Immunological processes of enhancers and suppressors of long non-coding RNAs associated with brain tumors and inflammation

Immunological processes, such as inflammation, can both cause tumor suppression and cancer progression. Moreover, deregulated levels of long non-coding RNA (lncRNA) expression in the brain may cause inflammation and lead to the growth of tumors. Like other biological processes, the immune system's role in cancer is complicated, varies, and can help or hurt the cancer's maintenance. According to research, inflammation and brain cancer are correlated via several signaling pathways. A variety of lncRNAs have recently been revealed to influence cancer by modulating inflammatory pathways. As a result, lncRNAs have the potential to influence carcinogenesis, tumor formation, or tumor suppression via an increase or decrease in inflammation functions. Although the study and targeting of lncRNAs have made great progress in the treatment of cancer, there are definitely limitations and challenges. Using new technologies like nanocarriers and cell-penetrating peptides (CPPs) to target treatments without hurting healthy body tissues has shown to be very effective. In this review article, we have collected significantly related lncRNAs and their inhibitory or stimulating roles in inflammation and brain cancer for the first time. However, there are limitations, such as side effects and damage to normal tissues. With the advancement of new targeting technologies, these lncRNAs may be candidates for the specific targeting therapy of brain cancers by limiting inflammation or stimulating the immune system against them in the future.

Automated volumetry of meningiomas in contrast-enhanced T1-Weighted MRI using deep learning

BACKGROUND

Meningiomas are among the most common intracranial tumors. In these tumors, volumetric assessment is not only important for planning therapeutic intervention but also for follow-up examination.However, a highly accurate automated volumetric method for meningiomas using single-modality magnetic resonance imaging (MRI) has not yet been reported. Here, we aimed to develop a deep learning-based automated volumetry method for meningiomas in MRI and investigate its accuracy and potential clinical applications.

METHODS

For deep learning, we used MRI images of patients with meningioma who were referred to Osaka University Hospital between January 2007 and October 2020. Imaging data of eligible patients were divided into three non-overlapping groups: training, validation, and testing. The model was trained and tested using the leave-oneout cross-validation method. Dice index (DI) and root mean squared percentage error (RMSPE) were measured to evaluate the model accuracy. Result: A total of 178 patients (64.6 ± 12.3 years [standard deviation]; 147 women) were evaluated. Comparison of the deep learning model and manual segmentation revealed a mean DI of 0.923 ± 0.051 for tumor lesions. For total tumor volume, RMSPE was 9.5 ± 1.2%, and Mann-Whitney U test did not show a significant difference between manual and algorithm-based measurement of the tumor volume (p = 0.96).

CONCLUSION

The automatic tumor volumetry algorithm developed in this study provides a potential volume-based imaging biomarker for tumor evaluation in the field of neuroradiological imaging, which will contribute to the optimization and personalization of treatment for central nervous system tumors in the near future.

Case Series of Soft Tissue Sarcoma Patients with Brain Metastasis with Implications from Genomic and Transcriptomic Analysis

PURPOSE

Brain metastasis rarely occurs in soft tissue sarcoma (STS). Here, we present five cases of STS with brain metastases with genetic profiles.

MATERIALS AND METHODS

We included five patients from Seoul National University Hospital who were diagnosed with STS with metastasis to the brain. Tissue from the brain metastasis along with that from the primary site or other metastases were used for DNA and RNA sequencing to identify genetic profiles. Gene expression profiles were compared with sarcoma samples from The Cancer Genome Atlas.

RESULTS

The overall survival after diagnosis of brain metastasis ranged from 2.2 to 34.3 months. Comparison of mutational profiles between brain metastases and matched primary or other metastatic samples showed similar profiles. In two patients, copy number variation profiles between brain metastasis and other tumors showed several differences including MYCL, JUN, MYC, and DDR2 amplification. Gene ontology analysis showed that the group of genes significantly highly expressed in the brain metastasis samples was enriched in the G-protein coupled receptor activity, structural constituent of chromatin, protein heterodimerization activity, and binding of DNA, RNA, and protein. Gene set enrichment analysis showed enrichment in the pathway of neuroactive ligand-receptor interaction and systemic lupus erythematosus.

CONCLUSION

The five patients had variable ranges of clinical courses and outcomes. Genomic and transcriptomic analysis of STS with brain metastasis implicates possible involvement of complex expression modification and epigenetic changes rather than the addition of single driver gene alteration.

Mobile phone use and brain tumour risk - COSMOS, a prospective cohort study

BACKGROUND

Each new generation of mobile phone technology has triggered discussions about potential carcinogenicity from exposure to radiofrequency electromagnetic fields (RF-EMF). Available evidence has been insufficient to conclude about long-term and heavy mobile phone use, limited by differential recall and selection bias, or crude exposure assessment. The Cohort Study on Mobile Phones and Health (COSMOS) was specifically designed to overcome these shortcomings.

METHODS

We recruited participants in Denmark, Finland, the Netherlands, Sweden, and the UK 2007-2012. The baseline questionnaire assessed lifetime history of mobile phone use. Participants were followed through population-based cancer registers to identify glioma, meningioma, and acoustic neuroma cases during follow-up. Non-differential exposure misclassification was reduced by adjusting estimates of mobile phone call-time through regression calibration methods based on self-reported data and objective operator-recorded information at baseline. Hazard ratios (HR) and 95% confidence intervals (CI) for glioma, meningioma, and acoustic neuroma in relation to lifetime history of mobile phone use were estimated with Cox regression models with attained age as the underlying time-scale, adjusted for country, sex, educational level, and marital status.

RESULTS

264,574 participants accrued 1,836,479 person-years. During a median follow-up of 7.12 years, 149 glioma, 89 meningioma, and 29 incident cases of acoustic neuroma were diagnosed. The adjusted HR per 100 regression-calibrated cumulative hours of mobile phone call-time was 1.00 (95 % CI 0.98-1.02) for glioma, 1.01 (95 % CI 0.96-1.06) for meningioma, and 1.02 (95 % CI 0.99-1.06) for acoustic neuroma. For glioma, the HR for ≥ 1908 regression-calibrated cumulative hours (90th percentile cut-point) was 1.07 (95 % CI 0.62-1.86). Over 15 years of mobile phone use was not associated with an increased tumour risk; for glioma the HR was 0.97 (95 % CI 0.62-1.52).

CONCLUSIONS

Our findings suggest that the cumulative amount of mobile phone use is not associated with the risk of developing glioma, meningioma, or acoustic neuroma.

Evidence-based clinical recommendations for hypofractionated radiotherapy: exploring efficacy and safety - Part 1. Brain and head and neck

Advances in radiotherapy (RT) techniques, including intensity-modulated RT and image-guided RT, have allowed hypofractionation, increasing the fraction size over the conventional dose of 1.8-2.0 Gy. Hypofractionation offers advantages such as shorter treatment times, improved compliance, and under specific conditions, particularly in tumors with a low α/β ratio, higher efficacy. It was initially explored for use in RT for prostate cancer and adjuvant RT for breast cancer, and its application has been extended to various other malignancies. Hypofractionated RT (HFRT) may also be effective in patients who are unable to undergo conventional treatment owing to poor performance status, comorbidities, or old age. The treatment of brain tumors with HFRT is relatively common because brain stereotactic radiosurgery has been performed for over two decades. However, re-irradiation of recurrent lesions and treatment of elderly or frail patients are areas under investigation. HFRT for head and neck cancer has not been widely used because of concerns regarding late toxicity. Thus, we aimed to provide a comprehensive summary of the current evidence for HFRT for brain tumors and head and neck cancer and to offer practical recommendations to clinicians faced with the challenge of choosing new treatment options.

Imaging features to distinguish posterior fossa ependymoma subgroups

OBJECTIVES

Posterior fossa ependymoma group A (EPN_PFA) and group B (EPN_PFB) can be distinguished by their DNA methylation and give rise to different prognoses. We compared the MRI characteristics of EPN_PFA and EPN_PFB at presentation.

METHODS

Preoperative imaging of 68 patients with posterior fossa ependymoma from two centers was reviewed by three independent readers, blinded for histomolecular grouping. Location, tumor extension, tumor volume, hydrocephalus, calcifications, tissue component, enhancement or diffusion signal, and histopathological data (cellular density, calcifications, necrosis, mitoses, vascularization, and microvascular proliferation) were compared between the groups. Categorical data were compared between groups using Fisher's exact tests, and quantitative data using Mann-Whitney tests. We performed a Benjamini-Hochberg correction of the p values to account for multiple tests.

RESULTS

Fifty-six patients were categorized as EPN_PFA and 12 as EPN_PFB, with median ages of 2 and 20 years, respectively (p = 0.0008). The median EPN_PFA tumoral volume was larger (57 vs 29 cm3, p = 0.003), with more pronounced hydrocephalus (p = 0.002). EPN_PFA showed an exclusive central position within the 4th ventricle in 61% of patients vs 92% for EPN_PFB (p = 0.01). Intratumor calcifications were found in 93% of EPN_PFA vs 40% of EPN_PFB (p = 0.001). Invasion of the posterior fossa foramina was mostly found for EPN_PFA, particularly the foramina of Luschka (p = 0.0008). EPN_PFA showed whole and homogeneous tumor enhancement in 5% vs 75% of EPN_PFB (p = 0.0008). All mainly cystic tumors were EPN_PFB (p = 0.002). The minimal and maximal relative ADC was slightly lower in EPN_PFA (p = 0.02 and p = 0.01, respectively).

CONCLUSION

Morphological characteristics from imaging differ between posterior fossa ependymoma subtypes and may help to distinguish them preoperatively.

CLINICAL RELEVANCE STATEMENT

This study provides a tool to differentiate between group A and group B ependymomas, which will ultimately allow the therapeutic strategy to be adapted in the early stages of patient management.

KEY POINTS

• Posterior fossa ependymoma subtypes often have different imaging characteristics. • Posterior fossa ependymomas group A are commonly median or lateral tissular calcified masses, with incomplete enhancement, affecting young children and responsible for pronounced hydrocephalus and invasion of the posterior fossa foramina. • Posterior fossa ependymomas group B are commonly median non-calcified masses of adolescents and adults, predominantly cystic, and minimally invasive, with total and homogeneous enhancement.

Engaging carers in neuropsychological rehabilitation for brain cancer survivors: The "I'm aware: Patients And Carers Together" (ImPACT) program

BACKGROUND

Cognitive impairment is a common late effect in child and adult brain cancer survivors (BCS). Still, there is a dearth of research aimed at therapeutic interventions and no standard treatment options for most BCS.

OBJECTIVE

To describe 1) a novel neuropsychological rehabilitation program for BCS - the "I'm aware: Patients And Carers Together" (ImPACT) program, and 2) two studies that aim to assess the feasibility of the ImPACT program in child and adult BCS, respectively. The program adapts the holistic neuropsychological approach pioneered by Leonard Diller and Yehuda Ben-Yishay to an outpatient setting.

METHODS

Two feasibility studies are described: 1) A single-armed study with 15 child BCS (10-17 years) (ImPACT Child); and 2) a randomized waitlist-controlled trial with 26 adult BCS (>17 years) (ImPACT Adult). In both studies, patients will undergo an 8-week program together with a cohabiting carer. Primary outcomes (i.e., cognitive and neurobehavioral symptoms), and secondary outcomes (i.e., behavioral and psychological symptoms, e.g., quality of life, fatigue) will be assessed at four time points: pre-, mid-, and post intervention, and 8 weeks follow-up. Adult waitlist controls will be assessed at equivalent time points and will be included in the intervention group after all study assessments. Semi-structured interviews will be conducted at follow-up.

EXPECTED OUTCOMES

Results will provide feasibility data in support of future larger scale trials.

DISCUSSION

The findings could potentially improve the management of cognitive impairment in BCS and transform available services. The program can be delivered in-person or remotely and harnesses existing resources in patients' lives.

Alterations in hypothalamic-pituitary axis (HPA) hormones 6 months after cranial radiotherapy in adult patients with primary brain tumors outside the HPA region

BACKGROUND

Cranial radiotherapy is a common treatment for brain tumors, but it can affect the hypothalamic-pituitary (H-P) axis and lead to hormonal disorders. This study aimed to compare serum levels of HPA hormones before and after cranial radiation.

MATERIALS AND METHODS

This study involved 27 adult patients who underwent brain tumor resection before the initiation of radiotherapy, and none had metastatic brain tumors. All participants had the HPA within the radiation field, and their tumors were located in brain areas outside from the HPA. Serum levels of HPA hormones were recorded both before and 6 months after cranial radiotherapy.

RESULTS

A total of 27 adult patients, comprising 16 (59.3%) males and 11 (40.7%) females, with a mean age of 56.37 ± 11.38 years, were subjected to evaluation. Six months post-radiotherapy, serum levels of GH and TSH exhibited a significant decrease. Prior to radiotherapy, a substantial and direct correlation was observed between TSH and FSH (p = 0.005) as well as LH (p = 0.014). Additionally, a significant and direct relationship was noted between serum FSH and LH (p < 0.001) before radiotherapy. After radiotherapy, a significant and direct correlation persisted between TSH and FSH (p = 0.003) as well as LH (p = 0.005), along with a significant and direct relationship between serum FSH and LH (p < 0.001). Furthermore, a significant and direct association was identified between changes in serum GH levels and FSH (p = 0.04), as well as between serum LH and FSH (p < 0.001).

CONCLUSION

Reduced serum levels of HPA hormones are a significant complication of cranial radiotherapy and should be evaluated in follow-up assessments.

Differentiating IDH-mutant astrocytomas and 1p19q-codeleted oligodendrogliomas using DSC-PWI: high performance through cerebral blood volume and percentage of signal recovery percentiles

OBJECTIVE

Presurgical differentiation between astrocytomas and oligodendrogliomas remains an unresolved challenge in neuro-oncology. This research aims to provide a comprehensive understanding of each tumor's DSC-PWI signatures, evaluate the discriminative capacity of cerebral blood volume (CBV) and percentage of signal recovery (PSR) percentile values, and explore the synergy of CBV and PSR combination for pre-surgical differentiation.

METHODS

Patients diagnosed with grade 2 and 3 IDH-mutant astrocytomas and IDH-mutant 1p19q-codeleted oligodendrogliomas were retrospectively retrieved (2010-2022). 3D segmentations of each tumor were conducted, and voxel-level CBV and PSR were extracted to compute mean, minimum, maximum, and percentile values. Statistical comparisons were performed using the Mann-Whitney U test and the area under the receiver operating characteristic curve (AUC-ROC). Lastly, the five most discriminative variables were combined for classification with internal cross-validation.

RESULTS

The study enrolled 52 patients (mean age 45-year-old, 28 men): 28 astrocytomas and 24 oligodendrogliomas. Oligodendrogliomas exhibited higher CBV and lower PSR than astrocytomas across all metrics (e.g., mean CBV = 2.05 and 1.55, PSR = 0.68 and 0.81 respectively). The highest AUC-ROCs and the smallest p values originated from CBV and PSR percentiles (e.g., PSRp70 AUC-ROC = 0.84 and p value = 0.0005, CBVp75 AUC-ROC = 0.8 and p value = 0.0006). The mean, minimum, and maximum values yielded lower results. Combining the best five variables (PSRp65, CBVp70, PSRp60, CBVp75, and PSRp40) achieved a mean AUC-ROC of 0.87 for differentiation.

CONCLUSIONS

Oligodendrogliomas exhibit higher CBV and lower PSR than astrocytomas, traits that are emphasized when considering percentiles rather than mean or extreme values. The combination of CBV and PSR percentiles results in promising classification outcomes.

CLINICAL RELEVANCE STATEMENT

The combination of histogram-derived percentile values of cerebral blood volume and percentage of signal recovery from DSC-PWI enhances the presurgical differentiation between astrocytomas and oligodendrogliomas, suggesting that incorporating these metrics into clinical practice could be beneficial.

KEY POINTS

• The unsupervised selection of percentile values for cerebral blood volume and percentage of signal recovery enhances presurgical differentiation of astrocytomas and oligodendrogliomas. • Oligodendrogliomas exhibit higher cerebral blood volume and lower percentage of signal recovery than astrocytomas. • Cerebral blood volume and percentage of signal recovery combined provide a broader perspective on tumor vasculature and yield promising results for this preoperative classification.

Outcomes of Patients with Brain Metastases from Renal Cell Carcinoma Receiving First-line Therapies: Results from the International Metastatic Renal Cell Carcinoma Database Consortium

Patients with brain metastases (BrM) from renal cell carcinoma and their outcomes are not well characterized owing to frequent exclusion of this population from clinical trials. We analyzed data for patients with or without BrM using the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC). A total of 389/4799 patients (8.1%) had BrM on initiation of systemic therapy. First-line immuno-oncology (IO)-based combination therapy was associated with longer median overall survival (OS; 32.7 mo, 95% confidence interval [CI] 22.3-not reached) versus tyrosine kinase inhibitor monotherapy (20.6 mo, 95% CI 15.7-24.5; p = 0.019), as were intensive focal therapies with stereotactic radiotherapy or neurosurgery (31.4 mo, 95% CI 22.3-37.5) versus whole-brain radiotherapy alone or no focal therapy (16.5 mo, 95% CI 10.2-21.1; p = 0.028). On multivariable analysis, IO-based regimens (HR 0.49, 95% CI 0.25-0.97; p = 0.040) and stereotactic radiotherapy or neurosurgery (HR 0.48, 95% CI 0.29-0.78; p = 0.003) were independently associated with longer OS, as was IMDC favorable or intermediate risk (HR 0.40, 95% CI 0.24-0.66; p < 0.001). Intensive systemic and focal therapies were associated with better prognosis in this population. Further studies should explore the clinical effectiveness of multimodal strategies. PATIENT SUMMARY: In a large group of patients with advanced kidney cancer, we found that 8.1% had brain metastases when starting systemic therapy. Patients with brain metastases had significantly poorer prognosis than those without brain metastases. Receipt of combination immunotherapy, stereotactic radiotherapy, or neurosurgery was associated with longer overall survival.

A deep learning model integrating multisequence MRI to predict EGFR mutation subtype in brain metastases from non-small cell lung cancer

BACKGROUND

To establish a predictive model based on multisequence magnetic resonance imaging (MRI) using deep learning to identify wild-type (WT) epidermal growth factor receptor (EGFR), EGFR exon 19 deletion (19Del), and EGFR exon 21-point mutation (21L858R) simultaneously.

METHODS

A total of 399 patients with proven brain metastases of non-small cell lung cancer (NSCLC) were retrospectively enrolled and divided into training (n = 306) and testing (n = 93) cohorts separately based on two timepoints. All patients underwent 3.0-T brain MRI including T2-weighted, T2-weighted fluid-attenuated inversion recovery, diffusion-weighted imaging, and contrast-enhanced T1-weighted sequences. Radiomics features were extracted from each lesion based on four sequences. An algorithm combining radiomics approach with graph convolutional networks architecture (Radio-GCN) was designed for the prediction of EGFR mutation status and subtype. The area under the curve (AUC) at receiver operating characteristic analysis was used to evaluate the predication capabilities of each model.

RESULTS

We extracted 1,290 radiomics features from each MRI sequence. The AUCs of the Radio-GCN model for identifying EGFR 19Del, 21L858R, and WT for the lesion-wise analysis were 0.996 ± 0.004, 0.971 ± 0.013, and 1.000 ± 0.000 on the independent testing cohort separately. It also yielded AUCs of 1.000 ± 0.000, 0.991 ± 0.009, and 1.000 ± 0.000 for predicting EGFR mutations respectively for the patient-wise analysis. The κ coefficients were 0.735 and 0.812, respectively.

CONCLUSIONS

The constructed Radio-GCN model is a new potential tool to predict the EGFR mutation status and subtype in NSCLC patients with brain metastases.

RELEVANCE STATEMENT

The study demonstrated that a deep learning approach based on multisequence MRI can help to predict the EGFR mutation status in NSCLC patients with brain metastases, which is beneficial to guide a personalized treatment.

KEY POINTS

• This is the first study to predict the EGFR mutation subtype simultaneously. • The Radio-GCN model holds the potential to be used as a diagnostic tool. • This study provides an imaging surrogate for identifying the EGFR mutation subtype.

Immunoglobulin G4-related hypertrophic pachymeningitis with an isolated scalp mass mimicking a brain tumor: a case report and literature review

Immunoglobulin G4-related disease (IgG4-RD) is an autoimmune disorder associated with fibroinflammatory conditions that can affect multiple organs. Hallmark histopathological findings of IgG4-RD include lymphocytic infiltration of IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis. However, little is known about central nervous system involvement of IgG4-RD. Hypertrophic pachymeningitis (HP) has recently been reported as a manifestation of IgG4-RD, which may have previously been demonstrated in a significant percentage of idiopathic cases. Herein, we report a rare case of a 63-year-old male who presented with a scalp mass that mimicked a brain tumor. He was diagnosed with IgG4-related HP (IgG4-RP) after surgery. This case suggests that awareness of a possibility of IgG4-RP in patients with isolated scalp masses, even in the absence of systemic symptoms, is crucial. A combination of careful history taking, evaluation of serum IgG4-levels and imaging as an initial work-up, followed by tissue biopsy, is important for the differential diagnosis of IgG4-RP, malignancy, and other infectious diseases.

Intracranial Involvement of Systemic Hodgkin Lymphoma: A Case Report and Literature Review

A 27-year-old male patient, previously diagnosed with Hodgkin lymphoma (HL), presented with gait disturbance. Brain MRI showed a 4.5 cm mass lesion in the right occipital lobe, suggesting either intracranial involvement of HL or a potential meningioma. Despite high-dose methotrexate and steroid treatment, the patient's symptoms persisted, and imaging showed an enlarging mass, leading to surgical intervention. Histopathological examination confirmed central nervous system (CNS) involvement of HL. Postoperatively, the patient underwent whole-brain radiotherapy and demonstrated marked clinical improvement. Our literature review from 1980 to 2023 identified only 46 cases of intracranial HL (IC-HL), underscoring its rarity. Lymphomas represent 2.2% of brain tumors, with 90%-95% being diffuse large B-cell lymphoma (DLBCL). In contrast, the incidence of CNS-HL patients is a mere 0.02%. Notably, IC-HL and intracranial DLBCL have differences in their typical locations and treatment strategies. Unlike DLBCL, which predominantly appears in the supratentorial region (87%), IC-HL is found there in 61.5% of cases. Additionally, 33.3% of IC-HL cases occur in the cerebellum, with 43.5% associated with posterior circulation regions. Furthermore, while biopsy followed by chemotherapy induction is a common strategy for DLBCL, 81.8% of IC-HL cases underwent surgical resection, and only 18.1% had a biopsy alone. The distinct characteristics of IC-HL tumors, including their larger size, attachment to the dura, and fibrotic nature with clear boundaries, might account for the preference for surgical intervention. The unique features of IC-HL compared to DLBCL highlight the need for distinct considerations in diagnosis and management.

The Role of Early and Delayed Surgery for Infants with Congenital Brain Tumors

Purpose

The present study aimed to evaluate the role of early and delayed surgery in congenital brain tumors and analyze the clinical outcomes of infantile brain tumors.

Materials and Methods

We performed a retrospective cohort study on 69 infantile brain tumors at a single institution from January 2008 to June 2023. Outcomes were assessed as early mortality (within 30 days following surgery) to evaluate the risk of early surgery in congenital brain tumors. Outcomes of recurrence and overall survival were analyzed in infantile brain tumors.

Results

Surgery-related early mortality appeared to occur in young and low-body-weight patients. Cut-off values of age and body weight were found to be 1.3 months and 5.2 kg to avoid early mortality. Three patients (3/10, 30%) showed early mortality in the early surgery group, and early mortality occurred in one patient (1/14, 7.14%) in the delayed surgery group, whose tumor was excessively enlarged. Younger age at diagnosis (< 3 months of age, HR: 7.1, 95% CI: 1.4 - 35.6, p=0.018) and leptomeningeal seeding (LMS, HR: 30.6, 95% CI: 3.7 - 253.1, p=0.002) were significant independent risk factors for high mortality in infantile brain tumors.

Conclusion

We suggest delaying surgery until the patient reaches 1.3 months of age and weighs over 5.2 kg with short-term imaging follow-up unless tumors grow rapidly in congenital brain tumors. Younger ages and the presence of LMS are independent risk factors for high mortality in infantile brain tumors.

Improved postprocessing of dynamic glucose-enhanced CEST MRI for imaging brain metastases at 3 T

BACKGROUND

Dynamic glucose-enhanced (DGE) chemical exchange saturation transfer (CEST) has the potential to characterize glucose metabolism in brain metastases. Since the effect size of DGE CEST is small at 3 T (< 1%), measurements of signal-to-noise ratios are challenging. To improve DGE detection, we developed an acquisition pipeline and extended image analysis for DGE CEST on a hybrid 3-T positron emission tomography/magnetic resonance imaging system.

METHODS

This cross-sectional study was conducted after local ethical approval. Static Z-spectra (from -100 to 100 ppm) were acquired to compare the use of 1.2 versus 2 ppm to calculate static glucose-enhanced (glucoCEST) maps in 10 healthy volunteers before and after glucose infusion. Dynamic CEST images were acquired during glucose infusion. Image analysis was optimized using motion correction, dynamic B0 correction, and principal component analysis (PCA) to improve the detection of DGE CEST in the sagittal sinus, cerebrospinal fluid, and grey and white matter. The developed DGE CEST pipeline was applied to four patients diagnosed with brain metastases.

RESULTS

GlucoCEST was strongest in healthy tissues at 2 ppm. Correcting for motion, B0, and use of PCA locally improved DGE maps. A larger contrast between healthy tissues and enhancing regions in brain metastases was found when dynamic B0 correction and PCA denoising were applied.

CONCLUSION

We demonstrated the feasibility of DGE CEST with our developed acquisition and analysis pipeline at 3 T in patients with brain metastases. This work enables a direct comparison of DGE CEST to 18F-fluoro-deoxy-D-glucose positron emission tomography of glucose metabolism in patients with brain metastases.

RELEVANCE STATEMENT

Contrast between brain metastasis and healthy brain tissue in DGE CEST MR images is improved by including principle component analysis and dynamic magnetic field correction during postprocessing. This approach enables the detection of increased DGE CEST signal in brain metastasis, if present.

KEY POINTS

• Despite the low signal-to-noise ratio, dynamic glucose-enhanced CEST MRI is feasible at 3 T. • Principal component analyses and dynamic magnetic field correction improve DGE CEST MRI. • DGE CEST MRI does not consequently show changes in brain metastases compared to healthy brain tissue. • Increased DGE CEST MRI in brain metastases, if present, shows overlap with contrast enhancement on T1-weighted images.

Development and validation of a radiomics-based prediction pipeline for the response to stereotactic radiosurgery therapy in brain metastases

OBJECTIVES

The first treatment strategy for brain metastases (BM) plays a pivotal role in the prognosis of patients. Among all strategies, stereotactic radiosurgery (SRS) is considered a promising therapy method. Therefore, we developed and validated a radiomics-based prediction pipeline to prospectively identify BM patients who are insensitive to SRS therapy, especially those who are at potential risk of progressive disease.

METHODS

A total of 337 BM patients (277, 30, and 30 in the training set, internal validation set, and external validation set, respectively) were enrolled in the study. 19,377 radiomics features (3 masks × 3 MRI sequences × 2153 features) extracted from 9 ROIs were filtered through LASSO and Max-Relevance and Min-Redundancy (mRMR) algorithms. The selected radiomics features were combined with 4 clinical features to construct a two-stage cascaded model for the prediction of BM patients' response to SRS therapy using SVM and an ensemble learning classifier. The performance of the model was evaluated by its accuracy, specificity, sensitivity, and AUC curve.

RESULTS

Radiomics features were integrated with the clinical features of patients in our optimal model, which showed excellent discriminative performance in the training set (AUC: 0.95, 95% CI: 0.88-0.98). The model was also verified in the internal validation set and external validation set (AUC 0.93, 95% CI: 0.76-0.95 and AUC 0.90, 95% CI: 0.73-0.93, respectively).

CONCLUSIONS

The proposed prediction pipeline could non-invasively predict the response to SRS therapy in patients with brain metastases thus assisting doctors to precisely designate individualized first treatment decisions.

CLINICAL RELEVANCE STATEMENT

The proposed prediction pipeline combines the radiomics features of multi-modal MRI with clinical features to construct machine learning models that noninvasively predict the response of patients with brain metastases to stereotactic radiosurgery therapy, assisting neuro-oncologists to develop personalized first treatment plans.

KEY POINTS

• The proposed prediction pipeline can non-invasively predict the response to SRS therapy. • The combination of multi-modality and multi-mask contributes significantly to the prediction. • The edema index also shows a certain predictive value.

Reirradiation with radiosurgery or stereotactic fractionated radiotherapy in association with regorafenib in recurrent glioblastoma

PURPOSE

No standard treatment has yet been established for recurrent glioblastoma (GBM). In this context, the aim of the current study was to evaluate safety and efficacy of reirradiation (re-RT) by radiosurgery or fractionated stereotactic radiotherapy (SRS/FSRT) in association with regorafenib.

METHODS

Patients with a histological or radiological diagnosis of recurrent GBM who received re-RT by SRS/FSRT and regorafenib as second-line systemic therapy were included in the analysis.

RESULTS

From January 2020 to December 2022, 21 patients were evaluated. The median time between primary/adjuvant RT and disease recurrence was 8 months (range 5-20). Median re-RT dose was 24 Gy (range 18-36 Gy) for a median number of 5 fractions (range 1-6). Median regorafenib treatment duration was 12 weeks (range 3-26). Re-RT was administered before starting regorafenib or in the week off regorafenib during the course of chemotherapy. The median and the 6‑month overall survival (OS) from recurrence were 8.4 months (95% confidence interval [CI] 6.9-12.7 months) and 75% (95% CI 50.9-89.1%), respectively. The median progression-free survival (PFS) from recurrence was 6 months (95% CI 3.7-8.5 months). The most frequent side effects were asthenia that occurred in 10 patients (8 cases of grade 2 and 2 cases of grade 3), and hand-foot skin reaction (2 patients grade 3, 3 patients grade 2). Adverse events led to permanent regorafenib discontinuation in 2 cases, while in 5/21 cases (23.8%), a dose reduction was administered. One patient experienced dehiscence of the surgical wound after reintervention and during regorafenib treatment, while another patient reported intestinal perforation that required hospitalization.

CONCLUSION

For recurrent GBM, re-RT with SRT/FSRT plus regorafenib is a safe treatment. Prospective trials are necessary.

Arterial spin labelling MRI for brain tumour surveillance: do we really need cerebral blood flow maps?

OBJECTIVES

Arterial spin labelling (ASL) perfusion MRI is one of the available advanced MRI techniques for brain tumour surveillance. The first aim of this study was to investigate the correlation between quantitative cerebral blood flow (CBF) and non-quantitative perfusion weighted imaging (ASL-PWI) measurements. The second aim was to investigate the diagnostic accuracy of ASL-CBF and ASL-PWI measurements as well as visual assessment for identifying tumour progression.

METHODS

A consecutive cohort of patients who underwent 3-T MRI surveillance containing ASL for treated brain tumours was used. ROIs were drawn in representative parts of tumours in the ASL-CBF maps and copied to the ASL-PWI. ASL-CBF ratios and ASL-PWI ratios of the tumour ROI versus normal appearing white matter (NAWM) were correlated (Pearson correlation) and AUCs were calculated to assess diagnostic accuracy. Additionally, lesions were visually classified as hypointense, isointense, or hyperintense. We calculated accuracy at two thresholds: low threshold (between hypointense-isointense) and high threshold (between isointense-hyperintense).

RESULTS

A total of 173 lesions, both enhancing and non-enhancing, measured in 115 patients (93 glioma, 16 metastasis, and 6 lymphoma) showed a very high correlation of 0.96 (95% CI: 0.88-0.99) between ASL-CBF ratios and ASL-PWI ratios. AUC was 0.76 (95%CI: 0.65-0.88) for ASL-CBF ratios and 0.72 (95%CI: 0.58-0.85) for ASL-PWI ratios. Diagnostic accuracy of visual assessment for enhancing lesions was 0.72.

CONCLUSION

ASL-PWI ratios and ASL-CBF ratios showed a high correlation and comparable AUCs; therefore, quantification of ASL-CBF could be omitted in these patients. Visual classification had comparable diagnostic accuracy to the ASL-PWI or ASL-CBF ratios.

CLINICAL RELEVANCE STATEMENT

This study shows that CBF quantification of ASL perfusion MRI could be omitted for brain tumour surveillance and that visual assessment provides the same diagnostic accuracy. This greatly reduces the complexity of the use of ASL in routine clinical practice.

KEY POINTS

• Arterial spin labelling MRI for clinical brain tumour surveillance is undervalued and underinvestigated. • Non-quantitative and quantitative arterial spin labelling assessments show high correlation and comparable diagnostic accuracy. • Quantification of arterial spin labelling MRI could be omitted to improve daily clinical workflow.

What to report in sellar tumor MRI? A nationwide survey among German pituitary surgeons, radiation oncologists, and endocrinologists

PURPOSE

While MRI has become the imaging modality of choice in the diagnosis of sellar tumors, no systematic attempt has yet been made to align radiological reporting of findings with the information needed by the various medical disciplines dealing with these patients. Therefore, we aimed to determine the prevailing preferences in this regard through a nationwide expert survey.

METHODS

First, an interdisciplinary literature-based catalog of potential reporting elements for sellar tumor MRI examinations was created. Subsequently, a web-based survey regarding the clinical relevance of these items was conducted among board certified members of the German Society of Neurosurgery, German Society of Radiation Oncology, and the Pituitary Working Group of the German Society of Endocrinology.

RESULTS

A total of 95 experts (40 neurosurgeons, 28 radiation oncologists, and 27 endocrinologists) completed the survey. The description of the exact tumor location, size, and involvement of the anatomic structures adjacent to the sella turcica (optic chiasm, cavernous sinus, and skull base), occlusive hydrocephalus, relationship to the pituitary gland and infundibulum, and certain structural characteristics of the mass (cyst formation, hemorrhage, and necrosis) was rated most important (> 75% agreement). In contrast, the characterization of anatomic features of the nasal cavity and sphenoid sinus as well as the findings of advanced MRI techniques (e.g., perfusion and diffusion imaging) was considered relevant by less than 50% of respondents.

CONCLUSION

To optimally address the information needs of the interdisciplinary treatment team, MRI reports of sellar masses should primarily focus on the accurate description of tumor location, size, internal structure, and involvement of adjacent anatomic compartments.

Multiregional radiomics of brain metastasis can predict response to EGFR-TKI in metastatic NSCLC

OBJECTIVES

To develop radiomics signatures from multiparametric magnetic resonance imaging (MRI) scans to detect epidermal growth factor receptor (EGFR) mutations and predict the response to EGFR-tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC) patients with brain metastasis (BM).

METHODS

We included 230 NSCLC patients with BM treated at our hospital between January 2017 and December 2021 and 80 patients treated at another hospital between July 2014 and October 2021 to form the primary and external validation cohorts, respectively. All patients underwent contrast-enhanced T1-weighted (T1C) and T2-weighted (T2W) MRI, and radiomics features were extracted from both the tumor active area (TAA) and peritumoral edema area (POA) for each patient. The least absolute shrinkage and selection operator (LASSO) was used to identify the most predictive features. Radiomics signatures (RSs) were constructed using logistic regression analysis.

RESULTS

For predicting the EGFR mutation status, the created RS-EGFR-TAA and RS-EGFR- POA showed similar performance. By combination of TAA and POA, the multi-region combined RS (RS-EGFR-Com) achieved the highest prediction performance, with AUCs of 0.896, 0.856, and 0.889 in the primary training, internal validation, and external validation cohort, respectively. For predicting response to EGFR-TKI, the multi-region combined RS (RS-TKI-Com) generated the highest AUCs in the primary training (AUC = 0.817), internal validation (AUC = 0.788), and external validation (AUC = 0.808) cohort, respectively.

CONCLUSIONS

Our findings suggested values of multiregional radiomics of BM for predicting EGFR mutations and response to EGFR-TKI.

CLINICAL RELEVANCE STATEMENT

The application of radiomic analysis of multiparametric brain MRI has proven to be a promising tool to stratify which patients can benefit from EGFR-TKI therapy and to facilitate the precise therapeutics of NSCLC patients with brain metastases.

KEY POINTS

• Multiregional radiomics can improve efficacy in predicting therapeutic response to EGFR-TKI therapy in NSCLC patients with brain metastasis. • The tumor active area (TAA) and peritumoral edema area (POA) may hold complementary information related to the therapeutic response to EGFR-TKI. • The developed multi-region combined radiomics signature achieved the best predictive performance and may be considered as a potential tool for predicting response to EGFR-TKI.

The role of CNS tumor location in health-related quality of life outcomes: A systematic review of supratentorial vs infratentorial tumors in childhood survivorship

Continued advancements in the treatment of pediatric brain tumors have resulted in a growing proportion of children surviving previously incurable diagnoses. However, survivors of pediatric brain tumors show reduced Health-Related Quality of Life (HRQoL) compared to healthy populations and non-CNS childhood cancer survivors. This review systematically evaluates the existing literature on the influence of supratentorial and infratentorial brain tumor locations on Health-Related Quality of Life outcomes in survivors of pediatric brain tumors. Five electronic databases were searched for relevant articles published between their inception and January 2022. A purpose-developed evaluative tool was constructed to assess the quality of eligible studies. 16 of the 5270 identified articles were included in this review (n = 1391). This review found little evidence relating to the impact of brain tumor location on HRQoL, with only one study finding a significant difference between supratentorial and infratentorial tumor survivors. Key limitations of the current evidence include poor statistical reporting, ambiguous construct definitions, and insufficient adjustment for confounds. Findings from this review show that recovery from a pediatric brain tumor extends beyond recovery post-treatment and that further study into the factors influencing survivor HRQoL, including the influence of tumor location, is necessary.

A Case Series of DuraMatrix-Onlay® Plus in Cranial Surgery Is Associated With a Low Complication Profile

BACKGROUND

DuraMatrix-Onlay® Plus is a collagen dura membrane derived from purified bovine Achilles tendon. The matrix provides a scaffold for collagen synthesis and is intended to be used as an onlay without the need for dural sutures. The study aims to describe our experience with 33 consecutive patients who underwent a duraplasty procedure using the novel DuraMatrix-Onlay® Plus collagen dura membrane.

METHODS

This is a retrospective case series of 33 patients who underwent a duraplasty procedure at a single academic hospital in Los Angeles, CA, USA between May 2016 and March 2017. The primary outcome was the incidence rate of cerebrospinal fluid (CSF) leak. Secondary outcomes included rates of patient infection, dural substitute complication, and removal.

RESULTS

Thirty-three patients underwent a duraplasty procedure using the DuraMatrix-Onlay® Plus material. The average age of the patients was 41.12±7.34 years (range 2-75 years). There were 18 (54.5%) females and 15 (45.5%) males. The majority of procedures were elective operations for the resection of a lesion (n=19, 58%), and the average graft size was 17.69±4.73 cm². At an average follow-up of 3 months, there were no postoperative CSF leaks. The rates of patient infection, dural substitute complication, and removal were 6%, 6%, and 3%, respectively.

CONCLUSION

DuraMatrix-Onlay® Plus is associated with a low rate of postoperative CSF leakage and an acceptable complication profile. This result supports the use of collagen matrices for dural closure in general neurosurgical procedures.

Construction and evaluation of a gated high-resolution neural network for automatic brain metastasis detection and segmentation

OBJECTIVES

To construct and evaluate a gated high-resolution convolutional neural network for detecting and segmenting brain metastasis (BM).

METHODS

This retrospective study included craniocerebral MRI scans of 1392 patients with 14,542 BMs and 200 patients with no BM between January 2012 and April 2022. A primary dataset including 1000 cases with 11,686 BMs was employed to construct the model, while an independent dataset including 100 cases with 1069 BMs from other hospitals was used to examine the generalizability. The potential of the model for clinical use was also evaluated by comparing its performance in BM detection and segmentation to that of radiologists, and comparing radiologists' lesion detecting performances with and without model assistance.

RESULTS

Our model yielded a recall of 0.88, a dice similarity coefficient (DSC) of 0.90, a positive predictive value (PPV) of 0.93 and a false positives per patient (FP) of 1.01 in the test set, and a recall of 0.85, a DSC of 0.89, a PPV of 0.93, and a FP of 1.07 in dataset from other hospitals. With the model's assistance, the BM detection rates of 4 radiologists improved significantly, ranging from 5.2 to 15.1% (all p < 0.001), and also for detecting small BMs with diameter ≤ 5 mm (ranging from 7.2 to 27.0%, all p < 0.001).

CONCLUSIONS

The proposed model enables accurate BM detection and segmentation with higher sensitivity and less time consumption, showing the potential to augment radiologists' performance in detecting BM.

CLINICAL RELEVANCE STATEMENT

This study offers a promising computer-aided tool to assist the brain metastasis detection and segmentation in routine clinical practice for cancer patients.

KEY POINTS

• The GHR-CNN could accurately detect and segment BM on contrast-enhanced 3D-T1W images. • The GHR-CNN improved the BM detection rate of radiologists, including the detection of small lesions. • The GHR-CNN enabled automated segmentation of BM in a very short time.

Immune checkpoint inhibition and single fraction stereotactic radiosurgery in brain metastases from non-small cell lung cancer: an international multicenter study of 395 patients

PURPOSE

Approximately 80% of brain metastases originate from non-small cell lung cancer (NSCLC). Immune checkpoint inhibitors (ICI) and stereotactic radiosurgery (SRS) are frequently utilized in this setting. However, concerns remain regarding the risk of radiation necrosis (RN) when SRS and ICI are administered concurrently.

METHODS

A retrospective study was conducted through the International Radiosurgery Research Foundation. Logistic regression models and competing risks analyses were utilized to identify predictors of any grade RN and symptomatic RN (SRN).

RESULTS

The study included 395 patients with 2,540 brain metastases treated with single fraction SRS and ICI across 11 institutions in four countries with a median follow-up of 14.2 months. The median age was 67 years. The median margin SRS dose was 19 Gy; 36.5% of patients had a V12 Gy ≥ 10 cm3. On multivariable analysis, V12 Gy ≥ 10 cm3 was a significant predictor of developing any grade RN (OR: 2.18) and SRN (OR: 3.95). At 1-year, the cumulative incidence of any grade and SRN for all patients was 4.8% and 3.8%, respectively. For concurrent and non-concurrent groups, the cumulative incidence of any grade RN was 3.8% versus 5.3%, respectively (p = 0.35); and for SRN was 3.8% vs. 3.6%, respectively (p = 0.95).

CONCLUSION

The risk of any grade RN and symptomatic RN following single fraction SRS and ICI for NSCLC brain metastases increases as V12 Gy exceeds 10 cm3. Concurrent ICI and SRS do not appear to increase this risk. Radiosurgical planning techniques should aim to minimize V12 Gy.

Treatment Outcome of the Brain Metastases in Peri-Rolandic Area: Comparison Between Surgery and Stereotactic Radiosurgery

BACKGROUND

Brain metastases of peri-Rolandic area is crucial as it directly impacts the quality of life for cancer patients. Surgery or stereotactic radiosurgery (SRS) is considered for peri-Rolandic brain metastases as for other brain metastases. However, the benefit of each treatment modality on functional outcome has not been clearly defined for this tumor. The purpose of this study is to compare the functional course of each treatment and to suggest an effective treatment for patients' quality of life.

METHODS

Fifty-two patients who had undergone SRS or surgery for brain metastasis confirmed by enhanced MRI were enrolled retrospectively. Overall survival (OS), progression free survival (PFS), and functional outcomes were estimated using the Kaplan-Meier method, univariate, multivariate analysis, and Cox proportional hazards regression.

RESULTS

Median OS and PFS were 13.3 months and 8.9 months in our study population. Treatment modalities were not significant factors for OS and PFS. Extracranial systemic cancer progression was significant factor for both parameters (p=0.030 for OS and p=0.040 for PFS). Median symptom improvement (improvement of at least 1 grade after surgery compared to preoperative state) time was significantly shorter in surgery group than in the SRS group (10.5 days vs. 37.5 days, p=0.034).

CONCLUSION

Surgery for brain metastases can contribute to a positive quality of life for the remaining duration of the patient's life.

Practical Guideline for Prevention of Patchy Hair Loss following CyberKnife Stereotactic Radiosurgery for Calvarial or Scalp Tumors: Retrospective Analysis of a Single Institution Experience

INTRODUCTION

Patchy alopecia is a common adverse effect of stereotactic radiosurgery (SRS) on the calvarium and/or scalp, yet no guidelines exist for its prevention. This study aims to investigate the incidence and outcomes of patchy alopecia following SRS for patients with calvarial or scalp lesions and establish preventive guidelines.

METHODS

The study included 20 patients who underwent CyberKnife SRS for calvarial or scalp lesions, resulting in a total of 30 treated lesions. SRS was administered as a single fraction for 8 lesions and hypofractionated for 22 lesions. The median SRS target volume was 9.85 cc (range: 0.81-110.7 cc), and the median prescription dose was 27 Gy (range: 16-40 Gy), delivered in 1-5 fractions (median: 3). The median follow-up was 15 months.

RESULTS

Among the 30 treated lesions, 11 led to patchy alopecia, while 19 did not. All cases of alopecia resolved within 12 months, and no patients experienced other adverse radiation effects. Lesions resulting in alopecia exhibited significantly higher biologically effective dose (BED) and single-fraction equivalent dose (SFED) on the overlying scalp compared to those without alopecia. Patients with BED and SFED exceeding 60 Gy and 20 Gy, respectively, were 9.3 times more likely to experience patchy alopecia than those with lower doses. The 1-year local tumor control rate for the treated lesions was 93.3%. Chemotherapy was administered for 26 lesions, with 11 lesions receiving radiosensitizing agents. However, no statistically significant difference was found.

CONCLUSION

In summary, SRS is a safe and effective treatment for patients with calvarial/scalp masses regarding patchy alopecia near the treated area. Limiting the BED under 60 Gy and SFED under 20 Gy for the overlying scalp can help prevent patchy alopecia during SRS treatment of the calvarial/scalp mass. Clinicians can use this information to inform patients about the risk of alopecia and the contributing factors.

Functional MRI but not white matter fibre dissection identifies language dominance

OBJECTIVES

Lateralisation of some language pathways has been reported in the literature using diffusion tractography, which is more feasible than functional magnetic resonance imaging (fMRI) in challenging patients. Our retrospective study investigates whether a correlation exists between threshold-independent fMRI language lateralisation and structural lateralisation using tractography in healthy controls and brain tumour patients.

METHODS

Fifteen healthy subjects and 61 patients underwent language fMRI and diffusion-weighted MRI. A regional fMRI laterality index (LI) was calculated. Tracts dissected were the arcuate fasciculus (long direct and short indirect tracts), uncinate fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus and frontal aslant tract. An asymmetry index (AI) for each tract was calculated using tract volume analysed with single tensor (ST) and spherical deconvolution (SD) models, as well as hindrance modulated orientational anisotropy (HMOA) for SD tracts. Linear regression assessed the correlation between LI and AI.

RESULTS

In all subjects, there was no significant correlation between LI and AI for any of the dissected tracts. Significant correlations were only found when handedness for controls and tumour volume for patients were included as covariates. In handedness subgroups, the average AI of some tracts showed the same laterality as LI, and some the opposite. Discordant results were observed for ST- and SD-based AIs.

CONCLUSIONS

Our results do not support using tractography in the assessment of language lateralisation. The discordant results between ST and SD indicate that either the structural lateralisation of dissected tracts is less robust than functional lateralisation, or tractography is not sensitive methodology. Other diffusion analysis approaches should be developed.

CLINICAL RELEVANCE STATEMENT

Although diffusion tractography may be more feasible than fMRI in challenging tumour patients and where sedation or anaesthesia is required, our results do not currently recommend replacing fMRI with tractography using volume or HMOA in the assessment of language lateralisation.

KEY POINTS

• No correlation found between fMRI and tractography in language lateralisation. • Discordance between asymmetry indices of different tractography models and metrics. • Tractography not currently recommended in language lateralisation assessment.

A comprehensive genomic study of 390 H3F3A-mutant pediatric and adult diffuse high-grade gliomas, CNS WHO grade 4

Malignant brain tumors, known as H3K27-altered diffuse midline glioma (DMG) and H3G34-mutant diffuse hemispheric glioma (DHG), can affect individuals of all ages and are classified as CNS WHO grade 4. We comprehensively characterized 390 H3F3A-mutant diffuse gliomas (201 females, 189 males) arising in pediatric patients (under 20 years old) and adults (20 years and older) evaluated by the CGP program at Foundation Medicine between 2013 and 2020. We assessed information from pathology reports, histopathology review, and clinical data. The cohort included 304 H3K27M-mutant DMG (156 females, 148 males) and 86 H3G34-mutant DHG (45 females, 41 males). Median patient age was 20 years (1-74 years). The frequency of H3K27M-mutant DMG was similar in both pediatric and adult patients in our cohort-48.6% of the patients were over 20 years old, 31.5% over 30, and 18% over 40 at initial diagnosis. FGFR1 hotspot point mutations (N546K and K656E) were exclusively identified in H3K27M-mutant DMG tumors (64/304, 21%; p = 0.0001); these tend to occur in older patients (median age: 32.5 years) and mainly arose in the diencephalon. H3K27M-mutant DMG had higher rates of mutations in NF1 (31.0 vs 8.1%; p = 0.0001) and PIK3CA/PIK3R1 (27.9% vs 15.1%; p = 0.016) compared to H3G34-mutant DHG. However, H3G34-mutant DHG had higher rates of targetable alterations in cell-cycle pathway genes (CDK4 and CDK6 amplification; CDKN2A/B deletion) (27.0 vs 9.0%). Potentially targetable PDGFRA alterations were identified in ~ 20% of both H3G34-mutant DHG and H3K27M-mutant DMG. Overall, in the present study H3K27M-mutant DMG occurred at similar rates in both adult and patient patients. Through our analysis, we were able to identify molecular features characteristic of DMG and DHG. By identifying the recurrent co-mutations including actionable FGFR1 point mutations found in nearly one-third of H3K27M-mutant DMG in young adults, our findings can inform clinical translational studies, patient diagnosis, and clinical trial design.

Study protocol for a multicenter randomised controlled trial on the (cost)effectiveness of biopsy combined with same-session MR-guided LITT versus biopsy alone in patients with primary irresectable glioblastoma (EMITT trial)

BACKGROUND

Glioblastoma (GBM) is the most common primary, malignant brain tumour with a 5-year survival of 5%. If possible, a glioblastoma is resected and further treated with chemoradiation therapy (CRT), but resection is not feasible in about 30% of cases. Current standard of care in these cases is a biopsy followed by CRT. Magnetic resonance (MR) imaging-guided laser interstitial thermal therapy (LITT) has been suggested as a minimally invasive alternative when surgery is not feasible. However, high-quality evidence directly comparing LITT with standard of care is lacking, precluding any conclusions on (cost-)effectiveness. We therefore propose a multicenter randomized controlled study to assess the (cost-)effectiveness of MR-guided LITT as compared to current standard of care (EMITT trial).

METHODS AND ANALYSIS

The EMITT trial will be a multicenter pragmatic randomized controlled trial in the Netherlands. Seven Dutch hospitals will participate in this study. In total 238 patients will be randomized with 1:1 allocation to receive either biopsy combined with same-session MR-guided LITT therapy followed by CRT or the current standard of care being biopsy followed by CRT. The primary outcomes will be health-related quality of life (HR-QoL) (non-inferiority) using EORTC QLQ-C30 + BN20 scores at 5 months after randomization and overall survival (superiority). Secondary outcomes comprise cost-effectiveness (healthcare and societal perspective) and HR-QoL of life over an 18-month time horizon, progression free survival, tumour response, disease specific survival, longitudinal effects, effects on adjuvant treatment, ablation percentage and complication rates.

DISCUSSION

The EMITT trial will be the first RCT on the effectiveness of LITT in patients with glioblastoma as compared with current standard of care. Together with the Dutch Brain Tumour Patient association, we hypothesize that LITT may improve overall survival without substantially affecting patients' quality of life.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov (NCT05318612).

[Pediatric supratentorial brain tumors]

BACKGROUND

Pediatric brain tumors differ regarding location and histopathological features compared to those in adults. In children, 30% of pediatric brain tumors are supratentorial lesions. Low-grade astrocytomas, e.g. pilocystic astrocytoma or craniopharyngioma, are the most common tumors.

IMAGING MODALITIES

Magnetic resonance imaging (MRI) is the default imaging technique that is used to evaluate the findings. Ultrasound and cranial computed tomography (CCT) accompany the imaging, although CCT is mainly used in emergency situations.

TOPICS COVERED

The following article describes the most common pediatric supratentorial brain tumors with reference to imaging criteria as well as changes in the World Health Organization (WHO) classification.

Linear accelerator-based stereotactic radiotherapy for brain metastases, including multiple and large lesions, carries a low incidence of acute toxicities: a retrospective analysis

BACKGROUND

Data on acute toxicities after stereotactic radiotherapy (SRT) for brain metastases, including multiple and large lesions, are lacking. We aimed to evaluate the incidence and nature of toxicities immediately after SRT using a linear accelerator.

METHODS

This retrospective study reviewed the medical records of 315 patients with brain metastases treated with SRT at our institution between May 2019 and February 2022. In total, 439 SRT sessions were performed for 2161 brain metastases. The outcome of interest was immediate side effects (ISEs), defined as new or worsening symptoms occurring during SRT or within 14 days after the end of SRT.

RESULTS

Grade ≥ 2 and ≥ 3 ISEs occurred in 16 (3.6%) and 7 (1.6%) cases, respectively. Among 63 treatments for 10 or more lesions (range: 10-40), 1 (1.6%) ISE occurred. Among 22 treatments for lesions with a maximum tumor volume of > 10 cc, 2 (9.1%) ISEs occurred. Grade ≥ 3 ISEs included 1, 4, 1, and 1 cases of grade 3 nausea, grade 3 new-onset partial and generalized seizures, grade 3 obstructive hydrocephalus, and grade 5 intracranial hemorrhage, respectively. ISEs were more common in patients with a larger maximum tumor volume, primary sites other than lung and breast cancer, and pre-treatment neurological symptoms.

CONCLUSION

SRT using a linear accelerator for brain metastases, including multiple and large lesions, is safe, with a low incidence of ISEs. Serious complications immediately after SRT are rare but possible; therefore, careful follow-up is necessary after treatment initiation.

Octogenarian Brain Tumor Registry: Single-Institution Surgical Outcomes and Mortality Study

BACKGROUND

Surgical intervention for brain tumor patients aged 80 to 89 years is controversial, as the comorbidities and physiology associated with aging are often thought to increase surgical risks. Surgical outcomes, however, are not well characterized for octogenarians. This review therefore assessed the outcomes and mortality risk associated with tumor removal in octogenarians at our academic institution.

METHODS

Retrospective review of patients aged 80 to 89 who underwent craniotomy for tumor resection (CTR) at our institution between 2004-2021 and who were diagnosed with meningioma, glioblastoma, or metastatic disease. Primary outcome was 30-day mortality.

RESULTS

Sixty-one CTRs were included in analysis. Median age was 83 (interquartile range 81-85) years, and the most common preoperative comorbidity was hypertension (n=44). Most patients (n=35) had a preoperative modified Rankin Scale (mRS) score between 0-2. Seventeen (27.9%) patients experienced postoperative complications (i.e., urinary tract infection, deep venous thrombosis, etc.), and 26.2% (n=16) experienced new-onset neurologic deficits postoperatively (i.e., aphasia, motor deficits, etc.). Upon discharge, most patients (n=43) had an mRS score of 3-4. Within 30 days of surgery, 14.8% (n=9) of patients were readmitted to the hospital and 8.2% (n=5) of patients died: 2 with meningioma, 1 with glioblastoma, and 2 with metastatic disease. The most common cause of death was intracranial hemorrhage (n=3). Three-month mortality was 23.0% (n=14). Mean survival after surgery was 33 months for meningioma patients, 6.9 months for glioblastoma patients, and 15 months for patients with metastatic lesions.

CONCLUSION

Our review found a 30-day mortality rate of 8.2% across all tumor types, and mean survival was similar to that previously reported for patients across all age groups. Surgical intervention for octogenarian tumor patients is therefore feasible, safe, and likely worthwhile for extending and improving lives.

Neurosurgical Applications of Magnetic Hyperthermia Therapy

Magnetic hyperthermia therapy (MHT) is a highly localized form of hyperthermia therapy (HT) that has been effective in treating various forms of cancer. Many clinical and preclinical studies have applied MHT to treat aggressive forms of brain cancer and assessed its role as a potential adjuvant to current therapies. Initial results show that MHT has a strong antitumor effect in animal studies and a positive association with overall survival in human glioma patients. Although MHT is a promising therapy with the potential to be incorporated into the future treatment of brain cancer, significant advancement of current MHT technology is required.

Awake Craniotomy and Intraoperative Musical Performance for Brain Tumor Surgery: Case Report and Literature Review

Music experience and creation is a complex phenomenon that involves multiple brain structures. Music mapping during awake brain surgery, in addition to standard speech and motor mapping, remains a controversial topic. Music function can be impaired selectively, despite overlap with other neural networks commonly tested during direct cortical stimulation. We describe the case of a 34-year-old male patient presenting with a glioma located within eloquent cortex, who is also a professional musician and actor. We performed an awake craniotomy (AC) that mapped the standard motor and speech areas, while the patient played guitar intraoperatively and sang. Outcomes were remarkable with preservation of function and noted improvements in his musical abilities in outpatient follow-up. In addition, we performed a review of the literature in which awake craniotomies were performed for the removal of brain tumors in patients with some background in music (e.g., score reading, humming/singing). To date, only 4 patients have played a musical instrument intraoperatively during an AC for brain tumor resection. Using awake cortical mapping techniques and paradigms for preserving speech function during an intraoperative musical performance with singing is feasible and can yield a great result for patients. The use of standard brain mapping over music processing mapping did not yield a negative outcome. More experience is needed to understand and standardize this procedure as the field of brain mapping continues to grow for tumor resections.

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.

Association between insomnia disorder and mortality among patients who underwent craniotomy for brain tumor resection: a South Korean nationwide cohort study

PURPOSE

To assess the prevalence and related factors of a newly developed insomnia disorder following craniotomy for brain tumor resection. Furthermore, we examined the association of pre- and postoperative insomnia with the 2-year mortality rate.

METHODS

The South Korean national registration cohort database was used as the data source. This study includes all adult patients who underwent craniotomy for brain tumor resection from January 1, 2011, to December 31, 2017. G47.0 and F51.0 (International Statistical Classification of Diseases and Related Health Problems 10th Revision codes) were used to identify insomnia disorders.

RESULTS

In total, 4,851 patients were included. Among them, 913 (18.8%) and 447 (9.2%) patients were assigned to the preoperative and postoperative insomnia groups, respectively. After modeling using multivariable logistic regression, older age (odds ratio (OR) 1.02, 95% confidence interval (CI) 1.01-1.03; P < 0.001), reoperation within 1 year (OR 2.12, 95% CI 1.47-3.06; P < 0.001), and newly acquired brain disability (OR 1.32, 95% CI 1.01-1.71; P = 0.043) were associated with an increased prevalence of newly developed postoperative insomnia disorder. After modeling using multivariable Cox regression, the preoperative and postoperative insomnia disorder groups showed a 1.17-fold (hazard ratio (HR) 1.17, 95% CI 1.02-1.34; P = 0.021) and a 1.85-fold (HR 1.85, 95% CI 1.59-2.15, P < 0.001) increased 2-year all-cause mortality risk compared to the control group, respectively.

CONCLUSION

In South Korea, 9.2% of the patients with brain tumors were newly diagnosed with an insomnia disorder following craniotomy for brain tumor resection, which was associated with an increased risk of 2-year mortality.

The effect of preoperative steroids for at least 10 days on complications following craniotomy for tumor resection: A database, retrospective cohort study

Introduction

The effect of chronic steroid therapy on postoperative outcomes after craniotomy for tumor resection remains understudied.

Research question

This study aimed to fill this gap and to identify risk factors of postoperative morbidity and mortality among patients on chronic steroid use undergoing craniotomy for tumor resection.

Materials and methods

Data from the American College of Surgeons National Surgical Quality Improvement Program were used. Patients who underwent craniotomy for tumor resection between 2011 and 2019 were included. Perioperative characteristics and complications were compared among patients with and without chronic steroid therapy, defined as steroid use for at least 10 days. Multivariable regression analyses were conducted to assess the impact of steroid therapy on postoperative outcomes. Subgroup analyses involving patients on steroid therapy were conducted to explore risk factors of postoperative morbidity and mortality.

Results

Of 27,037 patients, 16.2% were on steroid therapy. On regression analyses, steroid use was significantly associated with any postoperative complication, infectious complication, urinary tract infection, septic shock, wound dehiscence, pneumonia, non-infectious, pulmonary, and thromboembolic complications, cardiac arrest, blood transfusion, unplanned reoperation, readmission, and mortality. On subgroup analysis, risk factors for postoperative morbidity and mortality among patients on steroid therapy included older age, higher American Society of Anesthesiology physical status, functional dependence, pulmonary and cardiovascular comorbidities, anemia, dirty/infected wounds, prolonged operative time, disseminated cancer, and a diagnosis of meningioma.

Discussion and conclusion

Preoperative brain tumor patients on steroids for 10 or more days are at a relatively high risk of postoperative complications. We recommend a judicious use of steroids in brain tumor patients, both in terms of dosage and duration of treatment.

Contralesional macrostructural plasticity in patients with frontal low-grade glioma: a voxel-based morphometry study

PURPOSE

Neuroplasticity can partially compensate for the neurological deficits caused by brain tumors. However, the structural plasticity of the brain caused by brain tumors is not fully understood. This study aimed to assess the structural plasticity of the contralesional hemisphere in patients with frontal low-grade gliomas (LGGs).

METHODS

A total of 25 patients with left frontal LGGs (LFLGGs), 19 patients with right frontal LGGs (RFLGGs), and 25 healthy controls (HCs) were enrolled in this study. High-resolution structural T1-weighted imaging and fluid attenuation inversion recovery were performed on all participants. Voxel-based morphometry (VBM) analysis was used to detect differences in the brain structural plasticity between patients with unilateral LGGs and HCs.

RESULTS

VBM analysis revealed that compared with HCs, the gray matter volume (GMV) of the contralesional putamen and amygdala was significantly smaller and larger in the patients with RFLGGs and LFLGGs, respectively, while the GMVs of the contralesional cuneus and superior temporal gyrus (STG) were significantly larger in the patients with LFLGGs. The surviving clusters of the right hemisphere included 1357 voxels in the amygdala, 1680 voxels in the cuneus, 384 voxels in the STG, and 410 voxels in the putamen. The surviving clusters of the left hemisphere were 522 voxels in the amygdala and 320 voxels in the putamen.

CONCLUSION

The unilateral frontal LGGs are accompanied by structural plasticity in the contralesional cortex and vary with tumor laterality. Contralesional structural reorganization may be one of the physiological basis for functional reorganization or compensation in the frontal LGGs.

Imaging in a new pediatric brain tumor-a supratentorial neuroepithelial tumor with PLAGL1 fusion

Molecular diagnostics have dramatically influenced the classification of tumor groups in the 2021 WHO CNS tumor classification. Studies focusing on molecular diagnostics continue to identify new tumors. Soon after the summary of the new classification was published, "Supratentorial Neuroepithelial Tumor with PLAGL1 Fusion" was described as a distinct entity. Although this new entity is defined pathologically, its imaging features are undefined. This case report discusses the imaging findings and possible differential diagnosis of the new tumor.

Frequency and burden of potentially treatable symptoms in glioma patients with stable disease

Background & aims

Glioma patients experience a multitude of symptoms that negatively affect their health-related quality of life. Symptoms vary greatly across disease phases, and the patients' stable phase might be particularly suitable for assessing and treating symptoms. Identifying symptoms and patients' needs is a first step toward improving patient care. In glioma patients with stable disease, we assessed the frequency and burden of patient-reported symptoms, examined how these symptoms co-occur, and also determined whether patients would consider treatment to ameliorate specific symptoms.

Methods

In this retrospective study, patients rated the frequency and burden of seventeen symptoms on a seven-point Likert scale and stated whether they would consider treatment for these symptoms. Correlations between frequency, burden, and considering treatment were evaluated with Kendall's Tau correlation coefficients. Based on partial correlations between symptom frequencies we visualized the symptoms as a network.

Results

Fifty-two glioma patients with stable disease were included (31 WHO grade II/III, 21 WHO grade IV). The top five symptoms were fatigue, memory problems, reduced physical fitness, concentration problems, and drowsiness. Fatigue had the highest median frequency (4.5, interquartile range 2.5). Over half of the patients experienced three or more symptoms simultaneously and associations between all symptoms were depicted as a network. Overall, 35% of patients would consider treatment for at least one symptom. The wish to undergo symptom treatment correlated only moderately with symptom frequency and burden (range of correlations 0.24-0.57 and 0.28-0.61, respectively).

Conclusion

Glioma patients with stable disease experience multiple symptoms with a consequently high symptom burden. Despite the high prevalence of symptoms, the inclination for symptom management interventions was relatively low. The most frequent and burdensome symptoms and the way they are interrelated could serve as a roadmap for future research on symptom management in these patients.

Predictors of Survival After Stereotactic Radiosurgery for Untreated Single Non-Small Cell Lung Cancer Brain Metastases: 5- and 10-year Results

BACKGROUND

Stereotactic radiosurgery (SRS) presents as a good treatment option for smaller, deep-seated brain metastases (BMs). This study aims to determine predictors of SRS failure for patients with non-small cell lung cancer BMs.

METHODS

This was a retrospective study of single non-small cell lung cancer BMs treated using SRS. We included patients >18 years with a single, previously untreated lesion. Primary outcome was treatment failure, defined as BMs dimension increase above the initial values. Demographic, clinical, and radiological data were collected to study potential predictors of treatment failure.

RESULTS

Worse rates of progression-free survival (PFS) were associated with heterogeneous contrast enhancement (18.1 ± 4.1 vs. 41.9 ± 4 months; P < 0.001). Better rates of PFS were associated with volumes <1.06 cm³ (log-rank; P = 0.001). Graded prognostic assessment was significantly associated with survival at 120 months (log-rank; P < 0.001). Karnofsky Performance Scale was evaluated in 3 strata: 90-100, 80, and ≤70. Mean survival rates for these strata were 31.8 ± 3.9, 10.6 ± 2.2, and 9.8 ± 2.3 months, respectively (log-rank; P < 0.001). There were no differences regarding presence of extracranial metastases, age, or lesion location. A multivariable logistic regression found that volume <1.06 cm³ was associated with higher survival rates at 10 years (odds ratio: 3.2, 95% confidence interval: 1.3-8.0).

CONCLUSIONS

Contrast-homogeneous metastases and lesions <1.06 cm³ are associated with better rates of PFS. Karnofsky Performance Scale and graded prognostic assessment were associated with more favorable survival rates after 10 years. Volume <1.06 cm³ was the only significant predictor of survival in the multivariable analysis.

Uncommon metastases to the brain: Frontal lobe myoepithelial carcinoma

Background

Myoepithelial tumors have been widely described as a rare form of salivary gland neoplasm, although currently soft-tissue phenotypes have also been identified. These are tumors composed entirely of myoepithelial cells that exhibit a dual epithelial and smooth muscle phenotype. The occurrence of myoepithelial tumors within the central nervous system is also extremely rare, with only a few cases reported. Treatment options include surgical resection, chemotherapy, radiotherapy, or a combination of these approaches.

Case Description

The authors present a case of soft-tissue myoepithelial carcinoma with an unusual brain metastasis, rarely described in the literature. The purpose of this article is to present an update on the diagnosis and treatment of this pathology when affecting the central nervous system, through the review of the current evidence.

Conclusion

However, despite complete surgical resection, there is about a significative high rate of local recurrence and metastasis. Careful patient follow-up and staging is essential for better characterization and understanding of this tumor's behavior.

Gamma Knife radiosurgery - 12 years of experience in a high-complexity center of a middle-income country

Background

Gamma Knife radiosurgery (GKR) is a technique that consists of the release of a high dose of ionizing radiation onto a therapeutic target, which has been previously delimited. This technique was described by Lars Leksell and Borje Larsson in 1951. In Colombia, there is only one GKR unit functioning machine nowadays. The objective of this study is to describe the institutional experience of a single institution with Gamma Knife Perfexion over 12 years.

Methods

We conducted a retrospective observational study. A total of 1906 medical records, taken from the period between May 4, 2010, and May 4, 2022, were included in the study. Descriptive analysis was performed through STATA 17 as statistic tool. Measures of central tendency were calculated depending on the distribution of the continuous data and proportions were taken into account in the case of qualitative variables.

Results

A total of 1906 procedures were performed. Patients from 1 year to 99 years old were treated, with a median age of 51 years. The most frequent diagnoses were meningioma (20.8%), arteriovenous malformation (AVM) (17%), vestibular schwannoma (15.6%), metastases (9.81%), and trigeminal neuralgia (9.12%). At 3-year posttreatment, in meningiomas, tumor size stability was observed in 57.3%, size decrease in 36%, and disappearance in 1.3%. In AVM, complete obliteration of the lesion was described in 36.8% and a decrease in size in 52.6%. Intracranial hemorrhage occurred in 5.2% during the follow-up period and 3.5% of all treated patients required a new procedure due to residual malformation. In vestibular schwannomas, tumor size remained stable in 62.2% and decreased in 28.8%. No new cases of facial paralysis after the procedure were described. At 1-year posttreatment, in metastasis, the size of the lesions remained stable in 40% of the patients, decreased in 47.5%, and disappeared in 2.5%. In trigeminal neuralgia, 88.4% of patients had pain relief and recurrences occurred in 16.6%. Acute complications were generally uncommon, the main ones being headache, pain at frame fixation points, and nausea.

Conclusion

Our experience suggests that GKR is a noninvasive procedure with a broad spectrum of clinical applications, low frequency of complications, feasible, with good enough control size of tumor and vascular lesions in images, and good clinical results in the medium and long term.

MRI-based and robot-assisted stereotactic biopsy with intraoperative CT imaging

BACKGROUND

As a pioneer center in the field of stereotaxy, Sainte-Anne school has always advocated the use of intraoperative imaging for stereotactic procedures to optimize both safety and accuracy. With the advent of intraoperative mobile CT unit, the robot-assisted stereotactic biopsy procedure has been recently updated.

METHOD

Herein, we aim at describing our new surgical procedure that combines robotic assistance (NeuroMate, Renishaw) and intraoperative cone beam CT imaging (O-Arm, Medtronic).

CONCLUSION

Intraoperative imaging with the O-Arm was efficiently incorporated into the workflow. This new equipment leads to optimizing operative time and an easier realization of intraoperative imaging.

Radiomics can differentiate high-grade glioma from brain metastasis: a systematic review and meta-analysis

OBJECTIVE

(1) To evaluate the diagnostic performance of radiomics in differentiating high-grade glioma from brain metastasis and how to improve the model. (2) To assess the methodological quality of radiomics studies and explore ways of embracing the clinical application of radiomics.

METHODS

Studies using radiomics to differentiate high-grade glioma from brain metastasis published by 26 July 2021 were systematically reviewed. Methodological quality and risk of bias were assessed using the Radiomics Quality Score (RQS) system and Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool, respectively. Pooled sensitivity and specificity of the radiomics model were also calculated.

RESULTS

Seventeen studies combining 1,717 patients were included in the systematic review, of which 10 studies without data leakage suspicion were employed for the quantitative statistical analysis. The average RQS was 5.13 (14.25% of total), with substantial or almost perfect inter-rater agreements. The inclusion of clinical features in the radiomics model was only reported in one study, as was the case for publicly available algorithm code. The pooled sensitivity and specificity were 84% (95% CI, 80-88%) and 84% (95% CI, 81-87%), respectively. The performances of feature extraction from the volume of interest (VOI) or (semi) automatic segmentation in the radiomics models were superior to those of protocols employing region of interest (ROI) or manual segmentation.

CONCLUSION

Radiomics can accurately differentiate high-grade glioma from brain metastasis. The adoption of standardized workflow to avoid potential data leakage as well as the integration of clinical features and radiomics are advised to consider in future studies.

KEY POINTS

• The pooled sensitivity and specificity of radiomics for differentiating high-grade gliomas from brain metastasis were 84% and 84%, respectively. • Avoiding potential data leakage by adopting an intensive and standardized workflow is essential to improve the quality and generalizability of the radiomics model. • The application of radiomics in combination with clinical features in differentiating high-grade gliomas from brain metastasis needs further validation.

When is a staging scan required for newly diagnosed brain lesions on CT? A multivariate logistic regression analysis

PURPOSE

For patients with a new lesion on CT head (CTH) suspected to be a brain tumor, a staging chest, abdomen, and pelvis CT (CTCAP) is only warranted if a metastatic lesion is suspected. Unnecessary CTCAPs are often performed too early in a patient's journey due to poor patient selection. We sought to create a protocol to guide the selection of patients for CTCAPs based on their CTH findings.

METHODS

Patients with suspected new brain tumors discussed at the neuro-oncology MDT at a tertiary neurosurgical center were reviewed. Patient demographics and CTH features were collected. For protocol creation, data was collected from July to December 2020, and predictor variables were identified using multivariate logistic regression. Candidate protocols were assessed in a protocol testing stage using similar data collected from January to June 2021. Sensitivity, specificity, and area under the curve (AUC) were computed for each protocol.

RESULTS

Variables from the protocol creation stage (222 patients) were assessed in the protocol testing stage (216 patients). The most sensitive variables predicting metastatic disease were a previous history of cancer, multiple lesions, lesion < 4 cm, and infratentorial location. A protocol recommending a CTCAP based on the presence of one of these features has a sensitivity of 99.1% (AUC 0.704).

CONCLUSIONS

Unnecessary CTCAPs are reduced if performed only if a patient has one of the four identified predictor variables.

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.

Recent insights into the microRNA-dependent modulation of gliomas from pathogenesis to diagnosis and treatment

Gliomas are the most lethal primary brain tumors in adults. These highly invasive tumors have poor 5-year survival for patients. Gliomas are principally characterized by rapid diffusion as well as high levels of cellular heterogeneity. However, to date, the exact pathogenic mechanisms, contributing to gliomas remain ambiguous. MicroRNAs (miRNAs), as small noncoding RNAs of about 20 nucleotides in length, are known as chief modulators of different biological processes at both transcriptional and posttranscriptional levels. More recently, it has been revealed that these noncoding RNA molecules have essential roles in tumorigenesis and progression of multiple cancers, including gliomas. Interestingly, miRNAs are able to modulate diverse cancer-related processes such as cell proliferation and apoptosis, invasion and migration, differentiation and stemness, angiogenesis, and drug resistance; thus, impaired miRNAs may result in deterioration of gliomas. Additionally, miRNAs can be secreted into cerebrospinal fluid (CSF), as well as the bloodstream, and transported between normal and tumor cells freely or by exosomes, converting them into potential diagnostic and/or prognostic biomarkers for gliomas. They would also be great therapeutic agents, especially if they could cross the blood–brain barrier (BBB). Accordingly, in the current review, the contribution of miRNAs to glioma pathogenesis is first discussed, then their glioma-related diagnostic/prognostic and therapeutic potential is highlighted briefly.

Salvage resection plus cesium-131 brachytherapy durably controls post-SRS recurrent brain metastases

BACKGROUND

Salvage of recurrent previously irradiated brain metastases (rBrM) is a significant challenge. Resection without adjuvant re-irradiation is associated with a high local failure rate, while reirradiation only partially reduces failure but is associated with greater radiation necrosis risk. Salvage resection plus Cs131 brachytherapy may offer dosimetric and biologic advantages including improved local control versus observation, with reduced normal brain dose versus re-irradiation, however data are limited.

METHODS

A prospective registry of consecutive patients with post-stereotactic radiosurgery (SRS) rBrM undergoing resection plus implantation of collagen-matrix embedded Cs131 seeds (GammaTile, GT Medical Technologies) prescribed to 60 Gy at 5 mm from the cavity was analyzed.

RESULTS

Twenty patients underwent 24 operations with Cs131 implantation in 25 tumor cavities. Median maximum preoperative diameter was 3.0 cm (range 1.1-6.3). Gross- or near-total resection was achieved in 80% of lesions. A median of 16 Cs131 seeds (range 6-30), with a median air-kerma strength of 3.5 U/seed were implanted. There was one postoperative wound dehiscence. With median follow-up of 1.6 years for survivors, two tumors recurred (one in-field, one marginal) resulting in 8.4% 1-year progression incidence (95%CI = 0.0-19.9). Radiographic seed settling was identified in 7/25 cavities (28%) 1.9-11.7 months post-implantation, with 1 case of distant migration (4%), without clinical sequelae. There were 8 cases of radiation necrosis, of which 4 were symptomatic.

CONCLUSIONS

With > 1.5 years of follow-up, intraoperative brachytherapy with commercially available Cs131 implants was associated with favorable local control and toxicity profiles. Weak correlation between preoperative tumor geometry and implanted tiles highlights a need to optimize planning criteria.

Therapeutic role of memantine for the prevention of cognitive decline in cancer patients with brain metastasis receiving whole-brain radiotherapy: a narrative review

Brain metastases are the most common central nervous system tumors. The mainstay treatment for this tumor in low to middle income countries is whole brain radiation therapy. Irreversible cognitive decline is associated with the use of whole brain radiotherapy. Several pharmacologic and nonpharmacologic options have been employed in studies focusing on the prevention of cognitive decline following whole-brain radiation therapy. Memantine use has been shown to provide some benefit in reducing the rate of decline in cognitive function and time to cognitive failure. The objective of this review article is to provide a summary on available primary literature on the therapeutic role of memantine for the prevention of cognitive decline in cancer patients with brain metastasis receiving whole brain radiotherapy.