Mechanism of action and therapeutic potential of dimethyl fumarate in ischemic stroke.

Dimethyl fumarate (DMF) is an immunomodulatory drug currently approved for the treatment of multiple sclerosis and psoriasis. Its benefits on ischemic stroke outcomes have recently come to attention. To date, only tissue plasminogen activators (tPAs) and clot retrieval methods have been approved by the FDA for the treatment of ischemic stroke. Ischemic conditions lead to inflammation through diverse mechanisms, and recanalization can worsen the state. DMF and the nuclear factor erythroid-derived 2-related factor 2 (Nrf2) pathway it regulates seem to be important in postischemic inflammation, and animal studies have demonstrated that the drug improves overall stroke outcomes. Although the exact mechanism is still unknown, studies indicate that these beneficial impacts are due to the modulation of immune responses, blood-brain barrier permeability, and hemodynamic adjustments. One major component evaluated before, during, and after tPA therapy in stroke patients is blood pressure (BP). Recent studies have found that DMF may impact BP. Both hypotension and hypertension need correction before treatment, which may delay the appropriate intervention. Since BP management is crucial in managing stroke patients, it is important to consider DMF's role in this matter. That being said, it seems further investigations on DMF may lead to an alternative approach for stroke patients. In this article, we discuss the mechanistic roles of DMF and its potential role in stroke based on previously published literature and laboratory findings.

Is the risk of COVID-19 contraction increased in patients with epilepsy?

OBJECTIVE: The aim of the current study was to investigate the rates of contracting COVID-19 in various populations to provide evidence on the susceptibility of patients with epilepsy (PWE) to contracting symptomatic COVID-19. METHODS: We surveyed a random sample of three groups of people: patients with epilepsy, people with psychiatric problems, and a group of the general population. The survey included four general questions (age, sex, education, and medical/psychiatric problem) and four COVID-19 specific questions (contracting COVID-19, relatives with COVID-19, wearing a face mask, and frequent hand washings). RESULTS: Three hundred and fifty -eight people were surveyed (108 healthy individuals, 154 patients with epilepsy, and 96 patients with psychiatric problems). Thirty-eight (11%) people had a history of COVID-19 contraction. The only factor that had a significant association with COVID-19 contraction was a relative with COVID-19 (Odds Ratio: 5.82; 95% Confidence Interval: 2.85-11.86; p = 0.0001). Having epilepsy did not increase the risk of COVID-19 contraction. CONCLUSION: Symptomatic COVID-19 does not seem to be more likely in PWE. The single most important factor associated with contracting COVID-19 is a close relative with this infection. Isolation of people with SARS-CoV-2 infection and observation of their close contacts may reduce the risk of secondary infections.

Multimodality oncologic evaluation of superficial neck and facial lymph nodes.

Involvement of lymph nodes in patients with head and neck cancers impacts treatment and prognosis. Head and neck lymph nodes are comprised of superficial and deep groups which are interconnected. The deep lymph nodes, predominantly centered along internal jugular veins, are very well-known to radiologists and clinicians. However, superficial lymph nodes that drain lymph from the scalp, face, and neck are much less recognized. Here, we describe the anatomic and imaging features of these superficial lymph nodes on CT, MRI, and PET in oncologic settings.

Utility of susceptibility-weighted imaging and arterial spin perfusion imaging in pediatric brain arteriovenous shunting.

INTRODUCTION: The objectives of the study are to investigate the application of susceptibility-weighted imaging (SWI) and arterial spin labeling (ASL) imaging in the assessment of shunting and the draining veins in pediatric patients with arteriovenous shunting and compare the utility of SWI and ASL with conventional MR and digital subtraction angiography (DSA). METHODS: This study is a retrospective study of 19 pediatric patients with arteriovenous shunting on brain MRI who were also evaluated with DSA. We assessed the ability of conventional MRI sequences, susceptibility magnitude images, phase-filtered SWI images, and pulsed ASL images in the detection of arteriovenous (AV) shunting, number of draining veins and drainage pathways in comparison to DSA. RESULTS: The mean number of detected draining veins on DSA (3.63) was significantly higher compared to SWI phase-filtered image (mean = 2.72), susceptibility magnitude image (mean = 2.92), ASL (mean = 1.76) and conventional MRI (2.47) (p < 0.05). Pairwise comparison of DSA difference scores (i.e., difference between MR modalities in the number of missed draining veins) revealed no difference between the MR modalities (p > 0.05). ASL was the only method that correctly identified superficial and deep venous drainage in all patients. Regarding detection of shunting, ASL, SWI phase-filtered, and magnitude images demonstrated shunting in 100, 83, and 84% of patients, respectively. CONCLUSION: SWI depicts a higher number of draining vein compared to conventional MR pulse sequences. ASL is a sensitive approach in showing 100% sensitivity in the detection of AV shunting and in the diagnosis of the pattern of venous drainage. The present findings suggest the added utility of both SWI and ASL in the assessment of AV shunting.

High-resolution 3-T MR imaging of the temporal part of the caudate tail in children.

BACKGROUND AND PURPOSE: This study aims to investigate the high-resolution 3-T MRI appearance and morphological variation of the temporal part of the caudate tail in pediatric subjects with normal brain MR examinations. PATIENTS AND METHODS: One hundred pediatric patients were retrospectively evaluated using a high-resolution 3-T imaging protocol. Different morphological parameters including shape, size, and symmetry were evaluated. The appearance and shape of the caudate tail were classified into nodular, linear, or imperceptible. The location and relation of the caudate tail to the temporal horn and adjacent brain parenchyma were categorized. Relationships between age, gender, shape, location, side, and the cross-sectional area of the caudate tail were investigated. RESULTS: The caudate tail was imperceptible in 22 %, had a nodular shape in 66.5 %, and was flat in 11.5 %. There was asymmetry of the caudate tail between the two sides in 37 % of subjects. The caudate tail was completely embedded within the temporal lobe parenchyma in 8.3 %, completely protruding into the temporal horn in 27.5 %, or intermediate in 64.1 %. The mean cross-sectional area of the caudate tail was constant across ages despite the varied age range of the subjects. There was no difference in overall mean cross-sectional area of the caudate tail between the two sides. CONCLUSION: There is a wide variation in the appearance of the caudate tail adjacent to the temporal horn of the lateral ventricle. Identification of anatomical variation of the caudate tail may prevent potential diagnostic pitfalls, especially with respect to subependymal heterotopia.

Deep renal ectopia causing sciatic mononeuropathy.

INTRODUCTION: Sciatic mononeuropathy resulting from compression by an adjacent pelvic ectopic kidney has not been reported in the literature. Here, the authors present a case of a patient presenting with unilateral lower extremity paresthesia correlating to the sciatic nerve distribution. RESULTS: MRI examination demonstrated lumbosacral plexus compression by a very unusual deeply situated renal ectopia. Physicians should consider other rare causes of mechanical lumbosacral plexus compression in patients with sciatic symptomatology.

Intrarenal epidermoid cyst mimicking a cystic renal cell carcinoma: A case report and review of literature.

Key Clinical Message: This case highlights the diagnostic pitfalls that can occur when evaluating complex cystic renal masses. Distinguishing epidermoid cysts from renal cell carcinoma is difficult but imperative to guide conservative management when appropriate, avoiding unnecessary nephrectomy. Abstract: Renal epidermoid cysts are extremely rare, with only 12 cases reported in the literature. Their radiographic features often resemble cystic renal cell carcinoma, frequently prompting unnecessary nephrectomy. A 64-year-old man with a history of nephrolithiasis presented with left flank pain and hematuria. Imaging revealed a complex cystic renal mass suspicious for renal cell carcinoma. Following left radical nephrectomy, histopathology examination revealed a benign epidermoid cyst. Renal presentation of epidermoid cyst poses unique diagnostic and therapeutic challenges. Possible pathogenesis includes ectopic epidermal implantation during embryogenesis or squamous metaplasia following chronic irritation or deficiency. Radiographic distinction from concerning entities like renal cell carcinoma is difficult but imperative to avoid extensive surgery. This case highlights the diagnostic pitfalls and management considerations for renal epidermoid cysts. Additional study of clinical and imaging factors that distinguish epidermoid cysts from renal cell carcinoma can guide conservative management when appropriate, avoiding unnecessary nephrectomy for benign disease.

Osteoma in the upper cervical spine: A case report and comprehensive literature review.

INTRODUCTION AND IMPORTANCE: Osteoma is a benign, and usually asymptomatic bone tumor normally found in the skull and facial bones, although it can occasionally occur in the long bones and spine. CASE PRESENTATION: In this article, we present a 49-year-old male patient who experienced progressive neck pain accompanied by left-sided radicular pain symptoms. Clinical investigation using various imaging techniques confirmed a bone-forming lesion located within the C1 vertebrae region. Treatment involved performing hemilaminectomy of C1 along with resection for complete removal of this extradural bone lesion, ultimately achieving symptom relief. Histopathological examination of the resected specimen leads to the diagnosis of osteoma. Along with reporting this case, we conducted a comprehensive literature review of the previously reported spinal osteoma cases. CLINICAL DISCUSSION: Histopathological examination confirmed the diagnosis of osteoma. A comprehensive literature review was conducted, revealing 16 previously reported cases of spinal osteoma. Among these, only one case involved the C1 vertebra and presented similar neurological symptoms. The review underscores the rarity of spinal osteomas and the importance of surgical intervention for symptom relief. CONCLUSION: Spinal osteomas are rare but should be considered in the differential diagnosis of patients presenting with neck pain and radicular symptoms. Surgical removal of the lesion is often necessary for symptom relief, as highlighted by our case and supported by the literature review. This case adds to the limited body of evidence on spinal osteomas and emphasizes the importance of a multidisciplinary approach for optimal patient outcomes.

Effect of the COVID-19 Pandemic on Seizure Control Status in Patients with Epilepsy.

Background: Previous studies have shown that patients with epilepsy (PWE) perceived significant disruption in the quality and provision of care due to the coronavirus disease 2019 (COVID-19) pandemic. The present study aimed to investigate the effect of this pandemic on seizure control status and changes in seizure frequency in PWE. Methods: A consecutive sample of adult PWE registered in the database of Shiraz Epilepsy Center (Shiraz, Iran) was included in the study. In July 2021, phone interviews were conducted with all selected patients. Information such as age, sex, last seizure, seizure type, and frequency during the 12 months before the study, and history of COVID-19 contraction was extracted. The seizure control status of the patients in 2019 (pre-pandemic) was compared with that during the COVID-19 pandemic. Data were analyzed using SPSS software with the Fisher's exact test and Pearson's Chi squared test. P<0.05 was considered statistically significant. Results: A total of 158 patients were included in the study, out of which 62 (39.2%) patients had a stable seizure control status, 47 (29.7%) had fewer seizures, and 50 (31.6%) had more seizures. Breakthrough seizures were reported by 32 (34.4%) patients. Seizure frequency increased in 18 (27.7%) and decreased in 46 (70.7%) patients. Conclusion: Overall, the COVID-19 pandemic has not been a major precipitating factor nor has it affected the seizure control status of PWE. In treated epilepsy, a fluctuating course with periods of seizure freedom followed by relapses is part of its natural history.

COVID-19 Vaccine Hesitancy Among Patients With Epilepsy or Other Chronic Conditions.

OBJECTIVES: The aim of this study was to investigate the opinions of different groups of people in Iran on their willingness to receive a coronavirus disease 2019 (COVID-19) vaccine. METHODS: In this cross-sectional study, we surveyed a sample (based on consecutive referrals) of 5 groups of people in late 2020: a group of the general population from Shiraz (without a history of any chronic medical or psychiatric problems), patients with epilepsy, patients with diabetes mellitus (DM), patients with cardiac problems, and patients with psychiatric problems. The survey included 4 general questions and 3 COVID-19-specific questions. RESULTS: A total of 582 people participated. In total, 66 (11.3%) people expressed that they were not willing to receive a COVID-19 vaccine. Psychiatric disorders (odds ratio [OR]: 3.15; 95% confidence interval [CI]: 1.31-7.60; P = 0.006) and male sex (OR: 2.10; 95% CI: 1.23-3.58; P = 0.010) were significantly associated with COVID-19 vaccine hesitancy. CONCLUSION: Vaccine hesitancy is a global issue. Patients with psychiatric disorders had the highest rate of vaccine hesitancy. Previous studies have shown that depression and anxiety are associated with a reduced adherence to the recommended medical advice. Why male sex is associated with vaccine hesitancy is not clear. Researchers should investigate the rates and the factors affecting the vaccine hesitancy in their corresponding communities.

Mask Wearing Hesitancy During the COVID-19 Pandemic in South Iran.

PURPOSE: The aim of the current study was to investigate the prevalence of face mask wearing among different groups of people in south Iran. We also investigated the associations between mask wearing hesitancy and various factors. METHODS: We surveyed a sample (convenience sampling) of 5 groups of people: general population, people with epilepsy, people with diabetes mellitus (DM), people with cardiac problems, and people with psychiatric problems. The survey included 4 general questions (age, sex, education, and medical/psychiatric problem) and 4 coronavirus disease 2019 (COVID-19)-specific questions (contracting COVID-19, relatives with COVID-19, wearing a face mask while in crowded places, and the frequency of daily hand washings). RESULTS: A total of 582 people (153 people with epilepsy, 127 patients with DM, 98 people with cardiac problems, 96 patients with psychiatric disorders, and 108 healthy individuals) participated. Twenty-eight (4.8%) people expressed that they do not wear a face mask when at crowded places. A lower education and less frequent daily hand washings had associations with mask wearing hesitancy. CONCLUSIONS: Mask wearing hesitancy is a concern during a respiratory viral disease pandemic. Paying attention to personal variables, especially if they are modifiable (eg, education and hygiene), is probably productive and practical in promoting mask wearing culture.

Detection of Angiographically Occult Ruptured Basilar Sidewall Perforator Aneurysm by Vessel Wall MR Imaging.

Basilar artery perforator aneurysms are rare with a prevalence of less than 1%. These are particularly challenging to detect given their small size and tendency to intermittently thrombose. We describe a case of a ruptured basilar artery sidewall perforator aneurysm that was angiographically occult on computed tomographic angiogram and cerebral catheter angiogram. One day after the initial diagnostic work-up, intracranial vessel wall MR imaging (VWI) was performed which revealed a small outpouching along the right posterolateral basilar arterial wall with a punctate enhancing focus suggestive of a thrombosed basilar perforator artery aneurysm. Thrombus within the small aneurysm sac likely contributed to the poor opacification of the aneurysm sac on conventional lumen-based imaging techniques. Ruptured aneurysms have high morbidity and mortality due to their tendency to rebleed, making their expedient detection and treatment imperative. This case highlights the role VWI can play in detecting small ruptured aneurysms that intermittently thrombose and are otherwise challenging to diagnose with conventional vessel imaging.

Anatomical Variations, Mimics, and Pitfalls in Imaging of Patients with Epilepsy.

Epilepsy is among one of the most common neurologic disorders. The role of magnetic resonance imaging (MRI) in the diagnosis and management of patients with epilepsy is well established, and most patients with epilepsy are likely to undergo at least one or more MRI examinations in the course of their disease. Recent advances in high-field MRI have enabled high resolution in vivo visualization of small and intricate anatomic structures that are of great importance in the assessment of seizure disorders. Familiarity with normal anatomic variations is essential in the accurate diagnosis and image interpretation, as these variations may be mistaken for epileptogenic foci, leading to unnecessary follow-up imaging, or worse, unnecessary treatment. After a brief overview of normal imaging anatomy of the mesial temporal lobe, this article will review a few important common and uncommon anatomic variations, mimics, and pitfalls that may be encountered in the imaging evaluation of patients with epilepsy.

Pharmacotherapeutic approach toward urological medications and vaccination during COVID-19: a narrative review.

One year after the prevalence of the novel coronavirus pandemic, some aspects of the physiopathology, treatment and progression of coronavirus 2019 disease (COVID-19) have remained unknown. Since no comprehensive study on the use of urological medications in patients with COVID-19 has been carried out, this narrative review aimed to focus on clinically important issues about the treatment of COVID-19 and urologic medications regarding efficacy, modifications, side effects and interactions in different urologic diseases. In this review, we provide information about the pharmacotherapeutic approach toward urologic medications in patients with COVID-19 infection. This study provides an overview of medications in benign prostatic hyperplasia, prostate cancer, impotence and sexual dysfunction, urolithiasis, kidney transplantation and hypertension as the most frequent diseases in which the patients are on long-term medications. Also, the effect of urologic drugs on the efficacy of vaccination is briefly discussed.

Association of plasma cell-free DNA with survival in patients with IDH wild-type glioblastoma.

BACKGROUND: We aimed to determine whether plasma cell-free DNA (cfDNA) concentration is associated with survival in patients with isocitrate dehydrogenase (IDH) wild-type glioblastoma (GBM). METHODS: Pre-operative and post-chemoradiotherapy blood samples were prospectively collected from patients with newly diagnosed IDH wild-type GBM. Patients underwent surgical resection or biopsy and received adjuvant radiotherapy with concomitant temozolomide. Cell-free DNA (cfDNA) was isolated from plasma and quantified using SYBR Green-based q polymerase chain reaction (qPCR). RESULTS: Sixty-two patients were enrolled and categorized into high vs. low cfDNA groups relative to the pre-operative median value (25.2 ng/mL, range 5.7-153.0 ng/mL). High pre-operative cfDNA concentration was associated with inferior PFS (median progression-free survival (PFS), 3.4 vs. 7.7 months; log-rank P = .004; hazard ratio [HR], 2.19; 95% CI, 1.26-3.81) and overall survival (OS) (median OS, 8.0 vs. 13.9 months; log-rank P = .01; HR, 2.43; 95% CI, 1.19-4.95). After adjusting for risk factors, including O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status, pre-operative cfDNA remained independently associated with PFS (HR, 2.70; 95% CI, 1.50-4.83; P = .001) and OS (HR, 2.65; 95% CI, 1.25-5.59; P = .01). Post-hoc analysis of change in cfDNA post-chemoradiotherapy compared to pre-surgery (n = 24) showed increasing cfDNA concentration was associated with worse PFS (median, 2.7 vs. 6.0 months; log-rank P = .003; HR, 4.92; 95% CI, 1.53-15.84) and OS (median, 3.9 vs. 19.4 months; log-rank P < .001; HR, 7.77; 95% CI, 2.17-27.76). CONCLUSIONS: cfDNA concentration is a promising prognostic biomarker for patients with IDH wild-type GBM. Plasma cfDNA can be obtained noninvasively and may enable more accurate estimates of survival and effective clinical trial stratification.

Surgical approach is associated with complication rate in sinonasal malignancy: A multicenter study.

BACKGROUND: Management of sinonasal malignancy (SNM) often includes surgical resection as part of the multimodality treatment. Treatment-related surgical morbidity can occur, yet risk factors associated with complications in this population have not been sufficiently investigated. METHODS: Adult patients with histologically confirmed SNM whose primary treatment included surgical resection were prospectively enrolled into an observational, multi-institutional cohort study from 2015 to 2020. Sociodemographic, disease, and treatment data were collected. Complications assessed included cerebrospinal fluid leak, orbital injury, intracranial injury, diplopia, meningitis, osteoradionecrosis, hospitalization for neutropenia, and subsequent chronic rhinosinusitis. The surgical approach was categorized as endoscopic resection (ER) or open/combined resection (O/CR). Associations between factors and complications were analyzed using Student's t test, Fisher's exact test, and logistic regression modeling. RESULTS: Overall, 142 patients met the inclusion criteria. Twenty-three subjects had at least 1 complication (16.2%). On unadjusted analysis, adjuvant radiation therapy was associated with developing a complication (91.3% vs 65.5%, p = 0.013). Compared with the ER group (n = 98), the O/CR group (n = 44) had a greater percentage of higher T-stage lesions (p = 0.004) and more frequently received adjuvant radiation (84.1% vs 64.4%, p = 0.017) and chemotherapy (50.0% vs 30.6%, p = 0.038). Complication rates were similar between the ER and O/CR groups without controlling for other factors. Regression analysis that retained certain factors showed O/CR was associated with increased odds of experiencing a complication (odds ratio, 3.34; 95% confidence interval, 1.06-11.19). CONCLUSIONS: Prospective, multicenter evaluation of SNM treatment outcomes is feasible. Undergoing O/CR was associated with increased odds of developing a complication after accounting for radiation therapy. Further studies are warranted to build upon these findings.

Emerging Techniques in Imaging of Glioma Microenvironment.

Magnetic resonance imaging (MRI) has been the cornerstone of imaging of brain tumors in the past 4 decades. Conventional MRI remains the workhorse for neuro-oncologic imaging, not only for basic information such as location, extent, and navigation but also able to provide information regarding proliferation and infiltration, angiogenesis, hemorrhage, and more. More sophisticated MRI sequences have extended the ability to assess and quantify these features; for example, permeability and perfusion acquisitions can assess blood-brain barrier disruption and angiogenesis, diffusion techniques can assess cellularity and infiltration, and spectroscopy can address metabolism. Techniques such as fMRI and diffusion fiber tracking can be helpful in diagnostic planning for resection and radiation therapy, and more sophisticated iterations of these techniques can extend our understanding of neurocognitive effects of these tumors and associated treatment responses and effects. More recently, MRI has been used to go beyond such morphological, physiological, and functional characteristics to assess the tumor microenvironment. The current review highlights multiple recent and emerging approaches in MRI to characterize the tumor microenvironment.

Epilepsy Lesion Localization is not Predicted by Developmental Venous Anomaly Location or its FDG-PET Metabolic Activity.

BACKGROUND AND PURPOSE: This study's purpose is to correlate location and metabolic activity of developmental venous anomalies (DVAs) in epilepsy patients to the seizure focus as determined by ictal/interictal encephaloelectrogram (EEG). METHODS: A retrospective search was performed for epilepsy patients with DVAs who underwent brain 18 F-fluorodeoxyglucose positron emission tomography (18 F-FDG-PET) and magnetic resonance imaging (MRI). MRI exams were analyzed to characterize DVA location and associated structural findings. MRI and PET images were co-registered and assessment of 18 F-FDG uptake in the DVA territory was performed. The electronic medical record was reviewed for each subject to determine seizure semiology and site of seizure focus by ictal/interictal EEG. RESULTS: Twenty-eight DVAs in 25 patients were included. Twelve DVAs demonstrated regional metabolic abnormality on 18 F-FDG-PET. There was no significant correlation between DVA site and seizure focus on EEG. DVA location was concordant with EEG seizure focus in three subjects, and all three demonstrated hypometabolism on 18 F-FDG-PET. This significance remains indeterminate, as one of these DVAs was associated with cavernoma, which could serve as the true seizure focus, and one of the patients underwent resection of the DVA without decrease in seizure frequency. Furthermore, there was no statistically significant relationship between DVA metabolic activity and DVA-EEG lobar or laterality concordance. CONCLUSIONS: In this sample, there is no significant correlation between location of DVA and seizure focus, and hypometabolism within the DVA territory is not predictive of EEG/DVA co-localization. As use of 18 F-FDG-PET for evaluation of epilepsy increases, knowledge of this poor correlation is important to avoid diagnostic confusion and potentially unnecessary surgery in epilepsy patients.

Imaging and histopathologic correlates of plasma cell-free DNA concentration and circulating tumor DNA in adult patients with newly diagnosed glioblastoma.

BACKGROUND: Plasma cell-free DNA (cfDNA) concentration is lower in glioblastoma (GBM) compared to other solid tumors, which can lead to low circulating tumor DNA (ctDNA) detection. In this study, we investigated the relationship between multimodality magnetic resonance imaging (MRI) and histopathologic features with plasma cfDNA concentration and ctDNA detection in patients with treatment-naive GBM. METHODS: We analyzed plasma cfDNA concentration, MRI scans, and tumor histopathology from 42 adult patients with newly diagnosed GBM. Linear regression analysis was used to examine the relationship of plasma cfDNA concentration before surgery to imaging and histopathologic characteristics. In a subset of patients, imaging and histopathologic metrics were also compared between patients with and without a detected tumor somatic mutation. RESULTS: Tumor volume with elevated (>1.5 times contralateral white matter) rate transfer constant (K ep, a surrogate of blood-brain barrier [BBB] permeability) was independently associated with plasma cfDNA concentration (P = .001). Histopathologic characteristics independently associated with plasma cfDNA concentration included CD68+ macrophage density (P = .01) and size of tumor vessels (P = .01). Patients with higher (grade ≥3) perivascular CD68+ macrophage density had lower volume transfer constant (K trans, P = .01) compared to those with lower perivascular CD68+ macrophage density. Detection of at least 1 somatic mutation in plasma cfDNA was associated with significantly lower perivascular CD68+ macrophages (P = .01). CONCLUSIONS: Metrics of BBB disruption and quantity and distribution of tumor-associated macrophages are associated with plasma cfDNA concentration and ctDNA detection in GBM patients. These findings represent an important step in understanding the factors that determine plasma cfDNA concentration and ctDNA detection.