The course of neurocognitive functioning in high-grade glioma patients

Towards an adequate description of the dose-response relationship in BNCT of glioblastoma multiforme

BACKGROUND

Boron Neutron Capture Therapy (BNCT) is a binary radiotherapy based on the intravenous administration of a borated drug to the patient and the subsequent irradiation with a low-energy neutron beam. The borated formulation accumulates in the tumor cells, and when neutrons interact with boron, a nuclear capture reaction occurs, releasing high-linear energy transfer, short-range particles that cause lethal damage to the cancer cells. Due to its selectivity, BNCT has the potential to treat aggressive brain tumors such as glioblastoma multiforme (GBM), minimizing the side effects. GBM is a brain neoplasia that poses significant treatment challenges due to its invasiveness and resistance to conventional treatments.

PURPOSE

This work aims to find a suitable model for calculating the photon isoeffective dose for GBM, producing ad hoc radiobiological data to feed the model.

METHODS

To describe adequately the dose-effect relation of BNCT for GBM, the following strategy has been applied 1.We studied the impact of choosing two different photon radiation types (x- or gamma- rays) 2.We assumed that the correct description of the photon-equivalent dose is obtained with the photon isoeffective dose model. This model calculates the photon dose that equals the cell survival obtained with BNCT, taking into account synergism and sub-lethal damage (SLD). 3.Survival curves as a function of the dose for the human GBM U87 cell line were constructed using the clonogenic assays for irradiation with photons (reference), neutron beam, and BNCT. 4.Survival curves were fitted with the modified linear quadratic model, using SLD repair times derived for U87. The radiobiological parameters were determined for the photon isoeffective dose model. 5.The model was applied to a clinical case that received BNCT in Taiwan. Treatment planning has been simulated using an accelerator-based designed neutron beam following the real treatment process and parameters. The results were discussed and compared to the current method, which employs relative biological effectiveness (RBE) factors to obtain BNCT dosimetry in photon-equivalent units.

RESULTS

The dose-survival curves have been obtained with two different photon radiation sources as the reference with a thermal neutron beam and neutrons in the presence of boron. The fitted parameters have been obtained as the input for the photon isoeffective dose and the traditional RBE model. For the first time, the radiobiological parameters of a photon isoeffective dose model were produced for BNCT of GBM. Photon isoeffective dose value can differ up to 32% using gamma photons and low-energy x-rays. Photon isoeffective dose values are lower (17%) than the RBE model currently employed in clinical trials.

CONCLUSION

The results highlight the impact of the reference radiation chosen for the isoeffective dose calculation and the importance of feeding the model with the appropriate radiobiological parameters.The dosimetry obtained with the new radiobiological data is consistent with the dose delivered in modern stereotactic radiotherapy, enabling tumor control predictions.

Growth of the prefrontal cortical glioblastoma altered cognitive and emotional behaviors via mediating miRNAs and GABA-A receptor signaling pathways in rats

The present study investigated the impact of GABAergic signaling and miRNA expression on glioblastoma multiforme (GBM) growth within the medial prefrontal cortex (mPFC) and its associated cognitive and emotional impairments. The implantation of C6 cells into the mPFC induced GBM in this brain region (referred to as the mPFC-GBM) in male Wistar rats via stereotaxic surgery, as confirmed by Magnetic Resonance Imaging (MRI), and Hematoxylin and Eosin (H&E) staining. Repeated microinjections of muscimol, a potent GABAA receptor agonist, directly into the mPFC-GBM (1 µg/rat/2.5 μl) following tumor induction decreased tumor volume and weight, resulting in an increased survival rate. Conversely, a higher dose of muscimol (6 µg/rat/2.5 μl) increased tumor size and reduced survival. Behavioral alterations induced by GBM, including anxiety-like responses, exploratory behaviors, locomotor activity, and memory formation, were assessed using anxiety-like behavior task, the hole-board test, and the novel object recognition test. Muscimol treatment dose-dependently affected these behaviors in the animals with the mPFC-GBM, bringing their performance with that of the sham group at the dose of 1 µg/rat/2.5 μl. Changes in specific miRNAs expressions, including miR-208, -290-295, -345, -743 and -802 were associated with the growth of the mPFC-GBM under muscimol treatment. These findings suggest that GBM growth into the mPFC profoundly impacts cognitive and emotional behaviors which can be improved by muscimol treatment. Considering that the expression levels of targeted miRNAs could be influenced by the growth of the mPFC-GBM, both with or without muscimol treatment, these non-coding RNAs might serve as potential biomarkers for GBM.

Brain tumor-related epilepsy: an overview on neuropsychological, behavioral, and quality of life issues and assessment methodology

Brain tumor-related epilepsy (BTRE) is a rare disease in which brain tumor (BT) and epilepsy overlap simultaneously and can have a negative impact on a patient's neuropsychological, behavioral, and quality of life (QoL) spheres. In this review we (a) addressed the main neuropsychological, behavioral, and QoL issues that may occur in BTRE patients, (b) described how BT, BTRE, and their respective treatments can impact these domains, and (c) identified tools and standardized evaluation methodologies specific for BTRE patients. Neuropsychological disorders and behavioral issues can be direct consequences of BTRE and all related treatments, such as surgery, anti-cancer and anti-seizure medication, corticosteroids, etc., which can alter the structure of specific brain areas and networks, and by emotional aspects reactive to BTRE diagnosis, including the possible loss of autonomy, poor prognosis, and fear of death. Unfortunately, it seems there is a lack of uniformity in assessment methodologies, such as the administration of different batteries of neuropsychological tests, different times, frames, and purposes. Further research is needed to establish causality and deepen our understanding of the interplay between all these variables and our intervention in terms of diagnosis, treatment, psychosocial assessment, and their timing. We propose that the care of these patients to rely on the concepts of "BTRE-induced disability" and "biopsychosocial model" of BTRE, to prompt healthcare providers to handle and monitor BTRE-related psychological and social aspects, as to maintain the patient's best possible QoL.

"Non-Eloquent" brain regions predict neuropsychological outcome in tumor patients undergoing awake craniotomy

Supratotal resection of primary brain tumors is being advocated especially when involving "non-eloquent" tissue. However, there is extensive neuropsychological data implicating functions critical to higher cognition in areas considered "non-eloquent" by most surgeons. The goal of the study was to determine pre-surgical brain regions that would be predictive of cognitive outcome at 4-6 months post-surgery. Cortical reconstruction and volumetric segmentation were performed with the FreeSurfer-v6.0 image analysis suite. Linear regression models were used to regress cortical volumes from both hemispheres, against the total cognitive z-score to determine the relationship between brain structure and broad cognitive functioning while controlling for age, sex, and total segmented brain volume. We identified 62 consecutive patients who underwent planned awake resections of primary (n = 55, 88%) and metastatic at the University of New Mexico Hospital between 2015 and 2019. Of those, 42 (23 males, 25 left hemispheric lesions) had complete pre and post-op neuropsychological data available and were included in this study. Overall, total neuropsychological functioning was somewhat worse (p = 0.09) at post-operative neuropsychological outcome (Mean = -.20) than at baseline (Mean = .00). Patients with radiation following resection (n = 32) performed marginally worse (p = .036). We found that several discrete brain volumes obtained pre-surgery predicted neuropsychological outcome post-resection. For the total sample, these volumes included: left fusiform, right lateral orbital frontal, right post central, and right paracentral regions. Regardless of lesion lateralization, volumes within the right frontal lobe, and specifically right orbitofrontal cortex, predicted neuropsychological difference scores. The current study highlights the gaps in our current understanding of brain eloquence. We hypothesize that the volume of tissue within the right lateral orbital frontal lobe represents important cognitive reserve capacity in patients undergoing tumor surgery. Our data also cautions the neurosurgeon when considering supratotal resections of tumors that do not extend into areas considered "non-eloquent" by current standards.

Functional network disorganization and cognitive decline following fractionated whole-brain radiation in mice

Cognitive dysfunction following radiotherapy (RT) is one of the most common complications associated with RT delivered to the brain, but the precise mechanisms behind this dysfunction are not well understood, and to date, there are no preventative measures or effective treatments. To improve patient outcomes, a better understanding of the effects of radiation on the brain's functional systems is required. Functional magnetic resonance imaging (fMRI) has shown promise in this regard, however, compared to neural activity, hemodynamic measures of brain function are slow and indirect. Understanding how RT acutely and chronically affects functional brain organization requires more direct examination of temporally evolving neural dynamics as they relate to cerebral hemodynamics for bridging with human studies. In order to adequately study the underlying mechanisms of RT-induced cognitive dysfunction, the development of clinically mimetic RT protocols in animal models is needed. To address these challenges, we developed a fractionated whole-brain RT protocol (3Gy/day for 10 days) and applied longitudinal wide field optical imaging (WFOI) of neural and hemodynamic brain activity at 1, 2, and 3 months post RT. At each time point, mice were subject to repeated behavioral testing across a variety of sensorimotor and cognitive domains. Disruptions in cortical neuronal and hemodynamic activity observed 1 month post RT were significantly worsened by 3 months. While broad changes were observed in functional brain organization post RT, brain regions most impacted by RT occurred within those overlapping with the mouse default mode network and other association areas similar to prior reports in human subjects. Further, significant cognitive deficits were observed following tests of novel object investigation and responses to auditory and contextual cues after fear conditioning. Our results fill a much-needed gap in understanding the effects of whole-brain RT on systems level brain organization and how RT affects neuronal versus hemodynamic signaling in the cortex. Having established a clinically-relevant injury model, future studies can examine therapeutic interventions designed to reduce neuroinflammation-based injury following RT. Given the overlap of sequelae that occur following RT with and without chemotherapy, these tools can also be easily incorporated to examine chemotherapy-related cognitive impairment.

Radio-chemotherapy feasibility for biopsy-only unresectable IDH wild-type glioblastomas (BO-GBM)

Background

"Biopsy-only" glioblastoma (BO-GBM) is a heterogeneous, understudied group of patients associated with a poor outcome. Our objective was to explore the pattern of care and prognosis associated with BO-GBM in our center.

Methods

Patients with IDH wild-type BO-GBM included in a prospective regional cohort initiated in 2014 and closed in 2017 were retrospectively reviewed for patient characteristics, MRI findings, treatment allocation, and delivery.

Results

Of 535 patients included in the cohort, 137 patients were included in the present analysis. The median age was 66 years old and the median KPS was 70. Forty-six patients (33.6%) were referred to radiotherapy and chemotherapy (RT-TMZ) regimen, 75 (54.7%), considered unfitted for RT, received chemotherapy upfront (CT) and 16 (11.7%) were referred to palliative care (PC). Regarding the first group, 91% of patients completed the RT-TMZ. In the CT group, 11 of 75 patients (14.7%) underwent radiotherapy after chemotherapy upfront. Median overall survival was 12.3 months (95% CI, 15.30-24.16), 5.7 months (95% CI, 6.22-9.20), and 1.9 months (95% CI, 1.43-5.08) in RT-TMZ, CT, and PC groups, respectively. In multivariate analyses, progression-free survival was impacted by baseline KPS (P < .001) and MGMT status (P = .004). Overall survival was impacted by baseline KPS (P < .001) and age (P = .030).

Conclusion

BO-GBM constitute a large and heterogeneous population in which one-third of patients is amenable to the standard of care, with survival outcome close to one of the patients who underwent surgery. Reliable criteria are needed to help select patients for adequate treatment while new strategies are warranted for BO-GBM unfit for RT.

Disease Assessments in Patients with Glioblastoma

PURPOSE OF REVIEW

The neuro-oncology team faces a unique challenge when assessing treatment response in patients diagnosed with glioblastoma. Magnetic resonance imaging (MRI) remains the standard imaging modality for measuring therapeutic response in both clinical practice and clinical trials. However, even for the neuroradiologist, MRI interpretations are not straightforward because of tumor heterogeneity, as evidenced by varying degrees of enhancement, infiltrating tumor patterns, cellular densities, and vasogenic edema. The situation is even more perplexing following therapy since treatment-related changes can mimic viable tumor. Additionally, antiangiogenic therapies can dramatically decrease contrast enhancement giving the false impression of decreasing tumor burden. Over the past few decades, several approaches have emerged to augment and improve visual interpretation of glioblastoma response to therapeutics. Herein, we summarize the state of the art for evaluating the response of glioblastoma to standard therapies and investigational agents as well as challenges and future directions for assessing treatment response in neuro-oncology.

RECENT FINDINGS

Monitoring glioblastoma responses to standard therapy and novel agents has been fraught with many challenges and limitations over the past decade. Excitingly, new promising methods are emerging to help address these challenges. Recently, the Response Assessment in Neuro-Oncology (RANO) working group proposed an updated response criteria (RANO 2.0) for the evaluation of all grades of glial tumors regardless of IDH status or therapies being evaluated. In addition, advanced neuroimaging techniques, such as histogram analysis, parametric response maps, morphometric segmentation, radio pharmacodynamics approaches, and the integrating of amino acid radiotracers in the tumor evaluation algorithm may help resolve equivocal lesion interpretations without operative intervention. Moreover, the introduction of other techniques, such as liquid biopsy and artificial intelligence could complement conventional visual assessment of glioblastoma response to therapies. Neuro-oncology has evolved over the past decade and has achieved significant milestones, including the establishment of new standards of care, emerging therapeutic options, and novel clinical, translational, and basic research. More recently, the integration of histopathology with molecular features for tumor classification has marked an important paradigm shift in brain tumor diagnosis. In a similar manner, treatment response monitoring in neuro-oncology has made considerable progress. While most techniques are still in their inception, there is an emerging body of evidence for clinical application. Further research will be critically important for the development of impactful breakthroughs in this area of the field.

Neuropsychological monitoring of cognitive function and ICF-based mental components in patients with malignant brain tumours

BACKGROUND

Cognitive deficits are one of the important clinical features of patients with brain tumours, which can affect up to 30-90% of patients before treatment. The consequence is a significant and rapid degradation of the patient's intellectual functioning, seizures, paralysis and other symptoms that prevent independent functioning. This results in a reduced quality of life and a psychological crisis not only for the patient but also for their relatives. Maintaining the patient's function at the highest level for as long as possible is particularly important, given that long-term remission or a cure is unlikely or accompanied by significant disability.

PURPOSE

This paper aims to provide a narrative review to the neuropsychological procedure for monitoring cognitive function in patients with brain tumours, which may be helpful in developing adequate clinical practice and appropriate management procedures.

METHODS

A narrative review was applied to search broadly across disciplines, retrieving literature from several databases (PubMed, Web of Science, and EBSCOhost).

RESULTS

(1) discussing the methodological aspects of neuropsychological tools for monitoring cognitive function in brain tumour patients, (2) identifying the most commonly used tools and (3) their practical applicability according to the cognitive function components of the International Classification of Functioning, Disability and Health (ICF).

CONCLUSION

This article points to the need to systematise research tools or develop new ones, adapted to diagnostic needs with high psychometric characteristics, with particular attention to memory processes and learning effect. Rehabilitation of patients is also an important issue, which requires the use of adequate tools to assess functional disability. The International Classification of Functioning, Disability and Health (ICF) seems to be useful in this respect. The ICF has the advantage of targeting actions to improve the condition of the individual and to keep them as long as possible in a state of well-being that allows them to function effectively in society or to return to work. This is particularly important in view of the ageing population and the increasing number of diagnoses related to brain tumours.

Factors affecting cognitive functions of patients with high-grade gliomas: a systematic review

BACKGROUND

Gliomas make up approximately 26.5% of all primary CNS tumors and 80.7% of malignant tumors. They are classified according to histology, location, and genetics. Grade III and IV gliomas are considered high-grade gliomas (HGGs). The cognitive signs and symptoms are attributed to mass defects depending on location, growth rapidity, and edema. Our purpose is to review the cognitive status of patients diagnosed with HGGs; the effect of treatments including surgical resection, radiotherapy, and chemotherapy; and the predictors of the cognitive status.

METHODS

We utilized the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines as a template for the methodology. A comprehensive literature search was performed from three databases (PubMed, ScienceDirect, and Cochrane Library) for clinical trials and longitudinal studies on patients diagnosed with HGGs assessing their cognitive status.

RESULTS

Thirteen studies were selected among which 9 assessed cognitive function before and after treatment. One assessed the consistency of cognitive complaints and objective cognitive functioning. Three reported factors affecting disease progression and cognitive status. Most HGG patients have impairment in at least one cognitive domain. Treatments including surgical resection or radio-chemotherapy did not impair cognitive status.

DISCUSSION

The cognitive status could be used to assess sub-clinical tumor progression. Factors correlated to cognitive status were tumor location, edema, and grade. Patient characteristics correlated were pre-operative epilepsy, corticosteroid use, and age at the time of diagnosis.

CONCLUSION

Assessment of the cognitive status of HGG patients indicates sub-clinical tumor progression and may be used to assess treatment outcomes.

Voxel based morphometry-detected white matter volume loss after multi-modality treatment in high grade glioma patients

BACKGROUND

Radiotherapy (RT) and chemotherapy are components of standard multi-modality treatment of high grade gliomas (HGG) aimed at achieving local tumor control. Treatment is neurotoxic and RT plays an important role in this, inducing damage even distant to the RT target volume.

PURPOSE

This retrospective longitudinal study evaluated the effect of treatment on white matter and gray matter volume in the tumor-free hemisphere of HGG patients using voxel based morphometry (VBM).

METHOD

3D T1-weighted MR images of 12 HGG patients at multiple timepoints during standard treatment were analyzed using VBM. Segmentation of white matter and gray matter of the tumor-free hemisphere was performed. Multiple general linear models were used to asses white matter and gray matter volumetric differences between time points. A mean RT dose map was created and compared to the VBM results.

RESULTS

Diffuse loss of white matter volume, mainly throughout the frontal and parietal lobe, was found, grossly overlapping regions that received the highest RT dose. Significant loss of white matter was first noticed after three cycles of chemotherapy and persisted after the completion of standard treatment. No significant loss of white matter volume was observed between pre-RT and the first post-RT follow-up timepoint, indicating a delayed effect.

CONCLUSION

This study demonstrated diffuse and early-delayed decreases in white matter volume of the tumor-free hemisphere in HGG patients after standard treatment. White matter volume changes occurred mainly throughout the frontal and parietal lobe and grossly overlapped with areas that received the highest RT dose.

Alterations in white matter fiber density associated with structural MRI and metabolic PET lesions following multimodal therapy in glioma patients

BACKGROUND

In glioma patients, multimodality therapy and recurrent tumor can lead to structural brain tissue damage characterized by pathologic findings in MR and PET imaging. However, little is known about the impact of different types of damage on the fiber architecture of the affected white matter.

PATIENTS AND METHODS

This study included 121 pretreated patients (median age, 52 years; ECOG performance score, 0 in 48%, 1-2 in 51%) with histomolecularly characterized glioma (WHO grade IV glioblastoma, n=81; WHO grade III anaplastic astrocytoma, n=28; WHO grade III anaplastic oligodendroglioma, n=12), who had a resection, radiotherapy, alkylating chemotherapy, or combinations thereof. After a median follow-up time of 14 months (range, 1-214 months), anatomic MR and O-(2-[18F]fluoroethyl)-L-tyrosine (FET) PET images were acquired on a 3T hybrid PET/MR scanner. Post-therapeutic findings comprised resection cavities, regions with contrast enhancement or increased FET uptake and T2/FLAIR hyperintensities. Local fiber density was determined from high angular-resolution diffusion-weighted imaging and advanced tractography methods. A cohort of 121 healthy subjects selected from the 1000BRAINS study matched for age, gender and education served as a control group.

RESULTS

Lesion types differed in both affected tissue volumes and relative fiber densities compared to control values (resection cavities: median volume 20.9 mL, fiber density 16% of controls; contrast-enhanced lesions: 7.9 mL, 43%; FET uptake areas: 30.3 mL, 49%; T2/FLAIR hyperintensities: 53.4 mL, 57%, p<0.001). In T2/FLAIR-hyperintense lesions caused by peritumoral edema due to recurrent glioma (n=27), relative fiber density was as low as in lesions associated with radiation-induced gliosis (n=13, 48% vs. 53%, p=0.17). In regions with pathologically increased FET uptake, local fiber density was inversely related (p=0.005) to the extent of uptake. Total fiber loss associated with contrast-enhanced lesions (p=0.006) and T2/FLAIR hyperintense lesions (p=0.013) had a significant impact on overall ECOG score.

CONCLUSIONS

These results suggest that apart from resection cavities, reduction in local fiber density is greatest in contrast-enhancing recurrent tumors, but total fiber loss induced by edema or gliosis has an equal detrimental effect on the patients' performance status due to the larger volume affected.

Presurgical predictors of early cognitive outcome after brain tumor resection in glioma patients

Gliomas are commonly characterized by neurocognitive deficits that strongly impact patients' and caregivers' quality of life. Surgical resection is the mainstay of therapy, and it can also cause cognitive impairment. An important clinical problem is whether patients who undergo surgery will show post-surgical cognitive impairment above and beyond that present before surgery. The relevant rognostic factors are largely unknown. This study aims to quantify the cognitive impairment in glioma patients 1-week after surgery and to compare different pre-surgical information (i.e., cognitive performance, tumor volume, grading, and lesion topography) towards predicting early post-surgical cognitive outcome. We retrospectively recruited a sample of N = 47 patients affected by high-grade and low-grade glioma undergoing brain surgery for tumor resection. Cognitive performance was assessed before and immediately after (∼1 week) surgery with an extensive neurocognitive battery. Multivariate linear regression models highlighted the combination of predictors that best explained post-surgical cognitive impairment. The impact of surgery on cognitive functioning was relatively small (i.e., 85% of test scores across the whole sample indicated no decline), and pre-operative cognitive performance was the main predictor of early post-surgical cognitive outcome above and beyond information from tumor topography and volume. In fact, structural lesion information did not significantly improve the accuracy of prediction made from cognitive data before surgery. Our findings suggest that post-surgery neurocognitive deficits are only partially explained by preoperative brain damage. The present results suggest the possibility to make reliable, individualized, and clinically relevant predictions from relatively easy-to-obtain information.

Tumor-Associated Microenvironment of Adult Gliomas: A Review

The glioma-associated tumor microenvironment involves a multitude of different cells ranging from immune cells to endothelial, glial, and neuronal cells surrounding the primary tumor. The interactions between these cells and glioblastoma (GBM) have been deeply investigated while very little data are available on patients with lower-grade gliomas. In these tumors, it has been demonstrated that the composition of the microenvironment differs according to the isocitrate dehydrogenase status (mutated/wild type), the presence/absence of codeletion, and the expression of specific alterations including H3K27 and/or other gene mutations. In addition, mechanisms by which the tumor microenvironment sustains the growth and proliferation of glioma cells are still partially unknown. Nonetheless, a better knowledge of the tumor-associated microenvironment can be a key issue in the optic of novel therapeutic drug development.

Alterations in Molecular Profiles Affecting Glioblastoma Resistance to Radiochemotherapy: Where Does the Good Go?

Simple Summary

Glioblastoma is a type of brain cancer that remains incurable. Despite multiple past and ongoing preclinical studies and clinical trials, involving adjuvants to the conventional therapy and based on molecular targeting, no relevant benefit for patients’ survival has been achieved so far. The current first-line treatment regimen is based on ionizing radiation and the monoalkylating compound, temozolomide, and has been administered for more than 15 years. Glioblastoma is extremely resistant to most agents due to a mutational background that elicits quick response to insults and adapts to microenvironmental and metabolic changes. Here, we present the most recent evidence concerning the molecular features and their alterations governing pathways involved in GBM response to the standard radio-chemotherapy and discuss how they collaborate with acquired GBM’s resistance.

Abstract

Glioblastoma multiforme (GBM) is a brain tumor characterized by high heterogeneity, diffuse infiltration, aggressiveness, and formation of recurrences. Patients with this kind of tumor suffer from cognitive, emotional, and behavioral problems, beyond exhibiting dismal survival rates. Current treatment comprises surgery, radiotherapy, and chemotherapy with the methylating agent, temozolomide (TMZ). GBMs harbor intrinsic mutations involving major pathways that elicit the cells to evade cell death, adapt to the genotoxic stress, and regrow. Ionizing radiation and TMZ induce, for the most part, DNA damage repair, autophagy, stemness, and senescence, whereas only a small fraction of GBM cells undergoes treatment-induced apoptosis. Particularly upon TMZ exposure, most of the GBM cells undergo cellular senescence. Increased DNA repair attenuates the agent-induced cytotoxicity; autophagy functions as a pro-survival mechanism, protecting the cells from damage and facilitating the cells to have energy to grow. Stemness grants the cells capacity to repopulate the tumor, and senescence triggers an inflammatory microenvironment favorable to transformation. Here, we highlight this mutational background and its interference with the response to the standard radiochemotherapy. We discuss the most relevant and recent evidence obtained from the studies revealing the molecular mechanisms that lead these cells to be resistant and indicate some future perspectives on combating this incurable tumor.

Neurocognitive Outcome and Seizure Freedom After Awake Surgery of Gliomas

Objectives

Gliomas are often diagnosed due to epileptic seizures as well as neurocognitive deficits. First treatment choice for patients with gliomas in speech-related areas is awake surgery, which aims at maximizing tumor resection while preserving or improving patient’s neurological status. The present study aimed at evaluating neurocognitive functioning and occurrence of epileptic seizures in patients suffering from gliomas located in language-related areas before and after awake surgery as well as during their follow up course of disease.

Materials and Methods

In this prospective study we included patients who underwent awake surgery for glioma in the inferior frontal gyrus, superior temporal gyrus, or anterior temporal lobe. Preoperatively, as well as in the short-term (median 4.1 months, IQR 2.1-6.0) and long-term (median 18.3 months, IQR 12.3-36.6) postoperative course, neurocognitive functioning, neurologic status, the occurrence of epileptic seizures and number of antiepileptic drugs were recorded.

Results

Between 09/2012 and 09/2019, a total of 27 glioma patients, aged 36.1 ± 11.8 years, were included. Tumor resection was complete in 15, subtotal in 6 and partial in 6 patients, respectively. While preoperatively impairment in at least one neurocognitive domain was found in 37.0% of patients, postoperatively, in the short-term, 36.4% of patients presented a significant deterioration in word fluency (p=0.009) and 34.8% of patients in executive functions (p=0.049). Over the long-term, scores improved to preoperative baseline levels. The number of patients with mood disturbances significantly declined from 66.7% to 34.8% after surgery (p=0.03). Regarding seizures, these were present in 18 (66.7%) patients prior to surgery. Postoperatively, 22 (81.5%) patients were treated with antiepileptic drugs with all patients presenting seizure-freedom.

Conclusions

In patients suffering from gliomas in eloquent areas, the combination of awake surgery, regular neurocognitive assessment - considering individual patients´ functional outcome and rehabilitation needs – and the individual adjustment of antiepileptic therapy results in excellent patient outcome in the long-term course.

To Optimize Radiotherapeutic Plans for Superior Tumor Coverage Predicts Malignant Glioma Prognosis and Normal Tissue Complication Probability

Background: Radiotherapy (RT) provides a modern treatment to enhance the malignant glioma control rate. The purpose of our study was to determine the effect of tumor coverage on disease prognosis and to predict optimal RT plans to achieve a lower normal tissue complication probability (NTCP). Methods: Ten malignant-glioma patients with tumors adjacent to organs at risk (OARs) were collected. The patients were divided into two groups according to adequate coverage or not, and prognosis was analyzed. Then, using intensity-modulated radiation therapy (IMRT), volume-modulated arc therapy (VMAT), and helical tomotherapy (TOMO) to simulate new treatment plans for 10 patients, the advantages of these planning systems were revealed for subsequent prediction of NTCP. Results: The results of clinical analysis indicated that overall survival (p = 0.078) between the adequate and inadequate groups showed no differences, while the adequate group had better recurrence-free survival (p = 0.018) and progression-free survival (p = 0.009). TOMO had better CI (p < 0.001) and also predicted a lower total-irradiated dose to the normal brain (p = 0.001) and a lower NTCP (p = 0.027). Conclusions: The TOMO system provided optimal therapeutic planning, reducing NTCP and achieving better coverage. Combined with the clinical results, our findings suggest that TOMO can make malignant glioma patients close to OARs achieve better disease control.

Corticosteroids use and neurocognitive functioning in patients with recurrent glioblastoma: evidence from European Organization for Research and Treatment of Cancer (EORTC) trial 26101

Background

In patients with recurrent glioblastoma, corticosteroids are frequently used to mitigate intracranial pressure and to improve patient neurological functioning. To date, in these patients, no systematic studies have been performed to assess neurocognitive functioning (NCF) in relation to corticosteroid treatment.

Methods

Using baseline data (ie, prior to randomization) of European Organization for Research and Treatment of Cancer (EORTC) trial 26101, we performed regression analysis to assess the predictive value of corticosteroid intake on performance of the EORTC brain tumor clinical trial NCF test battery. The battery is comprised of the Hopkins Verbal Learning Test—Revised (HVLT-R), Controlled Oral Word Association Test (COWA), and Trail Making Test (A and B).

Results

Out of 321 patients, 148 (46.1%) were not using corticosteroids, and 173 were using dexamethasone (34.3%), methylprednisolone (9.7%), or other corticosteroids (9.9%). Patients on corticosteroids had worse performance on all neurocognitive tests. Regression analyses demonstrated a negative association between corticosteroids use and the HVLT-R free recall score (R² change = 0.034, F change (1, 272) = 13.392, P < .001) and HVLT-R Delayed Recall score (R² change = 0.028, F change (1, 270) = 10.623, P = .002). No statistically significant association was found for HVLT-R Delayed recognition, COWA, TMT part A and TMT part B (P > .05).

Conclusions

Glioblastoma patients prescribed with corticosteroids show poorer memory functions, expressive language, visual-motor scanning speed, and executive functioning than patients not using corticosteroids. Furthermore, we found a negative association between corticosteroid intake and memory functions. The possibility of deleterious effects of corticosteroids on NCF should be considered during clinical decision making.

Prognostication in brain tumors

Despite the use of aggressive multimodality therapies, the prognosis of brain tumor patients remains poor. Tumors of glial origin typically have the worst prognosis, with a predicted median survival of 12-15months for glioblastoma multiforme (WHO grade IV) and 2-5years for anaplastic glioma (WHO grade III). Palliative care problems and needs in patients with primary and secondary brain tumors are significantly different, both due to different trajectory of disease and to variable prognosis which in metastatic brain tumors is related to the natural history of primary tumors. This chapter describes the complex interactions influencing communication and the treatment decision process in primary brain tumor patients. The whole trajectory of disease and particularly the end-of-life (EOL) phase of brain tumor (BT) patients are quite different in respect to the expected trajectory observed in the general cancer population. The need to improve the communication of prognosis in BT patients has been clearly reported in neuro-oncological literature, but several issues may hinder a good communication in these patients. Adequate prognostic awareness (PA) is important for several reasons: to respect patient autonomy, to obtain her/his preferences about treatments and goal of care, and to share EOL treatment decisions. The high incidence of cognitive deficits in BT patients is one of the most challenging issues influencing the quality of communication and the participation of patients in the process of treatment decisions. Impaired neurocognitive functions may impact capacities of understanding, appreciation, reasoning, and expression of choice, reducing Medical Decisions Capacity (MDC). The lack of capacity to express preferences about EOL treatment decisions represents an important ethical issue, with a great impact on both the patient's family and healthcare professionals involved in the decision processes. Also, patients' coping styles may have an important influence in critical aspects of care such as communication of diagnosis and prognosis, discussion with patients and their caregivers about goal of treatments, early introduction of PC, and advanced planning of patients' preferences concerning EOL treatment and issues. Several barriers hinder good communication in BT patients. This chapter analyzes emerging literature data and possible strategies to improve communication about prognosis and goals of care and to promote patients' involvement in the treatment decision process particularly in the palliative care setting.

Changes of healthy brain tissue after salvage radiotherapy of glioblastoma

Background

Salvage radiotherapy (SRT) with photons is a valid treatment option for patients suffering from recurrent glioblastoma (GBM). However, the tolerance of healthy brain to ionizing radiation (IR) is limited. The aim of this study was to determine to what extent brain structures in the radiographically tumor-free hemisphere change after repeated radiotherapy.

Methods

Five of 26 patients treated with SRT for local recurrence of GBM were found to have magnetic resonance imaging (MRI) studies available for complete volumetric analysis before and after primary chemo-radiation and after SRT. Manual segmentation and joint segmentation (JS) based on a convolutional neural network were used for the segmentation of the gray matter, the white matter and the ventricles in T1 MRIs.

Results

Qualitative results of manual segmentation and JS were comparable. After primary chemo-radiation and SRT, the volume of the contralateral ventricles increased steadily by 1.3–4.75% (SD ± 2.8 %, R² = 0.82; P = <.01) with a manual segmentation and by 1.4–7.4% (SD 2.1%, R² = 0.48; P = .025) with JS. The volume of the cortex decreased by 3.4–7.3% except in one patient, the cortex volume increased by 2.5% (SD ± 2.9%, R² = 0.18; P = .19) when measured manually. When measured with JS GM decreased by 1.0–7.4%, in one case it increased by 3.0% (SD = 3.2%, P = .22, R² = 0.18). The white matter remained stable when assessed with manual segmentation (P = .84, R² = 0.004) or JS (P = .44, R² = 0.07).

Conclusion

SRT of relapsed GBM leads to continuous changes of the tumor-free contralateral brain by means of manual segmentation or JS. The cortex seems more susceptible to repeated RT compared to the white matter. Larger cohort studies and complementary functional analysis are encouraged.

Lesion-Function Analysis from Multimodal Imaging and Normative Brain Atlases for Prediction of Cognitive Deficits in Glioma Patients

Simple Summary

This prospective cross-sectional study utilized standard structural MR imaging and amino acid PET in conjunction with brain atlases of gray matter functional regions and white matter tracts, and elastic registration techniques to estimate the influence of the type and location of treatment-related brain damage or recurrent tumors on cognitive functioning in a group of well-doing WHO Grade III/IV glioma patients at follow-up after treatment. The negative impact of T2/FLAIR hyperintensities, supposed to be mainly caused by radiotherapy, on cognitive performance far exceeded that of surgical brain defects or recurrent tumors. The affection of functional nodes and fiber tracts of the left hemisphere and especially of the left temporal lobe by T2/FLAIR hyperintensities was highly correlated with verbal episodic memory dysfunction. These observations imply that radiotherapy for gliomas of the left hemisphere should be individually tailored by means of publicly available brain atlases and registration techniques.

Abstract

Cognitive deficits are common in glioma patients following multimodality therapy, but the relative impact of different types and locations of treatment-related brain damage and recurrent tumors on cognition is not well understood. In 121 WHO Grade III/IV glioma patients, structural MRI, O-(2-[18F]fluoroethyl)-L-tyrosine FET-PET, and neuropsychological testing were performed at a median interval of 14 months (range, 1–214 months) after therapy initiation. Resection cavities, T1-enhancing lesions, T2/FLAIR hyperintensities, and FET-PET positive tumor sites were semi-automatically segmented and elastically registered to a normative, resting state (RS) fMRI-based functional cortical network atlas and to the JHU atlas of white matter (WM) tracts, and their influence on cognitive test scores relative to a cohort of matched healthy subjects was assessed. T2/FLAIR hyperintensities presumably caused by radiation therapy covered more extensive brain areas than the other lesion types and significantly impaired cognitive performance in many domains when affecting left-hemispheric RS-nodes and WM-tracts as opposed to brain tissue damage caused by resection or recurrent tumors. Verbal episodic memory proved to be especially vulnerable to T2/FLAIR abnormalities affecting the nodes and tracts of the left temporal lobe. In order to improve radiotherapy planning, publicly available brain atlases, in conjunction with elastic registration techniques, should be used, similar to neuronavigation in neurosurgery.

Development of an EORTC questionnaire measuring instrumental activities of daily living (IADL) in patients with brain tumours: phase I-III

PURPOSE

Being able to function independently in society is an important aspect of quality of life. This ability goes beyond self-care, requires higher order cognitive functioning, and is typically measured with instrumental activities of daily living (IADL) questionnaires. Cognitive deficits are frequently observed in brain tumour patients, however, IADL is almost never assessed because no valid and reliable IADL measure is available for this patient group. Therefore, this measure is currently being developed.

METHODS

This international multicentre study followed European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group module development guidelines. Three out of four phases are completed: phases (I) generation of items, (II) construction of the item list, and (III) pre-testing. This paper reports the item selection procedures and preliminary psychometric properties of the questionnaire. Brain tumour patients (gliomas and brain metastases), their informal caregivers, and health care professionals (HCPs) were included.

RESULTS

Phase I (n = 44 patient-proxy dyads and 26 HCPs) generated 59 relevant and important activities. In phase II, the activities were converted into items. In phase III (n = 85 dyads), the 59 items were pre-tested. Item selection procedures resulted in 32 items. Exploratory factor analysis revealed a preliminary dimensional structure consisting of five scales with acceptable to excellent internal consistency (α = 0.73-0.94) and two single items. For three scales, patients with cognitive impairments had significantly more IADL problems than patients without impairments.

CONCLUSION

A phase IV validation study is needed to confirm the psychometric properties of the EORTC IADL-BN32 questionnaire in a larger international sample.

Late Sequelae of Radiotherapy—The Effect of Technical and Conceptual Innovations in Radiation Oncology

BACKGROUND

Approximately half of all patients with tumors need radiotherapy. Long-term survivors may suffer from late sequelae of the treatment. The existing radiotherapeutic techniques are being refined so that radiation can be applied more precisely, with the goal of limiting the radiation exposure of normal tissue and reducing late sequelae.

METHODS

This review is based on the findings of a selective search in PubMed for publications on late sequelae of conventional percutaneous radiotherapy, January 2000 to May 2020. Late sequelae affecting the central nervous system, lungs, and heart and the development of second tumors are presented, and radiobiological mechanisms and the relevant technical and conceptual considerations are discussed.

RESULTS

The current standard of treatment involves the use of linear accelerators, intensity-modulated radiotherapy (IMRT), image-guided and respiratory-gated radiotherapy, and the integration of positron emission tomography combined with computed tomography (PET-CT) in radiation treatment planning. Cardiotoxicity has been reduced with regard to the risk of coronary heart disease after radiotherapy for Hodgkin's lymphoma (hazard ratio [HR] 0.44 [0.23; 0.85]). It was also found that the rate of radiation- induced pneumonitis dropped from 7.9% with conformal treatment to 3.5% with IMRT in a phase III lung cancer trial. It is hoped that neurocognitive functional impairment will be reduced by hippocampal avoidance in modern treatment planning: an initial phase III trial yielded a hazard ratio of 0.74 [0.58; 0.94]. It is estimated that 8% of second solid tumors in adults are induced by radiotherapy (3 additional tumors per 1000 patients at 10 years).

CONCLUSION

Special challenges for research in this field arise from the long latency of radiation sequelae and the need for largescale, well-documented patient collectives in order to discern dose-effect relationships, and take account of cofactors, when the overall number of events is small. It is hoped that further technical and conceptual advances will be made in the areas of adaptive radiotherapy, proton and heavy-ion therapy, and personalized therapy.

Pre-Surgery Cognitive Performance and Voxel-Based Lesion-Symptom Mapping in Patients with Left High-Grade Glioma

(1) Background: The literature on the effects of high-grade glioma (HGG) growth on cognition is still scarce. (2) Method: A consecutive series of 85 patients with HGG involving the left hemisphere underwent an extended neuropsychological evaluation prior to surgery. Voxel-based lesion-symptom mapping (VLSM) was used to identify regions related to cognitive performance. (3) Results: The patients' mean level of pre-surgery accuracy was overall high. They showed the greatest difficulties in language with tasks such as naming (42.1% of patients impaired on nouns and 61.4% on verbs), reading (36.3% on words and 32.7% on pseudo-words), auditory lexical decisions (43.9%) and writing (41.3%) being most frequently impaired. VLSM analysis revealed anatomically separated areas along the temporal cortex and the white matter related to impairments on the different tasks, with voxels commonly shared by all tasks restricted to a small region in the ventral superior and middle temporal gyrus. (4) Conclusions: High-grade glioma affects cognition; nonetheless, lesions do not cause diffuse deficits but selectively impact the different language sub-domains along the ventral stream and the dorsal stream for language processing.

Advanced Imaging Techniques for Radiotherapy Planning of Gliomas

The accuracy of target delineation in radiation treatment (RT) planning of cerebral gliomas is crucial to achieve high tumor control, while minimizing treatment-related toxicity. Conventional magnetic resonance imaging (MRI), including contrast-enhanced T1-weighted and fluid-attenuated inversion recovery (FLAIR) sequences, represents the current standard imaging modality for target volume delineation of gliomas. However, conventional sequences have limited capability to discriminate treatment-related changes from viable tumors, owing to the low specificity of increased blood-brain barrier permeability and peritumoral edema. Advanced physiology-based MRI techniques, such as MR spectroscopy, diffusion MRI and perfusion MRI, have been developed for the biological characterization of gliomas and may circumvent these limitations, providing additional metabolic, structural, and hemodynamic information for treatment planning and monitoring. Radionuclide imaging techniques, such as positron emission tomography (PET) with amino acid radiopharmaceuticals, are also increasingly used in the workup of primary brain tumors, and their integration in RT planning is being evaluated in specialized centers. This review focuses on the basic principles and clinical results of advanced MRI and PET imaging techniques that have promise as a complement to RT planning of gliomas.

Machine Learning Analytics of Resting-State Functional Connectivity Predicts Survival Outcomes of Glioblastoma Multiforme Patients

Glioblastoma multiforme (GBM) is the most frequently occurring brain malignancy. Due to its poor prognosis with currently available treatments, there is a pressing need for easily accessible, non-invasive techniques to help inform pre-treatment planning, patient counseling, and improve outcomes. In this study we determined the feasibility of resting-state functional connectivity (rsFC) to classify GBM patients into short-term and long-term survival groups with respect to reported median survival (14.6 months). We used a support vector machine with rsFC between regions of interest as predictive features. We employed a novel hybrid feature selection method whereby features were first filtered using correlations between rsFC and OS, and then using the established method of recursive feature elimination (RFE) to select the optimal feature subset. Leave-one-subject-out cross-validation evaluated the performance of models. Classification between short- and long-term survival accuracy was 71.9%. Sensitivity and specificity were 77.1 and 65.5%, respectively. The area under the receiver operating characteristic curve was 0.752 (95% CI, 0.62–0.88). These findings suggest that highly specific features of rsFC may predict GBM survival. Taken together, the findings of this study support that resting-state fMRI and machine learning analytics could enable a radiomic biomarker for GBM, augmenting care and planning for individual patients.

Cognitive reserve protects language functions in patients with brain tumours

Cognitive reserve (CR) theory suggests that individual differences in general intelligence (IQ), occupational attainment or participation in leisure/recreational activities protect against cognitive decline. However the relationship between CR and cognitive functioning in patients with brain tumours has been very rarely investigated in past research. The present study systematically assesses whether CR concept can also be applied to cognitive functions of neurosurgical patients affected by brain tumours. We investigated the role of different CR proxies (education level, premorbid IQ, current IQ, working and leisure activity) in protecting language against brain tumours and surgery effects, considering interactions with demographic (sex/age), anatomical (hemisphere/lobe location of lesion) and clinical/biological variables (tumour type: High/Low Grade Glioma or Meningioma; lesion volume; lesion aggressiveness). One-hundred patients undergoing neuropsychological assessment before and immediately after surgery participated. A "Language Score" summarizing performance on all language tests was derived with Principal Component Analysis. Data were then analyzed with Multiple Regression and Classification and Regression Tree analyses to investigate possible relationships between predictors (CR proxies and clinical variables) and Language Score. We found that premorbid IQ was the best predictor of pre-operatory language integrity, above and beyond all clinical variables considered, also moderating lesion volume effects. Moreover, patients with lower pre-operatory language integrity and low-to-moderately aggressive tumours showed a mitigating effect of current IQ over surgery consequences. Results thus suggest that different CR proxies play a role in moderating cognitive decline following brain tumours and surgery.

Objective neurocognitive functioning and neurocognitive complaints in patients with high-grade glioma: Evidence of cognitive awareness from the European Organisation for Research and Treatment of Cancer brain tumour clinical trials

BACKGROUND

Neurocognitively impaired patients with brain tumour are presumed to have reduced cognitive awareness preventing them from adequately valuing and reporting their own functioning, for instance, when providing patient-reported outcomes (PROs) such as health-related quality of life instruments. In this cross-sectional study, we aimed at assessing the concordance of neurocognitive complaints (NCCs) and objective neurocognitive functioning (NCF) as a measure of cognitive awareness.

METHODS

NCF was assessed using an internationally accepted clinical trial battery. NCC was assessed using the cognitive functioning questionnaire from the Medical Outcome Study (MOS) and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire cognitive functioning subscale. Patients were divided in cognitively impaired and unimpaired groups, based on their NCF performance. Pearson's correlation coefficients between NCF and NCCs were calculated. The same procedure was used to evaluate the correlation of NCF and QLQ-C30 CF subscale.

RESULTS

Data from EORTC trials 26091 and 26101 were pooled into a data set of 546 patients. Twenty percent of patients could be characterised as unimpaired (109) and 80% as impaired (437). Impaired patients reported more cognitive complaints on the MOS scale than unimpaired patients. Correlations between NCF and NCCs were weak but significant for impaired patients and non-significant for unimpaired ones. Similar results were found for the correlation between NCF test performance and the QLQ-C30 CF subscale.

CONCLUSION

Correlations between NCF test scores and complaints were weak but suggesting that neurocognitive impairment in patients with HGG does not preclude cognitive awareness. However, considering the findings of this study, we would suggest not to use PROs as a surrogate of performance-based neurocognitive evaluation.

A Prospective Cohort Study of Neural Progenitor Cell-Sparing Radiation Therapy Plus Temozolomide for Newly Diagnosed Patients With Glioblastoma

BACKGROUND

In treating glioblastoma, irradiation of the neural progenitor cell (NPC) niches is controversial. Lower hippocampal doses may limit neurocognitive toxicity, but higher doses to the subventricular zones (SVZ) may improve survival.

OBJECTIVE

To prospectively evaluate the impact of limiting radiation dose to the NPC niches on tumor progression, survival, and cognition in patients with glioblastoma.

METHODS

Patients with glioblastoma received resection followed by standard chemoradiation. Radiation dose to the NPC niches, including the bilateral hippocampi and SVZ, was minimized without compromising tumor coverage. The primary outcome was tumor progression in the spared NPC niches. Follow-up magnetic resonance imaging was obtained bimonthly. Neurocognitive testing was performed before treatment and at 6- and 12-mo follow-up. Cox regression evaluated predictors of overall and progression-free survival. Linear regression evaluated predictors of neurocognitive decline.

RESULTS

A total of 30 patients enrolled prospectively. The median age was 58 yr. Median mean doses to the hippocampi and SVZ were 49.1 and 41.8 gray (Gy) ipsilaterally, and 16.5 and 19.9 Gy contralaterally. Median times to death and tumor progression were 16.0 and 7.6 mo, and were not significantly different compared to a matched historical control. No patients experienced tumor progression in the spared NPC-containing regions. Overall survival was associated with neurocognitive function (P ≤ .03) but not dose to the NPC niches. Higher doses to the hippocampi and SVZ predicted greater decline in verbal memory (P ≤ .01).

CONCLUSION

In treating glioblastoma, limiting dose to the NPC niches may reduce cognitive toxicity while maintaining clinical outcomes. Further studies are needed to confirm these results.

Distributed changes of the functional connectome in patients with glioblastoma

Glioblastoma might have widespread effects on the neural organization and cognitive function, and even focal lesions may be associated with distributed functional alterations. However, functional changes do not necessarily follow obvious anatomical patterns and the current understanding of this interrelation is limited. In this study, we used resting-state functional magnetic resonance imaging to evaluate changes in global functional connectivity patterns in 15 patients with glioblastoma. For six patients we followed longitudinal trajectories of their functional connectome and structural tumour evolution using bi-monthly follow-up scans throughout treatment and disease progression. In all patients, unilateral tumour lesions were associated with inter-hemispherically symmetric network alterations, and functional proximity of tumour location was stronger linked to distributed network deterioration than anatomical distance. In the longitudinal subcohort of six patients, we observed patterns of network alterations with initial transient deterioration followed by recovery at first follow-up, and local network deterioration to precede structural tumour recurrence by two months. In summary, the impact of focal glioblastoma lesions on the functional connectome is global and linked to functional proximity rather than anatomical distance to tumour regions. Our findings further suggest a relevance for functional network trajectories as a possible means supporting early detection of tumour recurrence.

The Malignant Role of Exosomes as Nanocarriers of Rare RNA Species

Nowadays, advancements in the oncology sector regarding diagnosis methods allow us to specifically detect an increased number of cancer patients, some of them in incipient stages. However, one of the main issues consists of the invasive character of most of the diagnosis protocols or complex medical procedures associated with it, that impedes part of the patients to undergo routine checkups. Therefore, in order to increase the number of cancer cases diagnosed in incipient stages, other minimally invasive alternatives must be considered. The current review paper presents the value of rare RNA species isolated from circulatory exosomes as biomarkers of diagnosis, prognosis or even therapeutic intervention. Rare RNAs are most of the time overlooked in current research in favor of the more abundant RNA species like microRNAs. However, their high degree of stability, low variability and, for most of them, conservation across species could shift the interest toward these types of RNAs. Moreover, due to their low abundance, the variation interval in terms of the number of sequences with differential expression between samples from healthy individuals and cancer patients is significantly diminished and probably easier to interpret in a clinical context.

Determining medical decision-making capacity in brain tumor patients: why and how?

Background

Brain tumor patients are at high risk of impaired medical decision-making capacity (MDC), which can be ethically challenging because it limits their ability to give informed consent to medical treatments or participation in research. The European Association of Neuro-Oncology Palliative Care Multidisciplinary Task Force performed a systematic review to identify relevant evidence with respect to MDC that could be used to give recommendations on how to cope with reduced MDC in brain tumor patients.

Methods

A literature search in several electronic databases was conducted up to September 2019, including studies with brain tumor and other neurological patients. Information related to the following topics was extracted: tools to measure MDC, consent to treatment or research, predictive patient- and treatment-related factors, surrogate decision making, and interventions to improve MDC.

Results

A total of 138 articles were deemed eligible. Several structured capacity-assessment instruments are available to aid clinical decision making. These instruments revealed a high incidence of impaired MDC both in brain tumors and other neurological diseases for treatment- and research-related decisions. Incapacity appeared to be mostly determined by the level of cognitive impairment. Surrogate decision making should be considered in case a patient lacks capacity, ensuring that the patient's "best interests" and wishes are guaranteed. Several methods are available that may help to enhance patients' consent capacity.

Conclusions

Clinical recommendations on how to detect and manage reduced MDC in brain tumor patients were formulated, reflecting among others the timing of MDC assessments, methods to enhance patients' consent capacity, and alternative procedures, including surrogate consent.

Role of the default mode resting-state network for cognitive functioning in malignant glioma patients following multimodal treatment

BACKGROUND

Progressive cognitive decline following multimodal neurooncological treatment is a common observation in patients suffering from malignant glioma. Alterations of the default-mode network (DMN) represent a possible source of impaired neurocognitive functioning and were analyzed in these patients.

METHODS

Eighty patients (median age, 51 years) with glioma (WHO grade IV glioblastoma, n = 57; WHO grade III anaplastic astrocytoma, n = 13; WHO grade III anaplastic oligodendroglioma, n = 10) and ECOG performance score 0-1 underwent resting-state functional MRI (rs-fMRI) and neuropsychological testing at a median interval of 13 months (range, 1-114 months) after initiation of therapy. For evaluation of structural and metabolic changes after treatment, anatomical MRI and amino acid PET using O-(2-[18F]fluoroethyl)-L-tyrosine (FET) were simultaneously acquired to rs-fMRI on a hybrid MR/PET scanner. A cohort of 80 healthy subjects matched for gender, age, and educational status served as controls.

RESULTS

The connectivity pattern within the DMN (12 nodes) of the glioma patients differed significantly from that of the healthy subjects but did not depend on age, tumor grade, time since treatment initiation, presence of residual/recurrent tumor, number of chemotherapy cycles received, or anticonvulsive medication. Small changes in the connectivity pattern were observed in patients who had more than one series of radiotherapy. In contrast, structural tissue changes located at or near the tumor site (including resection cavities, white matter lesions, edema, and tumor tissue) had a strong negative impact on the functional connectivity of the adjacent DMN nodes, resulting in a marked dependence of the connectivity pattern on tumor location. In the majority of neurocognitive domains, glioma patients performed significantly worse than healthy subjects. Correlation analysis revealed that reduced connectivity in the left temporal and parietal DMN nodes was associated with low performance in language processing and verbal working memory. Furthermore, connectivity of the left parietal DMN node also correlated with processing speed, executive function, and verbal as well as visual working memory. Overall DMN connectivity loss and cognitive decline were less pronounced in patients with higher education.

CONCLUSION

Personalized treatment strategies for malignant glioma patients should consider the left parietal and temporal DMN nodes as vulnerable regions concerning neurocognitive outcome.

Sensitivity of the Montreal Cognitive Assessment in screening for cognitive impairment in patients with newly diagnosed high-grade glioma

INTRODUCTION

Cognitive impairment is frequent in patients with high-grade glioma and requires cognitive follow-up. Cognitive screening tools such as the Montreal Cognitive Assessment (MoCA) have been used to assess cognition in these patients. Here we assessed the sensitivity of the MoCA in screening for cognitive impairment in a cohort of 156 patients with newly-diagnosed high-grade glioma, after surgery and before radiochemotherapy.

METHODS

We assessed cognitive performance with the MoCA and a neuropsychological battery. Cognitive scores were analyzed in terms of a previously validated framework designed to control false positives and data for 1003 control participants from the GRECOGVASC study. After comparison of performance on the tests, we used stepwise logistic regression to produce a cognitive summary score from the neuropsychological battery. Then we analyzed sensitivity and specificity of the MoCA with receiver operator characteristic (ROC) curve analysis.

RESULTS

Both raw and adjusted MoCA scores showed only moderate sensitivity. The area under the ROC curve was 0.759 (95% CI 0.703-0.815) for the raw score and 0.788 (95% CI 0.734-0.842) for the adjusted score. Optimal discrimination was obtained with a raw score ≤ 25 (sensitivity: 0.526; specificity: 0.832; positive predictive value: 0.2; negative predictive value: 0.96) and an adjusted score - 0.603 (sensitivity: 0.716; specificity: 0.768; positive predictive value: 0.24; negative predictive value: 0.96).

CONCLUSION

The moderate sensitivity of MoCA indicates that it is not a suitable screening tool for detecting cognitive impairment in patients with newly-diagnosed high-grade glioma.

Examining the Neuropsychiatric Sequelae Postsurgical Resection of Adult Brain Tumors Through a Scoping Review

BACKGROUND

Improving brain tumor survival rates have drawn increasing focus on neuropsychiatric and psychological outcomes.

OBJECTIVE

This review characterizes the literature on neuropsychiatric sequelae after neurosurgical resection of adult brain tumors.

METHODS

Using a scoping method, we reviewed articles describing patients with adult brain tumor who underwent partial or total brain resection and examined major neuropsychiatric domains after intervention.

RESULTS

The initial search yielded 9903 articles. After duplicate removal, abstract screening, review, and hand searching, 81 articles were found: 63 empirical and 18 nonempirical. Most articles centered on survivorship within the first year. Cognition was most widely studied with a transient worsening during the first month and usually recovery or improvement thereafter. Depression increased in frequency during survivorship and was associated with frontotemporal location, time to survival, quality of life, cognitive and physical parameters, and functional status. Anxiety, independent of depression, related to tumor histology and grading and had a weaker association with cognition and quality of life. Obsessive-compulsive symptoms, psychosis, mania, and delirium received little attention. Most studies did not include preoperative neuropsychiatric assessment, and treatment was poorly addressed.

CONCLUSION

This review highlights key gaps, including preoperative and postoperative neuropsychiatric assessment and a short follow-up. A better understanding of postresection neuropsychiatric outcomes can inform our ability to prognosticate and tailor management for patients at risk for these life-impairing conditions.

Long-term follow-up of neuropsychological functions in patients with high grade gliomas: can cognitive status predict patient's outcome after surgery?

BACKGROUND

Patients affected by a high-grade glioma (HGG) have a poor prognosis with a median survival of 12-16 months. Such poor prognosis affects the perception of the remaining life by patients and the neuropsychological status can strongly affect every-day functioning of these patients. Monitoring changes of neuropsychological functioning (NPF) overtime may provide better clinical information and optimize the neuro-oncological management. The aims of our work were (1) to investigate the feasibility of a complex neuropsychological battery in HGG patients before and during follow-up after surgery; (2) to study the neuropsychological profile of patients affected by HGGs and their relation with the disease status (relapse/death) across time after surgery.

METHODS

One hundred two patients who received surgery for HGG between 2011 and 2017 were studied. All clinical data were prospectively recorded. NPF was assessed during the neuro-oncological follow-up through the Milano-Bicocca Battery (MIBIB). Statistical analysis was performed on the neuropsychological results of the tests administered.

RESULTS

First, MIBIB proved to be suitable for patients with HGG tumors before and after surgery, and during long-term follow-up; it also showed a cluster structure representative of the principal cognitive domains. Second, we found a steep decline in the neuropsychological profile before death and/or tumor relapse for the 52% of the neuropsychological tests administered.

CONCLUSION

Complex neuropsychological batteries can be administered to HGG patients before and during follow-up after surgery. There is a correlation between neuropsychological deterioration and tumor relapse and/or death, which may reflect a progressive damage to cognitive functions due to tumor infiltration and progression.

Prediagnostic symptoms and signs of adult glioma: the patients' view

BACKGROUND

Little is known about the symptoms glioma patients experience in the year before diagnosis, either or not resulting in health care usage. This study aimed to determine the incidence of symptoms glioma patients experienced in the year prior to diagnosis, and subsequent visits to a general practitioner (GP).

METHODS

Glioma patients were asked to complete a 30-item study-specific questionnaire focusing on symptoms they experienced in the 12 months before diagnosis. For each indicated symptom, patients were asked whether they consulted the GP for this issue.

RESULTS

Fifty-nine patients completed the questionnaires, 54 (93%) with input of a proxy. The median time since diagnosis was 4 months (range 1-12). The median number of symptoms experienced in the year before diagnosis was similar between gliomas with favourable and poor prognosis, i.e. 6 (range 0-24), as were the five most frequently mentioned problems: fatigue (n = 34, 58%), mental tiredness (n = 30, 51%), sleeping disorder (n = 24, 41%), headache (n = 23, 39%) and stress (n = 20, 34%). Twenty-six (44%) patients visited the GP with at least one issue. Patients who did consult their GP reported significantly more often muscle weakness (11 vs 3, p = 0.003) than patients who did not, which remained significant after correction for multiple testing, which was not the case for paralysis in hand/leg (10 vs 4), focussing (11 vs 6) or a change in awareness (9 vs 4).

CONCLUSIONS

Glioma patients experience a range of non-specific problems in the year prior to diagnosis, but only patients who consult the GP report more often neurological problems.

Glioblastoma cells vampirize WNT from neurons and trigger a JNK/MMP signaling loop that enhances glioblastoma progression and neurodegeneration

Glioblastoma (GB) is the most lethal brain tumor, and Wingless (Wg)-related integration site (WNT) pathway activation in these tumors is associated with a poor prognosis. Clinically, the disease is characterized by progressive neurological deficits. However, whether these symptoms result from direct or indirect damage to neurons is still unresolved. Using Drosophila and primary xenografts as models of human GB, we describe, here, a mechanism that leads to activation of WNT signaling (Wg in Drosophila) in tumor cells. GB cells display a network of tumor microtubes (TMs) that enwrap neurons, accumulate Wg receptor Frizzled1 (Fz1), and, thereby, deplete Wg from neurons, causing neurodegeneration. We have defined this process as "vampirization." Furthermore, GB cells establish a positive feedback loop to promote their expansion, in which the Wg pathway activates cJun N-terminal kinase (JNK) in GB cells, and, in turn, JNK signaling leads to the post-transcriptional up-regulation and accumulation of matrix metalloproteinases (MMPs), which facilitate TMs' infiltration throughout the brain, TMs' network expansion, and further Wg depletion from neurons. Consequently, GB cells proliferate because of the activation of the Wg signaling target, β-catenin, and neurons degenerate because of Wg signaling extinction. Our findings reveal a molecular mechanism for TM production, infiltration, and maintenance that can explain both neuron-dependent tumor progression and also the neural decay associated with GB.

Management of epilepsy in brain tumors

Epilepsy in brain tumors (BTE) may require medical attention for a variety of unique concerns: epileptic seizures, possible serious adverse effects of antineoplastic and antiepileptic drugs (AEDs), physical disability, and/or neurocognitive disturbances correlated to tumor site. Guidelines for the management of tumor-related epilepsies are lacking. Treatment is not standardized, and overall management might differ according to different specialists. The aim of this document was to provide directives on the procedures to be adopted for a correct diagnostic-therapeutic path of the patient with BTE, evaluating indications, risks, and benefits. A board comprising neurologists, epileptologists, neurophysiologists, neuroradiologists, neurosurgeons, neuro-oncologists, neuropsychologists, and patients' representatives was formed. The board converted diagnostic and therapeutic problems into seventeen questions. A literature search was performed in September-October 2017, and a total of 7827 unique records were retrieved, of which 148 constituted the core literature. There is no evidence that histological type or localization of the brain tumor affects the response to an AED. The board recommended to avoid enzyme-inducing antiepileptic drugs because of their interference with antitumoral drugs and consider as first-choice newer generation drugs (among them, levetiracetam, lamotrigine, and topiramate). Valproic acid should also be considered. Both short-term and long-term prophylaxes are not recommended in primary and metastatic brain tumors. Management of seizures in patients with BTE should be multidisciplinary. The panel evidenced conflicting or lacking data regarding the role of EEG, the choice of therapeutic strategy, and timing to withdraw AEDs and recommended high-quality long-term studies to standardize BTE care.

Predicting disease progression in high-grade glioma with neuropsychological parameters: the value of personalized longitudinal assessment

PURPOSE

Progressive disease in patients with high-grade glioma may be reflected in cognitive decline. However, the cognitive functions most sensitive to progression may differ between patients. We investigated whether decline on a personalized selection of tests predicted progressive disease according to RANO criteria in high-grade glioma patients.

METHODS

Starting one day before surgery, patients underwent neuropsychological assessment every three months during standard treatment and clinical follow-up. We first made a personalized selection of three tests that showed the highest Reliable Change Index (RCI) values, i.e., most positive change, at the first post-surgical assessment for each patient. In subsequent follow up, a decline of RCI ≤ - 1 on at least two of the three tests in the selection was considered cognitive decline. We performed a discrete Cox proportional hazards model including a time-dependent coefficient cognitive decline (vs. stability) and covariate age to predict progressive disease.

RESULTS

Twenty five patients were included. Cognitive decline on the personalized test selection preceded or had occurred by the time progression was established in 9/15 patients with RANO confirmed progressive disease (60%). Decline was absent in 8/10 patients (80%) with stable disease during participation. The independent hazard ratio for progression in case of cognitive decline was 5.05 (p < 0.01) compared to stable performance.

CONCLUSIONS

Using only three patient-specific neuropsychological tests, we found a fivefold increased chance of disease progression in case of cognitive decline as compared to stable performance. Brief, patient-tailored cognitive assessment may be a noninvasive addition to disease monitoring without overburdening patients and clinical care.

Assessment of neurocognitive decline in cancer patients, except brain cancer, under long-term treatment with bevacizumab

PURPOSE

We performed a cross-sectional study of neurocognitive function in non-brain cancer patients treated with long-term bevacizumab.

METHODS/PATIENTS

From 2015 to 2017, we included patients with different types of cancer treated with bevacizumab with or without chemotherapy (BEV; N = 20) or only chemotherapy (ChT; N = 19) for at least 34 weeks, patients who received non-brain radiotherapy (RxT; N = 19), and healthy controls (HC; N = 19) were assessed once at week 34 of treatment (BEV and ChT) or at completion of radiotherapy. Neurocognition was evaluated with the Hopkins Verbal Learning Test-Revised (HVLT-R) total and delayed recall, the Trail Making Test A and B, and the Controlled Oral Word Association Test in the four groups. Non-parametric tests were used to assess differences between groups.

RESULTS

The BEV, ChT, and RxT groups scored significantly lower than the HC group on all tests and especially on the HVLT-R total recall. In no case were the mean scores of the BEV group significantly lower than those of the ChT or RxT groups.

CONCLUSIONS

Neurocognitive impairment was seen even in patients treated with local non-brain radiotherapy. Treatment with bevacizumab for a long period of time does not seem to worsen neurocognitive function to a greater extent than chemotherapy.

A systematic review of cognitive function in patients with glioblastoma undergoing surgery

Background

Patients with glioblastoma (GB) are more likely to suffer cognitive deficits with poor quality of life as compared with lower-grade glioma patient groups, for whom cognition research is plentiful. The objective of this systematic review is to evaluate the cognitive function of patients with GB before and after surgery.

Methods

This review was prospectively registered with PROSPERO. PubMed and EMBASE searches were performed, most recently March 15, 2018. Inclusion criteria were adult patients, histologically confirmed GB, and cognitive tests conducted before and/or after surgery. Screening and data extraction were carried out independently by 2 authors.

Results

A total of 512 abstracts were screened. Nineteen studies were included with 902 participants, of whom only 423 had histologically confirmed GB. Only 11 studies tested cognitive function both before and after surgery. A total of 114 different cognitive tests were used. The most common test was used in only 9 studies; 82 tests were used only once. Follow-up time ranged from 1 week to 16 months with extremely high dropout rates. Eighteen of 19 studies reported cognitive deficits in their samples, with prevalence ranging from 22% to 100% (median 64%, interquartile range 42%). Only 1/11 longitudinal studies reported normal cognitive function, 3/11 reported initial deficits with improvement after surgery, 3/11 reported static deficits, and 4/11 reported deterioration.

Conclusion

There is a consistently high risk of cognitive deficit for patients with GB undergoing surgery. The included studies showed marked heterogeneity in study design, case-mix of included diagnoses, and the type and timing of cognitive tests used. We highlight considerations for the design of future studies to avoid such bias.

Mass Effect Deformation Heterogeneity (MEDH) on Gadolinium-contrast T1-weighted MRI is associated with decreased survival in patients with right cerebral hemisphere Glioblastoma: A feasibility study

Subtle tissue deformations caused by mass-effect in Glioblastoma (GBM) are often not visually evident, and may cause neurological deficits, impacting survival. Radiomic features provide sub-visual quantitative measures to uncover disease characteristics. We present a new radiomic feature to capture mass effect-induced deformations in the brain on Gadolinium-contrast (Gd-C) T1w-MRI, and their impact on survival. Our rationale is that larger variations in deformation within functionally eloquent areas of the contralateral hemisphere are likely related to decreased survival. Displacements in the cortical and subcortical structures were measured by aligning the Gd-C T1w-MRI to a healthy atlas. The variance of deformation magnitudes was measured and defined as Mass Effect Deformation Heterogeneity (MEDH) within the brain structures. MEDH values were then correlated with overall-survival of 89 subjects on the discovery cohort, with tumors on the right (n = 41) and left (n = 48) cerebral hemispheres, and evaluated on a hold-out cohort (n = 49 subjects). On both cohorts, decreased survival time was found to be associated with increased MEDH in areas of language comprehension, social cognition, visual perception, emotion, somato-sensory, cognitive and motor-control functions, particularly in the memory areas in the left-hemisphere. Our results suggest that higher MEDH in functionally eloquent areas of the left-hemisphere due to GBM in the right-hemisphere may be associated with poor-survival.

Repeatable Battery for the Assessment of Neuropsychological Status (RBANS): preliminary utility in adult neuro-oncology

Background

Neurocognitive assessments have become integral to comprehensive neuro-oncology care. Existing screening tools may be insensitive to cognitive changes caused by medical treatments. Research supports the clinical value and psychometric properties of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in various medical populations; however, there is minimal evidence for its use in neuro-oncology. The purpose of the current study was to further explore the cognitive profile of patients with primary brain tumor (PBT) using the RBANS and to assess rates of below-expectation performance compared to normative data and estimated intellectual functioning.

Methods

Data were collected on 82 PBT patients (54% male; age range, 19-81 years). All patients were administered the RBANS-Update and the Advanced Clinical Solutions-Test of Premorbid Functioning (TOPF) according to standardized instructions. Cognitive strengths and weaknesses were identified for PBT patients. Descriptive analyses, t tests, and chi-squared tests were utilized to identify and compare cognitive profiles.

Results

Overall, cognitive performance was low average for PBT patients. When compared to standardization data, PBT patients performed significantly worse across all 5 RBANS indexes, with Attention and Memory showing the largest discrepancies. Estimated intelligence analyses reflected greater deficits in cognitive functioning than when compared to a normal distribution.

Conclusions

Preliminary research demonstrates the RBANS is an efficient screening tool to assess cognitive deficits in PBT patients. Data also support the importance of comparison to self, rather than normative distribution in ensuring proper identification and classification of patients.

Effects of surgery on neurocognitive function in patients with glioma: a meta-analysis of immediate post-operative and long-term follow-up neurocognitive outcomes

PURPOSE

This study aims to identify the neuropsychological tests commonly used for assessment in each neurocognitive domain, and quantify the post-operative changes in neurocognitive function in the immediate post-operation and follow-up.

METHODS

With the use of the PubMed, a comprehensive search of the English literature was performed following PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. There were 1021 publications identified for screening. Standardized mean differences (SMD) in neuropsychological task performance were calculated both for immediate post-operation (up to 1 week) and follow-up (up to 6 months).

RESULTS

Out of 12 studies which met the inclusion criteria, 11 studies were analyzed in this meta-analysis, with a total of 313 patients (age range 18-82, 50% males) with intracranial gliomas (45% high-grade, 55% low-grade). Complex attention, language and executive function were the most frequently tested neurocognitive domains. Surgery had a positive impact in the domains of complex attention, language, learning and memory tasks in the immediate post-operative period and sustained improvement at follow-up. In contrast, surgery was found to negatively impact performance for executive function in the immediate post-operative period with sustained decline in performance in the long term.

CONCLUSIONS

This meta-analysis suggests that surgery for glioma confers a benefit for the domains of complex attention, language, learning and memory, while negatively affecting executive function, in the periods immediately after surgery and at 6 months follow-up. In addition, awake surgery seemed to confer a beneficial effect on neurocognitive functions. Future research should attempt to standardize a battery of neuropsychological tests for patients undergoing surgical resection for glioma, perhaps with a particular focus on executive function.