Acta radiologica: oncology, radiation, physics, biology最新文献

The accumulation of 99Tcm-gluconate in the myocardium and liver of the rat during anoxia has been investigated on the cellular level and compared with the histopathologic changes. The conclusion is drawn that the uptake of isotope runs a course similar to that registered in vivo in human myocardial infarction.

Linear programming can be used to optimize intracavitary brachytherapy for carcinoma of the cervix. A method has been developed which gives meaningful output and is described. A set of reference points were necessary in addition to the standard reference points. Point A as well as an array of points for adjacent radiation sensitive normal structures were used in order to obtain isodose curves conforming to those commonly used for therapy. In addition, arbitrary upper and lower limits of dose at selected points were needed and were set to conform to systems commonly used clinically for intracavitary therapy. It was immediately evident that a wide variety of loadings can be used that deliver appropriate or improved doses to reference points while minimizing normal tissue dose. The loadings represent arrangements which are not commonly used in many clinics but offer potential for clinical use.

Rat brain was exposed to 30, 40 or 60 Gy of roentgen rays and different biochemical and physiologic parameters were assayed from one day to 2 years. The most important changes noted were an intermediate increase in DNA, an intermediate to late--dependent on dose--increase in collagen, a decrease in sialic acid, an early to intermediate increase in serotonin, an increase in cathepsin, an early depression, and intermediate enhancement and a late decrease in alpha amino isobutyrate uptake by brain, and an early reduction, an intermediate--and sometimes late--increase in blood flow. These changes suggest that all three principal systems 2n the brain, nerve cells, glia and vascular system, participate in late changes.

Long term treatment results for 254 patients with laryngeal carcinoma, primarily treated by irradiation, have been analysed according to a microscopic score, indicating the degree of malignancy. Deaths from carcinoma are significantly correlated to the microscopic score. It is strongly indicated that such correlations also exist for local recurrence/residual tumour and regional lymph node metastases. Therefore it is concluded that the microscopic grading system is a valuable prognostic factor supporting, and additional to, the T.N. classification. Larger series are needed in order to obtain correlations in subgroups, and accordingly primary therapeutic consequences can only be suggested, in doubtful cases.

Serum calcitonin determinations were carried out in 11 patients with histiocytosis X, 5 having lytic bone lesions. All serum calcitonin concentrations were within normal range. This makes serum calcitonin determinations useless as a marker of osteolytic activity in patients with histiocytosis X.

Undifferentiated giant and spindle cell carcinoma of the thyroid is a rapidly fatal disease. Most patients die from local tumour progression and with distant metastases. A combination of debulking surgery, irradiation and combination chemotherapy is reported. An improvement of the local results of treatment was observed. A combination of irradiation and chemotherapy resulted in local control in only one of 8 patients. Therefore, debulking surgery was added in the next 5 patients and a local control was achieved in 4.

The uptake and elimination of 14C leucine were analysed in controls and in rats irradiated 2 h before injection with 8 Gy whole-body irradiation. Plasma, small intestine, kidney and skin were assayed after homogenization for TCA soluble activity curves. In highly differentiated tissues with poor proliferative activity and low protein turnover, the uptake and elimination of the tracer did not appear to be affected by irradiation. In the small intestine differences between control and irradiated animals seemed significant.

A theory was developed for the perturbation correction to be applied in the calorimetric determination of the ferrous sulphate dosimeter G-value. Recent determinations of the molar extinction coefficient, epsilonm, have shown that systematic errors in epsilon may have influenced experimental G-values. With precision spectrophotometers this error is cancelled in the product epsilonm.G. It was shown that after applying the perturbation correction a very small spread was obtained in calorimetric epsilonm.G-values; the standard error of the mean being 0.2 per cent. The mean G-value is 2.3 per cent lower than that recommended in ICRU Report No. 21.

With a modified Lukes & Collins classification of non-Hodgkin's lymphomas applied retrospectively to a patient series the biologic and clinical implications of some microscopic features were analysed. It was found that, based on this classification, proliferation, dissemination and differentiation could be explained in a comprehensible way.