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.
Starting point for automatic adaptation of a dose distribution is a starting variant which parameters values are fixed as a matter of experience. On base of this starting variant a limited number of variants is produced and the "quality" of the attained dose distribution in each case is expressed by an added measure function value. A gradual improvement of adaptation of dose distribution to individual geometry of patients is done by pointed search of new parameter values for field breadths, field beginning points, field weights, and field insolation directions.
Male Wistar-H-rats were exposed monthly to a 60cobalt-source low dose whole body irradiation (0.25 Gy, total dose: 4.5 Gy). The glutathione disulphide:total glutathione ratio, the concentration of thiobarbituric acid-reactive substances and the activities of glutathione peroxidase and glutathione transferase in eight different organs and blood were analysed. The low dose irradiation is accompanied by distinct peroxidative changes in organs. These oxidative loadings occur in the small intestine, the spleen and the kidneys. The measurements of glutathione status and of thiobarbituric acid-reactive substances are proposed as sensitive parameters for low dose radiation induced changes.
In the present information results of clinical studies are represented to show the effectiveness of therapy with 6.3 MeV fast neutrons in 45 patients with superficial tumors in head and neck area. The reaction of tumor and of normal tissue was studied in dependence on different physical and biological factors. Two variants of neutron therapy planning were estimated by means of mathematical models of a factor of time-dose-fractionation for neutron (TDFN) from clinical point of view. Results of changes in oxygen-tension within the tumor are represented in 20 patients with metastases in cervical lymph-nodes during neutron therapy. The obtained data show a correlation of regression and reoxygenation rate of the tumor to its initial volume. The reaction of the tumor in therapy with fast neutrons was studied in dependence on its morphological structure. Complete regression of epidermoid and nonepidermoid cancer types was seen in 42 or 89% of the cases. With corrections for adipose tissue and the extent of dose fraction of fast neutrons the clinical test of the mathematical model of TDFN-factor made discernible that the reaction of normal tissue can be prognosticated quite exactly by means of this model in neutron therapy.
Between 1982 and 1987 we carried out a prospective randomized study to compare the effectiveness of high-dose half-body irradiation (HBI) (A), intensive combined chemotherapy (B), and local or locoregional radiotherapy (C) in the therapy of extended small cell lung carcinoma (SCLC). 99 patients with a histologically proved SCLC were assigned to the three therapeutic groups of series: A = 31 patients, B = 37 patients, C = 31 patients. The median survival period showed a statistically significant advantage (p less than 0.01) for the chemotherapy group (B = 46 weeks) versus the two radiotherapy groups (A = 19 weeks, C = 23 weeks). The survival after half a year, one year, and two years also gave a clear advantage for the chemotherapy group. No difference was found between the radiotherapy groups A and C. The high-dose HBI gave no improvement of the sad therapeutic situation for the extended SCLC.
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.
Surgery and radiotherapy complete each other in local control of suffering from rectal carcinoma. A radiotherapeutic effect on tumor is secured often. The adjuvant radiotherapy is the most interesting indication, though the most controversial as present too. Analysing all data and with experiences of an own irradiation study we have not any doubt that the indication is qualified for a combined therapy, if the therapeutic aim with priority is to prevent a local relapse as the most frequent and complained of form of therapeutic failure. In this problem, radical irradiation forms, as pre- and accumulating irradiation (sandwich-technique) and after-irradiation, render superior to an exclusive pre irradiation. In result of this study we practise a preirradiation of 25 Gy with immediately following operation and an accumulating irradiation to 50 Gy in proved high-risk-stage (T greater than or equal to 3 NoMo,Tx N1-3 Mo). If there is a primary local incurability by tumor invasion into the neighbourhood a pre-irradiation is done with 50 Gy and following explorative laparatomy within 4-6 weeks. Nearly 60% of these tumors become operable after that. Likewise we practise in unirradiated patients with locoregional tumor recurrence. Also here the extirpation quota of patients with general or systemic incurability, that a stoma construction is required in, we carry out a transanal tumor reduction and irradiate with 50 Gy after that. Especially this therapeutic principle has proved its worth in patients that are past eighty. Here with acceptable living quality and avoiding a stoma construction a survival can be reached that corresponds to the statistical survival of this stage of life.
In 90 patients with malignant neoplasia of larynx, stomach and cervix uteri the functional state of hemostasis was investigated within the process of radiotherapy and in radiotherapy and radiosensitization by metronidazole. Aim of this work is to answer the question if metronidazole affects the state of organism besides its effect on radiosensitivity of tumor tissue, especially the system of hemostasis, the impairment of which can not seldom result in thrombohemorrhagic complications in oncologic patients as is known. It was pointed out that the thrombophilic status of the blood of patients with stomach carcinoma continues to be unchanged and the patients are endangered for thrombosis potentially. In consequences of radiotherapy and doses of metronidazole the capacity for adhesion is decreased in thrombocytes of patients with laryngeal and cervical carcinomas to a high degree, whereby the thrombogenic potential of blood is reduced and with that the risk for origin of intravascular thrombosis.
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.
Presented is the method of selective decontamination by van der Waaj. It is based on the conception of colonisation resistance deduced from animal experiments. So it means the concurrence of defense mechanisms which prevent the settlement of pathogenic germs and stabilize the normal microflora. First clinical and experimental results are reported.
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.
Tritiated water (HTO) injected intraperitoneally to Swiss albino mice at the rate of 370 kBq (10 microCi)/g body weight has been found to cause certain alterations in blood parameters 1, 5, 7 and 15 days postinjectionem. Leucocyte count dropped significantly post treatment. Differential leucocyte counting showed lymphocytes to be most affected which were reduced by 38.29% on 5th day p.i. Erythrocyte count, haemoglobin and haematocrit values though showed no significant changes at early intervals, these values were significantly lower at later intervals than those of control.
Adult healthy specimens of Channa punctatus (fish) were exposed to three doses (i.e. 2.25, 4.50 and 9.00 Gy) of gamma radiations from a 60Cobalt source. Five animals were autopsied 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 and compared with control group. The radio lesions appeared on day 2 in 2.25 Gy dose group and on day 1 in 4.50 and 9.00 Gy dose groups. Signs of recovery was seen on day 7 in 2.25 Gy dose group. Liver exhibited normal picture on day 14 in 2.25 and 4.50 dose group but in 9.00 dose group the lesions persisted. The radiation effects were found dose dependent.
In therapy of plasmocytoma the radiotherapy has a well established place in addition to chemotherapy. At the Clinic and Policlinic for Radiology of the Medical Academy Erfurt 42 patients with a plasmocytoma were treated in the years 1967 to 1987, 38 of them were included into the presented study. In radiotherapy roentgen depth-therapy was used with total surface dose of 30 to 40 Gy as well as telecobalt therapy with TD of 40 to 50 Gy. 8 patients had a solitary plasmocytoma, in three times with extramedullary manifestation in mucosa of cheek and nose and in gingiva and five times with bone localisation. In 30 patients with a multiple plasmocytoma we irradiated 37 painful bone lesions; for 29 of these irradiated findings the patients stated painlessness or distinct mitigation. In two bone manifestations a pathological fracture existed additionally, in which a complete painlessness and a clear callus formation could be attained. 4 patients with an incomplete cross-section syndrome in consequence of vertebral destruction with extradural tumor spreading responded with clear mitigation and regression of paresis. Furthermore an infiltration into soft parts was diagnosed at 9 bone foci, that were reduced in part (6 infiltrations) or regressed completely (3 findings) after radiotherapy. Additionally to osseous manifestations an extramedullary tumor (peribronchial lymph-nodes, hypophysis) existed in 2 patients, that regressed completely after termination of radiotherapy. The following indications can be mentioned for radiotherapy in plasmocytoma: 1. Curative postoperative radiotherapy after exstirpation of a solitary extramedullary plasmocytoma, 2. Curative sole radiotherapy of a solitary extramedullary of medullary plasmocytoma after its histological proving.(ABSTRACT TRUNCATED AT 250 WORDS)
A semi-phenomenological model has been derived, which describes the inactivation effect on individual cells by survival curves. This model is applied to experimental data of pneumopathy in pigs. The corresponding survival curves as well as the relations between cell survival and complication probability are calculated and discussed. Furthermore, dose-response curves for single dose irradiation and different fractionation schemes are derived. The comparison between the response curve for single dose irradiation and similar curves from the literature shows a good agreement.
Starting from the chain of single steps in radiotherapy, the requirements of topometrical treatment planning are defined and current directions of development for the improvement of accuracy and clearness of treatment plans are shown. By far not all the possibilities of ultrasound tomography (UST) and NMR-tomography for use in radiotherapy have been clarified up to now. Particularly in case of UST the range of application in radiotherapy can be essentially widened due to technical developments. Computerized tomography (CT) today holds a very important place in radiotherapy. In the centre of current interest are simulators able to produce CT and computerized tomographs with the possibility to use them as simulators. Pinpointing some of such developments, the importance of three-dimensional treatment planning with its diverse possibilities is detailed. They put the physician and the physicist in a position to imagine and to interpret quickly and effectively the enormous variety of data in treatment planning.
The sensitivity vs. dose characteristics of two TL readers (Harshaw 2000 A + B and NHZ-203C) was compared both in the range of small doses (10 microGy to 100 mGy) as well as in the radiation therapy level by using individually calibrated LiF:Mg, Ti detectors manufactured in Poland. The performance of both systems can be predicted by a three parameter theoretical model. The very good reproducibility of the NHZ-203C reader (sigma/D = 0.6%) is important in radiation therapy while the high sensitivity (the lowest detectable dose limit = 3 S.D. of the background = 27 microGy) is useful for radiation protection measurements.
The record and verify system (EPS) answers the control and recording of carrying out irradiation. Connection between accelerator and personal computer is done by a process calculator. The EPS-programme runs at a personal computer and is written in TURBO-Pascal. A first realization will be done at linear accelerator NEPTUN 10p.
Actually CT-cross-sections are the best base for irradiation planning. Bases are represented to use CT-picture matrices of scanner TOMOSCAN CX (Philips) for irradiation planning. The direct application of CT-pictures is done in "off-line"-running with the magnetic tape set. For figuring on colour display and estimation of density matrix limits of Hounsfield values are given. Adjustment of the CT to take off scan planes requires a special work-regime for irradiation planning. Repair and use of defective CT-pictures are realized by input of specific outlines. In daily routine the output of sagittal dose distribution is most advantageous in form of a table. Application of this CT-irradiation planning system, being implemented on microcalculator K 1630, is shown for telecobalt irradiation of mammary carcinoma.
