Acta radiologica: therapy, physics, biology最新文献

A material of 61 malignant nasopharyngeal tumours were treated during the 10-year period 1959-1968. The primary tumour was in most cases treated with a supervoltage technique and the neck node regions were irradiated only when lymph metastases were found. The crude 5-year survival in the whole series was 43% and the symptom-free 5-year survival 34%. If the rare tumour types were excluded (plasmocytoma and salivary gland type adenocarcinoma) the corresponding figures were 41 and 33%, respectively. The retrospective analysis did not indicate that prophylactic neck irradiation could have increased the cure rate.

In a material of 167 cases with squamous cell carcinoma of the hypopharynx, treated between 1961 and 1971, radical irradiation was administered to 55 patients. Of these latter patients the 3- and 5-year survival rates were 36 and 25 per cent, respectively. The lesions of the upper part of the hypopharynx were found to be more curable than those of the lower part. Three cases are presented in detail.

The immediate effect of ionizing radiation on the activity of the ciliated epithelium of the trachea has been investigated using a light reflection method. This method enables continuous registration of the mucociliary activity both during and after irradiation. A notable increase of the mucociliary activity occurred within 5 seconds after beginning of irradiation and this activity reached its maximum 10 seconds after initial exposure with a dose rate of 0.34 Gy/s (34 rad/s). The mechanism causing the phenomena observed is not clear but theoretically it might be due to ATP, the source of energy of the cilia being freed by the irradiation, possibly through disturbances of the permeability in the mitochondrion membranes.

A series of 36 children with nephroblastoma treated between 1966 and 1973 was analysed. None of the patients with stages I or II and microscopic type I or II developed metastases; 5 of 7 patients with stages I or II and microscopic type III developed metastases. All patients in stage III developed metastases. Fifteen patients developed metastases after the termination of the primary treatment. Of 9 patients with pulmonary metastases only, 6 are free of disease, all patients with metastases in other sites are dead.

Forty-two patients with Hodgkin's disease were staged without laparotomy and considered to have only supradiaphragmatic disease. They were treated with the mantle technique and followed up for at least 3 years. Abdominal extension was later found in 31 per cent. It is concluded that occult abdominal disease usually in course of time will give symptoms.

Blood pressure and heart rate at rest in the supine and standing positions were followed before, during and after irradiation for malignant tumours in 114 patients. A statistically significant gradual reduction in blood pressure during the treatment period was established. This was more marked in older patients and in patients with higher initial blood pressure but was not related to the region irradiated or the type of tumour treated. Particularly if the patient experiences vertigo and nausea on change of position, it seems advisable to check the blood pressure during treatment.

A total of 121 patients were treated under the diagnosis: metastasis from an unknown primary tumour; 99 were irradiated. In 46 cases the primary tumour was detected from 6 months to 10 years after the primary treatment. The 3-year survival was 28.9 per cent, the 5-year 17.4 per cent and for 10 years or longer (up to 14 years) 9.1 per cent, after the primary treatment. The prognosis is correlated to the size of the metastases, their site and also their microscopic appearances.

LP-12 cells injected intravenously into ddY mice result in the formation of visible lung colonies which are introduced as a model for pulmonary metastases. Localized irradiation before tumour cell transplantation significantly increased the incidence of pulmonary metastases in the irradiated lung only. The changes of the vascular permeability of the lung indicate that dilatation of capillaries or increased permeability may be one of the main mechanisms of this phenomenon.

Measurements have been made on 60Co gamma rays from a point source and on 6 MV roentgen rays from a linear accelerator with a wall-less proportional counter. Single event spectra have been measured in sites of 0.5-2 mum in diameters stimulated with a tissue equivalent gas. Calculations of the relative variance in LET are performed and compared with the relative variance of the measured distributions for estimates about the straggling contribution.