- Neurology - Child Neurology
- Pediatric Neuro-Oncology
Clinical Assistant Professor, Neurology & Neurological Sciences
Pediatric Neuro-Oncology Fellowship Director, Stanford (2012 - Present)
Member, Executive Committee, Section of Neurology, American Academy of Pediatrics (2012 - Present)
Treasurer, Brain Tumor Epidemiology Consortium (2012 - 2014)
Board Certification: Neuro-Oncology, United Council for Neurologic Subspecialties (2011)
Board Certification: Neurology - Child Neurology, American Board of Psychiatry and Neurology (2007)
Board Certification: Pediatrics, American Board of Pediatrics (2007)
Residency:Brown University Hospitals (2002) RI
Residency:Children's Hospital and Regional Medical Center (2006) WA
Fellowship:, Packard Children's & Stanford Hospital, Neuro-Oncology (2007)
Medical Education:University of Missouri School of Medicine (2000) MO
Masters:, Stanford University, Epidemiology (2009)
Current Research and Scholarly Interests
My research interests involve the epidemiology, treatment and diagnosis of pediatric and young adult brain tumors. I am also interested in long-term neurologic effects and designing clinical trials to treat brain and spinal cord tumors.
Selumetinib in Treating Young Patients With Recurrent or Refractory Low Grade Glioma
This phase I/II trial studies the side effects and the best dose of selumetinib and how well it works in treating or re-treating young patients with low grade glioma that has come back or does not respond to treatment. Selumetinib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth.
DNA Analysis of Tumor Tissue Samples From Patients With Diffuse Brain Stem Glioma
This multi-institutional study will prospectively collect tumor and constitutional tissue samples from patients with diffuse brainstem glioma and other types of brainstem gliomas either during therapy or at autopsy to perform an extensive analysis of genetic and molecular abnormalities in these tumors.
A Clinical and Molecular Risk-Directed Therapy for Newly Diagnosed Medulloblastoma
Historically, medulloblastoma treatment has been determined by the amount of leftover disease present after surgery, also known as clinical risk (standard vs. high risk). Recent studies have shown that medulloblastoma is made up of distinct molecular subgroups which respond differently to treatment. This suggests that clinical risk alone is not adequate to identify actual risk of recurrence. In order to address this, we will stratify medulloblastoma treatment in this phase II clinical trial based on both clinical risk (low, standard, intermediate, or high risk) and molecular subtype (WNT, SHH, or Non-WNT Non-SHH). This stratified clinical and molecular treatment approach will be used to evaluate the following: - To find out if participants with low-risk WNT tumors can be treated with a lower dose of radiation to the brain and spine, and a lower dose of the chemotherapy drug cyclophosphamide while still achieving the same survival rate as past St. Jude studies with fewer side effects. - To find out if adding targeted chemotherapy after standard chemotherapy will benefit participants with SHH positive tumors. - To find out if adding new chemotherapy agents to the standard chemotherapy will improve the outcome for intermediate and high risk Non-WNT Non-SHH tumors. - To define the cure rate for standard risk Non-WNT Non-SHH tumors treated with reduced dose cyclophosphamide and compare this to participants from the past St. Jude study. All participants on this study will have surgery to remove as much of the primary tumor as safely possible, radiation therapy, and chemotherapy. The amount of radiation therapy and type of chemotherapy received will be determined by the participant's treatment stratum. Treatment stratum assignment will be based on the tumor's molecular subgroup assignment and clinical risk. The participant will be assigned to one of three medulloblastoma subgroups determined by analysis of the tumor tissue for tumor biomarkers: - WNT (Strata W): positive for WNT biomarkers - SHH (Strata S): positive for SHH biomarkers - Non-WNT Non-SHH, Failed, or Indeterminate (Strata N): negative for WNT and SHH biomarkers or results are indeterminable Participants will then be assigned to a clinical risk group (low, standard, intermediate, or high) based on assessment of: - How much tumor is left after surgery - If the cancer has spread to other sites outside the brain [i.e., to the spinal cord or within the fluid surrounding the spinal cord, called cerebrospinal fluid (CSF)] - The appearance of the tumor cells under the microscope - Whether or not there are chromosomal abnormalities in the tumor, and if present, what type (also called cytogenetics analysis).
An Open-label Safety and Tolerability Study of ISIS SMNRx in Patients With Spinal Muscular Atrophy Who Previously Participated in ISIS 396443-CS1
This study will test the safety and tolerability of ISIS-SMNRx administered into the spinal fluid as a single injection in patients with Spinal Muscular Atrophy, who previously participated in ISIS 396443-CS1
Stanford is currently not accepting patients for this trial. For more information, please contact Shirley Paulose, 650-724-3792.
Modafinil in Treating Children With Memory and Attention Problems Caused by Cancer Treatment for a Brain Tumor
RATIONALE: Modafinil may help improve memory, attention, and fatigue caused by cancer treatment. PURPOSE: This phase II randomized trial studies how well modafinil works in treating children with memory and attention problems caused by cancer treatment for a brain tumor.
Arginine Vasopressin Is a Blood-Based Biomarker of Social Functioning in Children with Autism.
2015; 10 (7)
Brain arginine vasopressin (AVP) critically regulates normative social behavior in mammals, and experimental disruption of the AVP signaling pathway produces social impairments in rodent models. We therefore hypothesized that AVP signaling deficits may contribute to social impairments in children with autism spectrum disorder (ASD). Since blood measures (which are far easier to obtain than brain measures) of AVP are most meaningful if they are related to brain AVP activity, Study 1 tested the relationship between AVP concentrations in concomitantly collected blood and CSF samples from children and adults (N = 28) undergoing clinical procedures. Study 2 tested whether blood AVP concentrations: 1) differed between children with ASD (N = 57), their ASD discordant siblings (N = 47), and neurotypical controls (N = 55); and 2) predicted social functioning (using the NEPSY-II Theory of Mind and Affect Recognition tasks and the Social Responsiveness Scale) in this large, well-characterized child cohort. Blood AVP concentrations significantly and positively predicted CSF AVP concentrations (F1,26 = 7.17, r = 0.46, p = 0.0127) in Study 1. In Study 2, blood AVP concentrations did not differ between groups or by sex, but significantly and positively predicted Theory of Mind performance, specifically in children with ASD, but not in non-ASD children (F1,144 = 5.83, p = 0.017). Blood AVP concentrations can be used: 1) as a surrogate for brain AVP activity in humans; and 2) as a robust biomarker of theory of mind ability in children with ASD. These findings also suggest that AVP biology may be a promising therapeutic target by which to improve social cognition in individuals with ASD.
View details for DOI 10.1371/journal.pone.0132224
View details for PubMedID 26200852
Decreased tumor apparent diffusion coefficient correlates with objective response of pediatric low-grade glioma to bevacizumab
JOURNAL OF NEURO-ONCOLOGY
2015; 122 (3): 491-496
Recent small, retrospective series suggest bevacizumab may be a therapeutic option for recurrent pediatric low-grade glioma (LGG). Assessment of therapeutic responses is complicated by the unpredictable natural history of these tumors. Because diffusion-weighted imaging quantifies microscopic water motion affected by cellular density and histologic features, we hypothesized that it may be helpful in monitoring therapeutic response of LGG to bevacizumab. We retrospectively reviewed eight consecutive patients, median age 4.8 (range 2.3-12.3) years at initiation of bevacizumab therapy for recurrent or refractory LGG. Patients received 10 mg/kg/dose every 2 weeks (median 16 doses/therapy course). Mean apparent diffusion coefficient (ADC) was measured and analyzed in respect to tumor volume. Following the first treatment course, seven of eight patients had reduced tumor volume (≥25 %) and ADC. The median decrease in tumor volume was 47% (range -6 to 78 %) and the median decrease in ADC was 14 % (range -5 to 30 %). The ADC was significantly decreased during therapy, whereas the decrease in volume was seen only after therapy completion. There was a positive correlation between percent change in tumor volume and ADC (p < 0.05). We report a decrease in tumor ADC during initial bevacizumab therapy that is accompanied by a decrease in volume following therapy. Imaging changes in microscopic water motion associated with histology may be useful in monitoring the therapeutic response of LGG to bevacizumab.
View details for DOI 10.1007/s11060-015-1754-9
View details for Web of Science ID 000354717800008
View details for PubMedID 25758812
Clinical course and progression-free survival of adult intracranial and spinal ependymoma patients
2015; 17 (3): 440-447
Ependymomas are rare CNS tumors. Previous studies describing the clinical course of ependymoma patients were restricted to small sample sizes, often with patients at a specific institution.Clinically annotated ependymoma tissue samples from 19 institutions were centrally reviewed. Patients were all adults aged 18 years or older at the time of diagnosis. Potential prognostic clinical factors identified on univariate analysis were included in a multivariate Cox proportional hazards model with backwards selection to model progression-free survival.The 282 adult ependymoma patients were equally male and female with a mean age of 43 years (range, 18-80y) at diagnosis. The majority were grade II (78%) with the tumor grade for 20 cases being reclassified on central review (half to higher grade). Tumor locations were spine (46%), infratentorial (35%), and supratentorial (19%). Tumor recurrence occurred in 26% (n = 74) of patients with a median time to progression of 14 years. A multivariate Cox proportional hazards model identified supratentorial location (P < .01), grade III (anaplastic; P < .01), and subtotal resection, followed or not by radiation (P < .01), as significantly increasing risk of early progression.We report findings from an ongoing, multicenter collaboration from a collection of clinically annotated adult ependymoma tumor samples demonstrating distinct predictors of progression-free survival. This unique resource provides the opportunity to better define the clinical course of ependymoma for clinical and translational studies.
View details for DOI 10.1093/neuonc/nou162
View details for Web of Science ID 000352479700016
View details for PubMedID 25121770
- Childhood Brain Tumor Epidemiology: A Brain Tumor Epidemiology Consortium Review CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION 2014; 23 (12): 2716-2736
MRI surrogates for molecular subgroups of medulloblastoma.
AJNR. American journal of neuroradiology
2014; 35 (7): 1263-1269
Recently identified molecular subgroups of medulloblastoma have shown potential for improved risk stratification. We hypothesized that distinct MR imaging features can predict these subgroups.All patients with a diagnosis of medulloblastoma at one institution, with both pretherapy MR imaging and surgical tissue, served as the discovery cohort (n = 47). MR imaging features were assessed by 3 blinded neuroradiologists. NanoString-based assay of tumor tissues was conducted to classify the tumors into the 4 established molecular subgroups (wingless, sonic hedgehog, group 3, and group 4). A second pediatric medulloblastoma cohort (n = 52) from an independent institution was used for validation of the MR imaging features predictive of the molecular subtypes.Logistic regression analysis within the discovery cohort revealed tumor location (P < .001) and enhancement pattern (P = .001) to be significant predictors of medulloblastoma subgroups. Stereospecific computational analyses confirmed that group 3 and 4 tumors predominated within the midline fourth ventricle (100%, P = .007), wingless tumors were localized to the cerebellar peduncle/cerebellopontine angle cistern with a positive predictive value of 100% (95% CI, 30%-100%), and sonic hedgehog tumors arose in the cerebellar hemispheres with a positive predictive value of 100% (95% CI, 59%-100%). Midline group 4 tumors presented with minimal/no enhancement with a positive predictive value of 91% (95% CI, 59%-98%). When we used the MR imaging feature-based regression model, 66% of medulloblastomas were correctly predicted in the discovery cohort, and 65%, in the validation cohort.Tumor location and enhancement pattern were predictive of molecular subgroups of pediatric medulloblastoma and may potentially serve as a surrogate for genomic testing.
View details for DOI 10.3174/ajnr.A3990
View details for PubMedID 24831600
Time-Dependent Structural Changes of the Dentatothalamic Pathway in Children Treated for Posterior Fossa Tumor
AMERICAN JOURNAL OF NEURORADIOLOGY
2014; 35 (4): 803-807
Injury to the dentatothalamic pathway that originates in the cerebellum has been suggested as a mechanism for neurologic complications in children treated for posterior fossa tumors. We hypothesized that time-dependent changes occur in the dentatothalamic pathway.Diffusion tensor evaluation was performed in 14 children (median age, 4.1 years; age range, 1-20 years) who underwent serial MR imaging at 3T as part of routine follow-up after posterior fossa tumor resection with or without adjuvant therapy. Tensor metrics were obtained in the acute (≤1 week), subacute (1 to <6 months), and chronic (≥6 months) periods after surgery. We evaluated the following dentatothalamic constituents: bilateral dentate nuclei, cerebellar white matter, and superior cerebellar peduncles. Serial dentate nuclei volumes were also obtained and compared with the patient's baseline.The most significant tensor changes to the superior cerebellar peduncles and cerebellar white matter occurred in the subacute period, regardless of the tumor pathology or therapy regimen, with signs of recovery in the chronic period. However, chronic volume loss and reduced mean diffusivity were observed in the dentate nuclei and did not reverse. This atrophy was associated with radiation therapy and symptoms of ataxia.Longitudinal diffusion MR imaging in children treated for posterior fossa tumors showed time-dependent tensor changes in components of the dentatothalamic pathway that suggest evolution of structural damage with inflammation and recovery of tissue directionality. However, the dentate nuclei did not show tensor or volumetric recovery, suggesting that the injury may be chronic.
View details for DOI 10.3174/ajnr.A3735
View details for Web of Science ID 000335343000032
Surveillance imaging in children with malignant CNS tumors: low yield of spine MRI
JOURNAL OF NEURO-ONCOLOGY
2014; 116 (3): 617-623
Magnetic resonance imaging (MRI) is routinely obtained in patients with central nervous system (CNS) tumors, but few studies have been conducted to evaluate this practice. We assessed the benefits of surveillance MRI and more specifically spine MRI in a contemporary cohort. We evaluated MRI results of children diagnosed with CNS tumors from January 2000 to December 2011. Children with at least one surveillance MRI following the diagnosis of medulloblastoma (MB), atypical teratoid rhabdoid tumor (ATRT), pineoblastoma (PB), supratentorial primitive neuroectodermal tumor, supratentorial high-grade glioma (World Health Organization grade III-IV), CNS germ cell tumors or ependymoma were included. A total of 2,707 brain and 1,280 spine MRI scans were obtained in 258 patients. 97 % of all relapses occurred in the brain and 3 % were isolated to the spine. Relapse was identified in 226 (8 %) brain and 48 (4 %) spine MRI scans. The overall rate of detecting isolated spinal relapse was 9/1,000 and 7/1,000 for MB patients. MRI performed for PB showed the highest rate for detecting isolated spinal recurrence with 49/1,000. No initial isolated spinal relapse was identified in patients with glioma, supratentorial primitive neuroectodermal tumor and ATRT. Isolated spinal recurrences are infrequent in children with malignant CNS tumors and the yield of spine MRI is very low. Tailoring surveillance spine MRI to patients with higher spinal relapse risk such as PB, MB with metastatic disease and within 3 years of diagnosis could improve allocation of resources without compromising patient care.
View details for DOI 10.1007/s11060-013-1347-4
View details for Web of Science ID 000330785900022
Cerebrospinal fluid and plasma oxytocin concentrations are positively correlated and negatively predict anxiety in children.
The neuropeptide oxytocin (OXT) exerts anxiolytic and prosocial effects in the central nervous system of rodents. A number of recent studies have attempted to translate these findings by investigating the relationships between peripheral (e.g., blood, urinary and salivary) OXT concentrations and behavioral functioning in humans. Although peripheral samples are easy to obtain in humans, whether peripheral OXT measures are functionally related to central OXT activity remains unclear. To investigate a possible relationship, we quantified OXT concentrations in concomitantly collected cerebrospinal fluid (CSF) and blood samples from child and adult patients undergoing clinically indicated lumbar punctures or other CSF-related procedures. Anxiety scores were obtained in a subset of child participants whose parents completed psychometric assessments. Findings from this study indicate that plasma OXT concentrations significantly and positively predict CSF OXT concentrations (r=0.56, P=0.0064, N=27). Moreover, both plasma (r=-0.92, P=0.0262, N=10) and CSF (r=-0.91, P=0.0335, N=10) OXT concentrations significantly and negatively predicted trait anxiety scores, consistent with the preclinical literature. Importantly, plasma OXT concentrations significantly and positively (r=0.96, P=0.0115, N=10) predicted CSF OXT concentrations in the subset of child participants who provided behavioral data. This study provides the first empirical support for the use of blood measures of OXT as a surrogate for central OXT activity, validated in the context of behavioral functioning. These preliminary findings also suggest that impaired OXT signaling may be a biomarker of anxiety in humans, and a potential target for therapeutic development in individuals with anxiety disorders.Molecular Psychiatry advance online publication, 4 November 2014; doi:10.1038/mp.2014.132.
View details for DOI 10.1038/mp.2014.132
View details for PubMedID 25349162
Relapse patterns in pediatric embryonal central nervous system tumors
JOURNAL OF NEURO-ONCOLOGY
2013; 115 (2): 209-215
Embryonal tumors of the central nervous system (CNS) share histological features and were therefore initially grouped as primitive neuroectodermal tumors (PNET) and treated similarly. We sought to determine the relapse patterns of specific embryonal CNS tumors. We conducted a historical cohort study of children diagnosed with CNS embryonal tumors from January 2000 to December 2011 in two pediatric neuro-oncology centers. Patients of 21 years of age or younger at time of presentation with a diagnosis of medulloblastoma, supratentorial PNET, pineoblastoma or atypical teratoid/rhabdoid tumor (ATRT) and at least one surveillance MRI were included. A total of 133 patients met inclusion criteria and 49 (37 %) patients relapsed during the observation period. The majority (79 %) of sPNET relapses were local, whereas all (100 %) PB relapses were associated with diffuse leptomeningeal disease. Relapse patterns for MB were more diverse with local recurrence in 27 %, distant recurrence in 35 % and diffuse leptomeningeal disease in 38 %. The frequency of relapses involving the spine differed (p < 0.001) between tumor types (MB 28/55 [51 %], sPNET 3/33 [9 %], ATRT 3/7 [43 %] and PB 12/12 [100 %]). No sPNET patients had isolated spinal relapse (0/14). Embryonal tumors were found to have divergent patterns of recurrence. While medulloblastoma has variable relapse presentations, sPNET relapses locally and pineoblastoma recurs with diffuse leptomeningeal disease involving the spine. These results point toward possibly new upfront treatment stratification among embryonal tumors in accordance with relapse pattern.
View details for DOI 10.1007/s11060-013-1213-4
View details for Web of Science ID 000325821900009
Increased focal hemosiderin deposition in pediatric medulloblastoma patients receiving radiotherapy at a later age.
Journal of neurosurgery. Pediatrics
2013; 12 (5): 444-451
Object Focal hemosiderin deposition (FHD) is commonly observed on brain MRI scans of patients treated for childhood medulloblastoma (MB). The authors sought to determine the clinical significance of FHD and its relationship to patient age, radiation dose, and cognitive outcomes. Methods A single-institution retrospective study of 93 MB patients at Lucile Packard Children's Hospital at Stanford from 1998 to 2011 identified 41 patients with a negative baseline MRI scan and at least 2 posttreatment MRI scans obtained with T2* gradient recalled echo (GRE). The number and cumulative rate of FHDs detectable by GRE were compared between patients aged 6 years and younger (early age) and aged 7-21 years (late age) at the time of radiotherapy (RT) and between low-dose (1800-2340 cGy) and high-dose (2920-3960 cGy) RT. Results The median age at MB diagnosis was 7.3 years (range 0.9-21.0 years), the median clinical follow-up period was 5.8 years (range 0.8-13.4 years), and the median 5-year overall survival was 81% ± 7%. Of 30 school-aged children with MB, 21 (70%) required special education, and the median IQ of 10 tested patients was 100 (range 50-118). Thirty-three patients (80%) had FHD after a median latency of 1.9 years (range 0.1-5.9 years). Ninety-four percent (436 of 466) of the lesions arose in the supratentorial region of the brain, whereas 29 (6%) resided in the brainstem or the cerebellum. No spinal lesions were observed on routine spine MRI scans using T2 fast spin echo imaging. The mean cumulative lesion rate per year was 2.23 ± 3.05, and this rate was higher in older children at the time of RT compared with younger children (3.23 vs 0.67 per year, p = 0.002) but did not differ among different RT doses (p = 0.395). A child's IQ or need for special education showed no significant correlation with the rate of lesion development or number of lesions. None of the lesions resulted in symptomatic hemorrhage that required surgical intervention. Conclusions More FHD was observed in children treated for MB at the older ages than in those treated at the younger ages. There was no significant association of the incidence of FHD with radiation dose or cognitive outcomes, and none of the lesions required surgical intervention.
View details for DOI 10.3171/2013.7.PEDS1330
View details for PubMedID 23992236
Histological Predictors of Outcome in Ependymoma are Dependent on Anatomic Site Within the Central Nervous System
2013; 23 (5): 584-594
Ependymomas originate in posterior fossa (PF), supratentorial (ST) or spinal cord (SC) compartments. At present, grading schemes are applied independent of anatomic site. We performed detailed histological examination on 238 World Health Organization grade II and III ependymomas. Among PF ependymomas, the presence of hypercellular areas, necrosis, microvascular proliferation and elevated mitotic rate (all P < 0.01) were significantly associated with worse progression-free survival (PFS), while extensive ependymal canal formation was not (P = 0.89). Similar to the PF tumors, microvascular proliferation (P = 0.01) and elevated mitotic rate (P = 0.03) were significantly associated with worse PFS in the ST tumors. However, in contrast to PF tumors, extensive ependymal canals (P = 0.03) were associated with worse clinical outcome in ST ependymomas, but hypercellularity (P = 0.57) and necrosis (P = 0.47) were not. On multivariate Cox regression, after adjusting for relevant clinical variables, individual histological factors and a composite histological score remained significant among ST and PF ependymoma. In contrast to both PF and ST ependymoma, histological features were not found to be associated with PFS in SC tumors. Taken together, the clinical relevance of specific histological features in ependymoma appears to be related to the anatomic site of origin and suggests that site-specific grading criteria be considered in future classification systems.
View details for DOI 10.1111/bpa.12050
View details for Web of Science ID 000329280700009
View details for PubMedID 23452038
Prognostic role for diffusion-weighted imaging of pediatric optic pathway glioma
JOURNAL OF NEURO-ONCOLOGY
2013; 113 (3): 479-483
Optic pathway glioma (OPG) has an unpredictable course, with poor correlation between conventional imaging features and tumor progression. We investigated whether diffusion-weighted MRI (DWI) predicts the clinical behavior of these tumors. Twelve children with OPG (median age 2.7 years; range 0.4-6.2 years) were followed for a median 4.4 years with DWI. Progression-free survival (time to requiring therapy) was compared between tumors stratified by apparent diffusion coefficient (ADC) from initial pre-treatment scans. Tumors with baseline ADC greater than 1,400 × 10(-6) mm(2)/s required treatment earlier than those with lower ADC (log-rank p = 0.002). In some cases, ADC increased leading up to treatment, and declined following treatment with surgery, chemotherapy, or radiation. Baseline ADC was higher in tumors that eventually required treatment (1,562 ± 192 × 10(-6) mm(2)/s), compared with those conservatively managed (1,123 ± 114 × 10(-6) mm(2)/s) (Kruskal-Wallis test p = 0.013). Higher ADC predicted earlier tumor progression in this cohort and in some cases declined after therapy. Evaluation of OPG with DWI may therefore be useful for predicting tumor behavior and assessing treatment response.
View details for DOI 10.1007/s11060-013-1140-4
View details for Web of Science ID 000320461300017
Distinctive MRI Features of Pediatric Medulloblastoma Subtypes
AMERICAN JOURNAL OF ROENTGENOLOGY
2013; 200 (4): 895-903
We hypothesized that the apparent diffusion coefficient (ADC) and other MRI features can be used to predict medulloblastoma histologic subtypes, as defined by the World Health Organization (WHO) in WHO Classification of Tumours of the Central Nervous System.A retrospective review of pediatric patients with medulloblastoma between 1989 and 2011 identified 38 patients with both pretreatment MRI and original pathology slides. The mean and minimum tumor ADC values and conventional MRI features were compared among medulloblastoma histologic subtypes.The cohort of 38 patients included the following histologic subtypes: 24 classic medulloblastomas, nine large cell (LC) or anaplastic medulloblastomas, four desmoplastic medulloblastomas, and one medulloblastoma with extensive nodularity. The median age at diagnosis was 8 years (range, 1-21 years) and the median follow-up time was 33 months (range, 0-150 months). The mean ADC (× 10(-3) mm(2)/s) was lower in classic medulloblastoma (0.733 ± 0.046 [SD]) than in LC or anaplastic medulloblastoma (0.935 ± 0.127) (Mann-Whitney test, p = 0.004). Similarly, the minimum ADC was lower in classic medulloblastoma (average ± SD, 0.464 ± 0.056) than in LC or anaplastic medulloblastoma (0.630 ± 0.053) (p = 0.004). The MRI finding of focal cysts correlated with the classic and desmoplastic subtypes (Fisher exact test, p = 0.026). Leptomeningeal enhancement positively correlated with the LC or anaplastic medulloblastoma subtype and inversely correlated with the classic medulloblastoma and desmoplastic medulloblastoma subtypes (p = 0.04). Ring enhancement correlated with tumor necrosis (p = 0.022) and with the LC or anaplastic medulloblastoma histologic subtype (p < 0.001).The LC or anaplastic medulloblastoma subtype was associated with increased ADC and with ring enhancement, the latter of which correlated with tumor necrosis. These features could be considered in the evaluation of high-risk medulloblastoma subtypes.
View details for DOI 10.2214/AJR.12.9249
View details for Web of Science ID 000316622100045
Concurrent cyclophosphamide and craniospinal radiotherapy for pediatric high-risk embryonal brain tumors
JOURNAL OF NEURO-ONCOLOGY
2012; 110 (2): 287-291
Embryonal tumors are an aggressive subtype of high-grade, pediatric central nervous system (CNS) tumors often with dismal survival rates. The 5-year survival for highest-risk embryonal tumors may be as low as 10 %. We report feasibility and efficacy from our experience using intravenous (IV) cyclophosphamide concurrently with craniospinal radiation (CSI) in high-risk embryonal CNS tumors of childhood. Ten consecutive children (aged: 3.5-15.5 years, median: 10.2 years, six male) with high-risk embryonal tumors, including: large cell/anaplastic medulloblastoma (6), atypical teratoid rhabdoid tumor (1), and leptomeningeal primitive neuroectodermal tumor (3), were treated with IV cyclophosphamide 1 g/M(2) on days 1 and 2 of CSI. Following a median of 36 Gy CSI plus tumor boosts, adjuvant treatment consisted of 21 doses of oral etoposide (7) and alkylator based chemotherapy from five to eight cycles in all. Of the ten patients thus treated, six remain alive with no evidence of disease and four are deceased. Median survival was 3.3 years, with a 3-year progression-free survival of 50 % (5/10). Median follow-up was: 3.3 years (range: 5 months-12.9 years) in the five patients with progression, median time-to-progression was: 1.3 years (range: 1 month-3 years). Median follow-up in the patients without progression is 8.8 years (range: 3-12.9 years). Complications due to adjuvant chemotherapy were typical and included myelosupression (10), necessitating shortened duration of chemotherapy in three, and hemorrhagic cystitis (1). In high-risk embryonal CNS tumors, cyclophosphamide given concurrently with CSI is well tolerated. Early results suggest that a phase II trial is warranted.
View details for DOI 10.1007/s11060-012-0969-2
View details for Web of Science ID 000311208100017
View details for PubMedID 22941430
Stroke and Cerebrovascular Complications in Childhood Cancer Survivors
SEMINARS IN PEDIATRIC NEUROLOGY
2012; 19 (1): 18-24
The outcomes for childhood cancer have drastically improved over the last several decades. Previously, irradiation was commonly used for blood-borne (leukemia, lymphoma) cancers and neck and brain tumors. Radiation therapy remains the mainstay of treatment for highly malignant cancers of head and neck and for some primary central nervous system tumors. Unfortunately, radiation therapy has been implicated as a contributor to many late effects of treatment, including cerebrovascular disease from large-vessel vascular injury, stroke, moyamoya, mineralizing microangiopathy, to stroke-like migraine. This review summarizes the pathophysiology of these disorders in relationship to treatment with and without radiation as well as the relevant manifestations of radiation-induced cerebrovascular disease. Patient populations at highest risk and current recommendations for health providers and patient education are emphasized when possible.
View details for DOI 10.1016/j.spen.2012.02.012
View details for Web of Science ID 000305263900004
View details for PubMedID 22641072
Birth Anomalies and Obstetric History as Risks for Childhood Tumors of the Central Nervous System
2011; 128 (3): E652-E657
The causes of childhood central nervous system (CNS) tumors are largely unknown. Birth characteristics have been examined as possible risk factors for childhood CNS tumors, although the studies have been underpowered and inconclusive. We hypothesized that birth anomalies and a mother's history of previous pregnancy losses, as a proxy for genetic defects, increase the risk for CNS tumors.From the California Cancer Registry, we identified 3733 patients aged 0 to 14 years with CNS tumors, diagnosed from 1988 through 2006 and linked to a California birth certificate. Four controls were matched to each patient. We calculated odds ratios (ORs) for the reported presence of a birth defect and for history of pregnancy losses by using logistic regression, adjusted for race, Hispanic ethnicity, maternal age, birth weight, and birth order.Offspring from mothers who had ? 2 fetal losses after 20 weeks' gestation had a threefold risk for CNS tumors (OR: 3.13 [95% confidence interval (CI): 1.32-7.41]) and a 14-fold risk for high-grade glioma (OR: 14.28 [95% CI: 1.56-130.65]). Birth defects increased risk for the CNS cancers medulloblastoma (OR: 1.70 [95% CI: 1.12-2.57]), primitive neuroectodermal tumor (OR: 3.64 [95% CI: 1.54-8.56]), and germ cell tumors (OR: 6.40 [95% CI: 2.09-19.56]).Multiple pregnancy losses after 20 weeks' gestation and birth defects increase the risk of a childhood CNS tumor. Previous pregnancy losses and birth defects may be surrogate markers for gene defects in developmental pathways that lead to CNS tumorigenesis.
View details for DOI 10.1542/peds.2010-3637
View details for Web of Science ID 000295406100022
View details for PubMedID 21824884
Liposomal cytarabine for central nervous system embryonal tumors in children and young adults
JOURNAL OF NEURO-ONCOLOGY
2011; 103 (3): 561-566
To assess the tolerability and efficacy of liposomal cytarabine (LC), an encapsulated, sustained-release, intrathecal (IT) formulation of cytosine arabinoside, in de novo and relapsed central nervous system (CNS) embryonal tumors in children and young adults. We studied retrospectively all patients less than age 30 at our institution treated consecutively with LC for medulloblastoma (MB), primitive neuroectodermal tumor (PNET), and atypical teratoid rhabdoid tumor (ATRT). Seventeen patients received LC (2 mg/kg up to 50 mg, every 2 weeks to monthly) at diagnosis of high-risk CNS embryonal tumor (2 PNET, 3 ATRT) or relapse of MB (12 MB; 9 had leptomeningeal metastases). Sixteen patients received concurrent systemic chemotherapy. A total of 108 doses were administered (IT 82, intraventricular 26) with a mean of six (range 1-16) treatments per patient. Only three administrations were associated with adverse effects of arachnoiditis or headache. None developed malignant cerebrospinal fluid (CSF) cytology while receiving LC. All the six evaluable patients with malignant CSF cytology and treated with at least two doses cleared their CSF (mean 3 doses, range 1-5). Median overall survival in relapse patients was 9.1 months. Five patients (4 de novo and 1 relapsed) remain alive in complete remission for a median 26.8 months from first LC. Liposomal cytarabine is an easily administered, well-tolerated, and active drug in patients with high-risk embryonal neoplasms. One-third of our cohort remains in remission from otherwise fatal diagnoses. Our findings warrant a phase II trial of LC in newly diagnosed or recurrent CNS embryonal tumors.
View details for DOI 10.1007/s11060-010-0419-y
View details for Web of Science ID 000291703000018
View details for PubMedID 20859651
Effect of chronic red cell transfusion therapy on vasculopathies and silent infarcts in patients with sickle cell disease
AMERICAN JOURNAL OF HEMATOLOGY
2011; 86 (1): 104-106
Regular, chronic red cell transfusions (CTX) have been shown to be effective prophylaxis against stroke in sickle cell disease (SCD) in those at risk. Because serial brain imaging is not routinely performed, little is known about the impact of CTX on silent infarcts (SI) and cerebral vascular pathology. Thus, we retrospectively evaluated the magnetic resonance imaging reports of a cohort of SCD patients who were prescribed CTX for either primary or secondary stroke prophylaxis. Seventeen patients with Hb SS were included (mean age 15 years, mean follow-up 4.3 years). Eight patients were on CTX for primary prophylaxis. New SI occurred in 17.6% of patients corresponding to an SI rate of 5.42 per 100 patient-years. Vasculopathy of the cerebral arteries was present in 65% of patients and progressed in 63% of these patients. Those who developed progressive vasculopathy were on CTX for an average of 8 years before lesions progressed. Patients on CTX for secondary prophylaxis had more SIs and evidence of progressive vascular disease than patients on CTX for primary prophylaxis. We conclude that adherence to CTX does not necessarily prevent SI or halt cerebral vasculopathy progression, especially in those with a history of overt stroke.
View details for DOI 10.1002/ajh.21901
View details for Web of Science ID 000285421300025
View details for PubMedID 21117059
Birth Weight and Order as Risk Factors for Childhood Central Nervous System Tumors
JOURNAL OF PEDIATRICS
2010; 157 (3): 450-455
To determine whether birth characteristics related to maternal-fetal health in utero are associated with the development of childhood central nervous system tumors.We identified, from the California Cancer Registry, 3733 children under age 15 diagnosed with childhood central nervous system tumors between 1988 and 2006 and linked these cases to their California birth certificates. Four controls per case, matched on birth date and sex, were randomly selected from the same birth files. We evaluated associations of multiple childhood CNS tumor subtypes with birth weight and birth order.Low birth weight was associated with a reduced risk of low-grade gliomas (OR=0.67; 95% CI, 0.46 to 0.97) and high birth weight was associated with increased risk of high-grade gliomas (OR=1.57; 95% CI, 1.16 to 2.12). High birth order (fourth or higher) was associated with decreased risk of low-grade gliomas (OR=0.75; 95% CI, 0.56 to 0.99) and increased risk of high-grade gliomas (OR=1.32; 95% CI, 1.01 to 1.72 for second order).Factors that drive growth in utero may increase the risk of low-grade gliomas. There may be a similar relationship in high-grade gliomas, although other factors, such as early infection, may modify this association. Additional investigation is warranted to validate and further define these findings.
View details for DOI 10.1016/j.jpeds.2010.04.006
View details for Web of Science ID 000281116100023
View details for PubMedID 20553692
Cerebrovascular disease in childhood cancer survivors A Children's Oncology Group Report
2009; 73 (22): 1906-1913
Curative therapy for childhood cancer has dramatically improved over past decades. Therapeutic radiation has been instrumental in this success. Unfortunately, irradiation is associated with untoward effects, including stroke and other cerebrovascular disease (CVD). The Children's Oncology Group (COG) has developed guidelines for screening survivors at risk for persistent or late sequelae of cancer therapy.This review summarizes the pathophysiology and relevant manifestations of radiation-induced CVD and outlines the specific patient groups at risk for early-onset stroke. The reader will be alerted to the availability of the COG recommendations for monitoring, and, when applicable, specific screening and treatment recommendations will be highlighted.A multidisciplinary task force critically reviewed the existing literature and scored the evidence to establish the current COG guidelines for monitoring health of survivors treated with head and neck irradiation.Previous head and neck exposure to therapeutic radiation is associated with latent CVD and increased risk for stroke in some patient groups. Common manifestations of radiation-induced CVD includes steno-occlusive disease, moyamoya, aneurysm, mineralizing microangiopathy, vascular malformations, and strokelike migraines.Risk for stroke is increased in survivors of pediatric CNS tumors, Hodgkin lymphoma, and acute lymphoblastic leukemia who received radiation to the brain and/or neck. As the population of survivors ages, vigilance for stroke and cerebrovascular disease needs to continue based on specific exposures during curative cancer therapy.
View details for DOI 10.1212/WNL.0b013e3181c17ea8
View details for Web of Science ID 000272205200015
View details for PubMedID 19812380
Medulloblastoma Incidence has not Changed Over Time A CBTRUS Study
JOURNAL OF PEDIATRIC HEMATOLOGY ONCOLOGY
2009; 31 (12): 970-971
Earlier studies have reported changes in the incidence of medulloblastoma (MB) but have conflicted, likely because of small sample size or misclassification of MB with primitive neuroectodermal tumor (PNET). The incidence of MB and PNET from 1985 to 2002 was determined from the Central Brain Tumor Registry of the United States, a large population-based cancer registry, using strict histologic and site codes. No statistically significant change in MB incidence was observed over the last 2 decades, but there was an increase in MB and PNET combined.
View details for Web of Science ID 000272658700019
View details for PubMedID 19887963
Levetiracetam For Seizures in Children With Brain Tumors and Other Cancers
PEDIATRIC BLOOD & CANCER
2009; 52 (2): 288-289
Children with brain tumors and other cancers can suffer from seizures. Unfortunately, most antiepileptic therapies are metabolized by the hepatic cytochrome P450 (CYP) system. Levetiracetam, a newer anticonvulsant, does not undergo CYP metabolism and does not alter the pharmacokinetics of chemotherapy, antiemetics, and corticosteroids, which are metabolized by the liver. We studied 23 patients with cancer and seizures treated with levetiracetam. Over 95% of patients had fewer seizures, with 65.2% becoming seizure free; only one patient experienced an adverse reaction. Levetiracetam is effective and well tolerated in children with brain tumors and other cancers, who are often on multiple enzyme-inducing drugs.
View details for DOI 10.1002/pbc.21772
View details for Web of Science ID 000261796000032
View details for PubMedID 18831033
- Neurological complications in children. Cancer treatment and research 2009; 150: 133-143
Update on new treatments and developments in childhood brain tumors
CURRENT OPINION IN PEDIATRICS
2007; 19 (6): 670-674
Childhood primary central nervous system tumors remain a therapeutic conundrum. As the second most common pediatric cancer, brain tumors lead to significantly worse survival and long-term effects compared with those seen with hematologic malignancies and other solid tumors. This review discusses current management strategies in three pediatric brain tumors, the long-term effects of therapy, as well as novel laboratory findings that may alter future treatment strategies.The current literature focuses on tactics to predict those at risk of treatment failure and long-term effects. By analyzing tumors at a molecular genetics level rather than traditional histology, new data have begun to emerge on methods to begin to consider targeted therapies, tailored to the individual child. Furthermore, as survivorship has improved with current radiation and chemotherapy regimens, long-term effects have been identified and merit clinical attention.Even though long-term survival for children with a brain tumor approaches 70%, the need for improved treatment regimens is striking. Secondary malignancies, neurocognitive deficits and treatment failure continue to afflict these children and young adults. The current review will inform clinicians of the challenges faced by basic scientists and clinicians when treating brain tumors, and point to future research directions.
View details for Web of Science ID 000251347800010
View details for PubMedID 18025934
- 50 Years Ago in The Journal of Pediatrics: Agenesis of the corpus callosum: report of eight cases in infancy. JOURNAL OF PEDIATRICS 2007; 150 (4): 399
50 Years Ago in The Journal of Pediatrics: Low cerebrospinal fluid glucose associated with meningeal neoplasia
JOURNAL OF PEDIATRICS
2007; 151 (2): 177
View details for DOI 10.1016/j.jpeds.2007.02.026
Spontaneously relapsing and remitting primary CNS lymphoma in an immunocompetent 45-year-old man
JOURNAL OF NEURO-ONCOLOGY
2006; 80 (3): 305-307
A 45-year-old immunocompetent man with primary central nervous system lymphoma (PCNSL) presented with multiple spontaneous relapses and remissions in the absence of steroid treatment. Because of the fluctuations with improvement in both the clinical course and MRI findings, alternative disorders were considered that led to delay of diagnosis and treatment prior to brain biopsy. This case and a handful of others with single remissions emphasize that PCNSL cannot be reliably ruled out by improving or disappearing symptoms, signs or traditional MR imaging abnormalities.
View details for DOI 10.1007/s11060-006-9192-3
View details for Web of Science ID 000243002600011
View details for PubMedID 16794747
Complications of a temozolomide overdose: a case report
JOURNAL OF NEURO-ONCOLOGY
2006; 80 (1): 57-61
This is a report of a 53 year-old man with a glioblastoma multiforme (GBM) treated with an excessive dose of temozolomide (TMZ).This is a single case review of all clinically relevant records. O6-methylguanine-DNA methyltransferase activity was determined by a biochemical assay.Following conventional radiotherapy (RT) without concurrent chemotherapy, the patient received 5,500 mg of TMZ over 2 days. At the standard dose of 200 mg/m2/day his total 5-day dose should have been 1,940 mg. Acutely he had nausea, vomiting and diarrhea for 2 days which cleared. The dominant severe toxicity was pancytopenia between one and four weeks after TMZ which was complicated by secondary infections that were successfully managed. Transient transaminitis occurred but there were no significant pulmonary, renal or other systemic toxicities. His progression free survival was 22 months and overall survival 24 months.His outcome suggests that TMZ may prove to be a good agent for dose-escalation trials with hematopoietic stem cell rescue.
View details for DOI 10.1007/s11060-006-9152-y
View details for Web of Science ID 000240802300009
View details for PubMedID 16645714
Prolonged but reversible migraine-like episodes long after cranial irradiation
2006; 66 (7): 1105-1107
The authors describe three patients with prolonged but reversible episodes of severe headaches and focal neurologic deficits developing years after irradiation for cranial neoplasms. Despite extensive evaluations, etiology of episodes in these three and eight other previously reported patients remains undetermined. Whether they all have the same condition is uncertain. Although some had cortical gadolinium enhancement on MRI, all 11 patients returned to baseline over hours to weeks.
View details for Web of Science ID 000236673300030
View details for PubMedID 16606929