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Biomedical subjects

W D Bloomer

Publications and source records attributed to W D Bloomer.

At least 91 records · Page 5Linked to original sources
PubMed1982

The role of postoperative local or regional irradiation in the treatment of stage I ovarian cancer.

Histological grade and cell type were major prognostic factors in a retrospective study of 63 patients with Stage I epithelial carcinoma of the ovary. Grading by architectural pattern seemed to predict relapse better than cytological grading. With serous, mucinous, and endometrioid cystadenocarcinomas, relapses increased with higher grades. Relapse occurred in none of 18 tumors of borderline malignancy, 2 of 27 (7%) with Grade I or II tumor, and 4 of 6 (67%) with Grade III. The upper abdomen and pelvis were both at risk. Because most recurrences were limited to the peritoneal surface in Grade III serous, mucinous, and endometrioid carcinoma, local and regional radiation therapy are justified; postoperative therapy is not recommended for borderline or Grade I tumors unless ascites or cytological evidence of peritoneal disease is present. Clear-cell carcinoma was uncommon and unfavorable; of 12 cases, 5 involved relapse, with 3 recurrences developing outside the abdomen.

Adult↗
PubMed1981

New therapeutic strategies in radiation therapy.

Radiation therapy has been an integral part of curative cancer therapy for many decades. The tolerance of normal tissues traversed by radiation and resistant tumor cell populations traditionally have limited the radiocurability to certain tumors, especially with higher clinical stages. However, research in radiobiology and radiation physics is providing ways to increase cure while limiting morbidity. Computer-controlled dynamic treatment, radioprotector drugs, hyperbaric oxygen, carbogen breathing during irradiation, particle irradiation, and hypoxic cell sensitizing drugs are presently undergoing clinical evaluation with some encouraging preliminary results. We review the fundamental concepts underlying these clinical trials and analyze the results.

Animals↗
PubMed1981

Astatine-211--tellurium radiocolloid cures experimental malignant ascites.

An investigation of the efficacy of astatine-211--tellurium colloid for the treatment of experimental malignant ascites in mice reveals that this alpha-emitting radiocolloid can be curative without causing undue toxicity to normal tissue. By comparison, negatron-emitting phosphorus-32 as colloidal chromic phosphate had no antineoplastic activity. The most compelling explanation for this striking difference is the dense ionization and short range of action associated with alpha-emission. These results have important implications for the development and use of alpha-emitters as radiocolloid therapy for the treatment of human tumors.

Alpha Particles↗
PubMed1981

Therapeutic intraperitoneal 32P: a clinical assessment of the dynamics of distribution.

With an Anger camera for scintigraphic recording of bremsstrahlung radiation from phosphorus-32, the distribution of intraperitoneal colloidal chromic phosphate was followed in patients with gynecologic tumors. Sequential pelvic, abdominal, and thoracic scintiphotos over a three-week period revealed rapid and persistent focal aggregation of the radiocolloid with no change in pelvic or peritoneal radionuclide distribution patterns. Visualization of intrathoracic lymph node uptake did not correlate with the presence of diaphragmatic tumor. This study demonstrates the utility of scintigraphy for monitoring the distribution of intraperitoneal beta emitters and the need for developing alternative methods of administering these therapeutic agents to achieve more uniform patterns of distribution.

Brachytherapy↗
PubMed1981

Mediastinal lymphoscintigraphy in ovarian cancer using intraperitoneal autologous technetium-99m-labelled erythrocytes.

99Tcm-labelled autologous erythrocytes (approximately 2.0 ml and 2.0 mCi) were administered intraperitoneally (IP) to 15 patients with ovarian cancer. Anterior abdominal images were then collected for up to six hours to evaluate both the dynamics of intraperitoneal tracer distribution and the potential for visualizing internal mammary lymph nodes as correlated with the presence of diaphragmatic tumour. Results indicated that dispersion of red cells closely resembled that seen during IP contrast studies; the distribution patterns were heterogeneous, remained constant with time, and were intimately related to bowel peristalsis. Visualization of internal mammary lymph nodes indicated patency of diaphragmatic lymphatics; non-visualized nodes correlated with the presence of diaphragmatic tumour. The test had a sensitivity of 0.80 and a specificity of 0.90 for defining disease. Results of this study suggest use of 99Tcm-red blood cells as a diagnostic test for diaphragmatic involvement by ovarian cancer and as a method for monitoring the effects of therapy.

Diaphragm↗
PubMed1978

Carcinoembryonic antigen (CEA): its role as a monitor of radiation therapy for colorectal cancer.

Serial CEA radioimmunoassays have been performed on patients receiving radiation therapy preoperatively or as treatment of recurrent or metastatic colorectal cancer. Pretreatment circulating CEA titers which were elevated showed a significant decrease with accumulating doses of irradiation, indicating that the bulk of CEA-producing tumor was within the radiation therapy portal. The decrease of circulating CEA with preoperative radiation therapy was short-lived and suggested that surgical resection should be performed within 8 weeks of irradiation. Serial CEA titers are useful as an adjunct to other clinical, laboratory and radiologic data in formulating patient management decisions.

Adult↗
PubMed1978

The complication probability factor: a method for selection of radiation treatment plans.

The problem of selecting the best radiation treatment plan from several that may offer subtle differences has been considered. A method is introduced in which the concept of a complication probability factor (CPF) can be used to quantify the relative merits of such treatment plans. The CPF is a variant of integral dose and consists of a weighted volume of irradiated normal tissue which may relate to radiation-related complications. Treatment plans for irradiation of a pelvic tumour volume using parallel opposed, 360 deg rotational and four-field techniques with X-ray beams of 4, 8, 22, and 45 MV have been analyzed to demonstrate the utility of the method. This analysis suggests that complex radiation delivery techniques may offer a substantial improvement in dose distribution characteristics, while higher beam energies are relatively less advantageous.

Dose-Response Relationship, Radiation↗