MRI sequences and interslice gap influence leptomeningeal metastasis detection in children with brain tumors.

Purpose: Accurate detection of leptomeningeal metastasis (LM) is critical for risk stratification and treatment of pediatric brain tumors. Poor-quality staging MRI has been associated with decreased survival in this population, but technical factors differentiating good from poor quality screening MRIs remain undefined. To test the hypothesis that key technical factors are associated with accurate MRI diagnosis of leptomeningeal metastasis in children with leptomeningeal seeding brain tumors.

Pretreatment Normal WM Magnetization Transfer Ratio Predicts Risk of Radiation Necrosis in Patients with Medulloblastoma.

Background And Purpose: Radiation necrosis, for which abnormal WM enhancement is a hallmark, is an uncommon complication of craniospinal irradiation in children with medulloblastoma. The magnetization transfer ratio measures macromolecular content, dominated by myelin in the WM. We investigated whether the pretreatment supratentorial (nonsurgical) WM magnetization transfer ratio could predict patients at risk for radiation necrosis after radiation therapy for medulloblastoma.

Revised clinical and molecular risk strata define the incidence and pattern of failure in medulloblastoma following risk-adapted radiotherapy and dose-intensive chemotherapy: results from a phase III multi-institutional study.

Background: We characterize the patterns of progression across medulloblastoma (MB) clinical risk and molecular subgroups from SJMB03, a Phase III clinical trial.

Methods: One hundred and fifty-five pediatric patients with newly diagnosed MB were treated on a prospective, multi-center phase III trial of adjuvant radiotherapy (RT) and dose-intense chemotherapy with autologous stem cell transplant. Craniospinal radiotherapy to 23.

Serial assessment of measurable residual disease in medulloblastoma liquid biopsies.

Nearly one-third of children with medulloblastoma, a malignant embryonal tumor of the cerebellum, succumb to their disease. Conventional response monitoring by imaging and cerebrospinal fluid (CSF) cytology remains challenging, and a marker for measurable residual disease (MRD) is lacking. Here, we show the clinical utility of CSF-derived cell-free DNA (cfDNA) as a biomarker of MRD in serial samples collected from children with medulloblastoma (123 patients, 476 samples) enrolled on a prospective trial.

The use of imaging to identify immunocompromised children requiring biopsy for invasive fungal rhinosinusitis.

Background And Purpose: Children with severe immunocompromise due to cancer therapy or hematopoietic cell transplant are at risk both for potentially lethal invasive fungal rhinosinusitis (IFRS), and for complications associated with gold-standard biopsy diagnosis. We investigated whether early imaging could reliably identify or exclude IFRS in this population, thereby reducing unnecessary biopsy.

Methods: We reviewed clinical/laboratory data and cross-sectional imaging from 31 pediatric patients evaluated for suspicion of IFRS, 19 without (age 11.

Utility of Pre-Hematopoietic Cell Transplantation Sinus CT Screening in Children and Adolescents.

Background And Purpose: The clinical benefit of pre-hematopoietic cell transplantation sinus CT screening remains uncertain, while the risks of CT radiation and anesthesia are increasingly evident. We sought to re-assess the impact of screening sinus CT on pretransplantation patient management and prediction of posttransplantation invasive fungal rhinosinusitis.

Materials And Methods: Pretransplantation noncontrast screening sinus CTs for 100 consecutive patients (mean age, 11.

Risk stratification in pediatric low-grade glioma and glioneuronal tumor treated with radiation therapy: an integrated clinicopathologic and molecular analysis.

Background: Management of unresectable pediatric low-grade glioma and glioneuronal tumor (LGG/LGGNT) is controversial. There are no validated prognostic features to guide use of radiation therapy (RT). Our study aimed to identify negative prognostic features in patients treated with RT using clinicopathologic and molecular data and validate these findings in an external dataset.

Septal dysembryoplastic neuroepithelial tumor: a comprehensive clinical, imaging, histopathologic, and molecular analysis.

Background: Dysembryoplastic neuroepithelial tumors (DNETs) are uncommon neural tumors presenting most often in children and young adults and associated with intractable seizures. Rare midline neoplasms with similar histological features to those found in DNETs have been described near the septum pellucidum and termed "DNET-like neoplasms of the septum pellucidum." Due to their rarity, these tumors have been described in just a few reports and their genetic alterations sought only in small series.

Tectal glioma as a distinct diagnostic entity: a comprehensive clinical, imaging, histologic and molecular analysis.

Tectal glioma (TG) is a rare low-grade tumor occurring predominantly in the pediatric population. There has been no detailed analysis of molecular alterations in TG. Risk factors associated with inferior outcome and long-term sequelae of TG have not been well-documented.

Isolated Optic Nerve Glioma in Children With and Without Neurofibromatosis: Retrospective Characterization and Analysis of Outcomes.

Isolated optic nerve glioma is a rare tumor with no consensus for the best therapeutic approach. Therefore, tumor control and preservation of visual function remain a challenge. In this retrospective study, we describe our experience over 30 years in a single-institutional cohort of children with isolated optic nerve glioma, focusing on treatments and visual outcomes.

Marked functional recovery and imaging response of refractory optic pathway glioma to BRAFV600E inhibitor therapy: a report of two cases.

Background: Despite appropriate therapeutic interventions, progressive optic pathway glioma (OPG) in children may result in loss of vision and other neurologic morbidities. Molecularly targeted therapy against the MAP kinase pathway holds promise in improving outcomes while resulting in lower treatment-related toxicities. We report two children with refractory OPG who had a substantial and early reversal of their neurologic deficits and an impressive imaging response of their tumor to BRAFV600E inhibition therapy.

Therapeutic and Prognostic Implications of BRAF V600E in Pediatric Low-Grade Gliomas.

Purpose BRAF V600E is a potentially highly targetable mutation detected in a subset of pediatric low-grade gliomas (PLGGs). Its biologic and clinical effect within this diverse group of tumors remains unknown. Patients and Methods A combined clinical and genetic institutional study of patients with PLGGs with long-term follow-up was performed (N = 510).

Disrupted development and integrity of frontal white matter in patients treated for pediatric medulloblastoma.

Background: Treatment of pediatric medulloblastoma is associated with known neurocognitive deficits that we hypothesize are caused by microstructural damage to frontal white matter (WM).

Methods: Longitudinal MRI examinations were collected from baseline (after surgery but before therapy) to 36 months in 146 patients and at 3 time points in 72 controls. Regional analyses of frontal WM volume and diffusion tensor imaging metrics were performed and verified with tract-based spatial statistics.

Developmental Venous Anomalies Mimicking Neoplasm on 11C-Methionine PET and DSC Perfusion MRI.

Elevated relative cerebral blood volume on perfusion MRI and increased uptake on C-methionine PET can be used to diagnose and guide biopsy of brain tumors but are not specific. We report increased uptake on C-methionine PET associated with 4 developmental venous anomalies (DVAs) in 3 children with brain tumors, which could potentially mimic tumor and misdirect biopsy. Because DVAs are not readily visible on CT, prevention of misdirected biopsy in patients with focally elevated C-methionine uptake and relative cerebral blood volume relies on close correlation with contrast-enhanced anatomic MRI to exclude DVA or other nonneoplastic etiology.

Relative ADC and Location Differ between Posterior Fossa Pilocytic Astrocytomas with and without Gangliocytic Differentiation.

Background And Purpose: Pilocytic astrocytomas, the most common posterior fossa tumors in children, are characterized by KIAA1549-BRAF fusions and shows excellent 5-year survival rates. Pilocytic astrocytoma with gangliocytic differentiation, a recently defined pilocytic astrocytoma variant that includes glial and neuronal elements similar to a ganglioglioma, may be distinguished from a classic ganglioglioma by molecular, radiologic, and histopathologic features. This study investigated whether imaging could distinguish posterior fossa pilocytic astrocytoma with and without gangliocytic differentiation.

Orbital Metastasis Is Associated With Decreased Survival in Stage M Neuroblastoma.

Background: Approximately 30% of patients with metastatic (stage M) neuroblastoma present with periorbital ecchymosis from orbital osseous disease. Though locoregional disease is staged by imaging, the prognostic significance of metastatic site in stage M disease is unknown. We hypothesize that, compared to nonorbital metastasis, orbital metastasis is associated with decreased survival in patients with stage M neuroblastoma, and that periorbital ecchymosis reflects location and extent of orbital disease.

Postoperative intraspinal subdural collections after pediatric posterior fossa tumor resection: incidence, imaging, and clinical features.

Background And Purpose: Postoperative intraspinal subdural collections in children after posterior fossa tumor resection may temporarily hinder metastasis detection by MR imaging or CSF analysis, potentially impacting therapy. We investigated the incidence, imaging and clinical features, predisposing factors, and time course of these collections after posterior fossa tumor resection.

Materials And Methods: Retrospective review of postoperative spine MRI in 243 children (5.

Transcatheter aortic valve implantation of the direct flow medical aortic valve with minimal or no contrast.

The 18F Direct Flow Medical (DFM) THV has conformable sealing rings, which minimizes aortic regurgitation and permits full hemodynamic assessment of valve performance prior to permanent implantation. During the DISCOVER trial, three patients who were at risk for receiving contrast media, two due to severe CKD and one due to a recent hyperthyroid reaction to contrast, underwent DFM implantation under fluoroscopic and transesophageal guidance without aortography during either positioning or to confirm the final position. Valve positioning was based on the optimal angiographic projection as calculated by the pre-procedural multislice CT scan.

Elevated cerebral blood volume contributes to increased FLAIR signal in the cerebral sulci of propofol-sedated children.

Background And Purpose: Hyperintense FLAIR signal in the cerebral sulci of anesthetized children is attributed to supplemental oxygen (fraction of inspired oxygen) but resembles FLAIR hypersignal associated with perfusion abnormalities in Moyamoya disease and carotid stenosis. We investigated whether cerebral perfusion, known to be altered by anesthesia, contributes to diffuse signal intensity in sulci in children and explored the relative contributions of supplemental oxygen, cerebral perfusion, and anesthesia to signal intensity in sulci.

Materials And Methods: Supraventricular signal intensity in sulci on pre- and postcontrast T2 FLAIR images of 24 propofol-sedated children (6.

Posterior fossa and spinal gangliogliomas form two distinct clinicopathologic and molecular subgroups.

Background: Gangliogliomas are low-grade glioneuronal tumors of the central nervous system and the commonest cause of chronic intractable epilepsy. Most gangliogliomas (>70%) arise in the temporal lobe, and infratentorial tumors account for less than 10%. Posterior fossa gangliogliomas can have the features of a classic supratentorial tumor or a pilocytic astrocytoma with focal gangliocytic differentiation, and this observation led to the hypothesis tested in this study - gangliogliomas of the posterior fossa and spinal cord consist of two morphologic types that can be distinguished by specific genetic alterations.