Biomedical subjects

P K Duffner

Publications and source records attributed to P K Duffner.

At least 37 records · Page 2Linked to original sources

PubMed1992

Changes in the approach to central nervous system tumors in childhood.

Current approaches to children with brain tumors are in a state of evolution. Currently, 50% of children with all types of brain tumors may be expected to survive 5 years. Therefore, the goals of neuro-oncology have broadened to include improved survival and improved quality of life. This article reviews changes in therapy that have altered survival as well as changes in therapy as a consequence of increasing recognition of complications and toxicity of treatment.

Brain↗

PubMed1991

Optic pathway tumors.

Overall, the majority of patients with optic pathway tumors will have stable disease regardless if they are radiated or receive chemotherapy. This is a very indolent tumor system and, for the most part, not a threat to life. Because of this, issues regarding appropriate therapeutic approaches have yet to be resolved. Most agree that in patients with progressive visual loss and tumor limited to the orbit, surgery can be associated with a cure. The downside is the loss of vision associated with surgical extirpation. Radiation rather than surgery has been the mainstay of treatment for intracranial tumors of the optic pathway. To eliminate side effects associated with radiotherapy in the young child, chemotherapy may be the more considered choice. However, on escape of control, i.e., conversion of stable disease to progressive disease, radiotherapy should be considered.

Child↗

PubMed1991

The long-term effects of central nervous system therapy on children with brain tumors.

Survivals of children with brain tumors have increased over the past 20 years owing to advances in surgery, radiation, and, most recently, chemotherapy. Unfortunately, central nervous system therapy, particularly radiation, may be associated with the development of dementia and learning disabilities, leukoencephalopathy, endocrinopathies, and oncogenesis. Recognition of these long-term effects of therapy is important as some are amenable to treatment and others may be prevented by modification of current treatment regimens.

Brain↗

PubMed1989

Treatment of CNS neoplasms in childhood by the Pediatric Oncology Group.

The incidence of brain tumors in children under 15 years of age in the United States is 2.4/100,000. Based upon a US population of approximately 60 million black and white children, there are only 1,200-1,500 newly diagnosed causes of CNS neoplasia diagnosed in children each year in the US. These relatively small numbers, the large geographic dispersion, and the multitude of histologic types, make it unlikely that all but a few medical centers can develop a large experience with this diverse group of tumors. The Brain Tumor Committee (BTC) of the Pediatric Oncology Group was formed, in part, to address this problem. Each of the four goals of the BTC will be addressed separately. A justification for the rationale for each goal is given, following which there is a discussion of how each goal is being met.

Antineoplastic Agents↗

PubMed1989

The significance of MRI abnormalities in children with neurofibromatosis.

We prospectively evaluated 47 children with neurofibromatosis to determine whether the previously reported high signals on magnetic resonance imaging (MRI) (prolonged T2) correlated with CT, brainstem auditory evoked responses (BAER), EEG, clinical examinations, cognitive abilities, or seizure disorder. Thirty percent of children had a history of seizures and 70% had either learning disabilities or mental retardation. Overall, 74% had an abnormal MRI examination. Sixty-two percent had high signals (prolonged T2) on T2-weighted images. Abnormal signals were located primarily in the basal ganglia, brainstem, and cerebellum. Twenty-five percent of patients had abnormal EEGs, 28% had abnormal CTs, and 27% had abnormal BAER examinations. The abnormal signals on MRI did not consistently relate to findings on CT, BAER, EEG, school placement, or clinical examination. The abnormal signals presumably reflect areas of abnormal brain parenchyma, either hamartomas, heterotopias, or local areas of brain dysplasia.

Adolescent↗

PubMed1988

Prospective intellectual testing in children with brain tumors.

Sixteen children with brain tumors received prospective intellectual evaluations with a follow-up of 2 to 5 years. All patients were treated with surgery and radiation and 5 received chemotherapy. Most of the children remained within the normal range of intelligence, but intelligence quotient (IQ) scores declined over time. Learning disabilities were present in 15 of 16 children after radiation, and 11 required special educational services. Risk factors associated with decline in IQ appear to be young age at time of radiation and adjuvant chemotherapy.

Brain Neoplasms↗

PubMed1988

Isolated optic nerve gliomas in children with and without neurofibromatosis.

With the advent of noninvasive neuroimaging of the orbits and brain, many asymptomatic patients with intraorbital optic gliomas have been identified. These children, predominantly with neurofibromatosis, present a therapeutic quandary to the treating physician. There is no consensus regarding either the natural history of intraorbital optic gliomas or the approach treatment. This paper reviews the literature on the treatment of 227 children with intraorbital optic gliomas with surgery, radiation or 'watchful waiting'. Based on this review, an approach to the management of children with intraorbital optic gliomas with and without neurofibromatosis is suggested.

Child↗

PubMed1986

Recent developments in pediatric neuro-oncology.

Although brain tumors represent the second most common malignancy in childhood, there are only 1200 to 1500 children diagnosed with brain tumors each year in the US. Approximately 50% of these children are treated at university or cancer treatment centers. Thus, therapeutic trials by default rather than design have been restricted to small numbers of patients. Information on histopathologic groupings, incidence of various tumor types according to age, general treatment trends and survival statistics are available from the Surveillance, Epidemiology, and End Results (SEER) registries of the National Cancer Institute. Although survivals in brain tumor cancers are worse than in other forms of childhood cancer, treatment advances in surgery, radiation and chemotherapy have significantly improved survivals in at least one brain tumor of childhood, medulloblastoma. Ironically, this treatment may have significant long-term adverse effects on intellect, endocrine function, and on the development of second malignancies. Prompt recognition of these delayed effects is of clinical importance, as some effects are amenable to treatment and others may be prevented by careful monitoring of drug and radiation administration.

Adolescent↗

PubMed1986

Survival of children with brain tumors: SEER Program, 1973-1980.

Eight hundred eighty-seven children with brain tumors were identified by the SEER registries (1973-1980). Twenty-five percent were low-grade supratentorial astrocytomas, medulloblastomas were 23%, cerebellar astrocytomas 12%, high-grade supratentorial astrocytomas 11%, brainstem gliomas 9%, and ependymomas 8%. The worst survivals were in children less than 2 years of age, and the best were in those aged 10 to 14 years. Five-year survivals of children with cerebellar astrocytomas were 91%, low-grade supratentorial astrocytomas 71%, high-grade supratentorial astrocytomas 35%, medulloblastomas 39%, ependymomas 28%, and brainstem gliomas 18%.

Adolescent↗

PubMed1986

Prognostic factors in brainstem gliomas.

Although brainstem gliomas carry the worst prognosis of any brain tumor in children, with median survivals of 9 to 12 months, there may be a subgroup of long-term survivors. We have identified 12 children with brainstem gliomas, 5 of whom have survived greater than 6 years and 6 less than or equal to 12 months. Another child, alive and well 3 years following diagnosis, was considered in the long-term survivor group. Favorable prognostic factors included neurofibromatosis, symptoms greater than or equal to 12 months before diagnosis, calcification on CT, exophytic location, and pathology suggesting a low-grade tumor. Recognition that certain patients with brainstem gliomas may have prolonged survivals even in the absence of definitive treatment must be taken into consideration when new treatment regimens are being formulated.

Adolescent↗

PubMed1985

Long-term effects of cranial irradiation on endocrine function in children with brain tumors. A prospective study.

This study prospectively evaluated the endocrine function of 11 children treated with cranial irradiation (CRT) for brain tumors. All tumors were remote from the hypothalamic-pituitary axis. Children were studied before treatment and at 3, 6, and 12 months after the completion of CRT. T4, thyroid-stimulating hormone, prolactin, plasma cortisol, and urinary follicle-stimulating hormone and luteinizing hormone values were normal before and after treatment in all patients. Growth hormone (GH) deficiency was identified in 0 of 7 patients before treatment, in 2 of 7 patients 3 months post-CRT, in 9 of 11 patients 6 months post-CRT, and in 7 of 8 patients 12 months post-CRT. Growth deceleration was identified in five of seven prepubertal patients. GH deficiency is an extremely common sequelae of CRT, beginning as early as 3 months after the completion of CRT. The deficit is progressive over time.

Adolescent↗

PubMed1985

Extraneural metastases of central nervous system tumors.

In the past, extraneural metastasis of central nervous system tumors was considered to be a rare event. However, more recently, a considerable body of literature has accumulated so that to date some 282 patients with extraneural metastases have been reported. Of these reported cases, 40.4% have occurred in children. Although central nervous system tumors can spread spontaneously beyond the confines of the central nervous system, most instances of extraneural metastasis occur after craniotomy or diversionary cerebrospinal fluid shunting. Extraneural metastases are universally fatal. Although it is not curative, chemotherapeutic treatment of metastases may greatly decrease the patient's discomfort and improve the quality and duration of survival. Every effort should be made to prevent this complication by avoiding diversionary cerebrospinal fluid shunting procedures or by incorporating a filtering device if a shunt becomes necessary.

Brain Neoplasms↗

PubMed1985

Ependymomas. Factors in clinical and diagnostic staging.

In ependymoma, there is evidence that indicates that age, sex, histologic patterns, functional status, location, duration of symptoms, size, and accessibility to surgical removal influence survival. The role of neuron-specific enolase and other biologic markers must await the accumulation of further information. Further advances in diagnostic imaging, immunodiagnostics, and intraoperative staging should lead to a better understanding of the disease and pinpoint prognostic factors more precisely. A profile that contains important information is suggested; this should eventually lead to the development of a staging system.

Adolescent↗

PubMed1985

The long-term effects of cranial irradiation on the central nervous system.

Cranial irradiation and chemotherapy may have significant long-term deleterious effects on children with brain tumors. Intellectual deterioration, endocrinopathies, leukoencephalopathy, extraneural metastases, and oncogenesis may all complicate the treatment of central nervous system neoplasia. These long-term effects of therapy have important implications, as some are amenable to treatment and others may be prevented by the careful monitoring of drug and radiation administration. Until recently, the survivals of children with brain tumors were limited, so that concerns over long-term effects of therapy were unnecessary. As children with certain types of brain tumors now have a better prognosis, these long-term and possibly remediable effects have important implications. This article emphasizes radiation effects on intellect, endocrine function, and oncogenesis. Recommendations for baseline and longitudinal evaluations of children with brain tumors are suggested.

Achievement↗

PubMed1985

The argument for a combined cancer consortium research data base.

Epidemiologic data that were obtained through the SEER registry (Surveillance Epidemiology End Results Program) are presented. Survival statistics for five major brain tumor types in childhood are presented for the years 1968 through 1979. Further survival statistics are compared in patients treated in community hospitals versus university hospitals. The lack of uniform reporting, absence of pathologic conformation, and limited number of patients seen throughout the country are emphasized. There is a need for the establishment of a data base composed of the member institutions of the childhood cancer consortiums. This data base would address questions of patterns of failure, benefits of surgical and clinical staging, and the value of a new putative pathologic grading system. Additionally, the opportunity to collect these patients should permit identification of long-term treatment effects. Identification of early morbidity may lead to modification of treatment programs. A data base containing treatment and diagnostic parameters would allow significant cross-correlations and would lead to the design of future studies that are based upon accurate data.

Brain Neoplasms↗

PubMed1985

Current therapy in childhood brain tumors.

This article reviews the current approach to the treatment of childhood brain tumors. Common childhood brain tumors are profiled in separate sections, and the conclusion includes a discussion of the long-term clinical effects of radiation and chemotherapy.

Antineoplastic Agents↗

PubMed1984

CT abnormalities and altered methotrexate clearance in children with CNS leukemia.

Seventeen children with CNS leukemia treated with chemotherapy and 5 children treated with both cranial radiation (CRT) and chemotherapy were evaluated. Eighty-eight percent of patients treated with chemotherapy alone had CT abnormalities, and all treated with CRT and chemotherapy had abnormal CT. The severity of CT abnormality paralleled intraventricular methotrexate levels and clinical signs of leukoencephalopathy. Children who receive chemotherapy for CNS leukemia, even without cranial irradiation, are more likely to have leukoencephalopathy than children without CNS leukemia. Moreover, patients with CNS leukemia may have abnormalities of CSF clearance of intraventricularly administered drugs.

Central Nervous System Diseases↗

PubMed1983

Myelopathy with severe structural derangement associated with combined modality therapy.

Myelopathy is a known complication of radiation therapy, but its association with chemotherapy has been less well documented. The authors report the case of a 12-year-old boy with medulloblastoma who had been followed for an 8 1/2-year period. In the context of accepted doses of intrathecal methotrexate and spinal irradiation, he developed an extensive myelopathy. At postmortem he was found to have profound fibrosis of the leptomeninges and necrosis with structural derangement of the spinal cord. It is speculated that these findings are secondary to a combination of radiation acting in synergism with methotrexate. The pertinent literature relating to myelopathy associated with radiation and chemotherapy is reviewed.

Antineoplastic Combined Chemotherapy Protocols↗