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Fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) scans are important for diagnosis, treatment planning, and monitoring of various brain tumors. Depending on the tumor type, the FLAIR hyperintensity volume is an important measure to assess the tumor volume, surrounding vasogenic edema, or treatment induced changes, such as gliosis. Automatic segmentation would therefore be valuable in the clinic and in clinical trials. In this study, around 5000 FLAIR images of various brain tumors types and acquisition time points, from different neurosurgical centers, were used to train a unified FLAIR hyperintensity segmentation model using an Attention U-Net architecture. The performance was compared against dataset-specific models and was validated on different tumor types, acquisition time points, and against BraTS. The unified model achieved an average Dice score of 88.65% for pre-operative meningiomas, 80.08% for pre-operative metastases, 90.92% for pre-operative and 84.60% for post-operative gliomas from BraTS, and 84.47% for pre-operative and 61.27% for post-operative lower grade gliomas. In addition, the results showed that the unified model achieved comparable segmentation performance to the dataset-specific models on their respective datasets. The documented generalization across tumor types and acquisition time points is a strong indicator for efficient deployment in a clinical setting. The model has been integrated into Raidionics, an open-source software for CNS tumor analysis.

ntroduction: Maximal safe resection is established goal of WHO grade 2 low-grade gliomas (LGG). Asleep motor mapping offers an alternative to awake surgery for tumors near motor areas and has been shown to be safe and effective in expert centers.

Research question: We aimed to identify predictors of postoperative motor deficits, and describe patient selection and intraoperative mapping techniques across Scandinavian centers.

Material and methods: We retrospectively analyzed patients (≥18) with WHO grade 2 gliomas who underwent asleep motor mapping across multiple Scandinavian neurosurgical centers. Clinical, surgical, and imaging data were extracted from medical records. The primary outcome was registered permanent postoperative motor deficits at 3 months. Associations with pre-, intraoperative, and radiological variables - including diffusion-weighted imaging (DWI) changes - were assessed using univariate and multivariate logistic regression.

Results: We included 74 patients from eight institutions. Median age was 48 years, 38 (51.4 %) were female and median preoperative tumor volume was 43.2 ml. 13 (17.6 %) patients achieved gross-total resection and median postoperative volume was 7.8 ml. Permanent postoperative motor deficits occurred in 19 cases (25.7 %), and 5 (6.8 %) were considered major deficits. In univariate analysis, preoperative motor deficits (p = 0.009), postoperative DWI changes (p = 0.022), and age (p = 0.043) were significantly associated with new or worsened permanent deficits. Only DWI changes and age was confirmed in penalized multivariate logistic regression.

Discussion and conclusion: Postoperative motor deficits were common despite use of asleep motor mapping. Preoperative motor deficits and diffusion-weighted imaging changes are predictors of permanent motor deficits in this setting.

OBJECTIVE: Iatrogenic ischemic injury is believed to be one of the major causes of postoperative neurological deterioration after resection for diffuse low-grade glioma (dLGG). Epidemiological data on ischemic injury following glioma surgery are limited. The aim of this study was to explore the incidence of postoperative ischemia in a population-based cohort and investigate any correlation with postoperative neurological deterioration.

METHODS: In this retrospective study, ischemic lesions following dLGG resections, performed at 9 hospitals in Sweden and Norway between 2012 and 2017, were identified on diffusion-weighted MRI and volumetrically segmented. The association between the incidence, size, or type of ischemic lesion (rim lesions, limited to the resection border, or sector lesions, extending further into the brain tissue) and postoperative neurological deficits was analyzed.

RESULTS: A total of 286 patients were eligible for study inclusion. A postoperative ischemic lesion was found in 245 (85.7%) cases. In 87 (30.4%) patients, lesions were classified as the rim type; 158 (55.2%) patients had the sector type. Larger ischemic lesions were observed among patients with permanent major deficits (4.2 vs 1.6 cm3, p = 0.022). Sector-shaped ischemic lesions were more often associated with transient neurological deterioration than the rim lesions. The use of advanced imaging, intraoperative monitoring, or other specific neurosurgical techniques and tools did not affect the incidence of ischemic lesions.

CONCLUSIONS: The authors found postoperative ischemic lesions to be common after the resection of dLGG. Large and sector-shaped, but not rim-shaped, lesions were associated with measured postoperative neurological deficits. Preventing or limiting the extent of these ischemic injuries is important for improving functional results in dLGG surgery.

Background: subperception (paresthesia-free) dorsal root ganglion (DRG) stimulation is increasingly used for focal neuropathic pain, but sham-controlled evidence remains limited. We conducted a randomized, double-blind, sham-controlled crossover trial with enriched enrollment design in established DRG-stimulation responders.

Methods: In this single-center trial, adults with chronic peripheral neuropathic or nociplastic pain with implanted DRG system and sustained response (≥50% pain reduction for ≥3 months on stable stimulation settings and medication) were randomized 1:1 to active→sham or sham→active stimulation. Participants completed two 5-day treatment periods separated by a 24-hour washout with stimulation off. Active stimulation was delivered at 90% of the perception threshold, and sham was stimulation off. The primary outcome was median pain intensity on a 0–10 Numeric Rating Scale (NRS). Secondary outcomes included patient satisfaction and Patient Global Impression of Change (PGIC) domains. Analyses used Wilcoxon signed-rank tests with Hodges-Lehmann estimates.

Results: In 20 randomized patients, pain intensity was lower during active than sham stimulation (median NRS 3.0 (IQR 2.0–4.0) vs 6.0 (IQR 4.0–7.0); Hodges-Lehmann median difference, −2.5; 95% CI −3.0 to −2.0; p<0.001). Patient satisfaction and all PGIC domains favored active stimulation. Two participants terminated one treatment period early per prespecified criteria; available data were retained. No serious or device-related adverse events were reported.

INTRODUCTION: Pain, comprising sensory and emotional elements, is influenced by pain catastrophizing, which magnifies pain and promotes helplessness and rumination. This study explores the relationship between pain catastrophizing and outcomes following selective nerve root blockade (SNRB) in patients with lumbar radicular pain (LRP).

METHODS: A prospective cohort study of 103 LRP patients, confirmed by MRI, was conducted. All participants underwent SNRB at Umeå University Hospital. Outcomes were measured using PROMIS-29 and the Pain Catastrophizing Scale (PCS) at baseline and several intervals up to 84 days post-intervention. Patients were categorized into responder (≥30% pain reduction) and non-responder groups and stratified into three groups based on baseline PCS scores. Changes in outcomes from baseline to 14 days post-SNRB were analyzed in relation to PCS groups. PCS changes over time were evaluated between responders and non-responders. Statistical analyses assessed PCS and outcome changes.

RESULTS: Baseline pain catastrophizing was not a significant predictor of pain response to SNRB. However, responders demonstrated significant reductions in pain catastrophizing following the intervention, suggesting that SNRB may influence cognitive coping mechanisms related to pain.

CONCLUSION: SNRB reduces pain catastrophizing in LRP patients, although baseline catastrophizing does not predict pain outcomes. Addressing catastrophizing remains important but may serve better as an outcome measure rather than a predictor of treatment response.

Serotonin and serotonin metabolism has for decades been understood as playing a critical role in mood disorders and has more recently also been implicated in brain tumour biology. However, in part due to the lack of direct investigation of genetic and epigenetic variation affecting serotonin pathways within human brain tissue this understanding has recently been challenged. We analysed genetic and epigenetic variation in the Monoamine oxidase A (MAOA) and serotonin transporter (5HTT) genes using 232 biobanked glioma tissue samples from 216 adult patients. We further examined the association between use of antidepressants (targeting serotonergic pathways), serotonin levels and methylation. In male patients, genetic variation in the MAOA gene was significantly associated with tissue serotonin levels. Further analysis identified five single nucleotide variants (SNVs) that may contribute to this association. In contrast, 5HTT variants were not statistically associated with serotonin pathway metabolites, nor were MAOA variants in females. Increased methylation at several 5HTT CpG sites was positively correlated with serotonin levels and negatively correlated with 5-HIAA levels. In males, one CpG site in the MAOA gene was negatively associated with the 5-HIAA/serotonin ratio, suggesting reduced enzymatic degradation of serotonin due to lower MAOA activity. Patients using antidepressants had lower tissue serotonin levels. In males, genetic variation in the MAOA gene was significantly associated with tissue serotonin levels, although this association was not mediated by methylation. Our result supports the notion that the MAOA and 5HTT genes are related to serotonin metabolism and that such metabolism is related to antidepressant use.

Background: Glioblastoma is the most aggressive and malignant brain tumor, characterized by a high degree of heterogeneity, invasiveness, and resistance to treatment. Patients with glioblastoma have a very poor prognosis despite multimodal interventions. In this study, we investigated how 18F-fluorothymidine (18F-FLT) PET combined with contrast-enhanced MRI and blood metabolomics can contribute to evaluate prognosis and treatment response for patients with glioblastoma.

Methods: Patients, scheduled for surgery due to suspected high-grade glioma were included in this clinical study and underwent four 18F-FLT-PET/MRI examinations prior to surgery and during standard treatment. Blood samples were collected and analyzed by metabolomics. Patients were grouped according to survival as long-time survivors (>3 years) and short-time survivors (<500 days).

Results: Both 2 and 6 weeks into treatment, short-time survivors displayed a significantly larger tumor volume than long-time survivors. When comparing MRI findings during treatment, long-time survivors displayed a substantial tumor decrease, whereas the short-time survivors showed minor or no effect. Regarding 18F-FLT-PET the results were not as unambiguous. Furthermore, there was a clear and significant separation in the metabolomic pattern in blood between the survival groups and across treatment time points.

Conclusions: MRI measures of tumor volume and growth during treatment appear to be prognostic clinical factors that affect outcome. Metabolomic patterns in blood differ significantly between the defined survival groups and may serve as support for an early forecast of prognosis. We also observe a clear separation in metabolite levels between different time points during treatment, which likely reflects treatment effects.

Background: This study aimed to explore the potential association between tumor shape, 1p/19q codeletion, EOR, and new postoperative focal deficits in patients with diffuse low-grade glioma.

Methods: We analyzed data from 225 WHO grade 2 glioma surgeries performed in nine centers in Norway and Sweden. The tumor measurements were based on automatic segmentations of preoperative T2/FLAIR MRI scans by Raidionics. Contact surface area (CSA) was defined as the area between the tumor and brain parenchyma and was estimated by subtracting the surface area covered by the dura from the total surface area. The sphericity index (SI) was defined as the quotient of the tumor surface area and the surface area of a sphere with equal volume. Focal deficits were defined as any new motor, language, or visual deficits postoperatively.

Results: The univariable analyses showed that a larger CSA was associated with higher age (p=0.02), lower EOR (p<0.0001), and more focal deficits (p=0.005), but not with 1p/19q codeletion (p=0.54). A higher SI was associated with higher age (p=0.02) and lower EOR (p<0.0001), but not with focal deficits (p=0.08) or 1p/19q codeletion (p=0.90). The multivariable linear regression model supported the univariable associations between EOR and CSA (p=0.0003) and SI (p=0.0013), respectively. Contrarily, the logistic regression model showed that focal deficits were associated with SI (p=0.014), but not with CSA (p=0.056)

Conclusion: The tumor shape appears to be independently associated with EOR and new focal deficits, but not with molecular diagnosis in patients with low-grade glioma.