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Biomedical subjects

E C Halperin

Publications and source records attributed to E C Halperin.

At least 109 records · Page 6Linked to original sources
PubMed1989

Selection of a management strategy for pediatric brainstem tumors.

Brainstem tumors arise in portions of the rhombencephalon and mesencephalon. Some authorities include diencephalic tumors in this group. We have reviewed our clinical experience of 69 children (less than 21 years of age) with brainstem tumors evaluated and treated at Duke University Medical Center (DUMC) from 1960 to 1986. There were 19 patients with group 1 tumors (thalamus, third ventricle region, or midbrain) and 50 with group II tumors (pons, medulla oblongata). The common presenting signs and symptoms were ataxia, headache, motor loss, and cranial nerve palsies. The most commonly employed diagnostic imaging studies were air examinations and CT. Preradiotherapy confirmation of malignancy was obtained in five group I patients (astrocytoma, 4; germinoma, 1) and 8 group II patients (astrocytoma, 3; anaplastic astrocytoma, 2; glioblastoma multiforme, 3). All patients received radiotherapy. The 5-year survival rate for the entire population was 40%. The survival rate for group I patients was significantly better than that observed for group II patients. In the 50 group II patients neither patient sex nor age nor presence of cranial nerve palsies nor pretreatment CT scan findings nor field size influenced survival. A long duration of symptoms positively influenced survival. The vast majority of tumor recurrences were within the radiation field. Half of the patients had either stable or improved Karnofsky status 6 months following completion of irradiation. The management strategy for childhood brainstem tumors is discussed.

Adolescent↗
PubMed1989

Radiation therapy treatment planning in supratentorial glioblastoma multiforme: an analysis based on post mortem topographic anatomy with CT correlations.

In a previous study of the brains of 15 adults with glioblastoma multiforme who received minimal or no radiotherapy we determined the topographic distribution of tumor cells. All 15 brains had been fixed and then cut in the coronal or horizontal plane. The distribution of neoplastic cells was determined and entered onto tracings of the whole mount histologic sections. The last CT scans obtained prior to death of 11 of the patients were reviewed independently by a neuroradiologist who traced, on the CT scans, the outer edge of both the contrast-enhancing area and the peritumoral low density "edema". Presented with the neuroradiologist's assessment of the contrast enhancing rim of tumor and of the "edema", a radiotherapist and a radiation dosimetrist, in the present study, prepared treatment plans for a 6 MeV linear accelerator. In 9 of the 11 cases in which immediately antemortum CT scans were available, radiation treatment of the contrast enhancing area alone with a 1 cm margin would have missed portions of the histologically identified tumor. Treatment of the contrast enhancing area along with the peritumoral "edema", with a 1 cm margin, would have covered histologically identified tumor in six of the 11 cases. Treatment of the contrast enhancing area, all "edema", and a 3 cm margin around the "edema" would have covered histologically identified tumor in all cases. Tumors tended to track along nerve pathways. In those lesions near the midline it was common for tumor to cross the corpus callosum. We conclude that radiotherapy with fields designed to treat the contrast enhancing region alone or this region plus "edema" with a tight margin will frequently miss tumor which can be histologically identified by our technique.

Adult↗
PubMed1989

Phase II treatment of medulloblastoma and pineoblastoma with melphalan: clinical therapy based on experimental models of human medulloblastoma.

We conducted a phase II study of intravenous (IV) melphalan in the treatment of children with recurrent medulloblastoma and in the initial treatment of children with poor-prognosis medulloblastoma and pineoblastoma. There was one complete response (CR) and two partial responses (PRs) among the 12 children with recurrent medulloblastoma. There were three PRs in the four patients initially treated with melphalan for poor-prognosis medulloblastoma or pineoblastoma. Toxicity was limited to severe myelosuppression with marked neutropenia and thrombocytopenia. These results support our laboratory studies demonstrating melphalan activity in human medulloblastoma, suggest that similar activity may be demonstrated against pineoblastoma, and support further trials with this agent (administered prior to radiotherapy) in the treatment of patients with newly diagnosed poor-prognosis medulloblastoma.

Adolescent↗
PubMed1989

Criteria for termination of phase II chemotherapy for patients with progressive or recurrent brain tumor.

We report six patients with progressive primary tumors of the brain who had prolonged periods with stable contrast-enhancing CT lesions following initial responses to chemotherapy. Chemotherapy was discontinued after 21 to 36 months, despite the persistence of apparent disease in each patient. PET using (F-18) fluorodeoxyglucose was performed in three patients, revealing hypometabolic lesions. All six patients are alive and well, with no clinical or radiographic evidence of progressive disease at 24 to 57+ months following termination of treatment. The usual criteria for terminating phase II chemotherapy in patients with a recurrent brain tumor are evidence of progressive disease or unacceptable toxicity. However, chemotherapeutic success mandates that these criteria be expanded to include patients whose response following the initiation of phase II treatment is followed by prolonged (greater than 1 year) radiographic and clinical stability. Complete response, ie, disappearance of all evidence of disease, is unusual in patients with recurrent primary brain tumors, even with highly effective therapy. Continued improvement in the therapy of patients with these tumors will allow wider application of these criteria.

Adolescent↗
PubMed1989

The effects of total lymphoid irradiation upon corneal vascularization in the rat following chemical cautery.

The effect of total lymphoid irradiation (TLI), a form of radiotherapy known to suppress the number of circulating lymphocytes, on corneal neovascularization was assessed in rats. The corneas of TLI-treated rats were cauterized with silver/potassium nitrate one day after delivering gamma irradiation in five equal fractions (10 Gy total dose). Corneal neovascularization was assessed quantitatively by computerized image analysis in corneal flat preparations 4 days after corneal injury following perfusion of the circulation with India ink. TLI reduced the total leukocyte, lymphocyte, neutrophil, and platelet counts below preirradiation levels. The number of circulating lymphocytes was reduced more than neutrophils and platelets. TLI caused a predominance of cytotoxic/suppressor lymphocytes. Tissue examinations 4 days after TLI disclosed an absence of the thymus, as well as a markedly reduced number and size of lymph nodes. TLI rats had less corneal vascularization than nonirradiated controls. Our findings are consistent with the hypothesis that leukocytes play an important role in the pathogenesis of corneal angiogenesis following chemical cautery, but this study does not indicate how TLI suppresses corneal neovascularization.

Animals↗
PubMed1988

Intracranial atherosclerosis following radiotherapy.

We describe a case of severe intracranial atherosclerosis in a young man who had received therapeutic radiation for a presumed brain neoplasm. Since there was no evidence of vascular disease outside the radiation ports, we speculate that accelerated atherosclerosis was induced by radiation and that hyperlipidemia may have predisposed him to this effect.

Arteriosclerosis↗
PubMed1988

A cytogenetic comparison of the responses of mouse and human peripheral blood lymphocytes to 60Co gamma radiation.

Experiments were conducted to compare the chromosome damaging effects of 60Co gamma radiation on mouse and human peripheral blood lymphocytes (PBLs). Either whole blood or isolated and pelleted mononuclear leucocytes (MNLs) were irradiated with a 60Co unit to yield exposures of 1, 2, 3, or 4 Gy. In addition, mice were whole-body irradiated in vivo with the same doses so that an in vitro-in vivo comparison could be made. The results indicate that mouse PBLs irradiated in whole blood, whether in vivo or in vitro, respond similarly to 60Co gamma rays as measured by dicentric chromosome formation. In addition, mouse and human PBLs showed a similar radiosensitivity, but because the mouse PBL data were best fitted to an exponential function and the human PBL data to a quadratic function, direct comparisons were difficult to make. Pelleted MNLs from mice were much less sensitive to the clastogenic effects of gamma radiation than whole blood. This is believed to be due to hypoxic conditions that developed during irradiation and transport. Human PBLs did not show a marked difference whether irradiated in whole blood or as pelleted MNLs in tissue culture medium.

Adult↗