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Biomedical subjects

A Gajjar

Publications and source records attributed to A Gajjar.

At least 19 recordsLinked to original sources
PubMed2000

Subtle white matter volume differences in children treated for medulloblastoma with conventional or reduced dose craniospinal irradiation.

Medulloblastoma is the most common malignant brain tumor in children, and approximately seventy percent of average-risk patients will achieve long-term survival. Craniospinal irradiation (CSI), combined with chemotherapy and surgery, is currently the mainstay of treatment but places children who survive at risk for serious neurocognitive sequelae. These sequelae are intensified with a younger age at treatment, greater elapsed time following treatment, and an increased radiation dose. Many newer treatment approaches have attempted to address this problem by reducing the dose of the CSI component of radiation therapy while maintaining the current survival rates. This study evaluates longitudinal MR imaging during therapy to assess the impact of the two CSI doses (conventional [36 Gy] and reduced [23.4 Gy]) on normal appearing white matter volumes (NAWMV) evaluated in a single index slice. Twenty-six children and young adults at least three years of age enrolled on an institutional protocol for newly diagnosed, previously untreated primary medulloblastoma had at least four MR examinations over a minimum nine month period following CSI. These serial volumes were evaluated as a function of time since CSI in three analyses: 1) all subjects, 2) subjects stratified by age at CSI, and 3) subjects stratified by CSI dose. The first analysis demonstrated that medulloblastoma patients treated with CSI have a significant loss of NAWMV in contradistiction to normally expected maturation. Stratifying the patients by age at CSI found no significant differences in the rate of NAWMV loss. The final analysis stratified the patients by CSI dose and revealed that the rate of NAWMV loss was 23% slower in children receiving reduced-dose. Serial quantitative MR measures of NAWMV may provide a neuroanatomical substrate for assessing functional impact of CSI on normal brain function following treatment for medulloblastoma.

Adolescent↗
PubMed2000

Individualized methotrexate dosing in children with relapsed acute lymphoblastic leukemia.

Although high-dose methotrexate has been extensively studied in children with newly diagnosed acute lymphoblastic leukemia (ALL), there are fewer data in children with relapsed ALL, many of whom have been heavily pretreated and have subclinical kidney dysfunction. We characterized the pharmacokinetics of adaptively controlled methotrexate given as a 24-h infusion during consolidation therapy in 24 children with relapsed ALL. To achieve the target steady-state concentration of 65 microM, dosage adjustments were required in 14 patients, with doses ranging from 2854 to 6700 mg/m2 per course. The mean steady-state plasma concentration (Cpss) of 68.0 microM was different (P = 0.025) than the predicted Cpss (mean = 87.4 microM; range 35.7-184 microM) had no adjustment in dose been made. The coefficient of variation in Cpss was reduced from 41% to 18% by individualizing doses. Predisposing factors that correlated with decreased methotrexate clearance were female sex (P = 0.03), age greater than 6 years (P = 0.01), and prior history of heavy amphotericin B treatment (>30 mg/kg) (P = 0.03), but no factor predicted low clearance as well as the measured initial methotrexate clearance during the infusion (P < 0.0001). There was no life-threatening toxicity with the regimen. We conclude that dosage individualization decreases interpatient variability and avoids potentially toxic methotrexate exposures in heavily pretreated ALL patients.

Adolescent↗
PubMed2000

Silent lacunar lesions detected by magnetic resonance imaging of children with brain tumors: a late sequela of therapy.

BACKGROUND: Cerebral lacunes, which generally appear on magnetic resonance imaging as foci of white matter loss, usually occur in adults after ischemic infarcts. We report the development of lacunes in children after therapy for brain tumors. PATIENTS AND METHODS: We reviewed the clinical characteristics and radiologic studies of 524 consecutive children with brain tumors treated over a 10-year period. We documented the neuropsychologic findings associated with lacunes and the factors predictive of lacunar development. RESULTS: Lacunes developed in none of the 103 patients observed or treated with surgery alone. Twenty-five of the 421 patients treated with chemotherapy or radiation therapy or both had lacunes. Patients were a median of 4.5 years old at the time of both diagnosis (range, 0.3 to 19.8 years) and radiotherapy (range, 1.5 to 20 years). Fourteen patients were treated with craniospinal irradiation, and 11 were treated with local radiotherapy. The median time from radiotherapy to the appearance of lacunes was 2.01 years (range, 0.26 to 5.7 years). For all patients, lacunes were an incidental finding with no corresponding clinical deficits. The factor most predictive of lacunar development was age less than 5 years at the time of radiotherapy (P =.010). There was no significant difference in estimated decline in intelligence quotient scores between patients with lacunes and age and diagnosis-matched controls. CONCLUSION: Lacunes may be caused by therapy-induced vasculopathy in children with brain tumors, with the most significant predictor being age less than 5 years at the time of radiotherapy.

Adolescent↗
PubMed1999

Neurocognitive deficits in medulloblastoma survivors and white matter loss.

Although previous studies have documented a significant risk of intellectual loss after treatment for childhood medulloblastoma (MED), the pathophysiology underlying this process is poorly understood. The purpose of this study was to test the hypotheses that (1) patients treated for MED in childhood have reduced volumes of normal white matter (NWM) related to their treatment with craniospinal irradiation with or without chemotherapy, and (2) deficits in NWM among patients surviving MED can at least partially explain deficits in their intellectual performance. Eighteen pediatric patients previously treated for MED were matched on the basis of age at the time of evaluation to 18 patients previously treated for low-grade posterior fossa tumors with surgery alone (mean difference, 3.7 months). Evaluations were conducted with age-appropriate neurocognitive testing and quantitative magnetic resonance imaging by using a novel automated segmentation and classification algorithm constructed from a hybrid neural network. Patients treated for MED had significantly less NWM (p < 0.01) and significantly lower Full-Scale IQ values than those treated for low-grade tumors (mean, 82.1 vs 92.9). In addition, NWM had a positive and statistically significant association with Full-Scale IQ among the patients treated for MED. We conclude that irradiation- or chemotherapy-induced destruction of NWM can at least partially explain intellectual and academic achievement deficits among MED survivors.

Adolescent↗
PubMed1999

Chemotherapy of medulloblastoma.

Recent advances in neurosurgical techniques and diagnostic imaging capabilities have facilitated gross total resection and accurate staging of disease extent in a greater proportion of patients. The addition of chemotherapy to surgery and craniospinal radiation has improved the outcome of patients diagnosed with medulloblastoma. Long-term follow-up studies have documented the neuroendocrine and neuropsychological deficits seen in the survivors. This paper reviews key studies using all three modalities over the past two decades and presents on-going therapeutic strategies using a risk-adapted approach. Further areas of basic research and evolving data on studies in relapsed patients are also briefly discussed.

Antineoplastic Agents↗
PubMed1999

Comparison of CSF cytology and spinal magnetic resonance imaging in the detection of leptomeningeal disease in pediatric medulloblastoma or primitive neuroectodermal tumor.

PURPOSE: Leptomeningeal disease (LMD) significantly affects the prognosis and treatment of pediatric patients with medulloblastoma or primitive neuroectodermal tumor (PNET). Examination of CSF for malignant cells, detection of LMD on spinal magnetic resonance imaging (MRI), or both are the methods routinely used to diagnose LMD. A recent study suggested 100% correlation between CSF and MRI findings in children with medulloblastoma. To determine the validity of this hypothesis, we compared the rate of detection of LMD between concurrent lumbar CSF cytology and spinal MRI performed at diagnosis in patients with medulloblastoma or PNET. PATIENTS AND METHODS: As a part of diagnostic staging, 106 consecutive patients newly diagnosed with medulloblastoma or PNET were evaluated with concurrent lumbar CSF cytology and spinal MRI. CSF cytology was examined for the presence of malignant cells and spinal MRI was reviewed independently for the presence of LMD. RESULTS: Thirty-four patients (32%) were diagnosed with LMD based on CSF cytology, spinal MRI, or both. There were 21 discordant results. Nine patients (8.5%) with positive MRI had negative CSF cytology. Twelve patients (11.3%) with positive CSF cytology had negative MRIs. The exact 95% upper bounds on the proportion of patients with LMD whose disease would have gone undetected using either CSF cytology or MRI as the only diagnostic modality were calculated at 14.4% and 17.7%, respectively. CONCLUSION: With the use of either CSF cytology or spinal MRI alone, LMD would be missed in up to 14% to 18% of patients with medulloblastoma or PNET. Thus, both CSF cytology and spinal MRI should routinely be used to diagnose LMD in patients with medulloblastoma or PNET.

Adolescent↗
PubMed1999

Survival and neurodevelopmental outcome of young children with medulloblastoma at St Jude Children's Research Hospital.

PURPOSE: Young children treated for medulloblastoma are at especially high risk for morbidity and mortality from their disease and therapy. This study sought to assess the relationship, if any, between patient outcome and M stage. Neuropsychologic and endocrine outcomes were also assessed. PATIENTS AND METHODS: Twenty-nine consecutively diagnosed infants and young children were treated for medulloblastoma at St Jude Children's Research Hospital between November 1984 and December 1995. All patients were treated with the intent of using postoperative chemotherapy to delay planned irradiation. RESULTS: The median age at diagnosis was 2.6 years. Six patients completed planned chemotherapy without progressive disease and underwent irradiation at completion of chemotherapy. Twenty-three children experienced disease progression during chemotherapy and underwent irradiation at the time of progression. The 5-year overall survival rate for the entire cohort was 51% +/- 10%. The 5-year progression-free survival rate was 21% +/- 8%. M stage did not impact survival. All patients lost cognitive function during and after therapy at a rate of -3.9 intelligence quotient points per year (P =.0028). Sensory functions declined significantly after therapy (P =.007). All long-term survivors required hormone replacement therapy and had growth abnormalities. CONCLUSION: The majority of infants treated for medulloblastoma experienced disease progression during initial chemotherapy. However, more than half of these patients can be cured with salvage radiation therapy, regardless of M stage. The presence of metastatic disease did not increase the risk of dying from medulloblastoma. All patients treated in this fashion have significant neuropsychologic deficits. Our experience demonstrates that medulloblastoma in infancy is a curable disease, albeit at a significant cost.

Age Factors↗
PubMed1999

Sex differences in prognosis for children with acute lymphoblastic leukemia.

PURPOSE: Whether recent improvements in the treatment of childhood acute lymphoblastic leukemia (ALL) have nullified the adverse prognosis associated with male sex remains unclear. Therefore, we analyzed the survival experience and presenting clinical and laboratory features of boys and girls with newly diagnosed ALL who were treated at our institution over the past three decades. PATIENTS AND METHODS: One thousand one hundred fifty-one boys and 904 girls were treated in 13 consecutive Total Therapy studies between 1962 and 1994. An overview analysis was used to investigate the impact of sex on overall and event-free survival, both for the entire cohort and for subgroups defined by treatment era and blast-cell immunophenotype. Stratified analyses were performed to adjust for treatment protocol and known risk factors, and in the modern treatment era, for protocol, immunophenotype, and the DNA content of leukemic cells (ie, DNA index). The pharmacokinetics of methotrexate, teniposide, and cytarabine, as well as the thiopurine methyltransferase activity of erythrocytes, were compared between boys and girls treated on a single protocol. RESULTS: Compared with girls, boys were more likely to have T-cell ALL (20.9% v 10.7%, P < .001) and seemed less likely to have a favorable DNA index (17.8% v 25.1%, P = .072). There were no other statistically significant differences between the two sexes with respect to presenting features, including leukemic-cell genetic abnormalities, nor were there significant sex differences in the pharmacokinetics of methotrexate, teniposide, or cytarabine or in erythrocyte thiopurine methyltransferase activity. Girls clearly fared better than boys (P < .001) on protocols used during the early era of treatment (10-year event-free survival +/- 1 SE, 43.1%+/-2.1% v 31.5%+/-1.7%). Although prognosis improved for both sexes in the modern era, the difference in outcome between girls and boys persisted (P = .025) (10-year event-free survival, 73.4%+/-3.7% v 63.5%+/-4.0%). However, stratification of modern-era patients by protocol, immunophenotype, and DNA index mitigated statistical evidence of a sex difference in overall survival (P = .263) and event-free survival (P = .124). CONCLUSION: Although boys and girls alike have benefited from improvements in ALL therapy, these gains have not completely eliminated the sex difference in prognosis that has persisted since the early 1960s. The apparent difference in outcome is partially explained by differences between boys and girls in the distributions of ALL immunophenotype and DNA index.

Adolescent↗
PubMed1999

Comparison of lumbar and shunt cerebrospinal fluid specimens for cytologic detection of leptomeningeal disease in pediatric patients with brain tumors.

PURPOSE: Leptomeningeal disease (LMD) significantly affects the prognosis and treatment of pediatric patients with primary CNS tumors. Cytologic examination of lumbar CSF is routinely used to detect LMD. To determine whether examination of CSF obtained from ventricular shunt taps is a more sensitive method of detecting LMD in these patients, we designed a prospective study to compare the findings of cytologic examinations of CSF obtained from concurrent lumbar and ventriculoperitoneal (VP) shunt taps. PATIENTS AND METHODS: As a part of diagnostic staging, follow-up testing, or both, 52 consecutive patients underwent concurrent lumbar and shunt taps on 90 separate occasions, ranging from the time of diagnosis to treatment follow-up. CSF from both sites was examined cytologically for malignant cells. RESULTS: The median age of the 28 males and 24 females was 7.5 years (range, 0.6 to 21.4 years). The primary CNS tumors included medulloblastoma (n = 29), astrocytoma (n = 10), ependymoma (n = 5), germinoma (n = 3), atypical teratoid rhabdoid tumor (n = 2), choroid plexus carcinoma (n = 2), and pineoblastoma (n = 1). Each site yielded a median CSF volume of 1.0 mL. Fourteen of 90 paired CSF test results were discordant: in 12, the cytologic findings from shunt CSF were negative for malignant cells, but those from lumbar CSF were positive; in two, the reverse was true. Malignant cells were detected at a higher rate in lumbar CSF than in shunt CSF (P =.0018). When repeat analyses were excluded, examination of lumbar CSF remained significantly more sensitive in detecting malignant cells (P =.011). Analysis of the subset of patients with embryonal tumors showed similar results (P =.0008). CONCLUSION: Cytologic examination of lumbar CSF is clearly superior to cytologic examination of VP shunt CSF for detecting leptomeningeal metastases in pediatric patients with primary CNS tumors.

Adolescent↗
PubMed1999

Infectious meningitis mimicking recurrent medulloblastoma on magnetic resonance imaging. Case report.

This report and the accompanying review of the literature address the challenges, when using surveillance magnetic resonance (MR) imaging, of establishing the origin of newly detected central nervous system lesions. Routine surveillance MR imaging in a 16-year-old boy, whose medulloblastoma had been successfully treated, demonstrated asymptomatic nodular leptomeningeal enhancement of the brain and spinal cord, which was consistent with recurrent disease. Examination of the cerebrospinal fluid, however, led to the diagnosis of bacterial meningitis. Two weeks after completion of antibiotic therapy, the original MR imaging findings were seen to have resolved. This case illustrates the importance of considering clinical and laboratory data, including results from a complete examination of the cerebrospinal fluid, when interpreting the origin of new lesions revealed by MR imaging.

Adolescent↗
PubMed1998

Carboplatin and etoposide with hyperfractionated radiotherapy in children with newly diagnosed diffuse pontine gliomas: a phase I/II study.

BACKGROUND: Diffuse pontine gliomas remain one of the most lethal of pediatric malignancies despite the use of increasingly intensive therapies. We delivered intensive chemotherapy during and following 70.2 Gy of hyperfractionated radiation therapy in an attempt to improve survival. PROCEDURE: Nine consecutive children with diffuse pontine gliomas were treated on this single arm study. Carboplatin, given in combination with fixed dose etoposide, was escalated in successive cohorts to determine its maximum tolerated systemic exposure (AUC). Outcome was coded based on imaging characteristics and clinical status. RESULTS: Eight of the nine children on this study died of their disease at a median of 44 weeks, essentially the same survival as those treated on a previous Pediatric Oncology Group study using hyperfractionated radiation therapy alone. Toxicity was almost exclusively hematologic and not associated with significant morbidity. CONCLUSIONS: The use of concurrent carboplatin and etoposide with hyperfractionated radiation therapy did not appear to improve the survival in this group of children with diffuse pontine gliomas. The toxicity of this chemotherapy during radiation therapy was primarily hematologic and well tolerated. New approaches to the treatment of these tumors need to be investigated.

Antineoplastic Agents, Phytogenic↗
PubMed1998

A pilot study of vincristine, ifosfamide, and doxorubicin in the treatment of pediatric non-rhabdomyosarcoma soft tissue sarcomas.

BACKGROUND: Standard therapy for pediatric nonrhabdomyosarcoma soft tissue sarcomas (PNRSTS) consists of surgical resection with or without radiotherapy. The role of chemotherapy in the treatment of these tumors has not yet been defined. We investigated the efficacy and toxicity of an ifosfamide-based regimen in controlling disease in children with high-risk PNRSTS. PATIENTS AND METHODS: Between January 1992 and June 1994 at St. Jude Children's Research Hospital, we treated 11 children and young adults with PNRSTS who were at high risk for treatment failure by using a combined modality regimen that comprised aggressive surgery, radiotherapy, and chemotherapy including vincristine, ifosfamide, and doxorubicin (VID). Nine of these patients had grade 3 disease and one had grade 2 tumor; due to insufficient tissue, the disease grade of the remaining patient could not be established. Metastases were present at diagnosis in 2 children. RESULTS: Therapy was generally well tolerated, with minimal morbidity and no mortality. The most common toxicity was grade 4 neutropenia, which occurred in 51% of evaluable courses. Among 4 patients evaluable for response to chemotherapy alone, 1 child attained a partial response and 3 had stable disease. One child had a response to chemotherapy and concurrent irradiation. At a median follow-up of 30 months, 10 of 11 patients are alive; 8 of 11 patients are alive without evidence of disease. CONCLUSION: Aggressive multimodality therapy for PNRSTS is well tolerated, despite frequent and profound neutropenia. Although adjuvant chemotherapy for this group of cancers remains unproved, the rate of tumor control achieved in this pilot study encourages further investigation in a multi-institutional setting.

Adolescent↗
PubMed1998

Bithalamic involvement predicts poor outcome among children with thalamic glial tumors.

Clinical features and treatment of 36 consecutive pediatric patients with thalamic glial tumors confirmed by histology and characterized by neuroimaging were reviewed to identify prognostic factors. The median age at diagnosis was 10 years (range 1-18 years). Twenty-four patients had low-grade tumors (juvenile pilocytic astrocytoma n = 9, fibrillary astrocytoma n = 6, astrocytomas not otherwise specified n = 6, ganglioglioma n = 2 and oligodendroglioma n = 1) and 12 patients had high-grade tumors (glioblastoma multiforme n = 7, anaplastic astrocytoma n = 4 and unclassified malignant tumor n = 1). With a median follow-up of 4.3 years among survivors, estimates of 4-year progression-free survival (PFS) and overall survival (OS) for the entire group are 28+/-10 and 37 +/- 10%, respectively. Low-grade tumors were associated with a significantly better 4-year PFS (36 +/- 12 vs. 0% for the high-grade group; p = 0.03) and OS (52 +/- 12 vs. 0%; p < 0.001). This review identified that bithalamic involvement, characterized by neuroimaging, exerted an independent and significant negative impact on PFS and OS for patients with low-grade tumors. Estimates of 4-year PFS and OS among patients with tow-grade bithalamic versus monothalamic tumors were 58 +/- 15 vs. 0% and 85 +/- 11 vs. 0% (p < 0.00001), respectively. The presence of bithalamic involvement did not affect outcome among patients with high-grade tumors. Additionally, age at diagnosis, enhancement with neuroimaging contrast, extension beyond the thalamus and extent of surgical resection did not correlate with overall outcome. Because treatment approaches varied during the study period, the impact of radiation therapy or chemotherapy could not be assessed. This contemporary, single-institution series of pediatric thalamic glial tumors demonstrates, for the First time, the statistical significance of bithalamic involvement as a marker of poor prognosis among patients with low-grade glial lesions.

Adolescent↗
PubMed1998

Algorithm for nutritional support: experience of the Metabolic and Infusion Support Service of St. Jude Children's Research Hospital.

The Metabolic and Infusion Support Service (MISS) at St. Jude Children's Research Hospital was established in 1988 to improve the quality of nutritional support given to children undergoing therapy for cancer. This multidisciplinary group, representing each of the clinical services within the hospital, provides a range of services to all patients requiring full enteral or parenteral nutritional support. In 1991, the MISS developed an algorithm for nutritional support which emphasized a demand for a compelling rationale for choosing parenteral over enteral support in patients with functional gastrointestinal tracts. Compliance with the algorithm was monitored annually for 3 years, with full compliance defined as meeting all criteria for initiating support and selection of an appropriate type of support. Compliance rates were 93% in 1992, 95% in 1993 and 100% in 1994. The algorithm was revised in 1994 to include criteria for offering oral supplementation to patients whose body weight was at least 90% of their ideal weight and whose protein stores were considered adequate. Full support was begun if no weight gain occurred. Patients likely to tolerate and absorb food from the gastrointestinal tract were classified into groups defined by the absence of intractable vomiting, severe diarrhea, graft-vs.-host disease affecting the gut, radiation enteritis, strictures, ileus, mucositis and treatment with allogeneic bone marrow transplant. Overall, the adoption of the algorithm has increased the frequency of enteral nutritional support, particularly via gastrostomies, by at least 3-fold. Our current emphasis is to define the time points in therapy at which nutritional intervention is most warranted.

Algorithms↗
PubMed1997

Patterns of failure in children with medulloblastoma: effects of preirradiation chemotherapy.

PURPOSE: To evaluate the effects of preirradiation chemotherapy on patterns of failure in children with medulloblastoma. METHODS AND MATERIALS: Fifty-three patients (pts) with medulloblastoma were given preirradiation chemotherapy as initial postoperative treatment at St. Jude Children's Research Hospital from November 1984 to September 1993. Patients < or = 3 years of age (n = 23) received chemotherapy (CH) with delayed craniospinal irradiation (CSI). Children > or = 3 years with more advanced disease (T3b-T4, M+ or measurable residual after resection) were given CH followed by CSI (30 patients). Chemotherapy regimen depended on protocol, but usually included cis- or carboplatin and etoposide, +/- cyclophosphamide and vincristine. RESULTS: Actuarial overall survival and event-free survival rates are 60% (95% confidence interval [41,79]) and 37% [19,55] at 5 years. Children < or = 3 at diagnosis: six of 23 pts completed CH without progression and received consolidative CSI; all six are alive with no evidence of disease (NED) at 2.4-9.1 years. Seventeen patients progressed during CH and were then given CSI. Sites of progression during CH were posterior fossa (PF) in 11 patients, neuraxis (NEUR) in 4, and PF+NEUR in 2. Following CSI, 7 patients are alive NED at 2.0-8.6 years; 10 patients died of progressive disease. Eleven patients had M0 disease at diagnosis; 8 (73%) progressed during CH, 3 in the neuraxis. Children > or = 3 at diagnosis: 20 of 30 patients completed pre-CSI CH without progression; 15 are alive NED at 1.3-9.2 years, and 5 showed post-CSI progression in the PF (n = 3), in the NEUR (n = 1) and in bone marrow (n = 1). Ten of the 30 (33%) patients progressed on CH (6 in NEUR, 4 in PF); 5 are alive and NED or with stable disease. Seventeen patients had M0 disease at diagnosis; 3 out of 17 (18%) progressed during CH, 2 in NEUR and 1 in an extraneural site. In the total group of 30 patients, 11 have had disease recurrence after completion of XRT. The actuarial rate of failure was 23 +/- 9% for the patients < or = 3 years of age and 21 +/- 8% for the older children when evaluated at 4 months after diagnosis (at the completion of chemotherapy in the older children but during the ongoing chemotherapy in the younger children). CONCLUSIONS: In patients presenting with M0 disease and receiving pre-CSI chemotherapy, the risk of neuraxis progression seems to increase with duration of chemotherapy. The sites of progression during preirradiation chemotherapy are nearly equally divided between posterior fossa and other neuraxis sites. CSI salvage of patients progressing on chemotherapy is possible in approximately 50% of patients. Following CSI, neuraxis progression is more frequent than posterior fossa relapse.

Adolescent↗
PubMed1997

Brain stem involvement in children with neurofibromatosis type 1: role of magnetic resonance imaging and spectroscopy in the distinction from diffuse pontine glioma.

OBJECTIVE: To evaluate the ability of magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (MRS) to distinguish neurofibromatosis Type 1 (NF-1) with brain stem enlargement from diffuse pontine glioma (PG) in pediatric patients. METHODS: A chart review was used to identify all patients with NF-1 and diffuse brain stem enlargement who were seen at our institution and who had undergone MRI. Comparison groups were as follows: 1) eight patients who did not have NF-1 but who did have diffuse PG, and 2) seven healthy children. Midsagittal diameters of the pons, midbrain, and medulla were measured in all patients, and the results were statistically analyzed. Two MRS variables were also statistically compared: N-acetyl aspartate and the vector sum of the metabolites choline and creatine/phosphocreatine. RESULTS: In MRI-based measurements, only the pontine midsagittal diameter differed significantly between the NF-1 and PG groups (P = 0.002). Altogether, 21 children underwent MRS, including 6 in the NF-1 group. Measures of both MRS variables were significantly lower in patients with PG than in the others (P < or = 0.007). The two MRS variables classified the 21 children into the three respective groups with 100% accuracy. Of the seven patients with NF-1, four presented with symptoms attributable to brain stem involvement. The brain stems of all seven patients with NF-1 were hyperintense on T2-weighted magnetic resonance images, and five were isointense on T1-weighted images; only one exophytic tumor was identified. Four of the patients with NF-1 were followed up clinically without treatment; all remained alive and neurologically stable for a median of 40 months. All eight patients in the PG group were symptomatic at presentation, and all except one died despite therapy. CONCLUSION: Both MRI measurements and MRS seem to be useful for distinguishing patients with NF-1 and diffuse brain stem enlargement from patients without NF-1 but with diffuse PG. They should be most helpful in differentiating symptomatic patients with NF-1 from patients with PG, thereby minimizing aggressive treatment and its side effects in patients destined to have better outcomes.

Adolescent↗
PubMed1997

Cerebellar pontine angle ependymoma in infants.

We discuss the surgical approach used for and outcome in 11 infants (< or =3 years) who were treated at our institution for ependymomas arising in the cerebellar-pontine (C-P) angle. The median age of the group was 19 months (range: 6-26 months). Of these 11 patients, the initial surgery for 8 was performed at our center and achieved a gross total resection (GTR) in 4 patients and a subtotal resection (STR) in the remaining 4. The 3 patients who had tumor debulking performed elsewhere were subsequently referred to our institution and had definitive surgery after receiving 3-4 courses of chemotherapy; one of these children had a GTR, whereas the remaining 2 had an STR. During the immediate postoperative period, 9 patients had cranial nerve deficits that necessitated placement of a tracheostomy and a gastrostomy feeding tube; these were discontinued in 6 of the 9 patients as the deficits resolved. The majority of the permanent cranial nerve deficits involved the sixth and seventh cranial nerves. Of the 11 patients, 4 have died (progressive disease, n = 1; accidental death, n = 2; withdrawal of life support, n = 1); the remaining 7 patients are alive, with a median follow-up of 37 months (range: 20-73 months). Aggressive surgical resection for tumors arising in the C-P region is associated with postoperative deficits, which resolve over time with appropriate supportive care. This approach may increase the number of children in whom GTR is achieved, thereby potentially increasing the cure rate for these patients.

Antineoplastic Agents↗