Symptom networks in glioma patients: understanding the multidimensionality of symptoms and quality of life

PURPOSE

To comprehend the complex relationship between symptoms and health-related quality of life (HRQoL) in patients with diffuse glioma, we applied symptom network analysis to identify patterns of associations between depression, cognition, brain tumor-related symptoms, and HRQoL. Additionally, we aimed to compare global strength between symptom networks to understand if symptoms are more tightly connected in different subgroups of patients.

METHODS

We included 256 patients and stratified the sample based on disease status (preoperative vs. postoperative), tumor grade (grade II vs. III/IV), and fatigue status (non-fatigued vs. fatigued). For each subgroup of patients, we constructed a symptom network. In these six networks, each node represented a validated subscale of a questionnaire and an edge represented a partial correlation between two nodes. We statistically compared global strength between networks.

RESULTS

Across the six networks, nodes were highly correlated: fatigue severity, depression, and social functioning in particular. We found no differences in GS between the networks based on disease characteristics. However, global strength was lower in the non-fatigued network compared to the fatigued network (5.51 vs. 7.49, p < 0.001).

CONCLUSIONS

Symptoms and HRQoL are highly interrelated in patients with glioma. Interestingly, nodes in the network of fatigued patients were more tightly connected compared to non-fatigued patients.

IMPLICATIONS FOR CANCER SURVIVORS

We introduce symptom networks as a method to understand the multidimensionality of symptoms in glioma. We find a clear association between multiple symptoms and HRQoL, which underlines the need for integrative symptom management targeting fatigue in particular.

Development and psychometric evaluation of item banks for memory and attention - supplements to the EORTC CAT Core instrument

BACKGROUND

Cancer patients may experience a decrease in cognitive functioning before, during and after cancer treatment. So far, the Quality of Life Group of the European Organisation for Research and Treatment of Cancer (EORTC QLG) developed an item bank to assess self-reported memory and attention within a single, cognitive functioning scale (CF) using computerized adaptive testing (EORTC CAT Core CF item bank). However, the distinction between different cognitive functions might be important to assess the patients' functional status appropriately and to determine treatment impact. To allow for such assessment, the aim of this study was to develop and psychometrically evaluate separate item banks for memory and attention based on the EORTC CAT Core CF item bank.

METHODS

In a multistep process including an expert-based content analysis, we assigned 44 items from the EORTC CAT Core CF item bank to the memory or attention domain. Then, we conducted psychometric analyses based on a sample used within the development of the EORTC CAT Core CF item bank. The sample consisted of 1030 cancer patients from Denmark, France, Poland, and the United Kingdom. We evaluated measurement properties of the newly developed item banks using confirmatory factor analysis (CFA) and item response theory model calibration.

RESULTS

Item assignment resulted in 31 memory and 13 attention items. Conducted CFAs suggested good fit to a 1-factor model for each domain and no violations of monotonicity or indications of differential item functioning. Evaluation of CATs for both memory and attention confirmed well-functioning item banks with increased power/reduced sample size requirements (for CATs ≥ 4 items and up to 40% reduction in sample size requirements in comparison to non-CAT format).

CONCLUSION

Two well-functioning and psychometrically robust item banks for memory and attention were formed from the existing EORTC CAT Core CF item bank. These findings could support further research on self-reported cognitive functioning in cancer patients in clinical trials as well as for real-word-evidence. A more precise assessment of attention and memory deficits in cancer patients will strengthen the evidence on the effects of cancer treatment for different cancer entities, and therefore contribute to shared and informed clinical decision-making.

PL02.4.A International validation study of an EORTC instrument measuring instrumental activities of daily living (IADL) in patients with brain tumours: EORTC IADL-BN32

Background

Brain tumour patients often have neurocognitive deficits which can result in problems with activities in daily living that are cognitively complex. Currently, no valid and reliable brain tumour-specific instrument to measure these instrumental activities of daily living (IADL) is available, but such an instrument is being developed. This study aimed to validate the EORTC IADL-BN32 questionnaire, comprising five multi-item and two single item scales, in a large set of international brain tumour patients.

Material and Methods

This international study was conducted in 10 countries worldwide. Primary and metastatic brain tumour patients and their proxies were requested to complete the EORTC IADL-BN32 and a subjective cognitive questionnaire (MOS COG-R) at multiple time points. Several psychometric properties were evaluated with baseline data, including the structural validity (bi-factor confirmatory factor analysis [CFA]), reliability (internal consistency), construct validity (known groups comparisons) and patient-proxy congruency (intra-class correlation coefficients [ICC], Spearman's correlation).

Results

At baseline, 326 patients ( 30% low-grade glioma, 37% high-grade glioma (HGG) and 33% brain metastases) and 311 proxies completed the EORTC IADL-BN32. The bi-factor CFA was found to have a satisfactory model fit (CFI=0.92 and TLI=0.90), and other parameters indicated a good fit (RMSEA=0.08 and SRMR=0.05), thereby validating the preliminary scale structure, but also an IADL sum score. The multi-item scales showed good (0.9&gt;α≥0.8) to excellent (α≥0.9) internal consistency (range α=0.86-0.97). Known groups comparisons analyses regarding patient’s cognitive status (indications vs. no cognitive impairment), subjective cognitive complaints (MOS COG-R ≤30 vs. &gt;30), basic ADL (Barthel Index &lt;100 vs. 100) and performance status (KPS &lt;70 vs. ≥70) showed significant differences on all IADL outcome measures in line with a priori defined hypotheses. On a group level, patient and proxy ratings had moderate to strong correlations, however, proxies tended to report more problems on all scales. The ICCs showed moderate to good congruency between patients and proxies (range ICC: 0.63-0.81).

Conclusion

The evaluated psychometric properties support the current scale structure of the EORTC IADL-BN32. Additional psychometric properties with longitudinal data are needed, such as test-retest reliability and responsiveness, to further validate the EORTC-IADL BN32 questionnaire.

P01.10.B The relation between executive functioning and MEG multilayer network centrality in glioma patients

Background

Many patients with glioma suffer from deficits in executive functioning (EF), regardless of tumor location and size. While some patients experience improving EF after tumor resection, others deteriorate over time. This variability in cognitive trajectories is still poorly understood, but neuroscientific approaches that view the brain as a network may bear correlative and predictive value in this respect. Particularly integrative network connectivity of the fronto-parietal network are crucial for EF, but studies so far have only investigated isolated neural frequency bands of interest. Here, we synergize fronto-parietal network connectivity across frequency bands and test its explanatory power for EF at diagnosis and 1 year after tumor resection.

Material and Methods

Patients with diffuse glioma (n=37) underwent neuropsychological assessments, including three tests for EF, and resting-state magnetoencephalography (MEG) at both time points. Patients’ EF performance was standardized to z-scores using validated norm scores, adjusting for age, sex and education. MEG was source-reconstructed using patients’ MRI in combination with a beamformer approach and time series were filtered into six classical frequency bands. Band-specific functional connectivity between 78 cortical regions was estimated, after which an interconnected multilayer, multi-frequency network was created per patient. Multilayer centrality was then calculated as a measure of integrative network connectivity per region, and averaged over all fronto-parietal network regions to yield a single value reflecting integrative, multi-frequency network connectivity per patient at each time point.

Results

At diagnosis, eight patients had z-scores &lt;-1.5, indicating clinically relevant cognitive deficits. Preoperatively, poorer performance on the Concept Shifting Task was associated with lower multilayer centrality (p=.017), while improving performance on this task from diagnosis to 1 year after resection was associated with an increase in multilayer centrality (p=.022). Multilayer centrality at diagnosis did not significantly predict EF at follow-up.

Conclusion

Our results establish a significant relationship between poorer and decreasing EF with lower and decreasing multilayer, multi-frequency integrative connectivity of the fronto-parietal network in glioma patients. Studies with larger and more homogeneous samples may further explore the relevance of this multilayer approach in understanding and particularly predicting postoperative decline in EF in these patients, as our sample was characterized by large heterogeneity in cognitively relevant patient and tumor characteristics.

Non-invasively measured brain activity and radiological progression in diffuse glioma

Non-invasively measured brain activity is related to progression-free survival in glioma patients, suggesting its potential as a marker of glioma progression. We therefore assessed the relationship between brain activity and increasing tumor volumes on routine clinical magnetic resonance imaging (MRI) in glioma patients. Postoperative magnetoencephalography (MEG) was recorded in 45 diffuse glioma patients. Brain activity was estimated using three measures (absolute broadband power, offset and slope) calculated at three spatial levels: global average, averaged across the peritumoral areas, and averaged across the homologues of these peritumoral areas in the contralateral hemisphere. Tumors were segmented on MRI. Changes in tumor volume between the two scans surrounding the MEG were calculated and correlated with brain activity. Brain activity was compared between patient groups classified into having increasing or stable tumor volume. Results show that brain activity was significantly increased in the tumor hemisphere in general, and in peritumoral regions specifically. However, none of the measures and spatial levels of brain activity correlated with changes in tumor volume, nor did they differ between patients with increasing versus stable tumor volumes. Longitudinal studies in more homogeneous subgroups of glioma patients are necessary to further explore the clinical potential of non-invasively measured brain activity.

OS09.4.A Health-related quality of life in low-grade glioma survivors 26 years after diagnosis

BACKGROUND

Many patients with low-grade gliomas (LGGs) continue to survive for many years, yet little is known about patients’ health-related quality of life (HRQOL) in long-term survivorship. We previously investigated HRQOL in LGG patients diagnosed on average 6 years prior to assessment (T1, N=195) with a follow-up in stable patients on average 12 years after diagnosis (T2, N=65). We present a final follow-up of LGG survivors (T3), now decades after diagnosis.

MATERIAL AND METHODS

We invited patients who participated in our previous assessment (N=65), regardless of disease status. Patients completed questionnaires to assess HRQOL, fatigue, and depressive symptoms: Short Form-36 Health Survey (SF-36), European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Brain Tumour Module (EORTC BN20), Checklist Individual Strength (CIS), and the Center for Epidemiological Studies Depression Scale (CES-D). Changes over time (T1-T2-T3) on group level and participant level were assessed.

RESULTS

Of the 65 patients, 18 (27.7%) were deceased, 3 (4.6%) experienced tumour progression to WHO III, 7 (10.8%) declined, and 3 (4.6%) could not be contacted. Thirty-four patients (52.3%) participated. Of these, 2 had missing HRQOL data, with 32 patients included in analysis. Survivors were M=52.0 (sd=11.3) years old and diagnosed M=26.2 (sd=3.7, range 19–35) years prior. On group level, a statistically significant (but not clinically relevant) improvement in mental health (p=0.049), and a clinically relevant (but not statistically significant) decline in emotional role functioning was found. No other group-level changes over time in HRQOL were found. Minimal detectable change in HRQOL scale scores over time was observed in individual participants (28.1% only improvement; 25.0% only decline; 21.9% both improvement and decline) with 25.0% remaining completely stable. At T3, 25.0% of survivors scored above the cut-off for high risk of clinical depression (≥16 CES-D), and 53.1% of survivors classed as severely fatigued (≥35 CIS).

CONCLUSION

In this cohort of LGG survivors, assessed decades after diagnosis and treatment, HRQOL does not appear to be greatly impacted during survivorship. However, depressive symptoms and fatigue remain relatively common. Findings can help inform patients, their families, and clinicians and can serve as a benchmark for treatment trials evaluating interventions that can have very long-term effects.

P11.01 Symptom networks in glioma: a novel approach to study multidimensional symptomatology in glioma patients

BACKGROUND

Glioma patients experience a high symptom burden contributing to poorer quality of life. Symptoms include depression, cognitive impairment, and fatigue and vary throughout the disease. These symptoms are rarely studied from a comprehensive perspective, while their interdependence may be relevant for their development, perpetuation, and ultimately successful treatment. The emerging field of symptom network analysis uncovers the multidimensional symptom space. Nodes are the symptoms, and edges are operationalized as the full conditional association, or partial correlation, between two symptom severity scores across patients. Highly connected nodes are considered central and may be particularly relevant targets for treatment as disruption of these central nodes impact the entire network. We visualized the overall glioma symptom network, compared multidimensional results to known literature, and statistically compared networks between relevant patient subgroups.

MATERIAL AND METHODS

A dataset comprised of 355 observations of 180 glioma patients at different disease phases was analysed. Cognitive testing and questionnaires regarding health-related and glioma-specific quality of life, fatigue, depression, and cognition resulted in the definition of 30 symptom nodes. Symptom clusters were visually explored in the resulting networks, as were node strength, betweenness, and closeness centrality measures for each node. Networks were statistically compared between preoperative patients and patients during stable disease, as well as patients with low versus high-grade gliomas. Networks of patients with normal versus severe levels of fatigue were also compared as cancer-/glioma-related fatigue has a strong impact on quality of life and can correlate with other common symptoms such as pain, depression, and/or sleep disturbance.

RESULTS

Symptom clusters existed between: 1) bodily pain, headache and physical functioning; 2) concentration and motivation; and 3) fatigue and drowsiness. Fatigue and mental health were the most central nodes in the networks. Furthermore, the overall connectivity between symptoms was significantly higher in the severely fatigued patients than in patients with normal fatigue. No network differences were found between low versus high-grade, and preoperative versus stable disease networks.

CONCLUSION

Fatigue is a central node in glioma patients’ burden of disease, and symptoms are more tightly intercorrelated in patients experiencing severe fatigue. From our data, we hypothesize that fatigue co-exists with or perpetuates other symptoms. Thus, although these results are preliminary, the network approach may innovate hypothesis generation in symptom management.

P14.53 Deconstructing pathologically increased MEG network clustering in glioma patients

Introduction

Functional brain networks in glioma patients are characterized by higher global clustering than healthy controls, indicating stronger connectivity in triads of brain regions when averaging across the entire brain. However, this could be due to either primary increased local clustering of (peri)tumor regions or higher local clustering throughout the entire brain.

METHODS

Magnetoencephalography recordings of 71 glioma patients and 53 HCs were analyzed by calculating functional connectivity with the phase lag index between source-localized time series of 78 cortical regions of the automated anatomical labelling atlas. Per participant, we calculated (1) global average clustering, (2) local clustering of tumor and non-tumor regions, and (3) Euclidean distance between tumor centroids and of all other region centroids.

RESULTS

Glioma patients had higher global average clustering (p=0.002) than HCs. This increase was indeed global: there was no difference between tumor and non-tumor regions (p=0.154) and no association between distance and local clustering (p=0.759). When splitting patients into high (top 25%, n=18) and normal global clustering (other 75%, n=53) to more specifically pick up on the determinants of pathological global average clustering, again no localized or distance-dependent effects were found. High clustering patients were younger than patients with normal global clustering (p=0.027). Posthoc analysis into tumor localization preference for particular network regions in the entire patient cohort revealed greater tumor occurrence in regions with high clustering in HC (p<0.001), while patients with high global clustering showed tumors localized in regions with lower clustering in HC (p=0.032).

CONCLUSION

The functional brain network of a subset of (relatively young) glioma patients is disturbed on a global level, suggesting that treatment thereof might benefit patients. Moreover, our exploratory analyses suggest that gliomas occur more often in normally highly clustered regions, but that tumors occurring in less clustered regions are associated with more extensive global network alterations. These findings may speculatively indicate that patients with and without such pathologically altered global clustering represent distinct phenotypes (both in terms of age and tumor localization) and may also need to be treated as such.

OS3.3 Development of an EORTC questionnaire measuring instrumental activities of daily living (IADL) in patients with brain tumours: phase I-III

BACKGROUND

In brain tumour patients, impairments in every day functioning can impact quality of life, and are therefore an important outcome in both clinical trials and practice. One way to measure every day functioning is with an activities of daily living (ADL) questionnaire. Instrumental ADL (IADL) are the cognitively more complex activities, that are essential to function autonomously within society. Cognitive decline may therefore negatively impact IADL, making these activities particularly relevant to brain tumour patients. The aim of this study is to develop a reliable and valid questionnaire to measure IADL in primary malignant and metastatic brain tumour patients.

MATERIAL AND METHODS

The questionnaire development study followed the standard European Organisation for Research and Treatment of Cancer (EORTC) four phase methodology: (I) generation of activities list, (II) construction of item list, (III) pre-testing, and (IV) field testing. This report covers phases I-III. To ensure cross-cultural validity, participants were recruited from different countries (The Netherlands, United Kingdom, Italy, Austria and Japan). In phase I, potential activities were identified based on a literature review and in-depth interviews with patients, proxies and healthcare professionals. In phase II, activities were turned into items, and translated into all required languages by the EORTC Translation Unit. In phase III, the item list was pre-tested in patient-proxy dyads. In accordance with predetermined decision rules to reduce items, final items were selected, and preliminary psychometric properties (i.e. factor structure, validity, reliability) were assessed.

RESULTS

Phase I (N=44 dyads) resulted in 59 IADL activities which were converted into 59 items in phase II. In phase III, N=85 dyads completed and reviewed this item list. The item list was subsequently reduced to 32 items. An exploratory factor analysis indicated several items measuring similar underlying constructs (e.g. domestic life and using computer/smartphone) showing acceptable to good (α≥0.7) internal consistency (range α=0.69–0.89). Seven items were less related to these underlying constructs (e.g. work or managing your own medication), and therefore single items. Construct validity, measured with known-group comparisons analyses between cognitively impaired and unimpaired patients, showed significant differences in scores between the two groups on some scales and several single items.

CONCLUSION

The currently developed EORTC IADL-BN32 questionnaire can be a valuable asset in assessing IADL functioning in brain tumour patients, but further validation in phase IV is required and is planned.

OS7.5 Healthcare utilization, medication use, and productivity loss in glioma patients with depressive symptoms and their family caregivers

BACKGROUND

Gliomas are associated with great societal burden through both direct (health and social care) and indirect (e.g., productivity loss) costs, but socioeconomic reports are scarce. We describe costs in a sample of glioma patients at high risk for depression and their family caregivers, and explore relationships between costs and treatable symptoms (depression; fatigue; cognitive complaints).

MATERIAL AND METHODS

Data from a nationwide randomised trial comparing internet-based therapy for depressive symptoms with waitlist controls were used.

Healthcare utilization, medication use, and productivity loss based on the

Trimbos/iMTA questionnaire for Costs associated with Psychiatric Illness (TIC-P) were described and costs in the past 4 weeks were calculated. Caregivers reported on their own costs and wellbeing

We used generalized linear regression models to predict costs using multiple observations per participant and robust standard errors. We included depressive symptoms (CES-D), fatigue (CIS), cognitive complaints (MOS), tumour grade (low-/high-grade), and disease status (stable/progression/active treatment).

RESULTS

Data from 91 glioma patients and 46 caregivers were used with multiple assessments from baseline through 12 months follow-up. Baseline data showed that over a 4 week period, 64.8% of patients (M=€394.99, sd=856.83) and 41.3% of caregivers (M=€131.11, sd=392.89) had used healthcare services. Medication was used by 90.1% of patients (M=€100.83, sd=191.07) and 43.5% of caregivers (M=€13.19, sd=21.03). Productivity loss resulted in M=€1231.19, sd=2185.35 for patients and M=€310.92, sd=841.36 for caregivers. In total, mean direct and indirect costs were €1632.22 (sd=2314.25) for patients and €447.85 (sd=1002.94) for caregivers. In patients, more depressive symptoms and cognitive complaints were associated with increased healthcare use costs; higher tumour grade and active disease were linked with higher medication costs (all p<.05). Active treatment was related to higher overall costs (p<.05). In caregivers, increased caregiver fatigue was associated with higher productivity loss and overall costs; more caregiver cognitive complaints were associated with higher total costs; higher tumour grade was associated with higher healthcare use and total costs; and patient active treatment was linked with higher healthcare use costs (all p<.05).

CONCLUSION

Direct and indirect costs are substantial in glioma patients and caregivers. This indicates that the true cost of brain tumours is a burden shared between patients, caregivers, the healthcare system, and society more widely. Tentative links between costs and symptoms of depression, fatigue, and cognitive complaints indicate that adequate support may lead to cost reductions. Multivariable regression models are currently being prepared.

OS7.2 Measuring change in health-related quality of life: the added value of analysis on the individual patient level in glioma patients in clinical decision making

BACKGROUND

Health-related quality of life (HRQoL) is often used as an outcome in glioma research, reflecting the impact of disease and treatment on a patient’s functioning and wellbeing. Data on changes in HRQoL scores may provide important information for clinical decision-making, but different analytical methods may lead to different interpretations of the impact of treatment on HRQoL. This study aimed to examine three different methods to evaluate change in HRQoL, and to study whether these methods result in different interpretations.

MATERIAL AND METHODS

HRQoL and sociodemographical/clinical data from 15 randomized clinical trials were combined. Change in HRQoL scores was analyzed in three ways: (1) at the group level, comparing mean changes in scale/item scores between treatment arms over time, (2) at the patient level per scale/item by calculating the percentage of patients that deteriorated, improved or remained stable on a scale/item per scale/item, and (3) at the individual patient level combining all scales/items.

RESULTS

Baseline and first follow-up HRQoL data were available for 3727 patients. At the group scale/item level (method 1), only the item ‘hair loss’ showed a significant and clinically relevant change (i.e. ≥10 points) over time, whereas change scores on the other scales/items showed a statistically significant change only (all p<.001, range in change score: 0.1–6.2). Analyses on the patient level per scale (method 2) indicated that, while a large proportion of patients had stable HRQoL over time (range 27–84%), many patients deteriorated (range: 6–43%) or improved (range: 8–32%) on a specific scale/item. At the individual patient level (method 3), the majority of patients (86%) showed both deterioration and improvement, while only 1% of the patients remained stable on all scales. Clustering on clinical characteristics (WHO performance status, sex, tumor type, type of resection, newly diagnosed versus recurrent tumor and age) did not identify subgroups of patients with a specific pattern of change in their HRQoL score.

CONCLUSION

Different analytical methods of changes in HRQoL result in distinct interpretations of treatment effects, all of which may be relevant for clinical decision-making. Additional information about the joint impact of treatment on all outcomes, showing that most patients experience both deterioration and improvement, may help patients and physicians to make the best treatment decision.

OS7.4 Calculating the net clinical benefit in brain tumor clinical trials by combining survival and health-related quality of life data using two methods: quality adjusted survival effect sizes (QASES) and joint modelling (JM)

BACKGROUND

The impact of treatment on both the quality and the quantity of life, i.e. the ‘net clinical benefit’, should be considered to inform glioma patients and facilitate shared decision making. We applied two methods (i.e. Quality Adjusted Effect Sizes (QASES) and Joint Modelling (JM)) that combine survival and health-related quality of life (HRQoL) data into one outcome, to gain insight in the net clinical benefit of a treatment strategy. In addition, we assessed if both methods result in similar interpretations.

MATERIAL AND METHODS

We calculated the net clinical benefit in one randomized controlled trial, EORTC 26951 comparing radiotherapy (RT) + PCV chemotherapy versus RT alone, as a proof of concept for other trials. With the QASES method, effect sizes for differences in survival and HRQoL between treatment arms were calculated. Next, the combined effect size can be determined by weighing the emphasis put on survival or HRQoL (e.g. survival more important). JM allows simultaneous modeling of a longitudinal outcome (HRQoL), and a time-to event outcome (survival). HRQoL scales/items that were selected for primary analysis in the main study were also selected for this analysis: fatigue, global health, social functioning, communication deficit, seizures, physical functioning, and nausea/vomiting.

RESULTS

288/386 patients completed baseline HRQoL forms and were included in the analysis. Overall survival (OS) was significantly longer with combined treatment (difference of 10.8 months). In contrast, the percentage of patients who experienced a clinically relevant deterioration (≥10 points) in nausea/vomiting, fatigue, social functioning and global health up to one year after treatment compared to baseline was larger in the RT+PCV arm. The QASES corresponded to a reduction in the median OS difference from 10.8 months to 6.8 months when adjusted for the HRQoL scales/items, when given equal weights to OS and HRQoL. JM analyses resulted in a theoretical loss of treatment effect in OS of 2–6% when adjusting for HRQoL.

CONCLUSION

Both methods showed that adjusting for the impact of treatment on a relevant HRQoL parameter reduced the survival benefit in the experimental treatment arm compared to standard treatment arm. Applying these methods may facilitate communicating the impact of treatment to patients in clinical practice.

Withdrawal of antiepileptic drugs in patients with low grade and anaplastic glioma after long-term seizure freedom: a prospective observational study

Background

When glioma patients experience long-term seizure freedom the question arises whether antiepileptic drugs (AEDs) should be continued. As no prospective studies exist on seizure recurrence in glioma patients after AED withdrawal, we evaluated the decision-making process to withdraw AEDs in glioma patients, and seizure outcome after withdrawal.

Methods

Patients with a histologically confirmed low grade or anaplastic glioma were included. Eligible patients were seizure free ≥ 1 year from the date of last antitumor treatment, or ≥ 2 years since the last seizure when seizures occurred after the end of the last antitumor treatment. Patients and neuro-oncologists made a shared decision on the preferred AED treatment (i.e. AED withdrawal or continuation). Primary outcomes were: (1) outcome of the shared decision-making process and (2) rate of seizure recurrence.

Results

Eighty-three patients fulfilled all eligibility criteria. However, in 12/83 (14%) patients, the neuro-oncologist had serious objections to AED withdrawal. Therefore, 71/83 (86%) patients were analyzed; In 46/71 (65%) patients it was decided to withdraw AED treatment. In the withdrawal group, 26% (12/46) had seizure recurrence during follow-up. Seven of these 12 patients (58%) had tumor progression, of which three within 3 months after seizure recurrence. In the AED continuation group, 8% (2/25) of patients had seizure recurrence of which one had tumor progression.

Conclusion

In 65% of patients a shared decision was made to withdraw AEDs, of which 26% had seizure recurrence. AED withdrawal should only be considered in carefully selected patients with a presumed low risk of tumor progression.

Diagnostic Accuracy of Neuroimaging to Delineate Diffuse Gliomas within the Brain: A Meta-Analysis

BACKGROUND

Brain imaging in diffuse glioma is used for diagnosis, treatment planning, and follow-up.

PURPOSE

In this meta-analysis, we address the diagnostic accuracy of imaging to delineate diffuse glioma.

DATA SOURCES

We systematically searched studies of adults with diffuse gliomas and correlation of imaging with histopathology.

STUDY SELECTION

Study inclusion was based on quality criteria. Individual patient data were used, if available.

DATA ANALYSIS

A hierarchic summary receiver operating characteristic method was applied. Low- and high-grade gliomas were analyzed in subgroups.

DATA SYNTHESIS

Sixty-one studies described 3532 samples in 1309 patients. The mean Standard for Reporting of Diagnostic Accuracy score (13/25) indicated suboptimal reporting quality. For diffuse gliomas as a whole, the diagnostic accuracy was best with T2-weighted imaging, measured as area under the curve, false-positive rate, true-positive rate, and diagnostic odds ratio of 95.6%, 3.3%, 82%, and 152. For low-grade gliomas, the diagnostic accuracy of T2-weighted imaging as a reference was 89.0%, 0.4%, 44.7%, and 205; and for high-grade gliomas, with T1-weighted gadolinium-enhanced MR imaging as a reference, it was 80.7%, 16.8%, 73.3%, and 14.8. In high-grade gliomas, MR spectroscopy (85.7%, 35.0%, 85.7%, and 12.4) and ¹¹C methionine-PET (85.1%, 38.7%, 93.7%, and 26.6) performed better than the reference imaging.

LIMITATIONS

True-negative samples were underrepresented in these data, so false-positive rates are probably less reliable than true-positive rates. Multimodality imaging data were unavailable.

CONCLUSIONS

The diagnostic accuracy of commonly used imaging is better for delineation of low-grade gliomas than high-grade gliomas on the basis of limited evidence. Improvement is indicated from advanced techniques, such as MR spectroscopy and PET.

Development of a questionnaire measuring instrumental activities of daily living (IADL) in patients with brain tumors: a pilot study

Both dementia and brain tumor patients exhibit cognitive decline during the course of their disease. They might therefore experience similar problems with cognitively complex daily activities (i.e., instrumental activities of daily living (IADL)). The study's objective is to evaluate if the Amsterdam IADL Questionnaire^© (A-IADL-Q), a 70-item IADL questionnaire developed for and validated in early dementia patients, is also applicable to glioma patients. The evaluation consisted of three steps. Predetermined decision rules defined which activities were retained, altered, added or excluded. In the first step, 6 neuro-oncology health care professionals (HCP) and 10 glioma patient-proxy dyads were asked to evaluate the 70 A-IADL-Q activities. In the second step, in-depth interviews were conducted with 6 HCPs and 6 other patient-proxy dyads to generate relevant activities specific to glioma patients not covered by the A-IADL-Q. In the third step, 6 new patient-proxy dyads were cognitively debriefed with the list of activities constructed in the previous steps. Results indicated that in step 1, after alterations and exclusions, 28/70 activities could be retained. Nine newly generated activities were subsequently added in step 2. In step 3, the 37 activities were presented to the patient-proxy dyads. Based on their input, several additional alterations and exclusions were made resulting in a list of 32 activities. In conclusion, this evaluation of the A-IADL-Q showed that dementia-specific IADL activities are only partly applicable to glioma patients, and that the addition of glioma specific IADL activities is necessary to capture the IADL construct. This underlines the need for a disease-specific IADL questionnaire for brain tumor patients.

Prognostic value of the S100B protein in newly diagnosed and recurrent glioma patients: a serial analysis

The S100B protein is associated with brain damage and a breached blood–brain barrier. A previous pilot study showed that high serum levels of S100B are associated with shorter survival in glioma patients. The aim of our study was to assess the prognostic value in terms of survival and longitudinal dynamics of serum S100B for patients with newly diagnosed and recurrent glioma. We obtained blood samples from patients with newly diagnosed and recurrent glioma before the start (baseline) and at fixed time-points during temozolomide chemotherapy. S100B-data were dichotomized according to the upper limit of the reference value of 0.1 μg/L. Overall survival (OS) was estimated with Kaplan–Meier curves and groups were compared with the log rank analysis. To correct for potential confounders a Cox regression analysis was used. We included 86 patients with newly-diagnosed and 27 patients with recurrent glioma. Most patients in both groups had baseline serum levels within normal limits. In the newly diagnosed patients we found no significant difference in OS between the group of patients with S100B levels >0.1 μg/L at baseline compared to those with <0.1 μg/L. In the patients with recurrent glioma we found a significantly shorter OS for patients with raised levels. In both groups, S100B values did not change significantly throughout the course of the disease. Serum S100B levels do not seem to have prognostic value in newly diagnosed glioma patients. In recurrent glioma patients S100B might be of value in terms of prognostication of survival.

Preoperative evaluation using magnetoencephalography: Experience in 382 epilepsy patients

OBJECTIVE

Identifying epilepsy patients for whom clinical MEG is likely to be beneficial avoids or optimizes burdensome ancillary investigations. We determined whether it could be predicted upfront if MEG would be able to generate a hypothesis about the location of the epileptogenic zone (EZ), and in which patients MEG fails to do so.

METHODS

MEG recordings of 382 epilepsy patients with inconclusive findings regarding EZ localization prior to MEG were acquired for preoperative evaluation. MEG reports were categorized for several demographic, clinical and MEG variables. First, demographic and clinical variables were associated with MEG localization ability for upfront prediction. Second, all variables were compared between patients with and without MEG location in order to characterize patients without MEG location.

RESULTS

Our patient group had often complex etiology and did not contain the (by other means) straightforward and well-localized cases, such as those with concordant tumor and EEG location. For our highly-selected patient group, MEG localization ability cannot be predicted upfront, although the odds of a recording with MEG location were significantly higher in the absence of a tumor and in the presence of widespread MRI abnormalities. Compared to the patients with MEG location, patients without MEG location more often had a tumor, widespread EEG abnormalities, non-lateralizing MEG abnormalities, non-concordant MEG/EEG abnormalities and less often widespread MRI abnormalities or epileptiform MEG activity. In a subgroup of 48 patients with known surgery outcome, more patients with concordant MEG and resection area were seizure-free than patients with discordant results.

CONCLUSIONS

MEG potentially adds information about the location of the EZ even in patients with a complex etiology, and the clinical advice is to not withhold MEG in epilepsy surgery candidates. Providing a hypothesis about the location of the EZ using MEG is difficult in patients with inconclusive EEG and MRI findings, and in the absence of specific epileptiform activity. More refined methods are needed for patients where MEG currently does not contribute to the hypothesis about the location of the EZ.

[Do not allow the patient immediate access to test results]

Over the last few years a considerable number of Dutch hospitals has introduced electronic patient charts. Many of these systems include an option for patients to have access to their own files, including 'real time' results of blood tests and scans. Although systems such as 'My Chart' should be supported in general, a problem might arise when patients have access to test results before these have been interpreted by the treating physician. Particularly for (cancer) patients being treated by a multidisciplinary team rather than a single physician, interpretation of test results and deciding on (non-) treatment is often organised through one or two (tumour) board meetings a week. Test results are often reinterpreted during such meetings and as it is generally acknowledged that multidisciplinary teams can improve the quality of clinical decision-making, systems such as My Chart should provide medical professionals the opportunity to discuss and reinterpret test results before patients themselves have access to them.

Central neurotoxicity of standard treatment in patients with newly-diagnosed high-grade glioma: a prospective longitudinal study

Following tumor resection, the majority of high-grade glioma (HGG) patients are treated with a combined modality regimen of radiotherapy and temozolomide. As a result of the tumor itself or as treatment-related neurotoxic side-effects, these patients may experience cognitive deficits. Additionally, radiological abnormalities expressed as white matter hyperintensities (WMH) and cerebral atrophy (CA) can develop. In this study, these functional and morphological parameters are evaluated, and their relation is investigated. After surgery, HGG patients underwent chemo-irradiation for six weeks, followed by six cycles of temozolomide. Assessments were performed before chemo-irradiation, post-concomitantly, after the third and sixth adjuvant cycle, and 3 and 7 months after treatment. Degree of WMH and CA was scored on MRI. Patients' neuropsychological performance was compared to healthy matched controls, yielding six cognitive domain z-scores. Development or progression of pre-existing WMH and CA during follow-up was observed in 36 and 45 % of the patients (n = 39) respectively. Cognitive functioning remained stable or improved in 70 % of the patients and deteriorated in 30 % of the patients (n = 33). Of the cognitive decliners, 80 % had tumor progression within 4 months thereafter. No clear association between cognitive functioning and WMH or CA was found. Central neurotoxic effects of combined modality treatment in HGG patients expressed by radiological abnormalities are encountered in approximately 40 % of patients. However, functional impact as indexed by cognitive functioning was found to be limited. Furthermore, development or progression of pre-existing WMH and CA does not consistently result in functional impairment as measured by cognitive tests.

Local polymorphic delta activity in cortical lesions causes global decreases in functional connectivity

Increasing evidence from neuroimaging and modeling studies suggests that local lesions can give rise to global network changes in the human brain. These changes are often attributed to the disconnection of the lesioned areas. However, damaged brain areas may still be active, although the activity is altered. Here, we hypothesize that empirically observed global decreases in functional connectivity in patients with brain lesions can be explained by specific alterations of local neural activity that are the result of damaged tissue. We simulated local polymorphic delta activity (PDA), which typically characterizes EEG/MEG recordings of patients with cerebral lesions, in a realistic model of human brain activity. 78 neural masses were coupled according to the human structural brain network. Lesions were created by altering the parameters of individual neural masses in order to create PDA (i.e. simulating acute focal brain damage); combining this PDA with weakening of structural connections (i.e. simulating brain tumors), and fully deleting structural connections (i.e. simulating a full resection). Not only structural disconnection but also PDA in itself caused a global decrease in functional connectivity, similar to the observed alterations in MEG recordings of patients with PDA due to brain lesions. Interestingly, connectivity between regions that were not lesioned directly also changed. The impact of PDA depended on the network characteristics of the lesioned region in the structural connectome. This study shows for the first time that locally disturbed neural activity, i.e. PDA, may explain altered functional connectivity between remote areas, even when structural connections are unaffected. We suggest that focal brain lesions and the corresponding altered neural activity should be considered in the framework of the full functionally interacting brain network, implying that the impact of lesions reaches far beyond focal damage.

Neurocognitive functioning and health-related quality of life in patients with radiologically suspected meningiomas

Few data are available concerning the neurocognitive outcome and health-related quality of life (HRQOL) following neurosurgery in meningioma patients, and even less is known about neurocognitive functioning and HRQOL in untreated patients with stable lesions. The present study aims at quantifying the nature and extent of neurocognitive deficits and HRQOL in suspected WHO grade I meningioma patients who have not received surgery and/or radiotherapy and compare outcome to that of healthy controls. Neurocognitive functioning was assessed by using a standardized test battery in 21 radiologically suspected WHO grade I meningioma patients with a wait-and-scan approach. HRQOL was assessed with the MOS SF-36 questionnaire. These patients were matched for age, sex, and education with 21 healthy controls. Associations between neurocognitive functioning on the one hand and HRQOL and tumor characteristics on the other were determined. Compared to healthy controls, meningioma patients had lower psychomotor speed (p = 0.011) and working memory capacity (p = 0.034) and furthermore attained lower levels of self-perceived general health and vitality. Neurocognitive functioning in untreated patients was not related to tumor volume, edema or tumor lateralization. No correlations were found between psychomotor speed or working memory and HRQOL. Untreated meningioma patients with stable lesions have limitations in neurocognitive functioning and HRQOL. In deciding upon a treatment strategy these reductions in functioning should be taken into consideration and communicated with the patient.

Connectivity in MEG resting-state networks increases after resective surgery for low-grade glioma and correlates with improved cognitive performance

Purpose

Low-grade glioma (LGG) patients often have cognitive deficits. Several disease- and treatment related factors affect cognitive processing. Cognitive outcome of resective surgery is unpredictable, both for improvement and deterioration, especially for complex domains such as attention and executive functioning. MEG analysis of resting-state networks (RSNs) is a good candidate for presurgical prediction of cognitive outcome. In this study, we explore the relation between alterations in connectivity of RSNs and changes in cognitive processing after resective surgery, as a stepping stone to ultimately predict postsurgical cognitive outcome.

Methods

Ten patients with LGG were included, who had no adjuvant therapy. MEG recording and neuropsychological assessment were obtained before and after resective surgery. MEG data were recorded during a no-task eyes-closed condition, and projected to the anatomical space of the AAL atlas. Alterations in functional connectivity, as characterized by the phase lag index (PLI), within the default mode network (DMN), executive control network (ECN), and left- and right-sided frontoparietal networks (FPN) were compared to cognitive changes.

Results

Lower alpha band DMN connectivity was increased after surgery, and this increase was related to improved verbal memory functioning. Similarly, right FPN connectivity was increased after resection in the upper alpha band, which correlated with improved attention, working memory and executive functioning.

Discussion

Increased alpha band RSN functional connectivity in MEG recordings correlates with improved cognitive outcome after resective surgery. The mechanisms resulting in functional connectivity alterations after resection remain to be elucidated. Importantly, our findings indicate that connectivity of MEG RSNs may be used for presurgical prediction of cognitive outcome in future studies.

Cognition is related to resting-state small-world network topology: an magnetoencephalographic study

Brain networks and cognition have recently begun to attract attention: studies suggest that more efficiently wired resting-state brain networks are indeed correlated with better cognitive performance. "Small-world" brain networks combine local segregation with global integration, hereby subserving information processing. Furthermore, recent studies implicate that gender effects may be present in both network dynamics and its correlations with cognition. This study reports on the relation between resting-state functional brain topology with overall and domain-specific cognitive performance in healthy participants and possible gender differences herein. Healthy participants underwent neuropsychological tests, of which individual scores were converted to z-scores. Network analysis was performed on resting-state, eyes-closed magnetoencephalography (MEG) data, after determining functional connectivity between each pair of sensors. The clustering coefficient (local specialization), average path length (overall integration and efficiency) and "small-world index" (i.e. ratio between clustering and path length) were calculated in six frequency bands. 14 male and 14 female participants were included. Better total cognitive performance was related to increased local connectivity in the theta band, higher clustering coefficient (in delta and theta bands) and higher small-worldness (in theta and lower gamma bands). Women showed less clustering and shorter path length in the delta band. There were no significant correlations between network topology and cognitive functioning in females. In contrast, higher cognitive scores in men were associated with increased theta band clustering and small-worldness. These results provide further evidence for the value of functional brain network topology for cognitive functioning and suggest that gender is an important factor in this respect.