The AANS/CNS Section on Tumors: a summary of 40 years of advocacy to advance the care of patients with brain and spine tumors.

The AANS/CNS Section on Tumors was founded 40 years ago in 1984 to assist in the education of neurosurgeons interested in neuro-oncology, and serves as a resource for other national organizations regarding the clinical treatment of nervous system tumors. The Section on Tumors was the first national physicians' professional organization dedicated to the study and treatment of patients with brain and spine tumors. Over the past 40 years, the Section on Tumors has built solid foundations, including establishing the tumor section satellite meetings, founding the Journal of Neuro-Oncology (the first medical journal dedicated to brain and spine surgical oncology), advancing surgical neuro-oncology education and research, promoting neurosurgical involvement in neuro-oncology clinical trials, and advocating for patients with brain and spine tumors. This review provides a synopsis of the Section on Tumors' history, its challenges, and its opportunities, drawing on the section's archives and input from the 17 section chairs who led it during its first 40 years.

Detection of diagnostic and prognostic methylation-based signatures in liquid biopsy specimens from patients with meningiomas.

Recurrence of meningiomas is unpredictable by current invasive methods based on surgically removed specimens. Identification of patients likely to recur using noninvasive approaches could inform treatment strategy, whether intervention or monitoring. In this study, we analyze the DNA methylation levels in blood (serum and plasma) and tissue samples from 155 meningioma patients, compared to other central nervous system tumor and non-tumor entities. We discover DNA methylation markers unique to meningiomas and use artificial intelligence to create accurate and universal models for identifying and predicting meningioma recurrence, using either blood or tissue samples. Here we show that liquid biopsy is a potential noninvasive and reliable tool for diagnosing and predicting outcomes in meningioma patients. This approach can improve personalized management strategies for these patients.

Detection of tumor-specific DNA methylation markers in the blood of patients with pituitary neuroendocrine tumors.

BACKGROUND: DNA methylation abnormalities are pervasive in pituitary neuroendocrine tumors (PitNETs). The feasibility to detect methylome alterations in circulating cell-free DNA (cfDNA) has been reported for several central nervous system (CNS) tumors but not across PitNETs. The aim of the study was to use the liquid biopsy (LB) approach to detect PitNET-specific methylation signatures to differentiate these tumors from other sellar diseases. METHODS: We profiled the cfDNA methylome (EPIC array) of 59 serum and 41 plasma LB specimens from patients with PitNETs and other CNS diseases (sellar tumors and other pituitary non-neoplastic diseases, lower-grade gliomas, and skull-base meningiomas) or nontumor conditions, grouped as non-PitNET. RESULTS: Our results indicated that despite quantitative and qualitative differences between serum and plasma cfDNA composition, both sources of LB showed that patients with PitNETs presented a distinct methylome landscape compared to non-PitNETs. In addition, LB methylomes captured epigenetic features reported in PitNET tissue and provided information about cell-type composition. Using LB-derived PitNETs-specific signatures as input to develop machine-learning predictive models, we generated scores that distinguished PitNETs from non-PitNETs conditions, including sellar tumor and non-neoplastic pituitary diseases, with accuracies above ~93% in independent cohort sets. CONCLUSIONS: Our results underpin the potential application of methylation-based LB profiling as a noninvasive approach to identify clinically relevant epigenetic markers to diagnose and potentially impact the prognostication and management of patients with PitNETs.

A serum-based DNA methylation assay provides accurate detection of glioma.

BACKGROUND: The detection of somatic mutations in cell-free DNA (cfDNA) from liquid biopsy has emerged as a noninvasive tool to monitor the follow-up of cancer patients. However, the significance of cfDNA clinical utility remains uncertain in patients with brain tumors, primarily because of the limited sensitivity cfDNA has to detect real tumor-specific somatic mutations. This unresolved challenge has prevented accurate follow-up of glioma patients with noninvasive approaches. METHODS: Genome-wide DNA methylation profiling of tumor tissue and serum cfDNA of glioma patients. RESULTS: Here, we developed a noninvasive approach to profile the DNA methylation status in the serum of patients with gliomas and identified a cfDNA-derived methylation signature that is associated with the presence of gliomas and related immune features. By testing the signature in an independent discovery and validation cohorts, we developed and verified a score metric (the "glioma-epigenetic liquid biopsy score" or GeLB) that optimally distinguished patients with or without glioma (sensitivity: 100%, specificity: 97.78%). Furthermore, we found that changes in GeLB score reflected clinicopathological changes during surveillance (eg, progression, pseudoprogression, and response to standard or experimental treatment). CONCLUSIONS: Our results suggest that the GeLB score can be used as a complementary approach to diagnose and follow up patients with glioma.

Substance abuse and insomnia.

Insomnia is a common complaint among people with substance use disorders. The relationship between sleep problems and substance abuse is bidirectional: People who have trouble sleeping may medicate with alcohol or illicit drugs or misuse prescription medications. And taking certain substances can interfere with sleep. This article reviews that relationship and presents information about the two evidence-based treatments for insomnia: prescription sleep medications and cognitive behavioral therapy for insomnia. Clinicians treating people with a substance use disorder or insomnia should be aware of the risks of comorbidity, and they should understand the risks and benefits of treatment for the insomnia.

Identification of regions of normal grey matter and white matter from pathologic glioblastoma and necrosis in frozen sections using Raman imaging.

In neurosurgical applications, a tool capable of distinguishing grey matter, white matter, and areas of tumor and/or necrosis in near-real time could greatly aid in tumor resection decision making. Raman spectroscopy is a non-destructive spectroscopic technique which provides molecular information about the tissue under examination based on the vibrational properties of the constituent molecules. With careful measurement and data processing, a spatial step and repeat acquisition of Raman spectra can be used to create Raman images. Forty frozen brain tissue sections were imaged in their entirety using a 300-µm-square measurement grid, and two or more regions of interest within each tissue were also imaged using a 25 µm-square step size. Molecular correlates for histologic features of interest were identified within the Raman spectra, and novel imaging algorithms were developed to compare molecular features across multiple tissues. In previous work, the relative concentration of individual biomolecules was imaged. Here, the relative concentrations of 1004, 1300:1344, and 1660 cm(-1), which correspond primarily to protein and lipid content, were simultaneously imaged across all tissues. This provided simple interpretation of boundaries between grey matter, white matter, and diseased tissue, and corresponded with findings from adjacent hematoxylin and eosin-stained sections. This novel, yet simple, multi-channel imaging technique allows clinically-relevant resolution with straightforward molecular interpretation of Raman images not possible by imaging any single peak. This method can be applied to either surgical or laboratory tools for rapid, non-destructive imaging of grey and white matter.

Glioblastoma and intracranial aneurysms: Case report and review of literature.

BACKGROUND: There is a paucity of data on the association of glioblastoma multiforme (GBM) with intracranial aneurysms. It is an important clinical entity for physicians to be aware of and its presence illustrates several critical features of the pathophysiology of malignant glioma. In this article we present a case of a middle cerebral artery (MCA) pseudoaneurysm that occurred in a patient with recurrent GBM as well discuss the current literature relating to this unique combination of pathologies. CASE DESCRIPTION: The authors present a case of a MCA pseudoaneurysm that developed in a patient with recurrent GBM and discuss the current literature. The authors identified 19 reports describing 23 patients harboring both GBM and an intracranial aneurysm. CONCLUSION: Several theories stand to explain the coincidental occurrence of intracranial aneurysms and GBM. The treating physician should be aware of this association when patients with intraaxial tumors present with unusual manifestation such as an intratumoral hemorrhage or angiogram negative subarachnoid hemorrhage. No guidelines exist to assist in the management of such patients; therefore, authors have attempted to address this issue using a classification and treatment algorithm.

Raman molecular imaging of brain frozen tissue sections.

Raman spectroscopy provides a molecular signature of the region being studied. It is ideal for neurosurgical applications because it is non-destructive, label-free, not impacted by water concentration, and can map an entire region of tissue. The objective of this paper is to demonstrate the meaningful spatial molecular information provided by Raman spectroscopy for identification of regions of normal brain, necrosis, diffusely infiltrating glioma and solid glioblastoma (GBM). Five frozen section tissues (1 normal, 1 necrotic, 1 GBM, and 2 infiltrating glioma) were mapped in their entirety using a 300-µm-square step size. Smaller regions of interest were also mapped using a 25-µm step size. The relative concentrations of relevant biomolecules were mapped across all tissues and compared with adjacent hematoxylin and eosin-stained sections, allowing identification of normal, GBM, and necrotic regions. Raman peaks and peak ratios mapped included 1003, 1313, 1431, 1585, and 1659 cm(-1). Tissue maps identified boundaries of grey and white matter, necrosis, GBM, and infiltrating tumor. Complementary information, including relative concentration of lipids, protein, nucleic acid, and hemoglobin, was presented in a manner which can be easily adapted for in vivo tissue mapping. Raman spectroscopy can successfully provide label-free imaging of tissue characteristics with high accuracy. It can be translated to a surgical or laboratory tool for rapid, non-destructive imaging of tumor margins.

Through the patient's eyes: the value of a comprehensive brain tumor center.

Since the founding of the Tumor Section of the American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) in 1984 much in neurosurgical oncology has changed. More than 40,000 papers have been published on glioma since the arrival of the AANS/CNS Tumor Section. Increasingly, research is focusing on more patient-centered care and quality of life. Preliminary work suggests that a greater emphasis on the patient and caregiver's experience of disease is crucial. Also, the provision of hope and appropriate information and communication with health care providers helps to lessen anxiety and promote improved quality of life. Lastly, our patients need a mechanism for continued symptom control and psychosocial support throughout their experience of this disease. An excellent venue for providing these facets of neurooncological patient care is the multidisciplinary brain tumor board and symptom management team. Herein, we present the philosophy and practice of the Hermelin Brain Tumor Center at the Henry Ford Health System as one type of approach to caring for the patient with a malignant glioma. The authors are aware of several brain tumor centers that share our philosophy and approach to patient care. Our comments are not meant to be exclusive to our experience and should be interpreted as representative of the growing movement in neurosurgery to provide comprehensive, multidisciplinary, patient-centered care.

Through the patient's eyes: an emphasis on patient-centered values in operative decision making in the management of malignant glioma.

The Joint Section on Tumors of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons is now in its 30th year. In many ways its growth and development has paralleled neurosurgery and medicine as a whole. This is most evident in our endeavor towards more patient-centered care and focus on quantity and quality of life. As the push towards evidence-based care continues, it is important to ensure that individualized care remains a guiding principle. Conscientious surgeons continue to refine techniques and develop technologies that push the boundaries of surgical efficacy while better defining the risks of surgery and the impacts of surgical complications. This article provides a review of the factors involved in minimizing risk and obtaining maximal outcomes for patients through insightful patient selection and evidence-based surgical decision-making. Herein, we present the philosophy and practice of the Hermelin Brain Tumor Center at the Henry Ford Health System as one type of approach to caring for the patient with a malignant glioma.

Key determinants of short-term and long-term glioblastoma survival: a 14-year retrospective study of patients from the Hermelin Brain Tumor Center at Henry Ford Hospital.

OBJECTIVE: Glioblastoma (GBM) is a heterogeneous neoplasm with a small percentage of long-term survivors. Despite aggressive surgical resection and advances in radiotherapy and chemotherapy, the median survival for patients with GBM is 12-14 months. Factors associated with a favorable prognosis include young age, high performance status, gross resection >98%, non-eloquent tumor location and O6-methylguanine methyltransferase (MGMT) promoter methylation. We retrospectively analyzed the relationship of clinical, epidemiologic, genetic and molecular characteristics with survival in patients with GBM. METHODS: This retrospective analysis of overall survival looked at the outcomes of 480 patients diagnosed with GBM over 14 years at a single institution. Multivariate analysis was performed examining multiple patient characteristics. RESULTS: Median survival time improved from 11.8 months in patients diagnosed from 1995 to 1999 to 15.9 months in those diagnosed from 2005 to 2008. Factors associated with survivor groups were age, KPS, tumor resection, treatment received and early progression. 18 cancer-related genes were upregulated in short-term survivors and five genes were downregulated in short-term survivors. CONCLUSIONS: Epidemiologic, clinical, and molecular characteristics all contribute to GBM prognosis. Identifying factors associated with survival is important for treatment strategies as well as research for novel therapeutics and technologies. This study demonstrated improved survival for patients over time as well as significant differences among survivor groups.

Raman spectroscopy to distinguish grey matter, necrosis, and glioblastoma multiforme in frozen tissue sections.

The need exists for a highly accurate, efficient and inexpensive tool to distinguish normal brain tissue from glioblastoma multiforme (GBM) and necrosis boundaries rapidly, in real-time, in the operating room. Raman spectroscopy provides a unique biochemical signature of a tissue type, with the potential to provide intraoperative identification of tumor and necrosis boundaries. We aimed to develop a database of Raman spectra from normal brain, GBM, and necrosis, and a methodology for distinguishing these pathologies. Raman spectroscopy was used to measure 95 regions from 40 frozen tissue sections using 785 nm excitation wavelength. Review of adjacent hematoxylin and eosin sections confirmed histology of each region. Three regions each of normal grey matter, necrosis, and GBM were selected as a training set. Ten regions were selected as a validation set, with a secondary validation set of tissue regions containing freeze artifact. Grey matter contained higher lipid (1061, 1081 cm(-1)) content, whereas necrosis revealed increased protein and nucleic acid content (1003, 1206, 1239, 1255-1266, 1552 cm(-1)). GBM fell between these two extremes. Discriminant function analysis showed 99.6, 97.8, and 77.5% accuracy in distinguishing tissue types in the training, validation, and validation with freeze artifact datasets, respectively. Decreased classification in the freeze artifact group was due to tissue preparation damage. This study shows the potential of Raman spectroscopy to accurately identify normal brain, necrosis, and GBM as a tool to augment pathologic diagnosis. Future work will develop mapped images of diffuse glioma and neoplastic margins toward development of an intraoperative surgical tool.

Patterns of failure after radiosurgery to two different target volumes of enhancing lesions with and without FLAIR abnormalities in recurrent glioblastoma multiforme.

Glioblastoma multiforme (GBM) invades beyond enhancing boundaries, and tumor cells are believed to exist in edematous peritumoral regions. We hypothesize that the concomitant treatment of both enhancing and FLAIR abnormalities on MRI by fractionated radiosurgery (FRS) would reduce local and regional recurrence. The purpose of this study was to demonstrate patterns of failure after FRS with simultaneous differential doses to two different target volumes of contrast enhancing lesions with/without FLAIR abnormality in recurrent GBM. Fifty-three patients with recurrent GBM were treated with FRS between 2008 and 2012. FRS was offered for the patients who had progressive tumors after the initial surgical resection followed by chemoradiation, and second-line chemotherapy. Radiosurgery Regimen A was 32 Gy (8 Gy × 4 treatments) to the contrast enhancing lesion only. Regimen B was 32 Gy (8 Gy × 4) to the contrast enhancing lesion and 24 Gy (6 Gy × 4) to the FLAIR abnormality delivered concomitantly. The study endpoint was radiographic failure on MRI at 2 months after FRS. Median survival after FRS was 7.5 months, and median progression-free survival after FRS was 4 months. Overall 82.4 % (42/51 lesions) recurred during follow-up. The local and regional failure rate was significantly lower in Regimen B (52 %) than in Regimen A (86.7 %) (p = 0.003). No sign of tumor progression in 10 % of Regimen A versus 28.6 % of Regimen B was shown during followup (p = 0.04). Instead, distant failure rate was higher in Regimen B. In conclusions, FRS was found to be a safe and effective salvage therapy for recurrent GBM. FRS to both contrast enhancing and FLAIR abnormalities appeared to improve local tumor control, and reduce regional tumor progression.

The Corpus Callosum Wallerian Degeneration in the Unilateral Brain Tumors: Evaluation with Diffusion Tensor Imaging (DTI).

PURPOSE: The purpose of this study was to evaluate whether DTI could demonstrate the water diffusivity changes in the corpus callosum (CC), which were not visible on the morphologic imaging in patients with glioblastoma multiforme (GBM) and brain metastases with no midline CC infiltration. MATERIALS AND METHODS: Twenty-seven patients with treatment naïve unilateral GBM and eleven patients with a solitary brain metastasis with no midline CC infiltration underwent DTI. Ten controls with normal brain MRI were also included. Based on the tensors, the principal diffusion directions, the anisotropy values, and the prior information about the diffusivity pattern in CC, a similarity measure was proposed. Subsequently, the CC was automatically divided into the Witelson subdivisions. RESULTS: We observed significantly decreased fractional anisotropy values in all the regions of CC in the patients with GBM and metastases as compared to those in the controls. The mean diffusivity values showed a significant increase in all the regions of CC, except the splenium in patients with GBM and the isthmus in the patients with metastases, as compared to that in the controls respectively. CONCLUSION: In conclusion, DTI is more sensitive than the morphologic MR imaging in the evaluation of changes within the CC, in brain tumours which do not infiltrate the CC. However, these changes of the DTI metrics in the CC are due to a Wallerian degeneration rather than a tumour infiltration, as was shown by our results, as similar changes were seen in the GBM as well as the non-infiltrating metastases patients.

TRAIL conjugated to nanoparticles exhibits increased anti-tumor activities in glioma cells and glioma stem cells in vitro and in vivo.

Glioblastomas (GBM) are characterized by resistance to chemotherapy and radiotherapy, and therefore, alternative therapeutic approaches are needed. TRAIL induces apoptosis in cancer but not in normal cells and is considered to be a promising anti-tumor agent. However, its short in vivo half-life and lack of efficient administration modes are serious impediments to its therapeutic efficacy. Nanoparticles (NP) have been used as effective delivery tools for various anticancer drugs. TRAIL was conjugated to magnetic ferric oxide NP by binding the TRAIL primary amino groups to activated double bonds on the surface of the NP. The effect of NP-TRAIL was examined on the apoptosis of glioma cells and self-renewal of glioma stem cells (GSCs). In addition, the ability of the NP-TRAIL to track U251 cell-derived glioma xenografts and to affect cell apoptosis, tumor volume, and survival among xenografted rats was also examined. Conjugation of TRAIL to NP increased its apoptotic activity against different human glioma cells and GSCs, as compared with free recombinant TRAIL. Combined treatment with NP-TRAIL and γ-radiation or bortezomib sensitized TRAIL-resistant GSCs to NP-TRAIL. Using rhodamine-labeled NP and U251 glioma cell-derived xenografts, we demonstrated that the NP-TRAIL were found in the tumor site and induced a significant increase in glioma cell apoptosis, a decrease in tumor volume, and increased animal survival. In summary, conjugation of TRAIL to NP increased its apoptotic activity both in vitro and in vivo. Therefore, NP-TRAIL represents a targeted anticancer agent with more efficient action for the treatment of GBM and the eradication of GSCs.

Radiosurgery to the surgical cavity as adjuvant therapy for resected brain metastasis.

BACKGROUND: The standard treatment of resected brain metastasis is whole-brain radiotherapy (WBRT). To avoid the potential toxicity of WBRT and to improve local control, we have used radiosurgery alone to the surgical cavity. OBJECTIVE: To demonstrate the rates of local control, new intracranial metastasis, and overall survival using this treatment scheme without WBRT. METHODS: Eighty-five consecutive patients with brain metastasis were treated with surgical resection of at least 1 lesion followed by radiosurgery alone to the surgical cavity and any unresected lesions from August 2000 to March 2011. Sixty-eight percent had gross total resections. After surgery, radiosurgery was delivered to the surgical cavity with a 2- to 3-mm margin. The median marginal radiosurgery dose was 16 Gy, and median target volume was 13.96 cm. Follow-up imaging and clinical examination were obtained every 2 to 3 months. RESULTS: Median follow-up time was 11.2 months. Overall local control was 81.2%. The 6-month, 1-year, and 2-year rates of local control were 88.7%, 81.4%, and 75.7%, respectively. Forty-seven patients (55%) developed new intracranial metastases at a median time of 5.6 months. For the entire population, the rate of new metastases was 32.1%, 58.1%, and 62.9% at 6 months, 1 year, and 2 years, respectively. Median overall survival time was 12.1 months. From initial treatment until death or last follow-up, only 30 patients (35%) received WBRT as salvage treatment. CONCLUSION: Radiosurgery to the surgical cavity without WBRT achieved excellent local control of resected brain metastasis. Close imaging follow-up allows early intervention for any new metastasis.

Segmentation of corpus callosum using diffusion tensor imaging: validation in patients with glioblastoma.

BACKGROUND: This paper presents a three-dimensional (3D) method for segmenting corpus callosum in normal subjects and brain cancer patients with glioblastoma. METHODS: Nineteen patients with histologically confirmed treatment naïve glioblastoma and eleven normal control subjects underwent DTI on a 3T scanner. Based on the information inherent in diffusion tensors, a similarity measure was proposed and used in the proposed algorithm. In this algorithm, diffusion pattern of corpus callosum was used as prior information. Subsequently, corpus callosum was automatically divided into Witelson subdivisions. We simulated the potential rotation of corpus callosum under tumor pressure and studied the reproducibility of the proposed segmentation method in such cases. RESULTS: Dice coefficients, estimated to compare automatic and manual segmentation results for Witelson subdivisions, ranged from 94% to 98% for control subjects and from 81% to 95% for tumor patients, illustrating closeness of automatic and manual segmentations. Studying the effect of corpus callosum rotation by different Euler angles showed that although segmentation results were more sensitive to azimuth and elevation than skew, rotations caused by brain tumors do not have major effects on the segmentation results. CONCLUSIONS: The proposed method and similarity measure segment corpus callosum by propagating a hyper-surface inside the structure (resulting in high sensitivity), without penetrating into neighboring fiber bundles (resulting in high specificity).

Computer-aided volumetric analysis as a sensitive tool for the management of incidental meningiomas.

INTRODUCTION: Meningiomas are typically slow-growing lesions that, depending on the location, can be relatively benign. Knowing their exact rate of growth can be helpful in determining whether surgery is necessary. METHODS: In this study we retrospectively reviewed the meningioma practices of the two senior authors (JR, MR). Our goal was to measure meningioma growth using a variety of methods (linear using diameters, and volumetric using the computer-aided perimeter and cross-sectional diameter methods) to compare rates of growth among the methods. Of 295 meningioma patients seen over an 8-year period, we identified a cohort of 31 patients with at least 30 months of follow-up. Volumes were calculated using medical imaging software with T1 post-contrast magnetic resonance imaging. Doubling times and growth rates were calculated. RESULTS: Of the 31 patients, 26 (84%) were shown to have growing meningiomas. The perimeter methodology measured higher growth rates than the diameter method for both doubling times as well as percentage annual growth (p<0.01). The mean doubling time was 13.4 years (range, 2.1­72.8 years) and 17.9 years (range, 4­92.3 years) comparing perimeter and diameter methods, respectively. The mean percentage of annual growth was 15.2% (range, 1.8­61.7%) and 5.6% (range, 0.7­12.2%), comparing perimeter and diameter methods, respectively. Linear growth was calculated at 0.7 mm/year. CONCLUSION: Overall, we found that computer-aided perimeter methods showed a more accurate picture of tumor progression than traditional methods, which generally underestimated growth.