Search PubMed⌕ Search

Biomedical subjects

S H Levitt

Publications and source records attributed to S H Levitt.

At least 127 records · Page 7Linked to original sources
PubMed1981

Pineal and ectopic pineal tumors: the role of radiation therapy.

Seventeen patients wih pineal tumors and one ectopic (suprasellar) germinoma were treated with radiation therapy. Surgery was restricted to decompression in 16 patients, and only two patients had resection of the tumor. Thirteen of 18 patients are alive without evidence for disease with a ten-year survival rate of 88%. The tumor dose ranged from 4000 rads to 6000 rads. No age or dose dependence in survival was noted, but patients with whole brain irradiation or generous volume to include ventricular system had better survival. No case of spinal metastasis was noted. The possibility of increased incidence of meningeal seeding following surgical intervention is considered. From their data, the authors feel that radiation therapy with or without surgical decompression should be the primary treatment for pinealoma. Surgery can be used for diagnosis and/or treatment of patients who show delayed response to radiation. Recommendation is made for the use of whole brain irradiation to 4000 rads followed by a boost to the tumor area to 5000 rads.

Adolescent↗
PubMed1981

Probability models in the analysis of radiation-related complications: utility and limitations.

In order to predict radiation-related enteric damage, 92 women were studied who had received identical radiation doses for cancer of the ovary from 1970 through 1977. A logistic model was used to predict the probability of complication as a function of number of laparotomies, hypertension, and thin physique. The utility and limitations of such probability models are presented.

Body Composition↗
PubMed1981

Effect of x-irradiation on immunocompetency of T-lymphocytes.

Effect of x-irradiation on various aspects of cell-mediated immune reactions is studied. The irradiated splenic lymphocytes could transform to blast cells upon stimulation with PHA, but could not divide into small lymphocytes. It was concluded that irradiation at doses higher than 500 rads inhibits the differentiation of lymphocytes to effector cells upon stimulation with antigens. The irradiated immune lymphocytes were able to kill target tumor cells when the cytotoxicity was tested immediately after irradiation with doses as high as 500 rads. The cytotoxicity of immune lymphocytes diminished, however, 7--10 hours after irradiation. The splenic lymphocytes irradiated with doses as high as 200 rads could stimulate allogeneic lymphocytes 2 days after the irradiation. It thus appeared that irradiation cannot immediately abolish the antigenicity of lymphocytes to stimulate allogeneic lymphocytes. The combined effect of irradiation and T-cell-mediated immune reaction to reduce clonogenecity of target tumor cells in vitro is simple additive.

Autoradiography↗
PubMed1981

Statistical inference in the analysis of radiation compliance and its relation to treatment outcome.

A recent report in the literature was unable to associate the local--regional recurrence rates in breast cancer with deviations from the protocol's recommended dosages. The investigators proceeded to infer that there was "acceptable leeway" in the use of radiotherapy. The present manuscript examines the validity of certain statistical inferences drawn by these investigators.

Adenocarcinoma↗
PubMed1980

Prognostic significance of mediastinal involvement in Hodgkin's disease treated with curative radiotherapy.

We evaluated the prognostic significance of mediastinal involvement in Hodgkin's disease in 79 consecutive newly diagnosed patients treated with curative-intent, nodal radiotherapy. Mediastinal masses were classified large or small depending on whether the ratio of the largest transverse diameter of the mass to the transverse diameter of the thorax at T5-6 was greater than or equal to 35. Forty-eight patients had mediastinal disease; 20 had large masses, and 28 small masses. Complete remissions were achieved in 19 patients with large masses, 26 with small masses and all patients with no mediastinal masses. Relapse have occurred in 74% of patients with large masses but in only 27% with small masses and 19% without masses (P < .001). This high recurrence rate among patients with large masses could not be explained by other known adverse prognostic factors. Survival was adversely influenced by mediastinal mass size (P = .03). We conclude that curative-intent, nodal irradiation is inadequate therapy for patients with large mediastinal masses. Controlled studies are needed to determine if survival can be improved by the addition of chemotherapy or whole lung irradiation.

Adolescent↗
PubMed1980

Sequential surgery, radiation therapy, and Alkeran in the management of epithelial carcinoma of the ovary.

In 1970, a prospective multidisciplinary protocol was initiated for Stages I through III obviously malignant ovarian epithelial carcinomas. The planned sequential therapy included 1) surgery, 2) radiotherapy (2000 rads to whole abdomen, 3000 rad boost to pelvis), 3) chemotherapy (ten cycles of Alkeran), and 4) a "second-look" surgical procedure. Ninety-six patients were enrolled in this program through 1976. Median follow-up of the survivors was greater than 44 months. Adjusted disease-free survival was 90 percent for Stage I, 64 percent for Stages IIB--IIC, and 16 percent for Stage III. Stage III patients with no palpable tumor at time of initiation of radiation therapy had a survival of 37 percent. No Stage III patient with palpable tumor at time of initiation of radiation therapy was cured. Eight percent of patients developed small bowel obstruction requiring surgical intervention. Three percent of all patients died of hematologic causes; of the 30-month-plus survivors, 5 percent (2 of 37) developed acute myelogenous leukemia. Cure and toxicity will be examined in detail and compared with the literature.

Adenocarcinoma↗
PubMed1980

Solitary extramedullary plasmacytoma of the upper respiratory and digestive tracts.

The diagnosis, treatment and follow-up data for patients with malignant solitary extramedullary plasmacytoma of the upper respiratory and digestive tracts for the period from 1949 to 1975 are presented. The neoplasm developed in the nasal fossae in 3 patients; in the maxillary sinuses in 2; in the supraglottic region in 1; and in the tonsillar fossa in 1. Curative radiation therapy is recommended after the diagnosis is established by biopsy examination only. In the present series, this practice resulted in complete regression of the tumors in all of the patients, with restoration of functions without local recurrence. In no case did the local disease transform into systemic myeloma.

Adult↗