Acta radiologica: therapy, physics, biology最新文献

The role of radiation therapy in the management of adrenal cortical carcinoma has had little documentation in the literature. Fourteen patients with this malignancy were given 18 courses of palliative, preoperative or postoperative irradiation. The clinical results are presented. Significant palliation was obtained in all patients along with occasional long term local control of unresectable lesions.

Results of irradiation, 1 to 3 years after treatment, are presented in 64 cases of nasopharyngeal carcinoma in East Africans. Two types of anatomic point indices are presented. Both correlate well with the results. Prophylactic irradiation of the mediastinum and both axillae was not followed by any evident improvement of the results.

A multifactorial microscopic grading of malignancy was performed on a clinically well examined series of 129 patients with laryngeal carcinoma. The microscopic score was statistically significantly correlated to the frequency or regional lymph-node metastases and to the death rate. It afforded important supplementary information for the T-classification and for the prognosis. Microscopic grading is an essential supplement to the clinical evaluation of risk groups.

The results of lymphangiography and other radiologic procedures are compared with those obtained by 67Ga scintigraphy in staging of 27 patients with Hodgkin's disease and 31 patients with non-Hodgkin's lymphoma. A high degree of correlation was found between lymphangiography and 67Ga scintigraphy. Exact localization, however, was only possible by lymphangiography. In some cases, the extent of disease found on scanning appeared to be smaller compared to radiography. Within the chest 67Ga scintigraphy and conventional radiography give almost similar results. Differentiation between neoplastic and inflammatory lymph node involvement is impossible.

In vivo dose measurements were performed in the hypopharnyx-oesophagus for 60 adult patients receiving mantle treatment with 60Co. The measurements of absorbed dose in more than 1 600 points were analysed and compared with dose plans for the same patients. For the technique used the mean difference between in vivo measured and planned absorbed dose is within +0.4 and -1.3 per cent with a standard error of the mean of 0.4 per cent.

The distribution of barium in the mouse has been determined qualitatively by whole-body autoradiography after i.v. administration of 133BaCl2 solution. The quantitative distribution of 104Ba and 140La has been analyzed after i.p. injections of the two nuclides in equilibrium by measuring the activity in excised organs in a two-channel scintillation counter. Approximate doses to the eyes and different parts of the skeleton have been calculated.

The value of an attenuation equalizing filter (equalizer) has been examined by calculation using a Monte Carlo technique. The contrast enhancement caused by the equalizer is the net result of three factors: (1) The first factor arises from the contrast change caused by the difference in detector characteristics at the different energies absorbed in the detector with and without equalizer. (2) The second factor is due to the contrast change caused by the different ratios of primary to total radiation reaching the detector. (3) Finally, the third factor describes how the transparency of the object is changed by the different primary filtration with equalizer. An example is given of the reduction in radiation energy absorbed by the patient and the question of how far the attenuation equalization can be driven is discussed.

By exposure measurements in an alcohol-water mixture simulating breast tissue, the absorbed dose, and dose distribution in the breast at the radiation qualities commonly used in mammary radiography have been calculated. The absorbed doses for different recording media have been compared at those radiation qualities which result in similar image qualities in the different recording media.

The RBE of an accelerated helium ion beam was determined on murine osteosarcomas ranging in size from single cells to visibly detectable lung colonies of approximately 1 X 10(-2) mm3. That the RBE increased as tumor size increased provides some biologic basis for the selection of advanced cases of neoplasia for clinical trials using relatively high LET radiation sources.