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

A new afterloading applicatory, together with a computer program, is described. A comparison of the calculated and measured dose distribution around different applicators shows that in the future the described computer program can be used. The development of the new applicator and the computer program increases the flexibility of possible dose distribution.

In 1971, 1973 and 1976 intercomparisons of absorbed dose and dose distribution over a mouse phantom for roentgen irradiation were performed as part of the program of the European Late Effects Project Group (EULEP). Sixteen institutes from 8 countries participated in the sessions of the third intercomparison. In general, progress has been made concerning accuracy and precision of the dosimetry; in 2 cases, discrepancies could be resolved after additional measurements. With regard to the dose distribution over a mouse phantom, the results are not satisfactory; 4 out of 15 participants are still unable to perform uniform irradiations. The necessity of repeated intercomparisons is clearly demonstrated to allow a comparison of biologic results obtained in cooperative research programs.

The method of estimating the mass of the thyroid gland from the area of the scintigraphic image has been compared with a method combining ultrasonic with scintigraphic images. The results for both methods were compared with surgical findings, and the scintiscan method alone was found to produce estimates which were on an average 79.5% of the surgical results. The corresponding estimates for the combined method were, on average, 100.4%.

Cell cycle kinetics and radiation response under hypoxic conditions were analyzed with human cells of the line NHIK 3025. The cells were either kept in continuous exponential growth by frequent reculturing, or went through log and plateau phase for each passage (recultured weekly). The cell cycle time for weekly recultured populations in early log phase was shorter than for cells in continous exponential growth. Cells in continuous exponential growth were more sensitive to radiation than cells in log phase. The difference in sensitivity was not due to partial synchrony of weekly recultured populations.

Seventy-three patients with carcinoma of the tongue were treated with 192Ir implantation. The total dose for control of the primary lesion without late radiation injury could be fixed to about 70 Gy with a variation of the dose rate between 0.25 and 1 Gy per hour. Additional external irradiation, without reduction of the dose from the interstitial irradiation, involves a high risk of local necrosis.

Bronchial angiography was performed in 17 patients with advanced non-oat cell bronchogenic carcinoma. The patients were treated 1 to 5 times with infusions of 10 mg of mitomycin-C (MMC) into the tumor-feeding bronchial artery. All but 2 patients received in addition small doses of vincristine (intravenously) and bleomycin (intramuscularly) or only bleomycin to potentiate the effect of MMC. No major side effects occurred and the systemic toxicity was insignificant. An objective tumor reponse was encountered in 11/17 patients. Intraarterial chemotherapy is strictly local and therefore effective especially in patients with limited or locally advanced disease. In patients with more extensive disease an adjunctive therapy of a more regional or systemic modality must be given.

Since 1966, 125 patients with carcinoma of the uterine cervix were treated with a 6 MV roentgen beam from a linear accelatro. The pelvis was irradiated with 60 Gy followed by 30 to 45 Gy to a small volume using a lateral pendulum. The small-field irradiation was performed using a new beam-directing device consisting of a rod with a central pivot. Favourable results were achieved, despite the fact that most of the patients had advanced carcinoma.

Cytologic smears obtained by needle aspiration biopsy of lytic bone lesions in 15 patients with histiocytosis X, Ewing's sarcoma and neuroblastoma were reviewed. After conventional staining, histiocytosis X could be diagnosed and differentiated from small cell tumours such as Ewing's sarcoma and neuroblastoma. The need for sampling material for cytochemical and ultrastructural analysis of these small cell tumours by needle aspiration is emphasized.