ABSTRACT
Congenital heart defect (CHD) is a birth defect that affects the structure of the heart. Although CHD is often multifactorial, it can also be inherited as part of a Mendelian disorder such as in congenital heart defect and ectodermal dysplasia (CHDED). This disorder is caused by de novo variants in PRKD1. Here, we describe a patient with a novel de novo variant of PRKD1 with phenotypic features consistent with CHDED. Previously unreported features were noted including high intracranial pressure (ICP), partial anomalous pulmonary venous return (PAPVR), and bifid uvula. We suggest that these features may be associated with CHDED.
Subject(s)
Cleft Palate , Ectodermal Dysplasia , Heart Defects, Congenital , Humans , Intracranial Pressure , Heart Defects, Congenital/complications , Heart Defects, Congenital/diagnosis , Heart Defects, Congenital/genetics , Ectodermal Dysplasia/complications , Ectodermal Dysplasia/diagnosis , Ectodermal Dysplasia/genetics , PhenotypeABSTRACT
OBJECTIVE: To test the hypothesis that de novo genetic variants are responsible for moyamoya disease (MMD) in children with unaffected relatives, we performed exome sequencing of 28 affected children and their unaffected parents. METHODS: Exome sequencing was performed on 28 trios of affected patients with MMD and unaffected parents. RESULTS: We identified 3 novel rare de novo RNF213 variants, 1 in the RING domain and 2 in a highly conserved region distal to the RING domain (4,114-4,120). These de novo cases of MMD present at a young age with aggressive MMD and uniquely have additional occlusive vascular lesions, including renal artery stenosis. Two previously reported cases had de novo variants in the same limited region and presented young with aggressive MMD, and 1 case had narrowing of the inferior abdominal aorta. CONCLUSIONS: These results indicate a novel syndrome associated with RNF213 rare variants defined by de novo mutations disrupting highly conserved amino acids in the RING domain and a discrete region distal to the RING domain delimited by amino acids 4,114 to 4,120 leading to onset of severe MMD before 3 years of age and occlusion of other arteries, including the abdominal aorta, renal, iliac, and femoral arteries.
Subject(s)
Adenosine Triphosphatases/genetics , Moyamoya Disease/genetics , Ubiquitin-Protein Ligases/genetics , Adult , Age of Onset , Aortic Diseases/genetics , Aortic Diseases/physiopathology , Arterial Occlusive Diseases/genetics , Arterial Occlusive Diseases/physiopathology , Child, Preschool , Female , Femoral Artery , Humans , Iliac Artery , Male , Moyamoya Disease/physiopathology , Mutation , Renal Artery Obstruction/genetics , Renal Artery Obstruction/physiopathologyABSTRACT
BACKGROUND: Frame registration is a critical step to ensure accurate electrode placement in stereotactic procedures such as stereoelectroencephalography (SEEG) and is routinely done by merging a computed tomography (CT) scan with the preoperative magnetic resonance (MR) examination. Three-dimensional fluoroscopy (XT) has emerged as a method for intraoperative electrode verification following electrode implantation and more recently has been proposed as a registration method with several advantages. METHODS: We compared the accuracy of SEEG electrode placement by frame registration with CT and XT imaging by analyzing the Euclidean distance between planned and post-implantation trajectories of the SEEG electrodes to calculate the error in both the entry (EP) and target (TP) points. Other variables included radiation dose, efficiency, and complications. RESULTS: Twenty-seven patients (13 CT and 14 XT) underwent placement of SEEG electrodes (319 in total). The mean EP and TP errors for the CT group were 2.3 mm and 3.3 mm, respectively, and 1.9 mm and 2.9 mm for the XT group, with no statistical difference (p = 0.75 and p = 0.246). The time to first electrode placement was similar (XT, 82 ± 10 min; CT, 84 ± 22 min; p = 0.858) and the average radiation exposure with XT (234 ± 55 mGy*cm) was significantly lower than CT (1245 ± 123 mGy*cm) (p < 0.0001). Four complications were documented with equal incidence in both groups. CONCLUSIONS: The use of XT as a method for registration resulted in similar implantation accuracy compared with CT. Advantages of XT are the substantial reduction in radiation dose and the elimination of the need to transfer the patient out of the room which may have an impact on patient safety and OR efficiency.
Subject(s)
Drug Resistant Epilepsy/diagnostic imaging , Drug Resistant Epilepsy/surgery , Electrodes, Implanted , Fluoroscopy , Imaging, Three-Dimensional , Adolescent , Electroencephalography , Female , Humans , Male , Postoperative Complications/etiology , Radiation Exposure , Stereotaxic Techniques , Tomography, X-Ray ComputedABSTRACT
PURPOSE: A preliminary survey of pediatric neurosurgeons working at different centers around the world suggested differences in clinical practice resulting in variation in the risk of pediatric cerebellar mutism (CM) and cerebellar mutism syndrome (CMS) after posterior fossa (PF) tumor resection. The purposes of this study were (1) to determine the incidence and severity of CM and CMS after midline PF tumor resection in children treated at these centers and (2) to identify potentially modifiable factors related to surgical management (rather than tumor biology) that correlate with the incidence of CM/CMS. METHODS: Attending pediatric neurosurgeons at British Columbia's Children's Hospital (BCCH) and neurosurgeons who completed a pediatric neurosurgery fellowship at BCCH were invited to provide data from the center where they currently practiced. Children aged from birth to less than 18 years who underwent initial midline PF tumor resection within a contemporary, center-selected 2-year period were included. Data was obtained by retrospective chart and imaging review. Modifiable surgical factors that were assessed included pre-resection surgical hydrocephalus treatment, surgical positioning, ultrasonic aspirator use, intraoperative external ventricular drain (EVD) use, surgical access route to the tumor, and extent of resection. CM was defined as decreased or absent speech output postoperatively and CMS as CM plus new or worsened irritability. RESULTS: There were 263 patients from 11 centers in 6 countries (Canada, Germany, the Netherlands, India, Indonesia, and the USA). Median age at surgery was 6 years (range < 1 to 17 years). The overall incidence of postoperative CM was 23.5% (range 14.7-47.6% for centers with data on ≥ 20 patients). The overall incidence of CMS was 6.5% (range 0-10.3% for centers contributing data on ≥ 20 patients). A multivariate logistic regression on the full data set showed no significant association between pre-resection surgical hydrocephalus treatment, prone position, ultrasonic aspirator use, EVD use, telovelar approach, complete or near total resection, or treating center and either postoperative CM or CMS. CONCLUSIONS: While there was variation in surgical management of midline PF tumors among centers participating in this study, the factors in management that were examined did not predict postoperative CM or CMS.
Subject(s)
Cerebellar Neoplasms , Infratentorial Neoplasms , Mutism , Adolescent , Canada , Child , Child, Preschool , Germany , Humans , India , Indonesia , Infant , Infratentorial Neoplasms/surgery , Mutism/epidemiology , Mutism/etiology , Netherlands , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Retrospective StudiesABSTRACT
Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups. Group 1 tumors arise in the cerebral hemispheres and harbor alterations in the receptor tyrosine kinases ALK, ROS1, NTRK and MET. These are typically single-events and confer an intermediate outcome. Groups 2 and 3 gliomas harbor RAS/MAPK pathway mutations and arise in the hemispheres and midline, respectively. Group 2 tumors have excellent long-term survival, while group 3 tumors progress rapidly and do not respond well to chemoradiation. We conclude that infant gliomas comprise 3 subgroups, justifying the need for specialized therapeutic strategies.
Subject(s)
Brain Neoplasms/genetics , DNA Methylation , Epigenomics/methods , Gene Expression Regulation, Neoplastic , Glioma/genetics , Receptor Protein-Tyrosine Kinases/genetics , Anaplastic Lymphoma Kinase/genetics , Anaplastic Lymphoma Kinase/metabolism , Brain Neoplasms/classification , Brain Neoplasms/metabolism , Female , Glioma/classification , Glioma/metabolism , Humans , Infant , Infant, Newborn , Male , Protein-Tyrosine Kinases/genetics , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-met/genetics , Proto-Oncogene Proteins c-met/metabolism , Receptor Protein-Tyrosine Kinases/metabolism , Receptor, trkA/genetics , Receptor, trkA/metabolism , Survival Analysis , Exome Sequencing/methodsABSTRACT
Flanged ventricular catheters are now used infrequently. Many patients with longstanding hydrocephalus still harbor these catheters, either as their current ventricular catheter, or as a retained catheter from a prior implant. The removal of flanged ventricular catheters is sometimes necessary, and may be challenging due to intraventricular adhesions. We describe the use of an endoscopic technique for the successful retrieval of flanged ventricular catheters in two patients. The technique described in this report may be helpful for patients that have flanged ventricular catheters that must be removed.
Subject(s)
Brain/surgery , Catheters , Hydrocephalus/surgery , Neuroendoscopy , Adolescent , Brain/diagnostic imaging , Humans , Hydrocephalus/diagnostic imaging , Male , Neuroendoscopy/methods , Treatment Outcome , Ventriculostomy/methodsABSTRACT
Posterior fossa ependymomas (EPN_PF) in children comprise two morphologically identical, but biologically distinct tumor entities. Group-A (EPN_PFA) tumors have a poor prognosis and require intensive therapy. In contrast, group-B tumors (EPN_PFB) exhibit excellent prognosis and the current consensus opinion recommends future clinical trials to test the possibility of treatment de-escalation in these patients. Therefore, distinguishing these two tumor subtypes is critical. EPN_PFA and EPN_PFB can be distinguished based on DNA methylation signatures, but these assays are not routinely available. We have previously shown that a subset of poorly prognostic childhood EPN_PF exhibits global reduction in H3K27me3. Therefore, we set out to determine whether a simple immunohistochemical assay for H3K27me3 could be used to segregate EPN_PFA from EPN_PFB tumors. We assembled a cohort of 230 childhood ependymomas and H3K27me3 immunohistochemistry was assessed as positive or negative in a blinded manner. H3K27me3 staining results were compared with DNA methylation-based subgroup information available in 112 samples [EPN_PFA (n = 72) and EPN_PFB tumors (n = 40)]. H3K27me3 staining was globally reduced in EPN_PFA tumors and immunohistochemistry showed 99% sensitivity and 100% specificity in segregating EPN_PFA from EPN_PFB tumors. Moreover, H3K27me3 immunostaining was sufficient to delineate patients with worse prognosis in two independent, non-overlapping cohorts (n = 133 and n = 97). In conclusion, immunohistochemical evaluation of H3K27me3 global reduction is an economic, easily available and readily adaptable method for defining high-risk EPN_PFA from low-risk posterior fossa EPN_PFB tumors to inform prognosis and to enable the design of future clinical trials.
Subject(s)
Ependymoma/metabolism , Infratentorial Neoplasms/metabolism , Jumonji Domain-Containing Histone Demethylases/metabolism , Child , Child, Preschool , Disease-Free Survival , Ependymoma/mortality , Ependymoma/pathology , Female , Humans , Infant , Infratentorial Neoplasms/mortality , Infratentorial Neoplasms/pathology , Male , Prognosis , Registries , Survival RateABSTRACT
OBJECTIVE Sagittal craniosynostosis results in a characteristic scaphocephalic head shape that is typically corrected surgically during a child's 1st year of life. The authors' objective was to determine the potential impact of being born with sagittal craniosynostosis by using validated health state utility assessment measures. METHODS An online utility assessment was designed to generate health utility scores for scaphocephaly, monocular blindness, and binocular blindness using standardized utility assessment tools, namely the visual analog scale (VAS) and the standard gamble (SG) and time trade-off (TTO) tests. Utility scores were compared between health states using the Wilcoxon and Kruskal-Wallis tests. Univariate regression was performed using age, sex, income, and education as independent predictors of utility scores. RESULTS Over a 2-month enrollment period, 122 participants completed the online survey. One hundred eighteen participants were eligible for analysis. Participants rated scaphocephaly due to sagittal craniosynostosis with significantly higher (p < 0.001) median utility scores (VAS 0.85, IQR 0.76-0.95; SG 0.92, IQR 0.84-0.98; TTO 0.91, IQR 0.84-0.95) than both monocular blindness (VAS 0.60, IQR 0.50-0.70; SG 0.84, IQR 0.68-0.94; TTO 0.84, IQR 0.67-0.91) and binocular blindness (VAS 0.25, IQR 0.20-0.40; SG 0.51, IQR 0.18-0.79; TTO 0.55, IQR 0.36-0.76). No differences were noted in utility scores based on participant age, sex, income, or education. CONCLUSIONS Using objective health state utility scores, authors of the current study demonstrated that the preoperatively perceived burden of scaphocephaly in a child's 1st year of life is less than that of monocular blindness. These relatively high utility scores for scaphocephaly suggest that the burden of disease as perceived by the general population is low and should inform surgeons' discussions when offering morbid corrective surgery, particularly when driven by aesthetic concerns.
Subject(s)
Cost of Illness , Craniosynostoses , Health Status , Adult , Age Factors , Blindness/economics , Blindness/psychology , Craniosynostoses/economics , Craniosynostoses/pathology , Craniosynostoses/psychology , Educational Status , Female , Humans , Income , Infant , Internet , Male , Perception , Prospective Studies , Quality of Life , Sex Factors , Surveys and QuestionnairesABSTRACT
BACKGROUND: Thalamic gliomas are rare. The natural history is unpredictable, and the optimal management of these tumors in children is poorly defined. The aim was to identify outcomes, prognostic factors, and response to various modalities of treatment in a relatively large population of pediatric thalamic tumors from many centers within a fairly homogeneous health care system. METHODS: We performed a Canadian multicenter retrospective review of pediatric thalamic tumors presenting during the MRI era (1989-2012). Radiology and pathology were reviewed by central independent reviewers. Paraffin shavings for RNA extraction were taken and tested for fusion events involving KIAA1549:BRAF. Tumors were classified as unilateral or bithalamic based on their origin on imaging. Univariate and multivariate analyses on factors influencing survival were performed. RESULTS: Seventy-two thalamic tumors were identified from 11 institutions. Females represented 53% of the study population, and the mean age at presentation was 8.9 years. Sixty-two tumors were unilateral and 10 bithalamic. Unilateral tumors had a greater propensity to grow inferiorly towards the brainstem. These tumors were predominantly low grade in comparison to bithalamic tumors which were high-grade astrocytomas. The 5-year overall survival was 61 ± 13% for unithalamic tumors compared to 37 ± 32% for bithalamic tumors (p = 0.097). Multivariate analysis indicated tumor grade as the only significant prognostic factor for unithalamic tumors. Six unilateral tumors, all low grade, were BRAF fusion positive. CONCLUSION: Unilateral and bilateral thalamic tumors behave differently. Surgical resection is an appropriate treatment option in unilateral tumors, most of which are low grade, but outcome is not related to extent of resection (EOR). Bilateral thalamic tumors have a poorer prognosis, but the occasional patient does remarkably well. The efficacy of chemotherapy and radiotherapy has not been clearly demonstrated. Novel therapeutic approaches are required to improve the prognosis for malignant unilateral thalamic tumors and bilateral thalamic tumors.
Subject(s)
Astrocytoma/therapy , Brain Neoplasms/therapy , Ependymoma/therapy , Thalamus , Adolescent , Astrocytoma/diagnosis , Astrocytoma/genetics , Brain Neoplasms/diagnosis , Brain Neoplasms/genetics , Canada , Chemotherapy, Adjuvant , Child , Child, Preschool , Ependymoma/diagnosis , Ependymoma/genetics , Female , Glioma/genetics , Glioma/therapy , Humans , Infant , Kaplan-Meier Estimate , Linear Models , Magnetic Resonance Imaging , Male , Multivariate Analysis , Neurosurgical Procedures , Oncogene Proteins, Fusion/genetics , Prognosis , Proportional Hazards Models , Radiotherapy, Adjuvant , Retrospective Studies , Treatment OutcomeSubject(s)
Arachnoid Cysts/surgery , Circle of Willis , Endoscopy , Hydrocephalus/surgery , Arachnoid Cysts/complications , Humans , Hydrocephalus/etiology , Infant , MaleABSTRACT
OBJECT Intraventicular hemorrhage (IVH) and posthemorrhagic hydrocephalus (PHH) are common in premature newborns. The epidemiology of these conditions has been described, but selection bias remains a significant concern in many studies. The goal of this study was to review temporal trends in the incidence of IVH, PHH, and shunt surgery in a population-based cohort of very preterm infants with no selection bias. METHODS All very preterm infants (gestational age ≥ 20 and ≤ 30 weeks) born from 1993 onward to residents of Nova Scotia were evaluated by the IWK Health Centre's Perinatal Follow-Up Program, and were entered in a database. Infants born to residents of Nova Scotia from January 1, 1993, to December 31, 2012, were included in this study. The incidences of IVH, PHH, and shunt surgery were calculated, basic demographic information was described, and chi-square test for trends over time was determined. RESULTS Of 1334 successfully resuscitated very preterm infants who survived to their initial screening ultrasound, 407 (31%) had an IVH, and 149 (11%) had an IVH Grade 3 or 4. No patients with IVH Grade 1 or 2 developed PHH. The percentage of very preterm infants with IVH Grade 3 or 4 has significantly increased over time (p = 0.013), as have the incidence of PHH and shunt surgery (p = 0.001 and p = 0.011, respectively) in infants with Grade 3 or 4 IVH. The proportion of patients with PHH receiving a shunt has not changed over time (p = 0.813). CONCLUSIONS The increasing incidence of high-grade IVH-and PHH and shunt surgery in infants with high-grade IVH-over time is worrisome. This study identifies a number of associated factors, but further research to identify preventable and treatable causal factors is warranted.
Subject(s)
Cerebral Hemorrhage/epidemiology , Cerebral Ventricles/pathology , Cerebrospinal Fluid Shunts/statistics & numerical data , Hydrocephalus/etiology , Infant, Premature, Diseases/epidemiology , Infant, Premature , Cerebral Hemorrhage/mortality , Databases, Factual , Female , Gestational Age , Humans , Hydrocephalus/surgery , Incidence , Infant , Infant, Extremely Premature , Infant, Newborn , Infant, Premature, Diseases/mortality , Infant, Premature, Diseases/surgery , Logistic Models , Male , Nova Scotia/epidemiology , Odds Ratio , Retrospective StudiesABSTRACT
OBJECT Intraventicular hemorrhage (IVH) is a common complication of preterm birth, and the prognosis of IVH is incompletely characterized. The objective of this study was to describe the outcomes of IVH in a population-based cohort with minimal selection bias. METHODS All very preterm (≥ 30 completed weeks) patients born in the province of Nova Scotia were included in a comprehensive database. This database was screened for infants born to residents of Nova Scotia from January 1, 1993, to December 31, 2010. Among very preterm infants successfully resuscitated at birth, the numbers of infants who died, were disabled, developed cerebral palsy, developed hydrocephalus, were blind, were deaf, or had cognitive/language scores assessed were analyzed by IVH grade. The relative risk of each outcome was calculated (relative to the risk for infants without IVH). RESULTS Grades 2, 3, and 4 IVH were significantly associated with an increased overall mortality, primarily in the neonatal period, and the risk increased with increasing grade of IVH. Grade 4 IVH was significantly associated with an increased risk of disability (RR 2.00, p < 0.001), and the disability appeared to be primarily due to cerebral palsy (RR 6.07, p < 0.001) and cognitive impairment (difference in mean MDI scores between Grade 4 IVH and no IVH: -19.7, p < 0.001). No infants with Grade 1 or 2 IVH developed hydrocephalus, and hydrocephalus and CSF shunting were not associated with poorer outcomes when controlling for IVH grade. CONCLUSIONS Grades 1 and 2 IVH have much better outcomes than Grades 3 or 4, including a 0% risk of hydrocephalus in the Grade 1 and 2 IVH cohort. Given the low risk of selection bias, the results of this study may be helpful in discussing prognosis with families of very preterm infants diagnosed with IVH.
Subject(s)
Cerebral Hemorrhage/complications , Cerebral Palsy/epidemiology , Cerebral Ventricles/pathology , Cerebrospinal Fluid Shunts , Hydrocephalus/epidemiology , Hydrocephalus/surgery , Infant, Premature , Blindness/epidemiology , Blindness/etiology , Cerebral Hemorrhage/epidemiology , Cerebral Hemorrhage/mortality , Cerebral Palsy/etiology , Cerebrospinal Fluid Shunts/statistics & numerical data , Cognition Disorders/epidemiology , Cognition Disorders/etiology , Databases, Factual , Deafness/epidemiology , Deafness/etiology , Female , Gestational Age , Humans , Hydrocephalus/etiology , Incidence , Infant , Infant, Extremely Premature , Infant, Newborn , Infant, Premature, Diseases/epidemiology , Infant, Premature, Diseases/mortality , Infant, Premature, Diseases/surgery , Logistic Models , Male , Nova Scotia/epidemiology , Odds Ratio , Retrospective Studies , Risk , Severity of Illness IndexABSTRACT
BACKGROUND: The cure rate for childhood intracranial ependymoma is approximately 70% in the setting of a gross total resection followed by radiation, but management remains challenging in patients with residual disease. Therefore, robust biomarkers are needed to guide the development of new targeted therapy. The authors evaluated the expression of several biomarkers in pediatric intracranial ependymoma and observed that the expression of enhancer of zeste homolog 2 (EZH2), a polycomb complex protein involved in epigenetic regulation of gene expression, was independently associated with poor survival. METHODS: Tissue microarray immunostaining was performed on 180 ependymoma samples from 12 of 16 Canadian pediatric centers. Expression levels of EZH2, Ki-67, B lymphoma Moloney-murine leukemia virus insertion region 1 homolog, tumor protein 16 (P16), Y-box binding protein 1, phosphorylated protein kinase B (pAKT), and epidermal growth factor receptor were evaluated. Cox regression analyses were performed, and the Kaplan-Meier method was used to construct survival curves. RESULTS: EZH2 expressed in 16% of tumors was associated with inferior 5-year overall survival. Ki-67 and pAKT levels were associated with a poor outcome in patients with posterior fossa ependymoma, and the absence of P16 was associated with a poor outcome in patients with supratentorial ependymoma. Multivariate analysis revealed that younger age and EZH2 expression (95% confidence interval, 1.1-36.0) were independent markers of a poor prognosis. CONCLUSIONS: EZH2 is a novel, independent marker of a poor prognosis in patients with ependymoma, especially in those who have tumors located in the posterior fossa. EZH2, pAKT, and P16 are potential therapeutic targets, particularly for patients who have tumors in which standard gross total resection plus fractionated radiotherapy is not feasible.
Subject(s)
Biomarkers, Tumor/metabolism , Brain Neoplasms/metabolism , Ependymoma/metabolism , Polycomb Repressive Complex 2/metabolism , Adolescent , Brain Neoplasms/mortality , Child , Child, Preschool , Enhancer of Zeste Homolog 2 Protein , Ependymoma/mortality , Female , Humans , Infant , Kaplan-Meier Estimate , Male , Multivariate Analysis , Prognosis , Proportional Hazards Models , Retrospective StudiesABSTRACT
PURPOSE: Gross total resection (GTR) of intracranial ependymoma is an accepted goal. More controversial is radiotherapy deferral. This study reports on children treated with gross total resection who did not receive upfront adjuvant radiotherapy. METHODS: We conducted a retrospective review of children with intracranial ependymoma in 12 Canadian centers. Patients who had GTR of their tumor and no upfront radiotherapy were identified. Immunostaining was performed for Ki-67, epidermal growth factor receptor (EGFR), and EZH2 on archived tissue. The Kaplan-Meier survival analysis was performed and compared with those who had GTR followed by radiation. RESULTS: Twenty-six children were identified treated with GTR alone at diagnosis; 12 posterior fossa ependymoma (PFE) WHO grade II, and 14 supratentorial ependymoma (STE). Progression-free survival (PFS) in ependymoma treated with GTR alone at diagnosis was inferior in those with high Ki-67 or positive EZH2 immunostaining. Survival was inferior for patients less than 2 years old at diagnosis (p = 0.002). Survival was comparable to PFE WHO grade II and STE who had GTR followed by radiation (p = 0.62). Five-year PFS and overall survival (OS) of those treated with GTR alone were 60 and 70% respectively for PFE and 45 and 70% respectively for STE (p = 0.2; 0.55). CONCLUSIONS: This study suggests that there is a subset of children with certain biologic features who, in the setting of a prospective clinical trial, might be candidates for observation following GTR. Good risk factors for this approach include age of 2 years or older, low Ki-67, and negative EZH2. If relapse occurs, it may be confined to the primary site, allowing for possible salvage with GTR followed by XRT.