Publications by authors named "Kovnar E"

Purpose: In June 1992, POG began accrual to a phase III study, POG-9239, designed to compare the time to disease progression, overall survival, and toxicities observed in children with newly diagnosed brainstem tumor treated with 100 mg/m2 of infusional cisplatin and randomized to either conventional vs. hyperfractionated radiotherapy.

Methods And Materials: Patients eligible for study were those between 3 and 21 years of age with previously untreated tumors arising in the pons.

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Medulloblastoma, a malignant tumor arising from the medullary velum, is the most common malignant brain tumor of childhood. Local extension into the cerebellar hemisphere, infiltration of the floor of the fourth ventricle, and seeding into the subarachnoid space are common. Early diagnosis and improved treatment consisting of surgery followed by radiation and chemotherapy for selected high-risk patients has contributed to a dramatic change in survival.

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Cerebrovascular arterial occlusion is a rare but devastating event causing long-term morbidity in children with tumors in the parasellar region. While usually associated with radiation therapy, there are a variety of host, tumor and treatment factors which predispose patients to significant vasculopathy. Case reports of 5 patients from St.

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Purpose: We evaluated the clinical efficacy of preirradiation carboplatin (CARBO) and etoposide (VP-16) in 25 patients with newly diagnosed embryonal CNS tumors.

Patients And Methods: Sixteen patients with high-risk medulloblastoma and nine with other embryonal tumors were treated with two daily doses of CARBO 350 mg/m2 and VP-16 100 mg/m2 (CARBO/VP) every 21 days for four cycles before standard craniospinal irradiation. Patients with disease progression (PD) before radiation therapy were additionally treated with intensive postirradiation cyclophosphamide (CYCLO) and vincristine (VINC).

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Despite reported activity in many other solid tumors, high-dose ifosfamide produces few objective responses in recurrent pediatric brain tumors. Alkylating agents such as cyclophosphamide (CYCLO) possess good activity in many of solid tumors, including brain tumors. Although Ifosfamide (IFOS), a structural congener of CYCLO, has been suggested to have greater activity in several tumors, its activity in brain tumors is uncertain.

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Malignant pediatric tumors of the central nervous system (CNS) have a poor prognosis, with local failure rates as high as 50%. In an attempt to improve local tumor control, we used stereotactic interstitial therapy with 125I implants in patients with recurrent/secondary or newly diagnosed CNS malignancies. Catheters were placed using computed tomography (CT) guidance; computerized dosimetry was completed with the aid of orthogonal films.

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Purpose: To evaluate survival and neurodevelopmental outcomes following radiation therapy in infants and young children with residual or progressive medulloblastoma after primary chemotherapy.

Patients And Methods: Thirteen young patients (< or = 36 months old) with medulloblastoma were treated with preirradiation multiagent chemotherapy and maximal surgical resection. Patients were scheduled to receive radiation therapy at the time of documented disease progression or upon completion of chemotherapy with residual disease.

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Thirty-two cases of neurofibromatosis Type I (NF1) were identified among 6,678 pediatric cancer patients treated at St. Jude Children's Research Hospital over a 29-year period. A total of 35 malignant neoplasms have been diagnosed in these patients.

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We report the uncommon occurrence of ventriculo-peritoneal shunt-associated peritoneal metastases in two patients with pineoblastoma. In one patient, the peritoneal cavity was the only site of recurrence; there was no evidence of disease recurrence in the central nervous system. One other patient with recurrent intracranial disease had synchronous, but asymptomatic, peritoneal metastases which were detected on an elective ultrasound.

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We report the magnetic resonance imaging (MRI) and clinico-histologic characterization of dorsally exophytic brain stem gliomas (DEBSGs). Between 1983 and 1991, 12 of 51 patients evaluated for the diagnosis of brain stem glioma were found to have DEBSGs emanating from the pons, pontomedullary junction or medulla. Eleven of the 12 patients had classic juvenile pilocytic astrocytomas.

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In order to describe the status of long-term survivors of brain stem glioma, neuropsychological and behavioral measures were obtained a median of 2.5 (range 1.5-5.

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A phase I Pediatric Oncology Group Study was performed combining 7,020 cGy hyperfractionated irradiation (117 cGy twice daily separated by 6 h) with increasing concurrent doses of cisplatin given with the intent of radiosensitization as treatment for children with newly diagnosed brain stem tumors. Cisplatin was infused over 120 h on weeks 1, 3, and 5 during a 6-week radiotherapy course. The following cisplatin dose levels were studied: (1) 50 mg/m2/120 h, (2) 75 mg/m2/120 h and (3) 100 mg/m2/120 h.

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Purpose: To assess the value of tumor-cell ploidy as a predictor of survival in medulloblastoma.

Patients And Methods: Ploidy determinations were based on the flow-cytometric analysis of cellular DNA content in fresh tumor specimens taken from 34 consecutively treated children with newly diagnosed medulloblastoma. Patients were assigned a high or low risk of failure depending on tumor size and invasiveness, and the presence or absence of metastatic disease.

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Purpose: Evaluation of high-dose chemotherapy with autologous bone marrow rescue (ABMR) in pediatric malignant gliomas.

Patients And Methods: Newly diagnosed (n = 11) and recurrent (n = 2) malignant glioma patients received high-dose chemotherapy within 4 weeks of surgery; three had near total and 10 had subtotal resection/biopsy. High-dose thiotepa (300 mg/m2) and cyclophosphamide (2 g/m2) daily for 3 days were followed by ABMR; response was evaluated at day 30.

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Background: Both thiotepa and its active metabolite, tepa, efficiently cross the blood-brain barrier. After intravenous administration, the cerebrospinal fluid concentrations achieved are nearly identical to those in plasma. This provides a strong rationale for testing this agent against brain tumors.

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Background: Ifosfamide with Mesna, given every other day over a 5-day period, was evaluated in 20 children with recurrent or progressive primary brain tumors.

Methods: The patients were assigned to dosage cohorts separated on the basis of prior exposure to cisplatin (n = 10) or the absence of such exposure (n = 10). The initial dose in each treatment arm was 2133 mg/m2 every other day for three doses, which represented 80% of the total dose delivered in our prior study of ifosfamide given daily over 5 days.

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Thirteen patients with low grade astrocytomas were treated with alkylating agent or platinum-based chemotherapy regimens. Eleven of these patients received chemotherapy as their initial postoperative treatment modality, and 2 others as treatment for progressive disease postradiation therapy. Responses were objectively determined using CT or MRI.

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Purpose: Because of concerns about late toxicities of treatment among infants diagnosed with acute lymphoblastic leukemia (ALL), and especially the effects of cranial radiation therapy (CRT), we compared the functional and neuropsychologic status of 26 long-term survivors of ALL who were diagnosed in the first 24 months of life versus 26 children who were treated previously for Wilms' tumor.

Patients And Methods: Of the children with ALL, CNS prophylaxis included no CRT in six, 18 Gy CRT in five, 20 Gy CRT in seven, and 24 Gy CRT in five. Three additional children experienced CNS relapse and received total CRT doses of 24, 40, and 44 Gy.

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Of 29 consecutive children treated for malignant primary tumors of the central nervous system (CNS) at this institution, postoperative examination showed radiographic or cytologic evidence of neuraxis dissemination in 10 (34%). Given the historically poor results in disseminated CNS tumors treated with surgery and radiation therapy alone, these ten patients were treated prospectively with an investigational Phase II protocol consisting of preirradiation cisplatin (90 mg/m2 on day 1) and etoposide (150 mg/m2 on days 3 and 4). The diagnoses included medulloblastoma (n = 4), malignant glioma (n = 3), cerebral primitive neuroectodermal tumor (n = 1), pineoblastoma (n = 1), and mixed glioma of the brainstem (n = 1).

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The authors report the clinicopathologic and neuroimaging findings in ten children with primary abdominal or thoracic neuroblastoma who relapsed in the central nervous system (CNS) without evidence of concurrent intracranial extension from adjacent bone, dura, or dural sinus metastases. At diagnosis, the patients ranged in age from 0.3 to 4.

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Although long-term transfusion therapy is at least 90% effective in preventing recurrent strokes after an initial cerebrovascular accident in patients with sickle cell disease, it is unknown how long transfusion therapy should be continued. To address this question, we prospectively discontinued transfusions in 10 patients with sickle cell disease whose median duration of transfusion therapy after an initial stroke was 9 1/2 years (range 5 to 12 years). Before the transfusions were discontinued, patients were examined by cerebral angiography, magnetic resonance imaging of the head, neuropsychologic testing, electroencephalography, and a complete neurologic examination.

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Medulloblastoma, pineoblastoma, and cerebral neuroblastoma are malignant embryonal tumors of the CNS that may demonstrate similar histologic features, a propensity for neuraxis dissemination and sensitivity to radiation therapy and, in certain cases, chemotherapy. To evaluate the activity of preirradiation chemotherapy in such tumors, 11 newly diagnosed children with measurable residual disease and characteristics indicative of poor prognosis were treated postoperatively with cisplatin (CDDP) and etoposide (VP-16). Responses graded on the basis of radiographic findings in areas of either macroscopic residual tumor or metastatic disease included two complete responses (CRs), eight partial responses (PRs), and one stable disease (SD).

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Despite the clinical experience with Ommaya reservoir-facilitated intraventricular methotrexate (MTX) therapy, established age-related dosage guidelines do not exist. In an attempt to design such a schedule, 49 courses of intra-Ommaya MTX (median dose, 6 mg) administered to 12 patients were studied. Using a fluorescence polarized immunoassay (TDx; Abbott, Dallas, TX), the median peak intraventricular CSF MTX concentration (CSF [MTX]) was 423 mumol/L.

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In an effort to reduce the severity of late neurotoxicities associated with cranial irradiation, 14 infants and young children with malignant brain tumors were given preirradiation chemotherapy for 2 to 22 months (median, 8 months). Prospective neurodevelopmental evaluations were routinely conducted and now extend from 35 to 60 months (median, 41 months) postdiagnosis, and 10 to 52 months (median, 31 months) postirradiation in the 12 surviving children. At the initiation of chemotherapy, less than one fourth of the patients displayed normal performance status or mental functioning on age-corrected tests; the majority remained stable or declined while receiving chemotherapy.

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