Is intracranial volume a risk factor for IDH-mutant low-grade glioma? A case-control study.

PURPOSE: Risk of cancer has been associated with body or organ size in several studies. We sought to investigate the relationship between intracranial volume (ICV) (as a proxy for lifetime maximum brain size) and risk of IDH-mutant low-grade glioma. METHODS: In a multicenter case-control study based on population-based data, we included 154 patients with IDH-mutant WHO grade 2 glioma and 995 healthy controls. ICV in both groups was calculated from 3D MRI brain scans using an automated reverse brain mask method, and then compared using a binomial logistic regression model. RESULTS: We found a non-linear association between ICV and risk of glioma with increasing risk above and below a threshold of 1394 ml (p < 0.001). After adjusting for ICV, sex was not a risk factor for glioma. CONCLUSION: Intracranial volume may be a risk factor for IDH-mutant low-grade glioma, but the relationship seems to be non-linear with increased risk both above and below a threshold in intracranial volume.

Survival of glioblastoma in relation to tumor location: a statistical tumor atlas of a population-based cohort.

PURPOSE: Previous studies on the effect of tumor location on overall survival in glioblastoma have found conflicting results. Based on statistical maps, we sought to explore the effect of tumor location on overall survival in a population-based cohort of patients with glioblastoma and IDH wild-type astrocytoma WHO grade II-III with radiological necrosis. METHODS: Patients were divided into three groups based on overall survival: < 6 months, 6-24 months, and > 24 months. Statistical maps exploring differences in tumor location between these three groups were calculated from pre-treatment magnetic resonance imaging scans. Based on the results, multivariable Cox regression analyses were performed to explore the possible independent effect of centrally located tumors compared to known prognostic factors by use of distance from center of the third ventricle to contrast-enhancing tumor border in centimeters as a continuous variable. RESULTS: A total of 215 patients were included in the statistical maps. Central tumor location (corpus callosum, basal ganglia) was associated with overall survival < 6 months. There was also a reduced overall survival in patients with tumors in the left temporal lobe pole. Tumors in the dorsomedial right temporal lobe and the white matter region involving the left anterior paracentral gyrus/dorsal supplementary motor area/medial precentral gyrus were associated with overall survival > 24 months. Increased distance from center of the third ventricle to contrast-enhancing tumor border was a positive prognostic factor for survival in elderly patients, but less so in younger patients. CONCLUSIONS: Central tumor location was associated with worse prognosis. Distance from center of the third ventricle to contrast-enhancing tumor border may be a pragmatic prognostic factor in elderly patients.

Moderate and severe traumatic brain injury in general hospitals: a ten-year population-based retrospective cohort study in central Norway.

BACKGROUND: Patients with moderate and severe traumatic brain injury (TBI) are admitted to general hospitals (GHs) without neurosurgical services, but few studies have addressed the management of these patients. This study aimed to describe these patients, the rate of and reasons for managing patients entirely at the GH, and differences between patients managed entirely at the GH (GH group) and patients transferred to the regional trauma centre (RTC group). We specifically examined the characteristics of elderly patients. METHODS: Patients with moderate (Glasgow Coma Scale score 9-13) and severe (score ≤ 8) TBIs who were admitted to one of the seven GHs without neurosurgical services in central Norway between 01.10.2004 and 01.10.2014 were retrospectively identified. Demographic, injury-related and outcome data were collected from medical records. Head CT scans were reviewed. RESULTS: Among 274 patients admitted to GHs, 137 (50%) were in the GH group. The transferral rate was 58% for severe TBI and 40% for moderate TBI. Compared to the RTC group, patients in the GH group were older (median age: 78 years vs. 54 years, p < 0.001), more often had a preinjury disability (50% vs. 39%, p = 0.037), and more often had moderate TBI (52% vs. 35%, p = 0.005). The six-month case fatality rate was low (8%) in the GH group when transferral was considered unnecessary due to a low risk of further deterioration and high (90%, median age: 87 years) when neurosurgical intervention was considered nonbeneficial. Only 16% of patients ≥ 80 years old were transferred to the RTC. For this age group, the in-hospital case fatality rate was 67% in the GH group and 36% in the RTC group and 84% and 73%, respectively, at 6 months. CONCLUSIONS: Half of the patients were managed entirely at a GH, and these were mainly patients considered to have a low risk of further deterioration, patients with moderate TBI, and elderly patients. Less than two of ten patients ≥ 80 years old were transferred, and survival was poor regardless of the transferral status.

Glioblastoma Surgery Imaging-Reporting and Data System: Validation and Performance of the Automated Segmentation Task.

For patients with presumed glioblastoma, essential tumor characteristics are determined from preoperative MR images to optimize the treatment strategy. This procedure is time-consuming and subjective, if performed by crude eyeballing or manually. The standardized GSI-RADS aims to provide neurosurgeons with automatic tumor segmentations to extract tumor features rapidly and objectively. In this study, we improved automatic tumor segmentation and compared the agreement with manual raters, describe the technical details of the different components of GSI-RADS, and determined their speed. Two recent neural network architectures were considered for the segmentation task: nnU-Net and AGU-Net. Two preprocessing schemes were introduced to investigate the tradeoff between performance and processing speed. A summarized description of the tumor feature extraction and standardized reporting process is included. The trained architectures for automatic segmentation and the code for computing the standardized report are distributed as open-source and as open-access software. Validation studies were performed on a dataset of 1594 gadolinium-enhanced T1-weighted MRI volumes from 13 hospitals and 293 T1-weighted MRI volumes from the BraTS challenge. The glioblastoma tumor core segmentation reached a Dice score slightly below 90%, a patientwise F1-score close to 99%, and a 95th percentile Hausdorff distance slightly below 4.0 mm on average with either architecture and the heavy preprocessing scheme. A patient MRI volume can be segmented in less than one minute, and a standardized report can be generated in up to five minutes. The proposed GSI-RADS software showed robust performance on a large collection of MRI volumes from various hospitals and generated results within a reasonable runtime.

Brain atlas for assessing the impact of tumor location on perioperative quality of life in patients with high-grade glioma: A prospective population-based cohort study.

BACKGROUND: Tumor location is important for surgical decision making. Particular attention is paid to regions that contain sensorimotor and language functions, but it is unknown if these are the most important regions from the patients' perspective. OBJECTIVE: To develop an atlas for depicting and assessing the potential importance of tumor location for perioperative health-related quality of life (HRQoL) in patients with newly diagnosed high-grade glioma. METHODS: Patient-reported HRQoL data and semi-automatically segmented preoperative 3D MRI-images were combined in 170 patients. The images were registered to a standardized space where the individual tumors were given the values and color intensity of the corresponding HRQoL. Descriptive brain maps of HRQoL, defined quantitative analyses, and voxel-based lesion symptom mapping comparing patients with tumors in different locations were made. RESULTS: There was no statistical difference in overall perioperative HRQoL between patients with tumors located in left or right hemisphere, between patients with tumors in different lobes, or between patients with tumors located in non-eloquent, near eloquent, or eloquent areas. Patients with tumors involving the internal capsule, and patients with preoperative motor symptoms and postoperative motor deficits, reported significantly worse overall HRQoL-scores. CONCLUSIONS: The impact of anatomical tumor location on overall perioperative HRQoL seems less than frequently believed, and the distinction between critical and less critical brain regions seems more unclear according to the patients than perhaps when judged by physicians. However, worse HRQoL was found in patients with tumors in motor-related regions, indicating that these areas are crucial also from the patients' perspective.

Does risk of brain cancer increase with intracranial volume? A population-based case control study.

Background: Glioma is the most common primary brain tumor and is believed to arise from glial stem cells. Despite large efforts, there are limited established risk factors. It has been suggested that tissue with more stem cell divisions may exhibit higher risk of cancer due to chance alone. Assuming a positive correlation between the number of stem cell divisions in an organ and size of the same organ, we hypothesized that variation in intracranial volume, as a proxy for brain size, may be linked to risk of high-grade glioma. Methods: Intracranial volume was calculated from pretreatment 3D T1-weighted MRI brain scans from 124 patients with high-grade glioma and 995 general population-based controls. Binomial logistic regression analyses were performed to ascertain the effect of intracranial volume and sex on the likelihood that participants had high-grade glioma. Results: An increase in intracranial volume of 100 mL was associated with an odds ratio of high-grade glioma of 1.69 (95% CI: 1.44‒1.98; P < 0.001). After adjusting for intracranial volume, female sex emerged as a risk factor for high-grade glioma (odds ratio for male sex = 0.56, 95% CI: 0.33‒0.93; P = 0.026). Conclusions: Intracranial volume is strongly associated with risk of high-grade glioma. After correcting for intracranial volume, risk of high-grade glioma was higher in women. The development of glioma is correlated to brain size and may to a large extent be a stochastic event related to the number of cells at risk.

Glioblastoma Segmentation: Comparison of Three Different Software Packages.

To facilitate a more widespread use of volumetric tumor segmentation in clinical studies, there is an urgent need for reliable, user-friendly segmentation software. The aim of this study was therefore to compare three different software packages for semi-automatic brain tumor segmentation of glioblastoma; namely BrainVoyagerTM QX, ITK-Snap and 3D Slicer, and to make data available for future reference. Pre-operative, contrast enhanced T1-weighted 1.5 or 3 Tesla Magnetic Resonance Imaging (MRI) scans were obtained in 20 consecutive patients who underwent surgery for glioblastoma. MRI scans were segmented twice in each software package by two investigators. Intra-rater, inter-rater and between-software agreement was compared by using differences of means with 95% limits of agreement (LoA), Dice's similarity coefficients (DSC) and Hausdorff distance (HD). Time expenditure of segmentations was measured using a stopwatch. Eighteen tumors were included in the analyses. Inter-rater agreement was highest for BrainVoyager with difference of means of 0.19 mL and 95% LoA from -2.42 mL to 2.81 mL. Between-software agreement and 95% LoA were very similar for the different software packages. Intra-rater, inter-rater and between-software DSC were ≥ 0.93 in all analyses. Time expenditure was approximately 41 min per segmentation in BrainVoyager, and 18 min per segmentation in both 3D Slicer and ITK-Snap. Our main findings were that there is a high agreement within and between the software packages in terms of small intra-rater, inter-rater and between-software differences of means and high Dice's similarity coefficients. Time expenditure was highest for BrainVoyager, but all software packages were relatively time-consuming, which may limit usability in an everyday clinical setting.

Computer-based assessment of symptoms and mobility in palliative care: feasibility and challenges.

The aims of the study were to explore the ability of cancer patients who are primarily receiving palliative care to use a touchscreen computer for assessment of symptoms and mobility and to investigate which factors predicted the need for assistance during the assessment. Before the main data collection, a pilot study was conducted to explore the preferences of these patients toward using such a computerized assessment tool. Patients were recruited from nine different inpatient and outpatient palliative care and general cancer clinics in Norway. The patients responded to 60 items on symptoms and mobility directly on the computer. In the pilot study (n=20), 11 patients (55.0%) preferred computerized assessment over paper and pencil, whereas five (25.0%) had no preference. In the main data collection, 370 patients (52.7% men with mean age 62 years and mean Karnofsky Performance Status score of 70) completed the assessment. Eighty-six patients (23.2%) required assistance. Patients requiring assistance were significantly older, had worse performance status, and poorer cognitive function than those not requiring assistance. Predictors for requiring assistance were age (P<0.001) and performance status (P<0.001). Because higher age and worse performance status resulted in more need of assistance, assessment tools should be short and user-friendly to ensure good compliance in frail patients.