Radiobiologia, radiotherapia最新文献

In radiotherapy approved standard irradiation techniques are available for almost all tumor localizations that has to be adapted to individual anatomic situations with the concrete particular case. A possibility is shown that allows an anatomic adaptation of four types of parameters for four coplanar irradiation fields in maximum with permissible expenditure of time. During the dose adaptation process the estimation of the separate dose distribution is done for the target area and for risk organs according to given criteria by an added measure function value that is calculated from measure function values for the areas to be estimated.

Adult healthy specimens of Uromastix hardwickii were exposed to three doses (i.e. 2.25, 4.50 and 9.00 Gy) of gamma radiation from a 60Cobalt source (experimental group). Five animals were sacrificed at each post-irradiation intervals of 1, 2, 3, 7 and 14 days. The liver was fixed in Bouin's fluid and after processing in a routine way, it was examined histologically. Five sham-irradiated animals (control group) were also sacrificed to compare the results. Low dose (i.e. 2.25 Gy) did not produce any apparent radiolesions in the liver. Changes in the form of cytoplasmic degranulation, swollen hepatocytes, pycnosis, increases in bile pigmentation were noticed after 4.50 and 9.00 Gy gamma ray exposure. Hyperaemia, widening of sinusoids and cytoplasmic vacuolation were also noticed in 9.00 Gy group. The liver exhibited normal picture on day 14 after exposure to both the doses. The radiolesions were found dose dependent.

Irradiated serum samples show characteristic alterations of their redoxpotential. This reaction is in close correlation to metabolic alterations, that for instance occur with tumor growth or severe inflammatory diseases. The role of ATP as universal biochemical energy transmitter led us to study the influence of ATP on redoxpotential in serum. In result the sole addition of ATP to serum in vitro gave a clear alteration of the redoxpotentials. In healthy persons a shifting of redoxpotentials was seen to high positive values. On the other hand ATP has slight influence on sera of tumor patients.

Efficacy of Venoruton--O-(hydroxyethyl) Rutoside--as a radioprotector has been tested on haematological profile of rats which were subjected to whole body radiation (500 rads). The results show radiation induced lesions in respect of total (TLC) and differential leukocyte counts (DLC)/and haemoglobin are significantly lessened when Venoruton was administered prior to radiation exposure.

The joint administration of magnesium aspartate and adenosine monophosphate, injected on days 1 to 4 post radiation, has been found to exert stimulatory effects on the recovery of hemopoietic functions in sublethally gamma irradiated mice. These therapeutical effects were enhanced in animals protected by peroral administration of cystamine. The treatment scheme used did not modify survival of lethally irradiated mice. The therapeutic effects of magnesium aspartate and adenosine monophosphate in sublethally irradiated mice are explained by the stimulatory action of these drugs on the cell adenylate cyclase system, which influences the erythropoietic functions.

The retrospective analysis of 242 patients treated for uterine cervix cancer at VUKEO Brno within 1977-1982 has been realized. The patients being only treated with radiotherapy alone using the external 42 MeV X-ray betatron beam irradiation of the pelvis, and the vaginal and intrauterine application of 226Ra, were included in this study. The complications of therapy were evaluated in accordance with the grade of severity, location and time of their source. The radiotherapeutical complications of the 2nd stage appeared for 27 patients (11.2%), and the complications of the 3rd stage appeared for 8 patients (3.3%). The total five-years' survival rate is 71%, 92% for 37 patients in the Ib stage, 78% for 105 patients in the IIa, b stages, and 54% for 100 patients in the IIIa, b stages.

Results are presented on investigations of diethone--a new pharmaceutical to prevent and treat radiogenic skin injuries. Diethone is a synthetic antioxidant of the dihydropyridine-line. In experiment on animals the preparation was used in form of an ointment. Irradiation was done with beta- and soft roentgen rays in doses of 20 to 60 Gy on conditions of a tele- or contact radiotherapy. A reduction of intensity and duration of radio reactions by more than 50% and a slighter occurrence of radio reactions were shown. The protecting effect of diethone is much stronger than that of mexamine, cystamine and other radioprotectors. Application of this preparation in treatment of radiogenic dermatitides results in relief of inflammation appearances, in shortening of recovery-time, and in accelerated skin regeneration. The intravital investigations of skin by means of contact-luminescence-microscope and investigations using light- and electron-microscopy did not give any alterations in structure of regenerated skin in diethone-treated animals compared with control. Also a better conservation of protected intracellular membranes especially of mitochondrial membranes were seen. Generally penetration of 14C-diethone into skin occurs within two hours after application of ointment. It can not be found hardly within inner media.

Malignant neoplasias in childhood generally are an increased risk for the patient to fall ill with a second tumor. Second tumors in former irradiation field are seldom, but are acknowledged radiogenically if histology is different to that of the first tumor and a sufficiently long period is between the two tumors. A patient is represented who had been operated and irradiated because of an adenosarcoma of the kidney at the age of seven and who has fallen ill with a neurogenic sarcoma in irradiation area more than 30 years later. The same patient had to suffer from radiogenic retardation during differentiation of lumbar apparatus of attitude and locomotion and on the other hand he became father of a healthy daughter at the age of 32.

For the concrete case of a central bronchial carcinoma the method, explained in parts I and II, is applied for an automatic dose adaptation. In result a dose distribution is found which has a better adaptation of target area isodoses opposite the starting variant and results in a lower exposure of risk regions altogether.