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Biomedical subjects

M Maor

Publications and source records attributed to M Maor.

At least 19 recordsLinked to original sources
PubMed2001

The clavicle: a vulnerable bone in pediatric oncology.

The clavicle is frequently incorporated into the radiation field in the treatment of malignant tumors located in the head and neck. From 1954 to 1995, 499 pediatric patients were treated with moderate to high-dose radiation therapy to the head and neck at the University of Texas M.D. Anderson Cancer Center. The medical records of 312 of these patients were available and were reviewed. The period of observation ranged from 5 to 30 years. Five late radiation-induced abnormalities of the clavicle were encountered: osteosarcoma; osteochondroma; malignant fibrous histiocytoma; radionecrosis and impaired healing following trauma and radionecrosis and lysis. The doses of radiation therapy which induced the abnormalities varied from 35 to 60.5 Gy (median 34.75 Gy). The interval from radiation therapy to discovery of the complications varied from 6 to 11 years. Two patients died: one from malignant fibrous histiocytoma and another from a radiation-induced meningioma of the brain (which accompanied radionecrosis of the clavicle). We conclude that the incidence of radiation-induced abnormalities of the clavicle in pediatric long-term survivors is low (1.5%). However, some of the late sequela are potentially fatal. The clavicle should be considered a vulnerable bone to radiation therapy and should be monitored in long-term survivors of childhood cancer. The experience is compared to radiation-induced abnormalities recorded in the literature.

Adolescent↗
PubMed1992

Adjuvant chemotherapy with carmustine and cisplatin for patients with malignant gliomas.

Forty-five patients with malignant gliomas were treated after aggressive surgical resection with alternating intravenous carmustine and cisplatin both during and after radiation therapy. Thirty-three patients were considered evaluable for responses, 17 had glioblastoma multiforme (GBM), 14 had anaplastic astrocytoma (AA) and 2 had anaplastic oligodendroglioma (AO). The median age of the evaluable patients was 47 years. The median time to tumor progression was 34.5 weeks, and the median survival for the entire group was 76 weeks. Early progression occurred more frequently in patients with glioblastoma than in those with AA or AO. Seventeen patients (55%) were alive at 18 months (6 GBM, 9 AA, 2 AO). Toxicity was mainly hematologic, otic and tolerable. The results suggest that further trial is warranted to assess the efficacy of alternating carmustine and cisplatin in conjunction with radiation therapy postoperatively in patients with malignant gliomas.

Adult↗
PubMed1990

Pilot study of PCNU and cranial radiation therapy in the treatment of patients with malignant gliomas.

A pilot study was performed administering PCNU with radiation therapy to treat patients with high-grade astrocytomas and to explore the toxic effects of this drug regimen. PCNU at an initial dose of 110 mg/m2 i.v. was administered to 14 patients within 4 weeks after completion of cranial irradiation. Courses were repeated every 6-8 weeks upon recovery from myelosuppression. Radiation therapy consisted of 5,000 rad to the whole brain followed by an additional 1,500 rad to the tumor site. Patients were followed by CT scan and neurologic examination. The median survival for the group was 80 weeks. Larger, randomized trials comparing PCNU to other nitrosoureas will be needed to assess its value as adjuvant therapy in patients with malignant gliomas. Myelosuppression, particularly, thrombocytopenia, was the main toxic effect in this study. Pulmonary infiltrates developed in 2 patients and was progressive and fatal in 1 patient after a total cumulative PCNU dose of 850 mg/m2. Hepatic dysfunction with hyperbilirubinemia also developed in 1 patient. PCNU can produce pulmonary and hepatic toxicity similar to that reported for other nitrosoureas. Regular monitoring of pulmonary and hepatic function tests should be performed during treatment with PCNU in future trials.

Adult↗
PubMed1988

Male reproductive function in long-term survivors of childhood cancer.

We evaluated reproductive function in 27 male long-term survivors of childhood cancer treated during the prepubertal and pubertal period. Sperm samples were obtained from 23 patients; four who refused to provide specimens indicated that they had fathered normal healthy children. Thirteen patients were 12 years old or younger at the time of diagnosis and initiation of therapy. Chemotherapy was calculated according to the cumulative amount of drug administered and correlated with the surface area. Sterility was associated with large doses of single alkylating agents or reduced doses administered with other agents in combination regimens. It was noted in boys treated in both the prepubertal and pubertal period. Sterility was also observed in patients who received testicular radiation alone or in combination with chemotherapy. However, it was not an inevitable consequence in all patients, despite treatment with similar or identical regimens. Fertility potential could not be predicted by clinical examination (testicular size) or gonadotrophin and testosterone values. The results were compared to published reports of treatment-induced sterility in adult males. Additional investigations are required to establish more accurate correlations of dosage with reproductive potential.

Adolescent↗
PubMed1988

Radiation port dermatophytosis.

We report two cases in which dermatophytic infection developed almost entirely within a radiation field mimicking an acute radiation effect. Radiotherapists and dermatologists should be aware of this possibility and be able to differentiate it from radiation dermatitis. Topical antifungal agents are the recommended treatment after diagnosis is established.

Adult↗
PubMed1986

Expression of albumin messenger RNA detected by in situ hybridization in preneoplastic and neoplastic lesions in rat liver.

The process of chemical hepatocarcinogenesis is characterized by the appearance of preneoplastic lesions showing changes in the expression of various marker enzymes. We have analyzed the phenotype of small preneoplastic foci and expansively growing nodules in liver sections obtained from rats treated with various carcinogens. Changes within the lesions in canalicular adenosine triphosphatase, gamma-glutamyl transpeptidase, NADPH-(cytochrome P-450) reductase, cytochrome P-450 PB2, epoxide hydrolase, and glycogen content were detected by means of enzyme histochemical and immunohistochemical staining procedures. In parallel sections the expression of albumin messenger RNA was investigated by in situ hybridization using a 35S-labeled albumin specific complementary DNA probe. In general, small preneoplastic lesions showed unchanged levels of albumin messenger RNA. In contrast, the expression of albumin messenger RNA was found to be reduced to varying degrees in large hepatic nodules. An expression of alpha-fetoprotein messenger RNA could not be detected in any of the nodules. No direct correlation between the enzyme phenotype of the lesions and the degree in reduction of albumin messenger RNA could be established except that the reduction was most pronounced in nodules which had lost their ability to store glycogen. Since the synthesis and excretion of albumin is a typical function of the differentiated hepatocyte in the adult animal, the observed decrease in albumin messenger RNA expression in large hepatic nodules is in accordance with the hypothesis of a gradual dedifferentiation or retrodifferentiation of the cell population during carcinogenesis. Hyperplastic nodules produced by continuous treatment of rats with 4-dimethylaminoazobenzene showed increased rather than decreased albumin levels. The analysis of albumin messenger RNA expression might therefore be used as a tool to discriminate between nodules of differing biological nature and fate.

Adenosine Triphosphatases↗
PubMed1985

Remission from central nervous system involvement in adults with acute leukemia. Effect of intensive therapy and prognostic factors.

Eighty-seven adult patients who had achieved bone marrow remission of leukemia developed one or more episodes of meningeal leukemia. Multiple patient characteristics were examined for their effect on probability of achieving complete remission from meningeal disease and for their effect on duration of meningeal remission. Presence of obtundation (P less than 0.01) or other symptoms of meningeal disease (P = 0.02) were associated with a low remission induction rate. Other factors which tended (P = 0.06-0.20) to be associated with low remission induction rates included high cerebrospinal fluid (CSF) opening pressure, absence of splenomegaly at initial diagnosis, high peripheral blood leukocyte count (WBC) at the episode of marrow disease most recently preceding the meningeal disease, and use of only one as opposed to two or more intrathecal drugs as treatment. Factors associated with long duration of meningeal remissions included diagnosis (AML greater than acute undifferentiated leukemia greater than ALL, P = 0.05), absence of symptoms (P = 0.04), low CSF WBC (P = 0.01), rapid attainment of meningeal remission (P = 0.01), rapid attainment of initial bone marrow remission (P = 0.02), and long duration of initial bone marrow remission (P less than 0.01). Absence of cranial or peripheral neuropathies, low CSF protein and opening pressure, and short time interval between diagnosis of marrow and meningeal disease also tended (P = 0.06-0.20) to be associated with long meningeal remissions. Patients treated according to an intensive protocol utilizing cranial irradiation and triple drug treatment via an Ommaya reservoir had substantially longer meningeal remissions than did patients treated with less intensive therapy (P = 0.01). Relapse-free survival curves suggest that some patients are cured of their meningeal disease.

Acute Disease↗
PubMed1985

Neuropsychological sequelae of childhood cancer in long-term survivors.

In order to assess the effects of various cancer treatments on neuropsychological functioning, 74 long-term survivors of childhood cancer were examined. A comprehensive battery of tests was administered to two CNS treatment groups (irradiated and nonirradiated leukemia and lymphoma patients) and a control group (solid tumor and Hodgkin disease patients receiving no CNS treatment). The CNS-irradiated group obtained lower scores than the other two groups, with significant differences in visual-motor and fine motor skills, spatial memory, and arithmetic achievement resulting in significant differences in IQ scores (VIQ, PIQ, FSIQ). The results are discussed in relation to: (1) the effects of CNS irradiation on cognitive development; (2) the specificity of these effects; and (3) the relationship of age at diagnosis to treatment effects. It is concluded that although there is a general lowering of scores after CNS irradiation, the effect is most pronounced for nonlanguage skills. Age at diagnosis was less important than the type of treatment, with CNS irradiation reducing performance regardless of when cancer was diagnosed. There were indications that children with any type of cancer diagnosed before age 5 years are more likely to have some cognitive difficulties.

Age Factors↗
PubMed1984

Diagnosis and treatment of lumbosacral plexopathies in patients with cancer.

Eleven patients were diagnosed as having lumbosacral plexopathy at M. D. Anderson Hospital, Houston, from August 1981 through July 1982. Four causes were documented: plexopathy secondary to metastatic disease (six cases); radiation-induced plexopathy (two cases); plexopathy secondary to intra-arterial chemotherapy (two cases); and plexopathy as the result of a second primary tumor (one case). Patients with plexopathies secondary to tumor or irradiation complained of pain in the ipsilateral lower extremity. Computed tomography of the pelvis was the most accurate method of documenting tumor in the region of the lumbosacral plexus. Radiation therapy records of patients with cervical carcinoma were reviewed with respect to positioning of intracavitary radium, which was thought to be responsible for the development of radiation-induced plexopathies. Radiation therapy and/or systemic chemotherapy provided relief of pain and improvement of neurologic deficits in three patients with metastatic involvement.

Adult↗
PubMed1983

Weekly Cisplatin during cranial irradiation for malignant melanoma metastatic to brain.

Because Cisplatin potentiates the effect of radiotherapy in animal tumor systems and because Cisplatin is capable of causing regressions of human malignant melanomas, a study was initiated in patients with malignant melanoma metastatic to brain to investigate the feasibility of administering Cisplatin once a week during cranial irradiation. Cisplatin 40 mg/m2/week (three doses) was given I.V. to 18 patients during whole brain irradiation, 3 000 rads in 12 fractions over 21/2 weeks. Eleven patients also received Cisplatin 120 mg/m2 every three weeks, starting three weeks after cranial irradiation. Median survival was ten weeks, and only one of 13 patients whose brain metastases had not been resected experienced neurological and CT scan improvement. Thirteen patients have died, and brain metastases were a major cause. No regression of extracerebral tumor was seen in 15 patients with evaluable extracerebral lesions. During weekly low-dose Cisplatin administration, nausea and vomiting were moderate to severe. No granulocytopenia was noted, although three courses were associated with mild thrombocytopenia. Mucositis, peri orbital swelling, vertigo, and headache were each noted in two of 51 courses of treatment and seizures, ototoxicity, pancreatitis, and hiccups were each noted in one course. Renal toxicity and ototoxicity each developed in three of the 11 patients receiving Cisplatin 120 mg/m2, and nausea and vomiting were severe.

Brain Neoplasms↗
PubMed1983

A pilot study of cis-diamminedichloroplatinum and radiation therapy in patients with high grade astrocytomas.

A pilot study was performed combining cis-diamminedichloroplatinum (CDDP) and radiation therapy to treat patients with high-grade astrocytomas. CDDP at a dose of 40 mg/m2/week intravenously was given during the course of cranial irradiation. Following irradiation, CDDP was given every three weeks on a schedule of 35-40 mg/m2/day for three days until toxicity became unacceptable or until tumor progression occurred. Radiation therapy consisted of 6 000 rads over a seven week period or 5 000 rads followed by an additional 1 500 rads to the tumor site. Patients were followed by computerized axial tomography (CT) scan and neurologic examination. Thirty patients were entered onto the study; 22 were considered evaluable. The median survival was 53 weeks and the median time to progression was 21 weeks. Toxicity was generally tolerable; however, ototoxicity may be enhanced by this treatment. CDDP combined with cranial irradiation is tolerable and feasible, although close follow-up is recommended in case CDDP has to be temporarily interrupted.

Adolescent↗
PubMed1982

Hypothalamic, pituitary and thyroid dysfunction after radiotherapy to the head and neck.

One hundred-ten patients who had nasopharyngeal cancer and paranasal sinus tumors and were free of the primary disease were studied one to 26 years following radiotherapy. There were 70 males and 40 females ranging in age from 4 to 75 years, with a mean age of 36.5 years. During therapy both the hypothalamus and the anterior pituitary gland were in the field of irradiation. The radiation dose to the hypothalamus and the anterior pituitary gland was estimated to be 400 to 7500 rad with a median dose of 5618 rad to the anterior pituitary gland and a median dose of 5000 rad to the hypothalamus. We found evidence of endocrine deficiencies in 91 of the 110 patients studied. Seventy-six patients showed evidence of one or more hypothalamic lesions and 43 patients showed evidence of primary pituitary deficiency. Forty of the 66 patients who received radiotherapy to the neck for treatment or prevention of lymph node metastasis showed evidence of primary hypothyroidism. The range of the dose to the thyroid area was 3000 to 8800 rad with a median of 5000 rad. One young adult woman who developed galactorrhea and amenorrhea 2 years following radiotherapy showed a high serum prolactin level, but had normal anterior pituitary function and sella turcica. She regained her menses and had a normal pregnancy and delivery following bromocriptine therapy. These results indicate that endocrine deficiencies after radiotherapy for tumors of the head and neck are common and should be detected early and treated. Long-term follow-up of these patients is indicated since complications may appear after the completion of radiotherapy.

Adolescent↗