Surveillance imaging of grade 1 astrocytomas in children: can duration and frequency of follow-up imaging and the use of contrast agents be reduced?

PURPOSE: The optimum strategy for the surveillance of low-grade gliomas in children has not been established, and there is concern about the use of gadolinium-based contrast agents (GBCAs), particularly in children, due to their deposition in the brain. The number of surveillance scans and the use of GBCAs in surveillance of low-risk tumours should ideally be limited. We aimed to investigate the consistency and utility of our surveillance imaging and also determine to what extent the use of GBCAs contributed to decisions to escalate treatment in children with grade 1 astrocytomas. METHODS: This was a retrospective single-centre study at a tertiary paediatric hospital. All children with a new diagnosis of a non-syndromic World Health Organization (WHO) grade 1 astrocytoma between 2007 and 2013 were included, with surveillance imaging up to December 2018 included in analysis. The intervals of surveillance imaging were recorded, and imaging and electronic health records were examined for decisions related to treatment escalation. RESULTS: Eighty-eight patients had 690 surveillance scans in the study period. Thirty-one patients had recurrence or progression leading to treatment escalation, 30 of whom were identified on surveillance imaging. The use of GBCAs did not appear to contribute to multidisciplinary team (MDT) decisions in the majority of cases. CONCLUSION: Surveillance imaging could be reduced in number and duration for completely resected cerebellar tumours. MDT decisions were rarely made on the basis of post-contrast imaging, and GBCA administration could therefore potentially be restricted in the setting of surveillance of grade 1 astrocytomas in children.

Neurosurgical experience of managing optic pathway gliomas.

BACKGROUND: Optic pathway gliomas (OPGs), also known as visual pathway gliomas, are debilitating tumors that account for 3-5% of all pediatric brain tumors. They are most commonly WHO grade 1 pilocytic astrocytomas and frequently occur in patients with neurofibromatosis type 1. The location of these tumors results in visual loss and blindness, endocrine and hypothalamic dysfunction, hydrocephalus, and premature death. Their involvement of the visual pathways and proximity to other eloquent brain structures typically precludes complete resection or optimal radiation dosing without incurring significant neurological injury. There are various surgical interventions that can be performed in relation to these lesions including biopsy, cerebrospinal fluid diversion, and partial or radical resection, but their role is a source of debate. This study catalogues our surgical experience and patient outcomes in order to support decision-making in this challenging pathology. METHODS: A retrospective review of all cases of OPGs treated in a single center from July 1990 to July 2020. Data was collected on patient demographics, radiographic findings, pathology, and management including surgical interventions. Outcome data included survival, visual function, endocrine, and hypothalamic dysfunction. RESULTS: One hundred twenty-one patients with OPG were identified, and 50 of these patients underwent a total of 104 surgical procedures. These included biopsy (31), subtotal or gross total resection (20 operations in 17 patients), cyst drainage (17), Ommaya reservoir insertion (9), or cerebrospinal fluid diversion (27). During the study period, there was 6% overall mortality, 18% hypothalamic dysfunction, 20% endocrine dysfunction, and 42% had some cognitive dysfunction. At diagnosis 75% of patients had good or moderate visual function in at least one eye, and overall, this improved to 83% at the end of the study period. In comparison the worst eye had good or moderate visual function in 56%, and this reduced to 53%. Baseline and final visual function were poorer in patients who had a surgical resection, but improvements in vision were still found-particularly in the best eye. DISCUSSION/CONCLUSION: OPG are debilitating childhood tumor that have lifelong consequences in terms of visual function and endocrinopathies/hypothalamic dysfunction; this can result in substantial patient morbidity. Decisions regarding management and the role of surgery in this condition are challenging and include cerebrospinal fluid diversion, biopsy, and in highly select cases cystic decompression or surgical resection. In this paper, we review our own experience, outcomes, and surgical philosophy.

Childhood medulloblastoma-a single institution's historical perspective on survival and functional morbidity.

PURPOSE: To compare results from a third (1995-2010) cohort of children with medulloblastoma with two previous series (J Neurosurg 86:13-21, 1997; Arch Dis Child 54:200-203, 1979) to analyse the effects of management changes aimed at improving both overall and event-free survivals (OS and EFS) and functional outcomes. METHODS: Review of neuro-oncology and imaging databases and previously published results. RESULTS: There was no statistically significant improvement in the 5-year OS for 104 children diagnosed 1995-2010, 61.5% (95% CI, 52.9, 71.6), compared with 50% of the 80 children presenting 1980-1990 (J Neurosurg 86:13-21, 1997) (difference 11.5%; 95% CI, 2.8, 25.4). Five-year OS for 96 children suitable for risk-stratification was overall 66% (95% CI, 57.9, 75.8); standard risk 77.8% (95% CI, 67.4, 89.7); high risk < 3 years 50.0% (95% CI, 32.3, 77.5); high risk ≥ 3 years 54.5% (95% CI, 37.2, 79.9); 5-year EFS were standard risk 68.5% (95% CI, 57.2, 82.1); high risk < 3 years 40.0% (95% CI, 23.4, 68.4); and high risk ≥ 3 years 36.4% (95% CI, 20.9, 63.2); overall 55.2% (95% CI, 46.1, 66.1). Of 62/63 ≥ 5-year survivor, 9 died later from tumour relapse and 4 from second malignancy. Functional outcomes of 62 of the 63 ≥ 5-year survivors: 67.7% had educational issues requiring remedial input; 18% restricted mobility indoors and outdoors; 59.7% hearing impairment (42% prescribed aids). CONCLUSIONS: 1. Comparison of this single-institution series with its predecessor found that revised chemotherapy and RT protocols and greater accuracy of risk stratification did not result in statistically significant improvements in either survival or treatment-related functional disability. 2. Extended (> 5-year) follow-up is essential if 20% of late deaths from relapse and second malignancies are not to be overlooked.

Outcomes in children with central nervous system tumors disseminated at presentation: a large single-center experience.

PURPOSE: Children with disseminated central nervous system (CNS) tumors have worse outcomes than those with solitary disease, but outcomes of disease dissemination at initial presentation have not been systematically studied and compared across tumor groups to date. We evaluated the impact of tumor dissemination at presentation on management and clinical outcomes in a cohort of consecutively treated children in a single neurosurgical unit over a 14-year period. METHODS: Method used was a retrospective review of data on children presenting to Great Ormond Street Hospital, London, UK, with medulloblastoma, primitive neuroectodermal tumor, atypical teratoid rhabdoid tumor, pilocytic astrocytoma, and ependymoma between 2003 and 2016 inclusive. Uni- and multi-variate analyses were performed to evaluate a range of outcome measures. RESULTS: Three-hundred sixty-one children were identified in total, 53 with disease dissemination at presentation (M:F = 34:19, median age = 3.8 years, range = 7 days-15.6 years) and 308 with solitary tumors (M:F = 161:147, median age = 5.8 years, range = 1 day-16.9 years). Median follow-up was similar irrespective of dissemination status (disseminated tumor 64.0 months, range = 5.2-152.0 months; solitary tumor 74.5 months, range = 4.7-170.1 months; P > 0.05). In multivariate analyses, tumor type and dissemination status at presentation were significantly associated with overall survival (P < 0.0001), risk of recurrence/disease progression (P < 0.01), and event-free survival (P < 0.0001). Subtotal resection was associated with shorter time to recurrence/disease progression (P < 0.01) and worse event-free (P < 0.0001) but not overall survival, whereas treatment with chemotherapy and radiotherapy were associated with improved overall (Ps < 0.0001) and event-free survival (Ps < 0.05). Differences between tumor groups were evident. CONCLUSIONS: Dissemination status at initial presentation significantly affects outcomes in children with CNS tumors.

Post-operative paediatric cerebellar mutism syndrome: time to move beyond structural MRI.

PURPOSE: To determine the value of structural magnetic resonance imaging (MRI) in predicting post-operative paediatric cerebellar mutism syndrome (pCMS) in children undergoing surgical treatment for medulloblastoma. METHODS: Retrospective cohort study design. Electronic/paper case note review of all children with medulloblastoma presenting to Great Ormond Street Hospital between 2003 and 2013. The diagnosis of pCMS was established through a scoring system incorporating mutism, ataxia, behavioural disturbance and cranial nerve deficits. MRI scans performed at three time points were assessed by neuroradiologists blinded to the diagnosis of pCMS. RESULTS: Of 56 children included, 12 (21.4%) developed pCMS as judged by a core symptom of mutism. pCMS was more common in those aged 5 or younger. There was no statistically significant difference in pre-operative distortion or signal change of the dentate or red nuclei or superior cerebellar peduncles (SCPs) between those who did and did not develop pCMS. In both early (median 5 days) and late (median 31 months) post-operative scans, T2-weighted signal change in SCPs was more common in the pCMS group (p = 0.040 and 0.046 respectively). Late scans also showed statistically significant signal change in the dentate nuclei (p = 0.024). CONCLUSIONS: The development of pCMS could not be linked to any observable changes on pre-operative structural MRI scans. Post-operative T2-weighted signal change in the SCPs and dentate nuclei underlines the role of cerebellar efferent injury in pCMS. Further research using advanced quantitative MRI sequences is warranted given the inability of conventional pre-surgical MRI to predict pCMS.

Optic pathway glioma in children: does visual deficit correlate with radiology in focal exophytic lesions?

PURPOSE: Unlike pilocytic astrocytomas in other parts of the brain, optic pathway gliomas (OPG) are usually diffuse lesions involving the anterior optic pathways and hypothalamus. Their infiltrative nature often precludes complete surgical resection. We sought to determine whether careful magnetic resonance (MR) analysis, correlated with visual deficits, could be sufficient to identify those focal lesions that may be amenable to more aggressive surgical resection at presentation. METHODS: We retrospectively reviewed the medical records of patients from two sites: children under 20 years of age treated for OPG between 1985 and 2009 at St Jude's Children's Research Hospital and children under 16 years of age treated at Great Ormond Street Hospital, London, UK, between 1984 and 2011. Patients with isolated optic nerve tumors were excluded. Visual acuity and visual field data at presentation were reviewed and correlated with MR characteristics, including extent of optic pathway involvement, symmetry, and lateral extension. RESULTS: Two hundred and one children were treated for OPG between 1984 and 2011 in the two institutions; 74 had neurofibromatosis 1 (NF1). At presentation, visual loss was symmetrical in 132 patients and asymmetrical in 69. Potential correlation between pattern of visual loss and tumor characteristics on routine MRI was found in only 13 patients with asymmetrical vision. There was no difference between patients with and without NF1. CONCLUSION: The decision for aggressive surgical resection for optic pathway gliomas should be based on clinical criteria, particularly in children with good vision in one eye and poor vision in the other, as current MRI results do not reliably predict visual field deficits.

Cytogenetic analysis of paediatric astrocytoma using comparative genomic hybridisation and fluorescence in-situ hybridisation.

Little is known about the cytogenetic and molecular genetic events that lead to the formation of paediatric astrocytoma. We have analysed 57 paediatric astrocytoma (WHO grades I-IV) using comparative genomic hybridisation in order to identify common regions of abnormality. Large regions of copy number alterations were infrequent with 71% of tumours demonstrating no genomic imbalance. Furthermore, the most frequent aberrations (including gain of 6q, 2q, and 7q, and loss of 16 and 12q) occurred in only a subset of cases. High-copy number amplification was seen in five tumours at 12 different regions. The presence of copy number alterations was significantly associated with increasing grade of malignancy, and gain of 12q and the presence of high-copy number amplification were associated with a poor outcome in patients with malignant astrocytoma (P = 0.0039 and 0.0085, respectively). FISH analysis confirmed loss of 1p36 identified by CGH. There was no evidence of amplification of EGFR, CDK4, MET, CDK6, c-myc, or MDM2.

Fourth ventricle tumors in children: complications and influence of surgical approach.

OBJECTIVES: The goal of this study was to characterize the complications and morbidity related to the surgical management of pediatric fourth ventricle tumors. METHODS: All patients referred to the authors' institution with posterior fossa tumors from 2002 to 2018 inclusive were screened to include only true fourth ventricle tumors. Preoperative imaging and clinical notes were reviewed to extract data on presenting symptoms; surgical episodes, techniques, and adjuncts; tumor histology; and postoperative complications. RESULTS: Three hundred fifty-four children with posterior fossa tumors were treated during the study period; of these, 185 tumors were in the fourth ventricle, and 167 fourth ventricle tumors with full data sets were included in this analysis. One hundred patients were male (mean age ± SD, 5.98 ± 4.12 years). The most common presenting symptom was vomiting (63.5%). The most common tumor types, in order, were medulloblastoma (94 cases) > pilocytic astrocytoma (30 cases) > ependymoma (30 cases) > choroid plexus neoplasms (5 cases) > atypical teratoid/rhabdoid tumor (4 cases), with 4 miscellaneous lesions. Of the 67.1% of patients who presented with hydrocephalus, 45.5% had an external ventricular drain inserted (66.7% of these prior to tumor surgery, 56.9% frontal); these patients were more likely to undergo ventriculoperitoneal shunt (VPS) placement at a later date (p = 0.00673). Twenty-two had an endoscopic third ventriculostomy, of whom 8 later underwent VPS placement. Overall, 19.7% of patients had a VPS sited during treatment.Across the whole series, the transvermian approach was more frequent than the telovelar approach (64.1% vs 33.0%); however, the telovelar approach was significantly more common in the latter half of the series (p < 0.001). Gross-total resection was achieved in 70.7%. The most common postoperative deficit was cerebellar mutism syndrome (CMS; 28.7%), followed by new weakness (24.0%), cranial neuropathy (18.0%), and new gait abnormality/ataxia (12.6%). Use of intraoperative ultrasonography significantly reduced the incidence of CMS (p = 0.0365). There was no significant difference in the rate of CMS between telovelar or transvermian approaches (p = 0.745), and multivariate logistic regression modeling did not reveal any statistically significant relationships between CMS and surgical approach. CONCLUSIONS: Surgical management of pediatric fourth ventricle tumors continues to evolve, and resection is increasingly performed through the telovelar route. CMS is enduringly the major postoperative complication in this patient population.

Surgical management of supratentorial ependymomas.

INTRODUCTION: Supratentorial ependymomas are rare neoplasms accounting for just ten to 15 new cases in the UK per year. This article discusses the surgical management of these tumours. MATERIALS AND METHODS: We present our experience over the past 12 years looking, in particular, at the location, histological grading, postoperative complications, survival and progression-free survival. A literature review of publications discussing the surgical management of ependymoma over the past 10 years is then presented. RESULTS: The data shows that complete surgical resection confers a significant survival advantage. There appears to be conflicting data with respect to prognosis when comparing supratentorial to infratentorial ependymoma. CONCLUSION: The authors suggest complete excision and advocate, where appropriate, the use of pre and intra-operative functional mapping and second-look surgery. The trade off neurological deficit in the pursuit of complete surgical excision in some instances should be considered.

Treatment factors associated with outcomes in children less than 3 years of age with CNS tumours.

INTRODUCTION: This study aimed to document cognitive outcomes in children treated for brain tumours with surgery and/or chemotherapy before the age of 3 years and to investigate the relationship between treatment factors and cognitive outcome. MATERIALS AND METHODS: Participants were 31 children aged 7-14 years who had been diagnosed and treated for brain tumours under the age of 3 years. Neuropsychological assessment included tests of cognitive functioning (WASI), memory (CMS) and executive functioning (BADS-C). RESULTS AND DISCUSSION: IQ and memory functioning scores were within the normal range but executive function was significantly below the expected level. Lower socio-economic status, younger age at treatment, having undergone more than one surgical intervention, motor problems and speech and language difficulties were found to be related to cognitive functioning. Although this group of children have good outcomes in terms of IQ and memory they have significant difficulties with executive functioning. CONCLUSION: Further research in this area is needed to allow for development of appropriate support packages for those who are most at risk.

Real-time quantitative PCR analysis of pediatric ependymomas identifies novel candidate genes including TPR at 1q25 and CHIBBY at 22q12-q13.

Loss of chromosome 22 and gain of 1q are the most frequent genomic aberrations in ependymomas, indicating that genes mapping to these regions are critical in their pathogenesis. Using real-time quantitative PCR, we measured relative copy numbers of 10 genes mapping to 22q12.3-q13.33 and 10 genes at 1q21-32 in a series of 47 pediatric intracranial ependymomas. Loss of one or more of the genes on 22 was detected in 81% of cases, with RAC2 and C22ORF2 at 22q12-q13.1 being deleted most frequently in 38% and 32% of ependymoma samples, respectively. Combined analysis of quantitative-PCR with methylation-specific PCR and bisulphite sequencing revealed a high rate (>60% ependymoma) of transcriptional inactivation of C22ORF2, indicating its potential importance in the development of pediatric ependymomas. Increase of relative copy numbers of at least one gene on 1q were detected in 61% of cases, with TPR at 1q25 displaying relative copy number gains in 38% of cases. Patient age was identified as a significant adverse prognostic factor, as a significantly shorter overall survival time (P = 0.0056) was observed in patients <2 years of age compared with patients who were >2 years of age. Loss of RAC2 at 22q13 or amplification of TPR at 1q25 was significantly associated with shorter overall survival in these younger patients (P = 0.0492 and P = < 0.0001, respectively). This study identifies candidate target genes within 1q and 22q that are potentially important in the pathogenesis of intracranial pediatric ependymomas.

Intracranial Neoplasms in the First Year of Life: Results of a Third Cohort of Patients From a Single Institution.

BACKGROUND: Brain tumors in the first year of life are rare and their management remains challenging. OBJECTIVE: To report on the contemporary management of brain tumors in infants with reference to previous series from our institution. METHODS: Retrospective cohort study design. Electronic/paper case note review of all brain tumors diagnosed at our institution in children aged <1 yr since the publication of our previous series. RESULTS: Ninety-eight patients were seen. The most common presentations were with vomiting and macrocrania, at a median age of 184 d. Sixty-two percent of tumors were supratentorial. Ninety-one patients underwent 230 procedures; 7 patients had no surgery. One hundred eighteen operations were directly on brain tumors (biopsy 37, subtotal resection 47, gross total resection 34). Ninety-one cerebrospinal fluid diversions, 9 endoscopic procedures, and 13 preoperative embolizations were performed. Operative mortality was 4.4%. Tumor types in order of frequency were choroid plexus papillomas (CPP, 17), primitive neuroectodermal tumor (12), atypical teratoid/rhabdoid tumor (10), high-grade glioma (9), optic glioma (9), ependymoma (8), low-grade glioma (6), pilocytic astrocytoma (6), choroid plexus carcinoma (5), and teratoma (5), with 11 miscellaneous tumors. Survival was 93% at 1 mo (91/98), 64% at 1 yr (61/95), 44% at 5 yr (32/73), 28% at 10 yr (16/58). No patients with CPP or low-grade glioma died. Five-year survival rates were lowest for anaplastic ependymoma, primitive neuroectodermal tumor, and atypical teratoid/rhabdoid tumor. Seventy-seven percent of children reaching school age were in mainstream schooling. CONCLUSION: Overall survival from neonatal brain tumors remains similar to previous series; analysis of tumor subtypes reveals improvements for CPP and gliomas. Despite increasing operative intervention, operative mortality continues to decline for this group of challenging patients.

Surgical decision-making in the management of childhood tumors of the CNS disseminated at presentation.

OBJECTIVE It is relatively unusual for pediatric CNS tumors to be disseminated at presentation, and the literature on the clinical features, management, and outcomes of this specific group is scarce. Surgical management in this population is often challenging, particularly in the presence of hydrocephalus. The authors present their recent experience of treating pediatric CNS tumors that were disseminated at presentation, and they compare these lesions with focal tumors. METHODS The authors performed a retrospective review of prospectively collected data on children presenting to a tertiary center between 2003 and 2016 inclusive. RESULTS Of 361 children with CNS tumors, the authors identified 53 patients with disease dissemination at presentation (male/female ratio 34:19, median age 3.8 years, age range 7 days to 15.6 years) and 308 without dissemination at presentation (male/female ratio 161:147, median age 5.8 years, age range 1 day to 16.9 years). Five tumor groups were studied: medulloblastoma (disseminated n = 29, focal n = 74), other primitive neuroectodermal tumor (n = 8, n = 17), atypical teratoid rhabdoid tumor (n = 8, n = 22), pilocytic astrocytoma (n = 6, n = 138), and ependymoma (n = 2, n = 57). The median follow-up duration in survivors was not significantly different between those with disease dissemination at presentation (64.0 months, range 5.2-152.0 months) and those without it (74.5 months, range 4.7-170.1 months) (p > 0.05). When combining data from all 5 tumor groups, dissemination status at presentation was significantly associated with a higher risk of requiring CSF diversion, a higher surgical complication rate, and a reduced likelihood of achieving gross-total resection of the targeted lesion (all variables p < 0.05). Differences between the 5 tumor groups were evident. No factors that predicted the need for permanent CSF diversion following temporary external ventricular drainage were identified on multivariate analysis, and there was no clear superiority of either ventriculoperitoneal shunt surgery or endoscopic third ventriculostomy as a permanent CSF diversion procedure. CONCLUSIONS Tumor type and dissemination status at initial presentation significantly affect outcomes across a range of measures. The management of hydrocephalus in patients with CNS tumors is challenging, and further prospective studies are required to identify the optimal CSF diversion strategy in this population.

Delineation of the visual pathway in paediatric optic pathway glioma patients using probabilistic tractography, and correlations with visual acuity.

Background: Radiological biomarkers which correlate with visual function are needed to improve the clinical management of optic pathway glioma (OPG) patients. Currently, these are not available using conventional magnetic resonance imaging (MRI) sequences. The aim of this study was to determine whether diffusion MRI could be used to delineate the entire optic pathway in OPG patients, and provide imaging biomarkers within this pathway which correlate with a patient's visual acuity (VA). Methods: Multi-shell diffusion MRI data were acquired in a cohort of paediatric OPG patients, along with VA measurements in each eye. Diffusion MRI data were processed using constrained spherical deconvolution and probabilistic fibre tractography, to delineate the white matter bundles forming the optic pathway in each patient. Median fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured in the optic nerves, tracts, and radiations, and correlated against each patient's VA. Results: In the optic nerves, median FA significantly correlated with VA (R2adj = 0.31, p = 0.0082), with lower FA associated with poorer vision. In the optic radiations, both lower FA and higher ADC were significantly associated with poorer vision (R2adj = 0.52, p = 0.00075 and R2adj = 0.50, p = 0.0012 respectively). No significant correlations between VA and either FA or ADC were found in the optic tracts. Conclusions: Multi-shell diffusion MRI provides in vivo delineation of the optic pathway in OPG patients, despite the presence of tumour invasion. This technique provides imaging biomarkers which are sensitive to microstructural damage to the underlying white matter in this pathway, which is not always visible on conventional MRI.

Incidence of cavernoma development in children after radiotherapy for brain tumors.

OBJECT: Cavernous hemangiomas (cavernomas) are benign vascular malformations that may cause seizures and/or hemorrhage when they develop in the brain. The incidence of cavernoma development after brain radiotherapy is unknown. The aim of this study was to assess the prevalence of cavernoma formation in patients who had previously received radiotherapy for brain tumors during childhood. METHODS: All patients were identified who were younger than 16 years of age and had undergone radiotherapy for brain tumors within a 16-year period (January 1, 1988-December 31, 2003). The patient data that were ascertained included age at diagnosis, sex, histopathology results, initial preoperative magnetic resonance (MR) imaging results, date of radiotherapy, and date of detection of cavernoma. Children who were followed up for less than 1 month after radiotherapy or who died during treatment were excluded, as were children with brainstem tumors. All patients had undergone diagnostic MR imaging before receiving radiotherapy, and no vascular malformations were revealed. Of the 379 patients identified, 297 satisfied the inclusion criteria. Ten patients (3.4%) developed cavernomas after radiation therapy. The ages of these patients ranged from 2 to 11 years at the time of radiotherapy (median 7 years), and the latency interval between radiotherapy and cavernoma development was 3 to 102 months (median 37 months). CONCLUSIONS: The prevalence of cavernomas in the present study was more than six times greater than the prevalence rate cited in the literature for this population. The authors conclude that there is an increased risk of developing an intracranial cavernoma after radiotherapy for brain tumors. The possibility of this complication arising should be mentioned when informed consent is sought before treatment using radiotherapy.

Surveillance imaging strategies following surgery and/or radiotherapy for childhood cerebellar low-grade astrocytoma.

OBJECT: The authors sought to evaluate surveillance strategies for the detection and monitoring of residual and recurrent disease in children with cerebellar low-grade astrocytomas (CLGAs) treated surgically or with radiotherapy. Patients were divided into three groups: (1) those in whom a "complete" resection was achieved; (2) those with residual disease with no immediate adjuvant therapy; and (3) those who received radiotherapy for residual/recurrent disease. METHODS: Magnetic resonance (MR) imaging studies and clinical data obtained in children with CLGA who presented between January 1988 and September 1998 were reviewed. Eighty-four children were followed for a mean period of 73 months (range 2-159 months). One child died. Of the 70 children in whom a complete resection was achieved, nine (13%) developed a recurrence detected by surveillance imaging at 6, 8, 9, 9, 13, 27, 39, 44, and 47 months, respectively. Following an incomplete resection, radiologically detected tumor progression leading to further treatment was detected at 7, 9, 12, 13, and 20 months, respectively, and an additional six tumors regressed or stablized. In 11 of 12 children treated with radiotherapy, stabilization/regression occurred radiologically at a mean of 14.9 months. CONCLUSIONS: The authors recommend surveillance MR imaging in children treated for CLGA at 6 months and 1, 2, 3.5, and 5 years following a complete resection and after radiotherapy performed either initially or following recurrence. For follow up of residual tumor, 6-month interval imaging for at least 3 years, yearly images for another 2 years, and subsequent 2-year imaging is recommended.

Neuroendocrine Morbidity After Pediatric Optic Gliomas: A Longitudinal Analysis of 166 Children Over 30 Years.

CONTEXT: Fifty percent of pediatric low-grade gliomas affect the optic pathway, hypothalamus, and suprasellar areas (OP/HSGs), resulting in significant long-term neuroendocrinopathy. OBJECTIVE: This study aimed to dissect tumor- from treatment-related risk factors for OP/HSG-associated neuroendocrinopathy. DESIGN: This was a retrospective case notes analysis of 166 children with newly diagnosed OP/HSGs at our quaternary center between 1980 and 2010 by multivariate Cox, linear, and logistic regression. RESULTS: Patients were of median (range) age 4.9 (0.2-15.4) years at diagnosis and followed up for 8.3 (0.04-26.8) years. Despite high 20-year overall survival (81.0%), progression-free and endocrine event-free survival (EEFS) were 47.2 and 20.8%, respectively. EEFS declined up to 15 years post-diagnosis, with hypothalamic involvement (P < .001) being implicated more than radiotherapy (P = .008) in earlier endocrinopathy; the reverse being true of its density (radiotherapy P < .001; hypothalamic involvement P = .006). GH deficiency (GHD) was most common (40.3%), followed by central precocious puberty (CPP, 26.0%), gonadotropin (GnD; 20.4%), TSH (13.3%), and ACTH (13.3%) deficiencies. GHD increased with later treatment eras (P < .01), but replacement did not increase progression. CPP was associated with future GnD (P < .05). Posterior pituitary dysfunction (PPD; 7.2%) occurred in 57.9% after only biopsies or shunt procedures, and was associated with 6/13 deaths; 50.2% became obese. Tumor extent, surgery, and increased endocrinopathy, rather than radiotherapy, predicted visuocognitive morbidity. CONCLUSIONS: This first longitudinal OP/HSG-specific study demonstrates that hypothalamo-pituitary dysfunction evolves hierarchically over decades. Tumor location predicts its speed of onset and radiotherapy its density. GnD can evolve from previous CPP, whereas life-threatening PPD can occur after any surgery. Our data suggest that recent radiation-avoiding chemotherapeutic strategies have increased GHD without improving survival.

Molecular analysis of pediatric brain tumors identifies microRNAs in pilocytic astrocytomas that target the MAPK and NF-κB pathways.

INTRODUCTION: Pilocytic astrocytomas are slow-growing tumors that usually occur in the cerebellum or in the midline along the hypothalamic/optic pathways. The most common genetic alterations in pilocytic astrocytomas activate the ERK/MAPK signal transduction pathway, which is a major driver of proliferation but is also believed to induce senescence in these tumors. Here, we have conducted a detailed investigation of microRNA and gene expression, together with pathway analysis, to improve our understanding of the regulatory mechanisms in pilocytic astrocytomas. RESULTS: Pilocytic astrocytomas were found to have distinctive microRNA and gene expression profiles compared to normal brain tissue and a selection of other pediatric brain tumors. Several microRNAs found to be up-regulated in pilocytic astrocytomas are predicted to target the ERK/MAPK and NF-κB signaling pathways as well as genes involved in senescence-associated inflammation and cell cycle control. Furthermore, IGFBP7 and CEBPB, which are transcriptional inducers of the senescence-associated secretory phenotype (SASP), were also up-regulated together with the markers of senescence and inflammation, CDKN1A (p21), CDKN2A (p16) and IL1B. CONCLUSION: These findings provide further evidence of a senescent phenotype in pilocytic astrocytomas. In addition, they suggest that the ERK/MAPK pathway, which is considered the major driver of these tumors, is regulated not only by genetic aberrations but also by microRNAs.

Surveillance neuroimaging of intracranial medulloblastoma in children: how effective, how often, and for how long?

OBJECT: The goal of this paper was to review brain and spine images obtained in children with medulloblastomas to determine the risk factors for tumor recurrence and to assess the impact of surveillance imaging on patient outcomes among patients who remain alive 1 month postsurgery. METHODS: Imaging studies and clinical data obtained in children with medulloblastomas, who presented between January 1987 and August 1998, were retrospectively reviewed. Images were termed surveillance if they were follow-up studies and symptom prompted if they were obtained to investigate new symptoms. One hundred seven patients (mean age 6 years and 3 months, range 2 months-15 years and 6 months) were entered into the study. Fifty-three children experienced tumor recurrence; 41 had one recurrence, nine had two, and three had three recurrences. Surveillance imaging revealed 10 of the first 53 recurrences and 15 of all 68 recurrences. When the first recurrence was identified by the emergence of symptoms (42 patients), the children tended to survive for a shorter time (hazard ratio 3.72, 95% confidence interval 1.42-9.76, p = 0.008) than children in whom the first recurrence was detected before symptoms occurred (10 patients). The median survival time following symptomatic tumor recurrence was 4 months and that after surveillance-detected tumor recurrence was 17 months. The median increased survival time among patients whose recurrence was asymptomatic and identified by imaging studies was 13 months, more than half the mean time between surveillance imaging sessions. Incomplete tumor resection was associated with a significantly reduced time to recurrence (p = 0.048) and to death (p = 0.002). The number of recurrences that were experienced was associated with a reduced time to death (p < 0.001). CONCLUSIONS: Surveillance imaging is associated with an increase in survival in children with medulloblastomas. More frequent surveillance imaging in children with incomplete tumor excision and recurrent disease may further improve the length of survival.