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Biomedical subjects

B E Keller

Publications and source records attributed to B E Keller.

10 recordsLinked to original sources
PubMed1978

The management of clinical stage I endometrial carcinoma.

A retrospective analyses of 307 cases with clinical Stage I endometrial carcinoma was done in an attempt to determine the role of radiation therapy in the optimal treatment of this disease. A review of the modern literature with over 9000 cases served as a useful tool to corroborate inferences and conclusions. The present series has 155 patients (51%) treated with preoperative megavoltage external pelvic radiation with a variation in doses of less than 6%. Five-year survival estimates (79%-83%) in clinical Stage I endometrial carcinoma are similar among the several main treatment combination that are employed; they become a useless parameter for any comparison. The pelvic failure rate constitutes a more useful guideline in assessing the most adequate therapy. The pathologic grade of the tumor is the main prognosticator in endometrial carcinoma. Intimately related to the tumor grade is the depth of myometrial invasion of the carcinoma. The size of the uterus and/or its cavity carry less prognostic significance than traditionally thought. For grade I lesions, there is little error in diagnosis, few pelvic failures and excellent survival (96%); they could be approached with initial surgery and postoperative radiation reserved for selected patients. For grade 2 tumors, the error in diagnosis and the failure rate increases with an overall survival of 87%. For grade 3 tumors, the error in diagnosis and failure rates are quite high with a 5 year survival of only 70%. Preoperative radiation, especially external beam therapy, is suggested for grades 2 and 3 Stage I tumors. The use of this treatment modality yields only 3% pelvic failure and an overall 5 year survival of almost 90%.

Carcinoma↗
PubMed1978

Electron-beam radiographs.

Good portal films can be obtained if the film is left in position throughout the daily fraction. Such films can delineate the outlines of the treatment field as well as the internal structures, making them valuable for future reference.

Radiotherapy↗
PubMed1976

Predictors of radiation response in lung cancer. A clinico-pathobiological analysis.

From February 1972 to July 1975, 200 lung cancer patients were seen at the University of Rochester Cancer Center's Division of Radiation Oncology; 40% had squamous cell tumors and 87.5% had advanced disease localized to the thorax. Of the 160 patients who completed treatment, 101 were treated with continuous therapy schedules, and 59 were treated with split-course schedules, and 59 were treated with split-course schedules; 40 patients did not complete treatment because of early metastatic disease or death. Radiation therapy was very effective in local tumor ablation. To assess local tumor response, doubling times were obtained in measurable lesions prior to treatment. The doubling times (DT) were 25 days for small cell cancers and 192 days for adenocarcinoma. More than 50% tumor shadow regression was a good prognosticator of local tumor response; this increased as the mean DT decreased. The order of kinetic increase in tumor ablation per histology was the opposite of the one-year survival results because of the metastatic spread patterns of the different tumors. Survival rates in lung cancer emerge as simplistic and inadequate to explain local radiation effectiveness. Survival is conditioned by stage, histology, and modality of treatment, total dose delivered, and local tumor response. Although the most effective treatment dose seems to be over 6000 rads, the most efficient schedules were split-course delivering lower tumor doses. This modality of treatment is proposed as the optimal schedule to be combined with other forms of therapy with the goal of achieving better survival.

Adenocarcinoma↗
PubMed1975

Chromosome constitution of cells from human gingiva.

This is a study of cells and chromosomes during serial transfer of tissue cultures, starting from the first mitosis occurring before explantation of normal gingival tissues and continuing until a genotypic variation was attained after explantation. From 16 specimens, 9 could be maintained in vitro for varying lengths of time, 7 for more than 50 weeks. In all cases, at 2 months in cultures and afterward, cells were found to be fibroblast-like cells with heteroploid chromosomal complement. The heteroploidy of the cells was due to extrasomy of chromosomes from all groups. However, chromosomes of the me cells before culturing showed the normal diploid number of 46 chromosomes.

Adult↗
PubMedDate not supplied

Method for calculating dose when lung tissue lies in the treatment field.

The absorbed dose in lung and beyond lung as a result of increased lung transmission of x and gamma irradiation is described. The correction factor used to calculate the absorbed dose is a function of beam energy, field area, lung density, and lung and soft tissue depth. Agreement between measurements and calculations in the Alderson phantom is within 3%. An example of how this technique can be used is described.

Cobalt Radioisotopes↗