ΔCETV per day; however, there was no effect of TTS on SPGR, Karnofsky Performance Status (KPS), postoperative deficits, survival, discharge location, or hospital length of stay. Subgroup analyses did not identify any high-risk groups for which a shorter TTS may be beneficial.

CONCLUSIONS

An increased TTS for patients with imaging concerning for GBM did not impact clinical outcomes, and while there was a significant association with ΔCETV, SPGR remained unaffected. However, SPGR was associated with a worse preoperative KPS, which highlights the importance of tumor growth speed over TTS. Therefore, while it is ill advised to wait an unnecessarily long time after initial imaging studies, these patients do not require urgent/emergency surgery and can seek tertiary care opinions and/or arrange for additional preoperative support/resources. Future studies are needed to explore subgroups for whom TTS may impact clinical outcomes.

Postoperative Complications and Neurological Deficits After Petroclival Region Meningioma Resection: A Case Series

BACKGROUND

Surgical management of meningiomas involving the petroclival junction remains a challenge because of nearby critical neurovascular structures.

OBJECTIVE

To describe surgical approach selection, outcomes, and factors associated with postoperative complications and neurological deficits in a series of patients undergoing resection of petroclival region meningiomas.

METHODS

Retrospective review of patients undergoing symptomatic petroclival region meningioma resection was performed. Logistic regression was performed to identify variables associated with postoperative complications and new neurological deficits.

RESULTS

Sixty-five patients underwent 54 one-stage and 11 two-stage resections with median follow-up of 51 months. Most tumors were World Health Organization grade 1 (90.8%), and the median volume was 23.9 cm 3 . Posterior petrosectomy and anterior petrosectomy were performed in 67.1% and 6.6% of operations, respectively. The gross or near total resection rate was 15.4%, and 8 patients (12.3%) progressed on follow-up. The surgical complication rate was 26.2% with no perioperative mortalities. Postoperatively, 45.8% of patients had new, persistent neurological deficits, with cranial nerves VII palsy being most common. On multivariate analysis, higher body mass index (odds ratio [OR]: 1.1, P = .04) was associated with risk of surgical complications. Longer operative time (OR: 1.4, P = .004) and staged procedures (OR: 4.9, P = .04) were associated with risk of new neurological deficit on follow-up, likely reflecting more challenging tumors. Comparing early vs later career surgeries performed by the senior author, rates of severe complications and neurological deficits decreased 23.1% and 22.3%, respectively.

CONCLUSION

Petroclival region meningiomas remain surgically challenging, but improved outcomes are seen with surgeon experience. These data help inform patients on perioperative morbidity risk and provide a guide for surgical approach selection.

Association of CDKN2A alterations with increased postoperative seizure risk after resection of brain metastases

OBJECTIVE

Seizures are common and significantly disabling for patients with brain metastases (BMs). Although resection can provide seizure control, a subset of patients with BMs may continue to suffer seizures postoperatively. Genomic BM characteristics may influence which patients are at risk for postoperative seizures. This work explores correlations between genomic alterations and risk of postoperative seizures following BM resection.

METHODS

All patients underwent BM resection at a single institution, with available clinical and sequencing data on more than 500 oncogenes. Clinical seizures were documented pre- and postoperatively. A random forest machine learning classification was used to determine candidate genomic alterations associated with postoperative seizures, and clinical and top genomic variables were correlated with postoperative seizures by using Cox proportional hazards models.

RESULTS

There were 112 patients with BMs who underwent 114 surgeries and had at least 1 month of postoperative follow-up. Seizures occurred preoperatively in 26 (22.8%) patients and postoperatively in 25 (21.9%). The Engel classification achieved at 6 months for those with preoperative seizures was class I in 13 (50%); class II in 6 (23.1%); class III in 5 (19.2%), and class IV in 2 (7.7%). In those with postoperative seizures, only 8 (32.0%) had seizures preoperatively, and preoperative seizures were not a significant predictor of postoperative seizures (HR 1.84; 95% CI 0.79-4.37; p = 0.156). On random forest classification and multivariate Cox analysis controlling for factors including recurrence, extent of resection, and number of BMs, CDKN2A alterations were associated with postoperative seizures (HR 3.22; 95% CI 1.27-8.16; p = 0.014). Melanoma BMs were associated with higher risk of postoperative seizures compared with all other primary malignancies (HR 5.23; 95% CI 1.37-19.98; p = 0.016). Of 39 BMs with CDKN2A alteration, 35.9% (14/39) had postoperative seizures, compared to 14.7% (11/75) without CDKN2A alteration. The overall rate of postoperative seizures in melanoma BMs was 42.9% (15/35), compared with 12.7% (10/79) for all other primary malignancies.

CONCLUSIONS

CDKN2A alterations and melanoma primary malignancy are associated with increased postoperative seizure risk following resection of BMs. These results may help guide postoperative seizure prophylaxis in patients undergoing resection of BMs.

Identification of risk factors associated with leptomeningeal disease after resection of brain metastases

OBJECTIVE

Resection of brain metastases (BMs) may be associated with increased risk of leptomeningeal disease (LMD). This study examined rates and predictors of LMD, including imaging subtypes, in patients who underwent resection of a BM followed by postoperative radiation.

METHODS

A retrospective, single-center study was conducted examining overall LMD, classic LMD (cLMD), and nodular LMD (nLMD) risk. Logistic regression, Cox proportional hazards, and random forest analyses were performed to identify risk factors associated with LMD.

RESULTS

Of the 217 patients in the cohort, 47 (21.7%) developed postoperative LMD, with 19 cases (8.8%) of cLMD and 28 cases (12.9%) of nLMD. Six-, 12-, and 24-month LMD-free survival rates were 92.3%, 85.6%, and 71.4%, respectively. Patients with cLMD had worse survival outcomes from the date of LMD diagnosis compared with nLMD (median 2.4 vs 6.9 months, p = 0.02, log-rank test). Cox proportional hazards analysis identified cerebellar/insular/occipital location (hazard ratio [HR] 3.25, 95% confidence interval [CI] 1.73-6.11, p = 0.0003), absence of extracranial disease (HR 2.49, 95% CI 1.27-4.88, p = 0.008), and ventricle contact (HR 2.82, 95% CI 1.5-5.3, p = 0.001) to be associated with postoperative LMD. A predictive model using random forest analysis with an area under the receiver operating characteristic curve of 0.87 in a test cohort identified tumor location, systemic disease status, and tumor volume as the most important factors associated with LMD.

CONCLUSIONS

Tumor location, absence of extracranial disease at the time of surgery, ventricle contact, and increased tumor volume were associated with LMD. Further work is needed to determine whether escalating therapies in patients at risk of LMD prevents disease dissemination.

Genomic alterations associated with rapid progression of brain metastases

OBJECTIVE

The aim of this study was to investigate associations between genomic alterations in resected brain metastases and rapid local and distant CNS recurrence identified at the time of postoperative adjuvant radiosurgery.

METHODS

This was a retrospective study on patients who underwent resection of intracranial brain metastases. Next-generation sequencing of more than 500 coding genes was performed on brain metastasis specimens. Postoperative and preradiosurgery MR images were compared to identify rapid recurrence. Genomic data were associated with rapid local and distant CNS recurrence of brain metastases using nominal regression analyses.

RESULTS

The cohort contained 92 patients with 92 brain metastases. Thirteen (14.1%) patients had a rapid local recurrence, and 64 (69.6%) patients had rapid distant CNS progression by the time of postoperative adjuvant radiosurgery, which occurred in a median time of 25 days (range 3-85 days) from surgery. RB1 and CTNNB1 mutations were seen in 8.7% and 9.8% of the cohort, respectively, and were associated with a significantly higher risk of rapid local recurrence (RB1: OR 13.6, 95% CI 2.0-92.39, p = 0.008; and CTNNB1: OR 11.97, 95% CI 2.25-63.78, p = 0.004) on multivariate analysis. No genes were found to be associated with rapid distant CNS progression. However, the presence of extracranial disease was significantly associated with a higher risk of rapid distant recurrence on multivariate analysis (OR 4.06, 95% CI 1.08-15.34, p = 0.039).

CONCLUSIONS

Genomic alterations in RB1 or CTNNB1 were associated with a significantly higher risk of rapid recurrence at the resection site. Although no genomic alterations were associated with rapid distant recurrence, having active extracranial disease was a risk factor for new lesions by the time of adjuvant radiotherapy after resection.

Molecular Features of Resected Melanoma Brain Metastases, Clinical Outcomes, and Responses to Immunotherapy

Importance

Central nervous system (CNS)-penetrant systemic therapies have significantly advanced care for patients with melanoma brain metastases. However, improved understanding of the molecular landscape and microenvironment of these lesions is needed to both optimize patient selection and advance treatment approaches.

Objective

To evaluate how bulk and single-cell genomic features of melanoma brain metastases are associated with clinical outcome and treatment response.

Design, Setting, and Participants

This cohort study analyzed bulk DNA sequencing and single nuclear RNA-sequencing data from resected melanoma brain metastases and included 94 consecutive patients with a histopathologically confirmed diagnosis of melanoma brain metastasis who underwent surgical resection at a single National Comprehensive Cancer Network cancer center in San Francisco, California, from January 1, 2009, to December 31, 2022.

Exposure

A Clinical Laboratory Improvement Amendments-certified targeted sequencing assay was used to analyze tumor resection specimens, with a focus on BRAF V600E alteration. For frozen pathologic specimens from CNS treatment-naive patients undergoing surgical resection, commercial single nuclear RNA sequencing approaches were used.

Main Outcomes and Measures

The primary outcome was overall survival (OS). Secondary outcomes included CNS progression-free survival (PFS), microenvironmental composition with decreased T-cell and macrophage populations, and responses to immunotherapy.

Results

To correlate molecular status with clinical outcome, Kaplan-Meier survival analysis of 94 consecutive patients (median age, 64 years [range, 24-82 years]; 70 men [74%]) with targeted BRAF alteration testing showed worse median intracranial PFS (BRAF variant: 3.6 months [IQR, 0.1-30.6 months]; BRAF wildtype: 11.0 months [IQR, 0.8-81.5 months]; P < .001) and OS (BRAF variant: 9.8 months [IQR, 2.5-69.4 months]; BRAF wildtype: 23.2 months [IQR, 1.1-102.5 months]; P = .005; log-rank test) in BRAF V600E variant tumors. Multivariable Cox proportional hazards regression analysis revealed that BRAF V600E status was an independent variable significantly associated with both PFS (hazard ratio [HR], 2.65; 95% CI, 1.54-4.57; P < .001) and OS (HR, 1.96; 95% CI, 1.08-3.55; P = .03). For the 45 patients with resected melanoma brain metastases undergoing targeted DNA sequencing, molecular classification recapitulated The Cancer Genome Atlas groups (NRAS variant, BRAF variant, NF1 variant, and triple wildtype) with no subtype enrichment within the brain metastasis cohort. On a molecular level, BRAF V600E variant lesions were found to have a significantly decreased tumor mutation burden. Moreover, single nuclear RNA sequencing of treatment-naive BRAF V600E variant (n = 3) brain metastases compared with BRAF wildtype (n = 3) brain metastases revealed increased immune cell populations in BRAF wildtype tumors (mean [SD], 11% [4.1%] vs 3% [1.6%] CD45-positive cells; P = .04). Survival analysis of postoperative immunotherapy responses by BRAF status revealed that BRAF wildtype lesions were associated with a response to checkpoint inhibition (median OS: with immunotherapy, undefined; without immunotherapy, 13.0 months [range, 1.1-61.7 months]; P = .001; log-rank test) while BRAF variant lesions (median OS: with immunotherapy, 9.8 months [range, 2.9-39.8 months]; without immunotherapy, 9.5 months [range, 2.5-67.2 months]; P = .81; log-rank test) were not.

Conclusions and Relevance

This molecular analysis of patients with resected melanoma brain metastases found that BRAF V600E alteration is an important translational biomarker associated with worse clinical outcomes, differential microenvironmental composition, and benefit from immunotherapy. Patients with BRAF V600E variant melanoma brain metastases may thus benefit from alternative CNS-penetrant systemic regimens.

Risk Factors for Significant Postoperative Hemorrhage After Pituitary Neuroendocrine Tumor Resection: A Case-Control Study of 1066 Surgeries

BACKGROUND

Postoperative hemorrhage is a rare but potentially serious complication after pituitary surgery. The risk factors for this complication are mostly unknown, and further knowledge would help guide postoperative management.

OBJECTIVE

To investigate the perioperative risks and clinical presentation of significant postoperative hemorrhage (SPH) after endonasal surgery for pituitary neuroendocrine tumors.

METHODS

A population of 1066 patients undergoing endonasal (microscopic and endoscopic) surgery for pituitary neuroendocrine tumor resection at a high-volume academic center was reviewed. SPH cases were defined as postoperative hematoma evident on imaging requiring return to the operating room for evacuation. Patient and tumor characteristics were analyzed with uni- and multivariable logistic regression, and postoperative courses were descriptively examined.

RESULTS

Ten patients were found to have SPH. On univariable analysis, these cases were significantly more likely to present with apoplexy ( P = .004), have larger tumors ( P < .001), and lower gross total resection rates ( P = .019). A multivariate regression analysis showed that tumor size (odds ratio 1.94, P = .008) and apoplexy at presentation (odds ratio 6.00, P = .018) were significantly associated with higher odds of SPH. The most common symptoms for patients with SPH were vision deficits and headache, and the median time for symptom onset was 1 day after surgery.

CONCLUSION

Larger tumor size and presentation with apoplexy were associated with clinically significant postoperative hemorrhage. Patients presenting with pituitary apoplexy are more likely to experience a significant postoperative hemorrhage and should be carefully monitored for headache and vision changes in the days after surgery.

Formal Closure of Endoscopic Endonasal Skull Base Defects With a "Bow Tie" Tri-Layer Graft

OBJECTIVE

Risk factors for a postoperative cerebrospinal fluid leak (CSF) after surgery include an intraoperative high flow of CSF, elevated body mass index, defect size, and defect site. In our prior series, a high postoperative CSF leak rate for tumors of the central skull base (planum, sella, and clivus) appeared to be due to graft migration. We changed our closure technique from a single layer of collagen +/- fat graft to a novel graft, termed a "Bow tie" (a tri-layer fat graft with two pieces of collagen matrix), and report our results in this study.

METHODS

Retrospective temporal epoch study of a single otolaryngologist's experience of closing skull base defects in our skull base center from 2005 to 2017.

RESULTS

One hundred and forty-nine patients met inclusion criteria in two time periods, pre- and post-introduction of the Bow tie technique. In epoch I, from 2005 to 2013, 79 patients had reconstruction with a single layer of dural graft (25 had additional free fat graft). In epoch II, from 2014 to 2017, 70 patients had reconstruction with the Bow tie.

RESULTS

CSF leak rates were 8.7% overall: 15.2% in epoch I and 1.4% in epoch II (p = 0.01). After controlling the procedure, defects with a size greater than 2 cm had a 5.7 greater likelihood of failure. Epoch II had a lower incidence of major complications.

CONCLUSION

Using a single surgeon's experience, the multilayer Bow tie has a significant reduction in postoperative CSF leak and associated major complications for defects of the central skull base.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1568-1575, 2023.

Correlation between tumor volume and serum prolactin and its effect on surgical outcomes in a cohort of 219 prolactinoma patients

OBJECTIVE

Prolactinoma is the most common pituitary adenoma and can be managed medically or surgically. The authors assessed the correlation between tumor volume and prolactin level and its effect on surgical outcomes.

METHODS

The authors reviewed 219 patients who underwent transsphenoidal prolactinoma resection at a single institution from 2012 to 2019. Outcomes were compared between patients with and without biochemical remission. Tumor volumes were quantified with BrainLab Smartbrush. Correlation analysis and linear regression were used to examine the association between tumor volume and serum prolactin level. Volume-adjusted prolactin level was defined as serum prolactin level divided by tumor volume. The authors utilized receiver operating characteristic (ROC) curve analysis to determine the thresholds for predicting biochemical remission status.

RESULTS

The mean tumor volume was 5.66 cm3, and the mean preoperative prolactin level was 752.3 µg/L. Men had larger prolactinomas than women (mean volume 11.32 vs 2.54 cm3; p < 0.001), and women had a greater volume-adjusted prolactin level (mean 412.5 vs 175.9 µg/L/cm3, p < 0.001). In total, 66.7% of surgical patients achieved biochemical remission 6 weeks after surgery, whereas a similar cohort of medically treated patients during the same time frame demonstrated a 69.4% remission rate. Pearson correlation and linear regression analysis revealed a strong association between preoperative tumor volume and prolactin levels, with an increase in serum prolactin level of 101.31 µg/L per 1-cm3 increase in tumor volume (p < 0.001). This held true for men (R = 0.601, p < 0.001) and women (R = 0.935, p < 0.001), with women demonstrating a greater increase in prolactin level per 1-cm3 increase in volume (185.70 vs 79.77 µg/L, p < 0.001). Patients who achieved remission exhibited a 66.08-µg/L increase in preoperative prolactin level per 1 cm3 of preoperative tumor volume (p < 0.001), which was less than the 111.46-µg/L increase per 1 cm3 in patients without remission (p < 0.001). Patients who failed to achieve remission had residual tumors with a 77.77-µg/L increase in prolactin per 1 cm3 of remaining tumor volume after resection (p < 0.001). ROC curve analysis revealed significant thresholds that optimally predicted lack of postoperative remission on the basis of preoperative prolactin and tumor volume. These thresholds were rendered nonsignificant in patients with documented Knosp grade ≥ 3.

CONCLUSIONS

Although the authors found a correlation between prolactinoma volume and serum prolactin level, patients without remission had a greater increase in serum prolactin level per increase in preoperative tumor volume than those who achieved remission, suggesting unique tumor composition. The authors also identified prolactin and tumor volume thresholds that optimally predicted biochemical remission status. The authors hope that their results can be used to identify prolactinomas for which surgery could achieve remission as an alternative to medical management.

Differences in Hearing, Balance, and Quality-of-Life Outcomes in Petroclival Versus Nonpetroclival Posterior Fossa Meningiomas

OBJECTIVE

To compare hearing, tinnitus, balance, and quality-of-life treatment outcomes of petroclival meningioma and nonpetroclival cerebellopontine angle meningioma cohorts.

STUDY DESIGN

A retrospective cohort study of 60 patients with posterior fossa meningiomas, 25 petroclival and 35 nonpetroclival, who were treated at a single tertiary care center between 2000 and 2020.

INTERVENTION

A survey battery that included the Hearing Effort of the Tumor Ear, Speech and Spatial Qualities of Hearing, Tinnitus Functional Index, Dizziness Handicap Inventory (DHI), and Short Form Health Survey. Petroclival and nonpetroclival cohorts were matched for tumor size and demographic features.

MAIN OUTCOME MEASURES

Differences between groups in hearing, balance outcomes, and quality of life and patient factors that influence posttreatment quality of life.

RESULTS

Petroclival meningioma patients reported poorer audiovestibular outcomes with a higher rate of deafness in the tumor ear (36.0% versus 8.6%, p = 0.032) and lower functional hearing by the Hearing Effort of the Tumor Ear, Speech and Spatial Qualities of Hearing (76.6 [6.1] versus 82.0 [4.4], p < 0.001). Current dizziness rate was higher (48.0% versus 23.5%, p = 0.05), with more severe dizziness by DHI (18.4 [4.8] versus 5.7 [2.2], p < 0.001). Both cohorts had similar high quality of life and low tinnitus severity indices. Quality-of-life Short Form Health Survey predictors were tumor size (p = 0.012) and DHI (p = 0.005) in multivariable analysis.

CONCLUSIONS

Hearing and dizziness treatment outcomes of petroclival meningioma are poorer relative to other posterior fossa meningiomas. Despite audiovestibular outcome distinctions, the overall posttreatment quality of life was high for both petroclival and nonpetroclival meningioma.

On-Call Junior Neurosurgery Residents Spend 9 hours of Their On-Call Shift Actively Using the Electronic Health Record

BACKGROUND

The electronic health record (EHR) is central to clinical workflow, yet few studies to date have explored EHR usage patterns among neurosurgery trainees.

OBJECTIVE

To describe the amount of EHR time spent by postgraduate year (PGY)-2 and PGY-3 neurosurgery residents during on-call days and the distribution of EHR activities in which they engage.

METHODS

This cohort study used the EHR audit logs, time-stamped records of user activities, to review EHR usage of PGY-2 and PGY-3 neurosurgery residents scheduled for 1 or more on-call days across 2 calendar years at the University of California San Francisco. We focused on the PGY-2 and PGY-3, which, in our training program, represent the primary participants in the in-house on-call pool.

RESULTS

Over 723 call days, 12 different residents took at least one on-call shift. The median (IQR) number of minutes that residents spent per on-call shift actively using the EHR was 536.8 (203.5), while interacting with an average (SD) of 68.1 (14.7) patient charts. There was no significant difference between Active EHR Time between residents as PGY-2 and PGY-3 on paired t -tests. Residents spent the most time on the following EHR activities: patient reports, notes, order management, patient list, and chart review.

CONCLUSION

Residents spent, on average, 9 hours of their on-call shift actively using the EHR, and there was no improved efficiency as residents gained experience. We noted several areas of administrative EHR burden, which could be reduced.

Mutational Status and Clinical Outcomes Following Systemic Therapy with or without Focal Radiation for Resected Melanoma Brain Metastases

BACKGROUND

Brain metastases occur frequently in advanced melanoma and traditionally require surgery and radiation therapy. New evidence demonstrates that systemic therapies are effective for controlling metastatic melanoma brain metastases. This study evaluated outcomes after resection of melanoma brain metastases treated with systemic therapy, with or without focal radiotherapy.

METHODS

All patients received immunotherapy or BRAF/MEK inhibitors preoperatively or in the immediate 3 months postoperatively. Resection cavity failure, distant central nervous system progression, and adverse radiation effects were reported in the presence and absence of focal radiotherapy using the Kaplan-Meier method.

RESULTS

Between 2011 and 2020, 37 resection cavities in 29 patients met criteria for analysis. Of lesions, 22 (59%) were treated with focal radiotherapy, and 15 (41%) were treated with targeted therapy or immunotherapy alone. The 12- and 24-month freedom from local recurrence was 64.8% (95% confidence interval [CI] 42.1%-99.8%) and 46.3% (95% CI 24.5%-87.5%), respectively, for systemic therapy alone and 93.3% (95% CI 81.5%-100%) at both time points for focal radiotherapy (P = 0.01). On univariate analysis, focal radiotherapy was the only significant factor associated with reduction of local recurrence risk (hazard ratio 0.10, 95% CI 0.01-0.85; P = 0.04). There were no significant differences in central nervous system progression-free survival or overall survival between patients who received systemic therapy plus focal radiotherapy compared with systemic therapy alone. BRAF mutation status was reviewed for either the brain metastasis (n = 9 patients, 31%) or the primary site (n = 20 patients, 69%), and patients harboring BRAF^V600E mutations had worse progression-free survival (P = 0.043).

CONCLUSIONS

Focal radiotherapy with systemic therapy for resected melanoma brain metastases significantly decreased resection cavity recurrence compared with systemic therapy alone. BRAF mutation status correlated with poorer outcomes.

CDKN2A/B co-deletion is associated with increased risk of local and distant intracranial recurrence after surgical resection of brain metastases

Background

While genetic alterations in brain metastases (BMs) have been previously explored, there are limited data examining their association with recurrence after surgical resection. This study aimed to identify genetic alterations within BMs associated with CNS recurrence after surgery across multiple cancer types.

Methods

A retrospective, single-center study was conducted with patients who underwent resection of a BM with available clinical and gene sequencing data available. Local and remote CNS recurrence were the primary study outcomes. Next-generation sequencing of the coding regions in over 500 oncogenes was performed in brain metastasis specimens. Cox proportional hazards analyses were performed to identify clinical features and genomic alterations associated with CNS recurrence.

Results

A total of 90 patients undergoing resection of 91 BMs composed the cohort. Genes most frequently mutated in the cohort included TP53 (64%), CDKN2A (37%), TERT (29%), CDKN2B (23%), NF1 (14%), KRAS (14%), and PTEN (13%), all of which occurred across multiple cancer types. CDKN2A/B co-deletion was seen in 21 (23.1%) brain metastases across multiple cancer types. In multivariate Cox proportional hazard analyses including patient, tumor, and treatment factors, CDKN2A/B co-deletion in the brain metastasis was associated with increased risk of local (HR 4.07, 95% CI 1.32-12.54, P = 0.014) and remote (HR 2.28, 95% CI 1.11-4.69, P = 0.025) CNS progression. Median survival and length of follow-up were not different based on CDKN2A/B mutation status.

Conclusions

CDKN2A/B co-deletion detected in BMs is associated with increased CNS recurrence after surgical resection. Additional work is needed to determine whether more aggressive treatment in patients with this mutation may improve outcomes.

Supervised machine learning algorithms demonstrate proliferation index correlates with long-term recurrence after complete resection of WHO grade I meningioma

OBJECTIVE

Meningiomas are the most common primary intracranial tumor, and resection is a mainstay of treatment. It is unclear what duration of imaging follow-up is reasonable for WHO grade I meningiomas undergoing complete resection. This study examined recurrence rates, timing of recurrence, and risk factors for recurrence in patients undergoing a complete resection (as defined by both postoperative MRI and intraoperative impression) of WHO grade I meningiomas.

METHODS

The authors conducted a retrospective, single-center study examining recurrence risk for adult patients with a single intracranial meningioma that underwent complete resection. Uni- and multivariate nominal logistic regression and Cox proportional hazards analyses were performed to identify variables associated with recurrence and time to recurrence. Two supervised machine learning algorithms were then implemented to confirm factors within the cohort that were associated with recurrence.

RESULTS

The cohort consisted of 823 patients who met inclusion criteria, and 56 patients (6.8%) had recurrence on imaging follow-up. The median age of the cohort was 56 years, and 77.4% of patients were female. The median duration of head imaging follow-up for the entire cohort was 2.7 years, but for the subgroup of patients who had a recurrence, the median follow-up was 10.1 years. Estimated 1-, 5-, 10-, and 15-year recurrence-free survival rates were 99.8% (95% confidence interval [CI] 98.8%-99.9%), 91.0% (95% CI 87.7%-93.6%), 83.6% (95% CI 78.6%-87.6%), and 77.3% (95% CI 69.7%-83.4%), respectively, for the entire cohort. On multivariate analysis, MIB-1 index (odds ratio [OR] per 1% increase: 1.34, 95% CI 1.13-1.58, p = 0.0003) and follow-up duration (OR per year: 1.12, 95% CI 1.03-1.21, p = 0.012) were both associated with recurrence. Gradient-boosted decision tree and random forest analyses both identified MIB-1 index as the main factor associated with recurrence, aside from length of imaging follow-up. For tumors with an MIB-1 index < 8, recurrences were documented up to 8 years after surgery. For tumors with an MIB-1 index ≥ 8, recurrences were documented up to 12 years following surgery.

CONCLUSIONS

Long-term imaging follow-up is important even after a complete resection of a meningioma. Higher MIB-1 labeling index is associated with greater risk of recurrence. Imaging screening for at least 8 years in patients with an MIB-1 index < 8 and at least 12 years for those with an MIB-1 index ≥ 8 may be needed to detect long-term recurrences.

Adverse radiation effect and freedom from progression following repeat stereotactic radiosurgery for brain metastases

OBJECTIVE

The authors previously evaluated risk and time course of adverse radiation effects (AREs) following stereotactic radiosurgery (SRS) for brain metastases, excluding lesions treated after prior SRS. In the present analysis they focus specifically on single-fraction salvage SRS to brain metastases previously treated with SRS or hypofractionated SRS (HFSRS), evaluating freedom from progression (FFP) and the risk and time course of AREs.

METHODS

Brain metastases treated from September 1998 to May 2019 with single-fraction SRS after prior SRS or HFSRS were analyzed. Serial follow-up magnetic resonance imaging (MRI) and surgical pathology reports were reviewed to score local treatment failure and AREs. The Kaplan-Meier method was used to estimate FFP and risk of ARE measured from the date of repeat SRS with censoring at the last brain MRI.

RESULTS

A total of 229 retreated brain metastases in 124 patients were evaluable. The most common primary cancers were breast, lung, and melanoma. The median interval from prior SRS/HFSRS to repeat SRS was 15.4 months, the median prescription dose was 18 Gy, and the median duration of follow-up imaging was 14.5 months. At 1 year after repeat SRS, FFP was 80% and the risk of symptomatic ARE was 11%. The 1-year risk of imaging changes, including asymptomatic RE and symptomatic ARE, was 30%. Among lesions that demonstrated RE, the median time to onset was 6.7 months (IQR 4.7-9.9 months) and the median time to peak imaging changes was 10.1 months (IQR 5.6-13.6 months). Lesion size by quadratic mean diameter (QMD) showed similar results for QMDs ranging from 0.75 to 2.0 cm (1-year FFP 82%, 1-year risk of symptomatic ARE 11%). For QMD < 0.75 cm, the 1-year FFP was 86% and the 1-year risk of symptomatic ARE was only 2%. Outcomes were worse for QMDs 2.01-3.0 cm (1-year FFP 65%, 1-year risk of symptomatic ARE 24%). The risk of symptomatic ARE was not increased with tyrosine kinase inhibitors or immunotherapy before or after repeat SRS.

CONCLUSIONS

RE on imaging was common after repeat SRS (30% at 1 year), but the risk of a symptomatic ARE was much less (11% at 1 year). The results of repeat single-fraction SRS were good for brain metastases ≤ 2 cm. The authors recommend an interval ≥ 6 months from prior SRS and a prescription dose ≥ 18 Gy. Alternatives such as HFSRS, laser interstitial thermal therapy, or resection with adjuvant radiation should be considered for recurrent brain metastases > 2 cm.

Treated large posterior fossa vestibular schwannoma and meningioma: Hearing outcome and willingness-to-accept brain implant for unilateral deafness

Background/Objective

To compare functional hearing and tinnitus outcomes in treated large (~ 3 cm) vestibular schwannoma (VS) and posterior fossa meningioma cohorts, and construct willingness-to-accept profiles for an experimental brain implant to treat unilateral hearing loss.

Methods

A two-way MANOVA model with two independent variables (tumor type; time from treatment) and three dependent variables (hearing effort of tumor ear; abbreviated Speech, Spatial, and Qualities of Hearing scale (SSQ12); Tinnitus Functional Index (TFI)) was used to analyze data from VS (N = 32) and meningioma (N = 50) patients who were treated at a tertiary care center between 2010 and 2020. A query to probe acceptance of experimental treatment for hearing loss relative to expected benefit was used to construct willingness-to-accept profiles.

Results

Tumor type was statistically significant on the combined dependent variables analysis (F[3, 76] = 19.172, p < .0005, Wilks' Λ = 0.569). Meningioma showed better outcome for hearing effort (F[1, 76] = 14.632, p < .0005) and SSQ12 (F[1, 76] = 16.164, p < .0005), but not for TFI (F[1, 76] = 1.247, p = .268) on univariate two-way ANOVA analyses. Superior hearing effort and SSQ12 indices in the short-term (< 2 years) persisted in the long-term (> 2 years) (p ≤ .017). At the 60% speech understanding level, 77% of respondents would accept an experimental brain implant.

Conclusion

Hearing outcome is better for posterior fossa meningioma compared to VS. Most patients with hearing loss in the tumor ear would consider a brain implant if the benefit level would be comparable to a cochlear implant.

Level of Evidence

2.

Resection with intraoperative cesium-131 brachytherapy as salvage therapy for recurrent brain tumors

OBJECTIVE

The authors' objective was to examine the safety and efficacy of salvage intracranial cesium-131 brachytherapy in combination with resection of recurrent brain tumors.

METHODS

The authors conducted a retrospective chart review of consecutive patients treated with intraoperative intracranial cesium-131 brachytherapy at a single institution. Permanent suture-stranded cesium-131 seeds were implanted in the resection cavity after maximal safe tumor resection. The primary outcomes of interest were local, locoregional (within 1 cm), and intracranial control, as well as rates of overall survival (OS), neurological death, symptomatic adverse radiation effects (AREs), and surgical complication rate graded according to Common Terminology Criteria for Adverse Events version 5.0.

RESULTS

Between 2016 and 2020, 36 patients received 40 consecutive cesium-131 implants for 42 recurrent brain tumors and received imaging follow-up for a median (interquartile range [IQR]) of 17.0 (12.7-25.9) months. Twenty patients (55.6%) with 22 implants were treated for recurrent brain metastasis, 12 patients (33.3%) with 16 implants were treated for recurrent atypical (n = 7) or anaplastic (n = 5) meningioma, and 4 patients (11.1%) were treated for other recurrent primary brain neoplasms. All except 1 tumor (97.6%) had received prior radiotherapy, including 20 (47.6%) that underwent 2 or more prior radiotherapy treatments and 23 (54.8%) that underwent prior resection. The median (IQR) tumor size was 3.0 (2.3-3.7) cm, and 17 lesions (40.5%) had radiographic evidence of ARE prior to salvage therapy. Actuarial 1-year local/locoregional/intracranial control rates for the whole cohort and patients with metastases and meningiomas were 91.6%/83.4%/47.9%, 88.8%/84.4%/45.4%, and 100%/83.9%/46.4%, respectively. No cases of local recurrence of any histology (0 of 27) occurred after gross-total resection (p = 0.012, log-rank test). The 1-year OS rates for the whole cohort and patients with metastases and meningiomas were 82.7%, 79.1%, and 91.7%, respectively, and the median (IQR) survival of all patients was 26.7 (15.6-36.4) months. Seven patients (19.4%) experienced neurological death from progressive intracranial disease (7 of 14 total deaths [50%]), 5 (13.9%) of whom died of leptomeningeal disease. Symptomatic AREs were observed in 9.5% of resection cavities (n = 4), of which 1 (2.4%) was grade 3 in severity. The surgical complication rate was 16.7% (n = 7); 4 (9.5%) of these patients had grade 3 or higher complications, including 1 patient (2.4%) who died perioperatively.

CONCLUSIONS

Cesium-131 brachytherapy resulted in good local control and acceptable rates of symptomatic AREs and surgical complications in this heavily pretreated cohort, and it may be a reasonable salvage adjuvant treatment for this patient population.

Identifying risk factors for postoperative diabetes insipidus in more than 2500 patients undergoing transsphenoidal surgery: a single-institution experience

OBJECTIVE

Diabetes insipidus (DI) following transsphenoidal surgery can adversely impact quality of life and be difficult to manage. This study sought to characterize pre- and perioperative risk factors that may predispose patients to DI after pituitary surgery.

METHODS

A retrospective review of patients treated at a single institution from 2007 to 2019 was conducted. DI was defined as postoperative sodium > 145 mEq/L and urine output > 300 ml/hr and/or postoperative desmopressin (ddAVP) use. DI was further characterized as transient or permanent. Uni- and multivariate analyses were performed to determine variables associated with postoperative DI.

RESULTS

The authors identified 2529 patients who underwent transsphenoidal surgery at their institution. Overall, DI was observed in 270 (10.7%) of the 2529 patients, with 114 (4.5%) having permanent DI and 156 (6.2%) with transient symptoms. By pathology type, DI occurred in 31 (46.3%) of 67 craniopharyngiomas, 10 (14.3%) of 70 apoplexies, 46 (14.3%) of 322 Rathke's cleft cysts, 77 (7.7%) of 1004 nonfunctioning pituitary adenomas (NFPAs), and 62 (7.6%) of 811 functioning pituitary adenomas (FPAs). Final lesion pathology significantly affected DI rates (p < 0.001). Multivariate analysis across pathologies showed that younger age (odds ratio [OR] 0.97, p < 0.001), intraoperative CSF encounter (OR 2.74, p < 0.001), craniopharyngioma diagnosis (OR 8.22, p = 0.007), and postoperative hyponatremia (OR 1.50, p = 0.049) increased the risk of DI. Because surgery for each pathology created specific risk factors for DI, the analysis was then limited to the 1815 pituitary adenomas (PAs) in the series, comprising 1004 NFPAs and 811 FPAs. For PAs, younger age (PA: OR 0.97, p < 0.001; NFPA: OR 0.97, p < 0.001; FPA: OR 0.97, p = 0.028) and intraoperative CSF encounter (PA: OR 2.99, p < 0.001; NFPA: OR 2.93, p < 0.001; FPA: OR 3.06, p < 0.001) increased DI rates in multivariate analysis. Among all PAs, patients with DI experienced peak sodium levels later than those without DI (postoperative day 11 vs 2). Increasing tumor diameter increased the risk of DI in FPAs (OR 1.52, p = 0.008), but not in NFPAs (p = 0.564).

CONCLUSIONS

In more than 2500 patients treated at a single institution, intraoperative CSF encounter, craniopharyngioma diagnosis, and young age all increased the risk of postoperative DI. Patients with postoperative hyponatremia exhibited higher rates of DI, suggesting possible bi- or triphasic patterns to DI. Greater vigilance should be maintained in patients meeting these criteria following transsphenoidal surgery to ensure early recognition and treatment of DI.

Socioeconomic predictors of case presentations and outcomes in 225 nonfunctional pituitary adenoma resections

OBJECTIVE

Clinical presentations and outcomes of nonfunctional pituitary adenoma (NFPA) resections can vary widely, and very little prior research has analyzed this variance through a socioeconomic lens. This study sought to determine whether socioeconomic status (SES) influences NFPA presentations and postoperative outcomes, as these associations could aid physicians in understanding case prognoses and complications.

METHODS

The authors retrospectively analyzed 225 NFPA resections from 2012 to 2019 at their institution. Race, ethnicity, insurance status, estimated income, and having a primary care provider (PCP) were collected as 5 markers of SES. These markers were correlated with presenting tumor burden, presenting symptoms, surgical outcomes, and long-term clinical outcomes.

RESULTS

All 5 examined SES markers influenced variance in patient presentation or outcome. Insurance status's effects on patient presentations disappeared when examining only patients with PCPs. Having a PCP was associated with significantly smaller tumor size at diagnosis (effect size = 0.404, p < 0.0001). After surgery, patients with PCPs had shorter postoperative hospital lengths of stay (p = 0.043) and lower rates of readmission within 30 days of discharge (OR 0.256, p = 0.047). Despite continuing follow-up for longer durations (p = 0.0004), patients with PCPs also had lower rates of tumor recurrence (p < 0.0001). Higher estimated income was similarly associated with longer follow-up (p = 0.002) and lower rates of tumor recurrence (p = 0.013). Among patients with PCPs, income was not associated with recurrence.

CONCLUSIONS

This study found that while all 5 variables (race, ethnicity, insurance, PCP status, and estimated income) affected NFPA presentations and outcomes, having a PCP was the single most important of these socioeconomic factors, impacting hospital lengths of stay, readmission rates, follow-up adherence, and tumor recurrence. Having a PCP even protected low-income patients from experiencing increased rates of tumor recurrence. These protective findings suggest that addressing socioeconomic disparities may lead to better NFPA presentations and outcomes.

Salvage Surgery for Local Control of Brain Metastases After Previous Stereotactic Radiosurgery: A Single-Center Series

BACKGROUND

Although overall survival (OS) has improved in patients with brain metastases (BMs), control of recurrent BMs remains a therapeutic challenge. Salvage surgery may achieve acceptable control rates in the setting of progression after previous stereotactic radiosurgery (SRS), yet it remains a question how additional adjuvant therapies may affect outcomes and how patient selection for salvage surgery may be optimized.

METHODS

Patients receiving salvage surgery for BM progression after previous SRS were retrospectively reviewed from a single center. Outcomes of interest included local tumor progression, leptomeningeal dissemination, and OS. Cox proportional hazard models and nominal logistic regression were applied to determine factors associated with outcomes of interest.

RESULTS

A total of 43 patients with 50 BMs were included. After salvage surgery, local progression was observed for 17 BMs (34%), leptomeningeal dissemination was observed in 17 patients (39.5%), and censored median OS was 17.9 months. On multivariate analysis, use of brachytherapy was associated with improved local control (hazard ratio [HR], 0.15; 95% confidence interval [CI], 0.04-0.6; P = 0.008). For patients treated with SRS ≥4.5 months before salvage surgery, both brachytherapy (HR, 0.07; 95% CI, 0.01-0.39; P = 0.002) and postoperative adjuvant SRS (HR, 0.14; 95% CI, 0.02-1.00; P = 0.05) were associated with improved local control compared with no adjuvant radiation therapy. Presence of extracranial malignancy (HR, 6.70; 95% CI, 2.58-17.42; P < 0.0001) was associated with shorter survival. Graded prognostic assessment underestimated survival in 79.1% of patients, with a mean difference of 18.9 months between graded prognostic assessment-estimated and actual OS.

CONCLUSIONS

In properly selected patients, salvage surgery may be an appropriate therapy for BM progression after previous SRS. Adjuvant brachytherapy and repeat SRS can offer significant benefit for local control with salvage resection.

Microsurgical resection of an intravestibular schwannoma: a review of surgical technique and management considerations

Intravestibular schwannomas are rare tumors within the intralabyrinthine region and involve different management considerations compared to more common vestibular schwannomas. In this report, the authors review a case of a 52-year-old woman who presented with hearing loss and vestibular symptoms and was found to have a left intravestibular schwannoma. Given her debilitating vestibular symptoms, she underwent microsurgical resection. In this video, the authors review the relevant anatomy, surgical technique, and management considerations in these patients.

The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID2187

Comparison of Outcomes following Primary and Repeat Resection of Craniopharyngioma

Introduction The management of recurrent craniopharyngioma is complex with limited data to guide decision-making. Some reports suggest reoperation should be avoided due to an increased complication profile, while others have demonstrated that safe reoperation can be performed. For other types of skull base lesions, maximal safe resection followed by adjuvant therapy has replaced radical gross total resection due to the favorable morbidity profiles.

Methods Seventy-one patients underwent resection over a 9-year period for craniopharyngioma and were retrospectively reviewed. Patients were separated into primary resection and reoperation cohorts and stratified by surgical approach (endonasal vs. cranial) and survival analyses were performed based on cohort and surgical approach.

Results Fifty patients underwent primary resection, while 21 underwent reoperation for recurrence. Fifty endonasal transsphenoidal surgeries and 21 craniotomies were performed. Surgical approaches were similarly distributed across cohorts. Subtotal resection was achieved in 83% of all cases. There were no differences in extent of resection, visual outcomes, subsequent neuroendocrine function, and complications across cohorts and surgical approaches. The median time to recurrence was 87 months overall, and there were no differences by cohort and approach. The 5-year survival rate was 81.1% after reoperation versus 93.2% after primary resection.

Conclusion Compared with primary resection, reoperation for craniopharyngioma recurrence is associated with similar functional and survival outcomes in light of individualized surgical approaches. Maximal safe resection followed by adjuvant radiotherapy for residual tumor likely preserves vision and endocrine function without sacrificing overall patient survival.

Posterior petrous face meningiomas presenting with Ménière's-like syndrome: a case series and review of the literature

OBJECTIVE

Ménière's disease is an inner ear disorder classically characterized by fluctuating hearing loss, tinnitus, and aural fullness accompanied by episodic vertigo. While the pathogenesis of Ménière's remains under debate, histopathological analyses implicate endolymphatic sac dysfunction with inner ear fluid homeostatic dysregulation. Little is known about whether external impingement of the endolymphatic sac by tumors may present with Ménière's-like symptoms. The authors present a case series of 7 patients with posterior fossa meningiomas that involved the endolymphatic sac and new onset of Ménière's-like symptoms and review the literature on this rare clinical entity.

METHODS

A retrospective review of patients undergoing resection of a posterior petrous meningioma was performed at the authors' institution. Inclusion criteria were age older than 18 years; patients presenting with Ménière's-like symptoms, including episodic vertigo, aural fullness, tinnitus, and/or hearing loss; and tumor location overlying the endolymphatic sac.

RESULTS

There were 7 cases of posterior petrous face meningiomas involving the vestibular aperture presenting with Ménière's-like symptoms. Imaging and intraoperative examination confirmed no cranial nerve VIII compression or labyrinthine artery involvement accounting for audiovestibular symptoms. Of the 7 patients in the series, 6 experienced significant improvement or resolution of their vertigo, and all 7 had improvement or resolution of their tinnitus after resection. Of the 5 patients who had preoperative hearing loss, 2 experienced improvement or resolution of their ipsilateral preoperative hearing deficit, whereas the other 3 had unchanged hearing loss compared to preoperative evaluation.

CONCLUSIONS

Petrous face meningiomas overlying the endolymphatic sac can present with a Ménière's syndrome. Early recognition and microsurgical excision of these tumors is critical for resolution of most symptoms and stabilization of hearing loss.

Clinical characteristics and outcomes of null-cell versus silent gonadotroph adenomas in a series of 1166 pituitary adenomas from a single institution

OBJECTIVE

Nonfunctioning pituitary adenomas present without biochemical or clinical signs of hormone excess and are the second most common type of pituitary adenomas. The 2017 WHO classification scheme of pituitary adenomas differentiates null-cell adenomas (NCAs) and silent gonadotroph adenomas (SGAs). The present study sought to highlight the differences in patient characteristics and clinical outcomes between NCAs and SGAs.

METHODS

The records of 1166 patients who underwent transsphenoidal surgery for pituitary adenoma between 2012 and 2019 at a single institution were retrospectively reviewed. Patient demographics and clinical outcomes were collected.

RESULTS

Of the overall pituitary adenoma cohort, 12.8% (n = 149) were SGAs and 9.2% (n = 107) NCAs. NCAs were significantly more common in female patients than SGAs (61.7% vs 26.8%, p < 0.001). There were no differences in patient demographics, initial tumor size, or perioperative and short-term clinical outcomes. There was no significant difference in the amount of follow-up between patients with NCAs and those with SGAs (33.8 months vs 29.1 months, p = 0.237). Patients with NCAs had significantly higher recurrence (p = 0.021), adjuvant radiation therapy usage (p = 0.002), and postoperative diabetes insipidus (p = 0.028). NCA pathology was independently associated with tumor recurrence (HR 3.64, 95% CI 1.07-12.30; p = 0.038), as were cavernous sinus invasion (HR 3.97, 95% CI 1.04-15.14; p = 0.043) and anteroposterior dimension of the tumor (HR 2.23, 95% CI 1.09-4.59; p = 0.030).

CONCLUSIONS

This study supports the definition of NCAs and SGAs as separate subgroups of nonfunctioning pituitary adenomas, and it highlights significant differences in long-term clinical outcomes, including tumor recurrence and the associated need for adjuvant radiation therapy, as well as postoperative diabetes insipidus. The authors also provide insight into independent risk factors for these outcomes in the adenoma population studied, providing clinicians with additional predictors of patient outcomes. Follow-up studies will hopefully uncover mechanisms of biological aggressiveness in NCAs and associated molecular targets.

Oncology and Spinal Neurosurgeons Performing Resections of Intramedullary Ependymomas Compared with Single Neurosurgeons: A 13-Year Experience at a Single Institution

OBJECTIVE

Resection of intramedullary spinal ependymomas carries great risk of postoperative neurological deficits. The objective of this study was to describe our experience using co-neurosurgeon teams to address intramedullary ependymomas to determine if the use of 2 experienced attending neurosurgeons with expertise in both neurosurgical oncology and spine pathology can improve outcomes for intramedullary ependymoma resections.

METHODS

We retrospectively compared surgical and disease control outcomes in intramedullary ependymoma cases performed by co-neurosurgeon (one neurosurgical oncologist and one neurosurgeon trained in spinal surgery) and single-neurosurgeon teams over a 13-year period at a single institution.

RESULTS

Co-neurosurgeons performed resections in 34 (47.9%) patients, and a single neurosurgeon performed resections in 37 (52.1%) patients. There were no significant differences in the frequency of gross total resection in the co-neurosurgeon versus single-neurosurgeon group (85.7% vs. 78.4%, P = 0.45). Posterior spinal fusion was more common in the co-neurosurgeon group (35.3%) compared with the single-neurosurgeon group (8.1%) (P = 0.01). Two (5.9%) patients in the co-neurosurgeon group and 5 (13.5%) patients in the single-neurosurgeon group had complications requiring surgical revision (P = 0.28). Recurrence rates were similar in both groups (5.9% vs. 10.8%, P = 0.50). At last follow-up, 76% of patients who presented with mild or no deficits remained functionally independent.

CONCLUSIONS

Resection of intramedullary ependymomas by co-neurosurgeon teams resulted in similar rates of gross total resection, postoperative complications, and recurrence compared with surgeries performed by a single neurosurgeon. Functional neurological outcomes were not impacted by co-neurosurgeons performing ependymoma resections.

Are preoperative chlorhexidine gluconate showers associated with a reduction in surgical site infection following craniotomy? A retrospective cohort analysis of 3126 surgical procedures

OBJECTIVE

Surgical site infection (SSI) is a complication linked to increased costs and length of hospital stay. Prevention of SSI is important to reduce its burden on individual patients and the healthcare system. The authors aimed to assess the efficacy of preoperative chlorhexidine gluconate (CHG) showers on SSI rates following cranial surgery.

METHODS

In November 2013, a preoperative CHG shower protocol was implemented at the authors' institution. A total of 3126 surgical procedures were analyzed, encompassing a time frame from April 2012 to April 2016. Cohorts before and after implementation of the CHG shower protocol were evaluated for differences in SSI rates.

RESULTS

The overall SSI rate was 0.6%. No significant differences (p = 0.11) were observed between the rate of SSI of the 892 patients in the preimplementation cohort (0.2%) and that of the 2234 patients in the postimplementation cohort (0.8%). Following multivariable analysis, implementation of preoperative CHG showers was not associated with decreased SSI (adjusted OR 2.96, 95% CI 0.67-13.1; p = 0.15).

CONCLUSIONS

This is the largest study, according to sample size, to examine the association between CHG showers and SSI following craniotomy. CHG showers did not significantly alter the risk of SSI after a cranial procedure.

Abstract PO-073: Mutational status and clinical outcomes following systemic therapy and focal radiation for melanoma brain metastases

Brain metastases are the most common intracranial neoplasm yet clinical outcomes remain poor. The purpose of this study was to evaluate the efficacy of multimodal therapy comprising surgery followed by focal radiation, and/or systemic therapy and elucidate clinically significant biomarkers for resected melanoma brain metastases. Forty consecutive patients with newly diagnosed melanoma brain metastases who underwent surgical resection and targeted mutational analysis at UCSF between 2011 and 2020 were identified. Demographic, clinical, and outcome data were extracted from the medical record and institutional cancer registry. Surgical cavity local recurrence free survival (LRFS), intracranial progression free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The median age of patients in this cohort was 58 years (range: 27-75 years) with median MRI follow up of 13.15 months. Twenty patients (50%) were treated with concurrent stereotactic radiation (1-5 fractions) and systemic therapy while 16 patients (40%) were treated with systemic therapy only. Mutational testing demonstrated the most common pathogenic variant was BRAF V600E, found in 16 patients (40%), while the remaining 24 patients (60%) did not harbor this mutation. Microsatellite instability (MSI) estimation was available for 8 patients (20%), all of which were found to be MSI low (&lt;2%). Median LRFS was significantly improved with combined focal radiation and systemic therapy compared to systemic therapy alone (NR versus 15 months, p=0.01; log-rank test). Patients harboring BRAF V600E mutations had worse intracranial PFS compared to those without V600E mutation (4 months versus 12 months, p=0.048; log-rank test), as well as a trend toward worse OS (NR vs 13 months, p=0.09; log-rank test). Systemic agent choice was heterogeneous, with 24 patients (60%) treated with immunotherapy alone, 12 patients (30%) treated with dual BRAF/MEK inhibitor therapy alone, and the remainder treated with mixed regimens (10%) with no differences in efficacy or toxicity between these subgroups. Our results suggest combined focal radiation and systemic therapy is effective for melanoma brain metastases. Moreover, specific molecular alterations such as BRAF V600E mutation are associated with poorer outcomes, and all brain metastases in our cohort were MSI low. Limitations of our study include its retrospective nature, limited sample size, and heterogeneity of systemic regimens, and future prospective validation and multiplatform genomic analysis are needed to build on our findings.

Citation Format: Harish N. Vasudevan, Matthew S. Susko, Lijun Ma, Jean L. Nakamura, David R. Raleigh, Lauren Boreta, Shannon Fogh, Philip V. Theodosopoulos, Michael W. McDermott, Katy K. Tsai, Penny K. Sneed, Steve E. Braunstein. Mutational status and clinical outcomes following systemic therapy and focal radiation for melanoma brain metastases [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-073.

Genetic Events and Signaling Mechanisms Underlying Schwann Cell Fate in Development and Cancer

In this review, we describe Schwann cell development from embryonic neural crest cells to terminally differentiated myelinated and nonmyelinated mature Schwann cells. We focus on the genetic drivers and signaling mechanisms mediating decisions to proliferate versus differentiate during Schwann cell development, highlighting pathways that overlap with Schwann cell development and are dysregulated in tumorigenesis. We conclude by considering how our knowledge of the events underlying Schwann cell development and mouse models of schwannoma, neurofibroma, and malignant peripheral nerve sheath tumor can inform novel therapeutic strategies for patients with cancers derived from Schwann cell lineages.

Meningioma surgical outcomes and complications in patients aged 75 years and older

OBJECTIVE

Meningioma incidence increases with age, yet limited data exist on how comorbidities impact complication rates in elderly patients undergoing meningioma resection. The objective of this study was to report surgical outcomes and identify risk factors for perioperative complications.

METHODS

We performed a retrospective study of patients 75 years and older undergoing meningioma resection. Outcomes included survival and complications. Major complications were those requiring surgical intervention or causing permanent neurological deficit. Recursive partitioning, Kaplan-Meier survival, univariate and multi-variate (MVA) analyses were performed.

RESULTS

From 1996 to 2014, 103 patients with a median age of 79 years (IQR 77-83 years) underwent cranial meningioma resection. Median follow-up was 5.8 years (IQR 1.7-8.7 years). Median actuarial survival was 10.5 years. Complications occurred in 32 patients (31.1%), and 13 patients (12.6%) had multiple complications. Major complications occurred in 16 patients (15.5%). Increasing age was not a significant predictor of any (p = 0.6408) or major complication (p = 0.8081). On univariate analysis, male sex, Charlson Comorbidity Index greater than 8, and cardiovascular comorbidities were significantly associated with major complications. On MVA only cardiovascular comorbidities (OR 3.94, 95% CI 1.05-14.76, p = 0.0238) were significantly associated with any complication. All patients with major complications had cardiovascular comorbidities, and on MVA male gender (OR 3.78, 95%CI 1.20-11.93, p = 0.0212) was associated with major complications.

CONCLUSIONS

Cardiovascular comorbidities and male gender are significant risk factors for complications after meningioma resection in patients aged 75 years and older. While there is morbidity associated with meningioma resection in this cohort, there is also excellent long-term survival.

Use of Ultrasound for Navigating the Internal Carotid Artery in Revision Endoscopic Endonasal Skull Base Surgery

While the use of image-guided navigation is an excellent adjunct to the use of anatomical landmarks, dynamic changes that may occur in the position of critical structures are not accounted for during and after tumor resection. Unlike navigation, Doppler ultrasonography provides real-time imaging of the anterior skull base and can be used to accurately identify the location of vital structures during skull base surgery.

A 56-year-old female initially presented with new onset left eye visual deficits. She previously underwent sublabial transsphenoidal subtotal resection of the tumor, confirmed as clival chordoma. She subsequently presented to our institution. She was treated with an expanded endonasal resection of the remaining chordoma followed by CyberKnife radiosurgery. Two years later, surveillance imaging identified tumor recurrence within the right clivus posterior to the carotid artery. Intraoperatively, in the previously operated irradiated skull base, the normal bony architecture of the sella was absent, resulting in the inability to distinguish the anterior genu of the internal carotid artery (ICA) from the adjacent tumor. Using Doppler ultrasonography, the course of the ICA was imaged in real time, allowing for safe, gross total tumor resection.

In the setting of prior operation, radiation, or extensive disease, the normal bony architecture of the sella may be disrupted, placing the cavernous ICA at risk. We report what we believe is the first use of intraoperative ultrasound during the endoscopic endonasal approach in the setting of a previously operated, radiated sella.

Postoperative diffusion-weighted imaging and neurological outcome after convexity meningioma resection

OBJECTIVE

Convexity meningiomas are commonly managed with resection. Motor outcomes and predictors of new deficits after surgery are poorly studied. The objective of this study was to determine whether postoperative diffusion-weighted imaging (DWI) was associated with neurological deficits after convexity meningioma resection and to identify the risk factors for postoperative DWI restriction.

METHODS

A retrospective review of patients who had undergone convexity meningioma resection from 2014 to 2018 was performed. Univariate and multivariate logistic regressions were performed to identify variables associated with postoperative neurological deficits and a DWI signal. The amount of postoperative DWI signal was measured and was correlated with low apparent diffusion coefficient maps to confirm ischemic injury.

RESULTS

The authors identified 122 patients who had undergone a total of 125 operations for convexity meningiomas. The median age at surgery was 57 years, and 70% of the patients were female. The median follow-up was 26 months. The WHO grade was I in 62% of cases, II in 36%, and III in 2%. The most common preoperative deficits were seizures (24%), extremity weakness/paralysis (16%), cognitive/language/memory impairment (16%), and focal neurological deficit (16%). Following resection, 89% of cases had no residual deficit. Postoperative DWI showed punctate or no diffusion restriction in 78% of cases and restriction > 1 cm in 22% of cases. An immediate postoperative neurological deficit was present in 14 patients (11%), but only 8 patients (7%) had a deficit at 3 months postoperatively. Univariate analysis identified DWI signal > 1 cm (p < 0.0001), tumor diameter (p < 0.0001), preoperative motor deficit (p = 0.0043), older age (p = 0.0113), and preoperative embolization (p = 0.0171) as risk factors for an immediate postoperative deficit, whereas DWI signal > 1 cm (p < 0.0001), tumor size (p < 0.0001), and older age (p = 0.0181) were risk factors for deficits lasting more than 3 months postoperatively. Multivariate analysis revealed a DWI signal > 1 cm to be the only significant risk factor for deficits at 3 months postoperatively (OR 32.42, 95% CI 3.3-320.1, p = 0.0002). Further, estimated blood loss (OR 1.4 per 100 ml increase, 95% CI 1.1-1.7, p < 0.0001), older age (OR 1.1 per year older, 95% CI 1.0-1.1, p = 0.0009), middle third location in the sagittal plane (OR 16.9, 95% CI 1.3-216.9, p = 0.0026), and preoperative peritumoral edema (OR 4.6, 95% CI 1.2-17.7, p = 0.0249) were significantly associated with a postoperative DWI signal > 1 cm.

CONCLUSIONS

A DWI signal > 1 cm is significantly associated with postoperative neurological deficits, both immediate and long-lasting. Greater estimated blood loss, older age, tumor location over the motor strip, and preoperative peritumoral edema increase the risk of having a postoperative DWI signal > 1 cm, reflective of perilesional ischemia. Most immediate postoperative deficits will improve over time. These data are valuable when preoperatively communicating with patients about the risks of surgery and when postoperatively discussing prognosis after a deficit occurs.

Endonasal endoscopic approach to the pterygopalatine and infratemporal fossae

The pterygopalatine fossa and infratemporal fossa are spaces located under the skull base, housing important neurovascular structures. Surgical access to these spaces is challenging because of their deep location and complex anatomy. Their surgical access has been classically carried out through multiple craniofacial approaches until the advent of endoscopic endonasal surgery at the end of the XX^th century. Our goal is to describe the transmaxillary-transsphenoidal-transpterygoid approach to the pterygopalatine and infratemporal fossae through endonasal endoscopic surgery based on anatomo-surgical dissection and an illustrative clinical case. We conclude that after careful radiologic evaluation of the feasibility of this technique, the endonasal endoscopic access to these spaces for tumor resection is efficient with reduced surgical morbidities. The endonasal approach is versatile and can be fashioned according to the nature and extent of the lesion.

A Prognostic Gene-Expression Signature and Risk Score for Meningioma Recurrence After Resection

BACKGROUND

Prognostic markers for meningioma are needed to risk-stratify patients and guide postoperative surveillance and adjuvant therapy.

OBJECTIVE

To identify a prognostic gene signature for meningioma recurrence and mortality after resection using targeted gene-expression analysis.

METHODS

Targeted gene-expression analysis was used to interrogate a discovery cohort of 96 meningiomas and an independent validation cohort of 56 meningiomas with comprehensive clinical follow-up data from separate institutions. Bioinformatic analysis was used to identify prognostic genes and generate a gene-signature risk score between 0 and 1 for local recurrence.

RESULTS

We identified a 36-gene signature of meningioma recurrence after resection that achieved an area under the curve of 0.86 in identifying tumors at risk for adverse clinical outcomes. The gene-signature risk score compared favorably to World Health Organization (WHO) grade in stratifying cases by local freedom from recurrence (LFFR, P < .001 vs .09, log-rank test), shorter time to failure (TTF, F-test, P < .0001), and overall survival (OS, P < .0001 vs .07) and was independently associated with worse LFFR (relative risk [RR] 1.56, 95% CI 1.30-1.90) and OS (RR 1.32, 95% CI 1.07-1.64), after adjusting for clinical covariates. When tested on an independent validation cohort, the gene-signature risk score remained associated with shorter TTF (F-test, P = .002), compared favorably to WHO grade in stratifying cases by OS (P = .003 vs P = .10), and was significantly associated with worse OS (RR 1.86, 95% CI 1.19-2.88) on multivariate analysis.

CONCLUSION

The prognostic meningioma gene-expression signature and risk score presented may be useful for identifying patients at risk for recurrence.

Consensus-based perioperative protocols during the COVID-19 pandemic

OBJECTIVE

During the COVID-19 pandemic, quaternary-care facilities continue to provide care for patients in need of urgent and emergent invasive procedures. Perioperative protocols are needed to streamline care for these patients notwithstanding capacity and resource constraints.

METHODS

A multidisciplinary panel was assembled at the University of California, San Francisco, with 26 leaders across 10 academic departments, including 7 department chairpersons, the chief medical officer, the chief operating officer, infection control officers, nursing leaders, and resident house staff champions. An epidemiologist, an ethicist, and a statistician were also consulted. A modified two-round, blinded Delphi method based on 18 agree/disagree statements was used to build consensus. Significant disagreement for each statement was tested using a one-sided exact binomial test against an expected outcome of 95% consensus using a significance threshold of p < 0.05. Final triage protocols were developed with unblinded group-level discussion.

RESULTS

Overall, 15 of 18 statements achieved consensus in the first round of the Delphi method; the 3 statements with significant disagreement (p < 0.01) were modified and iteratively resubmitted to the expert panel to achieve consensus. Consensus-based protocols were developed using unblinded multidisciplinary panel discussions. The final algorithms 1) quantified outbreak level, 2) triaged patients based on acuity, 3) provided a checklist for urgent/emergent invasive procedures, and 4) created a novel scoring system for the allocation of personal protective equipment. In particular, the authors modified the American College of Surgeons three-tiered triage system to incorporate more urgent cases, as are often encountered in neurosurgery and spine surgery.

CONCLUSIONS

Urgent and emergent invasive procedures need to be performed during the COVID-19 pandemic. The consensus-based protocols in this study may assist healthcare providers to optimize perioperative care during the pandemic.

Clinical characteristics and outcomes in elderly patients undergoing transsphenoidal surgery for nonfunctioning pituitary adenoma

OBJECTIVE

Life expectancy has increased over the past century, causing a shift in the demographic distribution toward older age groups. Elderly patients comprise up to 14% of all patients with pituitary tumors, with most lesions being nonfunctioning pituitary adenomas (NFPAs). Here, the authors evaluated demographics, outcomes, and postoperative complications between nonelderly adult and elderly NFPA patients.

METHODS

A retrospective review of 908 patients undergoing transsphenoidal surgery (TSS) for NFPA at a single institution from 2007 to 2019 was conducted. Clinical and surgical outcomes and postoperative complications were compared between nonelderly adult (age ≥ 18 and ≤ 65 years) and elderly patients (age > 65 years).

RESULTS

There were 614 and 294 patients in the nonelderly and elderly groups, respectively. Both groups were similar in sex (57.3% vs 60.5% males; p = 0.4), tumor size (2.56 vs 2.46 cm; p = 0.2), and cavernous sinus invasion (35.8% vs 33.7%; p = 0.6). Regarding postoperative outcomes, length of stay (1 vs 2 days; p = 0.5), extent of resection (59.8% vs 64.8% gross-total resection; p = 0.2), CSF leak requiring surgical revision (4.3% vs 1.4%; p = 0.06), 30-day readmission (8.1% vs 7.3%; p = 0.7), infection (3.1% vs 2.0%; p = 0.5), and new hypopituitarism (13.9% vs 12.0%; p = 0.3) were similar between both groups. Elderly patients were less likely to receive adjuvant radiation (8.7% vs 16.3%; p = 0.009), undergo future reoperation (3.8% vs 9.5%; p = 0.003), and experience postoperative diabetes insipidus (DI) (3.7% vs 9.4%; p = 0.002), and more likely to have postoperative hyponatremia (26.7% vs 16.4%; p < 0.001) and new cranial nerve deficit (1.9% vs 0.0%; p = 0.01). Subanalysis of elderly patients showed that patients with higher Charlson Comorbidity Index scores had comparable outcomes other than higher DI rates (8.1% vs 0.0%; p = 0.006). Elderly patients’ postoperative sodium peaked and troughed on postoperative day 3 (POD3) (mean 138.7 mEq/L) and POD9 (mean 130.8 mEq/L), respectively, compared with nonelderly patients (peak POD2: mean 139.9 mEq/L; trough POD8: mean 131.3 mEq/L).

CONCLUSIONS

The authors’ analysis revealed that TSS for NFPA in elderly patients is safe with low complication rates. In this cohort, more elderly patients experienced postoperative hyponatremia, while more nonelderly patients experienced postoperative DI. These findings, combined with the observation of higher DI in patients with more comorbidities and elderly patients experiencing later peaks and troughs in serum sodium, suggest age-related differences in sodium regulation after NFPA resection. The authors hope that their results will help guide discussions with elderly patients regarding risks and outcomes of TSS.

Residual Tumor Volume and Location Predict Progression After Primary Subtotal Resection of Sporadic Vestibular Schwannomas: A Retrospective Volumetric Study

BACKGROUND

Preservation of functional integrity during vestibular schwannoma surgery has become critical in the era of patient-centric medical decision-making. Subtotal tumor removal is often necessary when dense adhesions between the tumor and critical structures are present. However, it is unclear what the rate of tumor control is after subtotal resection (STR) and what factors are associated with recurrence.

OBJECTIVE

To determine the rate of residual tumor growth after STR and identify clinical and radiographic predictors of tumor progression.

METHODS

A single-institution retrospective study was performed on all sporadic vestibular schwannomas that underwent surgical resection between January 1, 2002 and December 31, 2015. Clinical charts, pathology, radiology, and operative reports were reviewed. Volumetric analysis was performed on all pre- and postoperative MR imaging. Univariate and multivariate logistic regression was performed to identify predictors of the primary endpoint of tumor progression. Kaplan-Meier analysis was performed to compare progression free survival between 2 groups of residual tumor volumes and location.

RESULTS

In this cohort of 66 patients who underwent primary STR, 30% had documented progression within a median follow up period of 3.1 yr. Greater residual tumor volume (OR 2.0 [1.1-4.0]) and residual disease within the internal auditory canal (OR 3.7 [1.0-13.4]) predicted progression on multivariate analysis.

CONCLUSION

These longitudinal data provide insight into the behavior of residual tumor, helping clinicians to determine if and when STR is an acceptable surgical strategy and to anchor expectations during shared medical decision-making consultation with patients.