Strahlentherapie最新文献

An improvement is achieved by palliative X-ray irradiation in about 70% out of 47 patients with scapulohumeral periarthritis and local cervical syndrome and/or cervicobrachial syndrome which was hitherto resistant to medicomechanical treatment. Higher rates of success (84%) can be achieved if the patients present an identical symptomatology, but less severe alterations of the vertebral column, even if the vertebral column is not irradiated. In case of severe alterations of the vertebral column, the success of palliative irradiation is diminished, even if the cervical vertebral column is additionally irradiated.

The serum concentration of 3 acute phase reactants (APR) (Caeruloplasmin, Alpha-1-antitrypsin and C-reactive protein) was measured by Mancini-technique praetherapeutically in a group of 214 patients with different sites of gynecological tumors. A group of 27 healthy women was used for comparison. In benign tumors Caeruloplasmin had in cases of myoma significantly (5%-standard) more elevated levels than normal group. In all cases with malignancies all 3 APR had significantly more elevated levels than in benign tumors. In cases of carcinoma of ovary all 3 APR had significant more elevated levels than benign ovarian tumors. The percentage of praetherapeutically elevated Alpha-1-antitrypsin levels was higher, while the percentage of elevated CRP-levels in cases with benign ovarian tumors ("false positive") was lower in comparison to accepted markers for ovarian cancer. Thus it appears to be indicated to prove the value of measurement of APR for monitoring in gynecological oncology.

The dose distribution around an isotropic, point radiation source can be expressed by the dose rate constant, the quadratic law of distance, and a radial dose function which depends on the absorption and scatter processes occurring in the surrounding material. The radial dose function and the dose rate constant of a point iodine-125 source can be represented in a clear and rather exact manner as simple functions of the linear attenuation and energy absorption coefficients, because the average photon energy does not considerably vary with the growing distance from the source. This representation is in contrast with some functions defined in a distance of 1 cm, in conformity with the definition of the dose rate constant in the air according to DIN 6814, part 3.

The treatment results of 45 patients with carcinoma of the base of the tongue treated in the Rotterdam Radio-Therapeutic Institute in the period 1970 to 1980 are evaluated. Most patients were treated with split course radiotherapy, three patients were operated after the first course of radiotherapy. Eighteen patients with stage III and IV disease were treated with a combination of chemotherapy and radiotherapy. Overall 5-year survival was 27%, intercurrent death corrected survival was 40%. Adequate staging is a problem in carcinoma of the base of the tongue, especially in T2 and T3 lesions. A systemic combined approach of radiotherapy and surgery is recommended.

Male Sprague Dawley rats were continuously irradiated at a dose-rate of either 5 or 7 cGy/day, up to a total dose of 900 cGy. Changes in spermatogenesis with irradiation and the recovery of the testis during 33 weeks after irradiation were studied. No clear dose-rate effect with testicular weight occurred. During the irradiation time, increased dose and dose-rate induced a decrease in A spermatogonia and preleptotene spermatocyte number. In our experimental conditions germ cell production did not plateau, as shown by the increasing number of tubular cross sections devoid of germ cells beyond 500 cGy. The recovery of seminiferous epithelium occurred essentially within nine weeks. It was not dose-rate dependent and was still incomplete after 33 weeks. This lack of recovery might be due to limited compensatory division ability of the stem cells. Clusters of Sertoli cells were observed in the lumen of the seminiferous tubules; impaired function of these cells could also prevent the complete recovery of the seminiferous epithelium. By 16 weeks after the end of irradiation 67% of 5 cGy/day irradiated rats and 34% of 7 cGy/day irradiated rats recovered fertility.

C57BL++ mice were either whole body X-irradiated with a dose of 200 R or, 15 minutes before X-irradiation injected with AET, MEA, or 5-HT, in a dose of 40 mg/kg of body weight, on the first day of gestation. Uterine contents were examined on the nineteenth day of pregnancy. The number of corpora lutea was assumed as 100% and the percentage values of live and dead foetuses, resorptions, and non-implanted embryos were calculated. The percentage ratio of females with live foetuses in the uterus, in relation to the total number of those with a vaginal plug was also determined. X-irradiation of pregnant mice influenced the embryonic survival. As compared with controls, in only X-irradiated mice a lower percentage value of live foetuses and higher percentage values of non-implanted embryos and resorptions were found. One dead foetus was only observed in X-irradiated females. Percentage value of X-irradiated females with live foetuses was lower than that of control ones. High mortality of embryos occurred more often before than after the implantation of blastocysts. The percentage value of non-implanted embryos was higher than that of resorptions. AET, MEA, and 5-HT when injected to mice before their X-irradiation acted as radioprotectors. The strongest radioprotective effect was obtained following AET administration, intermediate after 5-HT treatment and the weakest one when MEA was injected.

Mice of the strains C3H, DBA, NZB, and NMRI were X-irradiated with 0.475 Gy and 2.85 Gy (or 3.80 Gy) at newborn stage or at the age of six months. Their livers were prepared at the age of one to maximum 18 months and the hepatocytes isolated. The DNA content of both whole cells and separated nuclei was measured by flow cytometry and the liver ploidy pattern was determined applying a correcting calculation. Irradiation with 0.475 Gy of newborns of strain C3H results in a relative decrease of octoploid cells and an increase of tetraploid nuclei during lifetime (significance level of 0.001). After irradiation with 3.80 Gy a reversed reaction was observed. However, if the animals were irradiated as adults with a dose of 3.80 Gy the 8c cells decreased significantly three months later. Similarly, newborns of the outbred strain NMRI irradiated with 2.85 Gy, showed an increase of octoploid cells from the third month on, but an oscillating pattern of the 4c nuclear DNA content. In strains DBA and NZB, significantly altered ploidy values could not be found, perhaps due to a too great variance of experimental values.

The hemopoietic regeneration following midlethal irradiation in Wv/+ mice had similarly biphasic kinetics as in their hematologically normal +/+ littermates. The first abortive phase of regeneration was either severely reduced (formation of transient endogenous spleen colonies, reticulocyte count, granulocyte count) or absent (spleen and femur cellularity, platelet count, PCV) in Wv/+ mice, when compared to +/+ mice. The second phase leading to permanent recovery of hemopoiesis was in Wv/+ mice delayed in time. Moreover, although to a lesser extent the values of spleen and femur cellularity, PCV and platelet count were decreased in Wv/+ mice. Postirradiation bleeding, which stimulated particularly the 1st phase of regeneration both in Wv/+ and +/+ mice did not lead to the minimization of differences between above two genotypes. It is suggested that the observed differences in the abortive regeneration between Wv/+ and +/+ mice are primarily dependent on the presence in Wv/+ mice of selective defect of transient endogenous colony forming units (TE-CFUs). Moreover, it is possible that the differences in the second phase of regeneration leading to permanent recovery are secondarily dependent on the TE-CFUs defect, as most probably the TE-CFU is the step in stem cell differentiation to mature cells.

After many years of clinical application of a 42 MeV betatron, the following indications were found for deep therapy with electrons above 20 MeV: tumors situated in the brain, mediastinum, kidney, liver, bladder, rectum, as well as peripheral tumors situated in different body regions. For eight different cases, the total body exposure and the radiation exposure of some risk organs was calculated for an irradiation with electrons alone, a combination of electrons and photons, an irradiation with 42 MeV X-rays and with Co-60 gamma rays alone. All these calculations were based on a most favorable irradiation technique. The results showed that electrons up to 40 MeV can spare more than 30% of the total body dose; a combination of electrons and photons allows a reduction of the total dose of about 15% as against that of photons alone, which makes possible a better conservation of skin. This total dose reduction corresponds to that achieved by the substitution of ultrahard X-radiation for Co-60 gamma radiation in deep therapy. The radiation exposure of risk organs can often be reduced by the use of electrons, too. Thus electron deep therapy shows to be justified for the mentioned tumor cases. This is also confirmed by clinical experience.

The investigations reported were performed to test applicability of non-invasive methods for the measurement of the parameters determining the growth of a solid experimental tumor and to measure these data for the tumor system sarcoma-180/NMRI-mice. It could be shown that non-invasive methods can be used for the measurement of tumor growth, especially the fraction of proliferating cells (growth fraction) which is of special importance for tumor therapy. For the tumor system under investigation, the growth is completely determined by an exponential decrease of the growth fraction.