[The value of hyperfractionated irradiation from the viewpoint of radiobiological model findings].

From radiobiological model investigations it is deduced that hyperfractionated irradiation can render possible a better tumor regression than conventional fractionation with the same complication rate in tumors growing not too quick.

[Results of combined operative-radiologic therapy of bladder cancer from the viewpoint of optimizing the physical-technical irradiation planning].

In 294 patients with bladder carcinoma, in which after transurethral or transvesical operation a high-voltage irradiation with daily 1.5 Gy and a total target dose of 60 Gy (four fields cross firing technique) was done, the influence of quality of physical-technical irradiation planning is studied on survival rates, portion of recurrences, side-, and late effects. The group of patients with individually computer-based optimizing of irradiation parameters based on a patient's cross-section, ascertained on therapy simulator, significantly shows better results with regard to above-mentioned criteria than the groups of patients with standard irradiation technique without and with definition of bladder topography.

[A prospective randomized study on the fractionation of afterloading therapy of cancer of the cervix and endometrium].

A prospective randomized clinical study is made on patients with uterine cervix and endometrium carcinomas treated only by radiotherapy. The fractionation schemes of 4 times 10 Gy, and 5 times 8 Gy, and 8 times 5 Gy at the reference points A and My, respectively, of a short-term afterloading therapy combined with percutaneous telecobalt therapy with 45 Gy at the pelvic wall are investigated. A tendency is shown towards better tumor control and less radiogenic effects with an increased number of fractions.

[Dose-time optimization in fractionated radiotherapy].

On the basis of an evaluation of different isoeffect correlations for normal tissue reactions supported by a clinical study, a number of correlations for the dose-time optimization of irradiations with equal fractionation intervals are derived from a simple approach for the survival rate of irradiated tumor cells based on a linear quadratic dose-effect function for an exponential cell proliferation. This allows to determine optimum single doses for every given fractionation interval which, applied with the number of fractions tolerated by normal tissue, lead to a maximum reduction of tumor cells. The values of these optimum fractionation parameters depend from cell proliferation and radiosensitivity of the tumoral tissue and vary with respect to a normal tissue tolerance for early and late reactions.

[Histologic changes in the normal bladder wall following fractionated irradiation--an animal experimental study].

The histopathologic alterations of the bladder wall were investigated in 180 rabbits irradiated with different fractionations and total focal doses. Animals sacrificed on week after the end of irradiation showed alterations of the urothelium (desquamation, increased polymorphism of nuclei vacuolizations) as well as oedematous and hyperemic reactions in submucosa and muscularis. These alterations became stronger when the single and total focal dose and the ret value were increased.

[Results of percutaneous radiotherapy of bladder cancer using 1 and 2 series of irradiation].

In a randomized prospective clinical study, the authors investigate the results of percutaneous radiotherapy (telecobalt) with two rhythms of fractionation in patients with vesical carcinomas. A one-series irradiation with 1.5 Gy daily (except the weekends) up to a total dose of 60 Gy is compared to a two-series irradiation (in the first series 3 Gy three days per week up to 30 Gy, then irradiation-free interval of four weeks, in the second series 1.

[Results of radiotherapeutic optimization within the scope of combined operative-radiologic therapy of urinary bladder cancer].

The results of a prospective randomized clinical study for the comparison of a uniserial irradiation with a biserial irradiation are demonstrated. The investigations were performed on altogether 191 patients. Patients after cystectomy and supravesical by-pass of the urine were excluded.

[The problem of preoperative radiotherapy of renal adenocarcinomas from the viewpoint of tumor biology].

Tumour biological examinations were carried out on 26 patients with pulmonary metastases of renal adenocarcinomas; growth functions were used to calculate the point in time at which metastases began to grow, in relation to the time of operation. The aim was to derive information on the indications for pre-operative radiation therapy. In 3 patients out of 26 (11.

[A prospective trial on osteoporosis following bilateral ovariectomy with and without oestrogen replacement (author's transl)].

During four years a prospective study was carried out on 59 women, who had ovariectomized bilaterally for non-malignant diseases. It was studied the loss of the body length, the loss of bone mineral content in a middle phalanx expressed as percentage and several x-ray criteria. By means of combined performance signs of a beginning osteoporosis were found in 59 per cent of women after 2 years and in 68 per cent after 4 years after ovariectomy.