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Biomedical subjects

A C Voss

Publications and source records attributed to A C Voss.

54 records · Page 3Linked to original sources
PubMed1980

[Problems of multiple field technique in radiation therapy of cancer of the breast (author's transl)].

A method of adjustment frequently used for postoperative telecobalt irradiation of the mammary carcinoma was verified with the help of film-dosimetric measurements at a phantom. Special interest was taken in the regions with possible overlapping of contiguous fields, where serious complications may occur as a consequence of overlapping. Thus, apposition of several fields requires consideration of the divergence of rays and of the mapping precision of 50%-isodoses in the radiation field, as there lie the principal reasons. For realization of a nearly homogeneous dose distribution, on the one hand, there is necessary parallelism of marginal rays of the neighbouring useful ray beams, the radiation head being tilted laterally by half the angle of aperture; on the other hand, the 50% boundary lines at the light beam localizer have to be shifted parallel by a corresponding distance. In spite of this possibility of optimization, it is distinctly more advantageous, with regard to time and technical aspects, to use a linear accelerator, being additionally applicable for electron pendulum irradiation of the thoracic wall.

Breast Neoplasms↗
PubMed1979

[Ultrahard longitudinal pendulum irradiation of tumors in the region of the visceral cranium (author's transl)].

An analysis of 71 patients with malignant, mostly extended tumors in the region of the visceral cranium is made, and the irradiation technique as well as the results of a longitudinal pendulum irradiation with high-energy ultrahard X-rays are reported. The advantages in comparison with rays of another quality and with other techniques of irradiation consist in a very small radiation exposure of the skin and in a homogeneous distribution of the dose in the target volume as well as a sparing of the contralateral eye. The adjustment is simple and easy to reproduce, the acute side-effects are small and reversible, the cosmetic result is very good.

Aged↗
PubMed1979

[The inoperable carcinoma of the esophagus: results from radiation therapy and conclusions for irradiation planning (author's transl)].

Conclusions are drawn for irradiation planning from treatment results of 161 patients with inoperable esophageal carcinomas, comparable with reference to the technique applied using moving-field irradiation and delivering a total focal dose of 6000 rd. The palliative effect of radiation therapy is obtained by measurable dilatation of the stenosis in more than 90% of the patients. 5-year survival, however, was found only in cases of an average target volume comprising 500 cm3 within the 80% isodose, largely independent of the stage of the primary tumor. The best correlation between tumor extension and target volume is found in T3 tumors. A target volume larger than 700 cm3 does not seem to be required. The rate and localization of the recurrences are showing that a minimum safety distance beyond the radiologically ascertained tumor expansion is indispensable.

Aged↗
PubMed1978

[Radiotherapeutic aspects of testicular tumours: results and problems (author's transl)].

The five-year survival rate of patients with seminoma (61 cases) of all stages was 81% (seven-year survival rate 67%). Within this group the T1-2N0M0 stage had a five-year survival rate of 100%. Patients with tumours other than seminoma (52 cases) of all stages had a five-year survival rate of 54% (seven-year survival rate 47%). These results and those reported by others are the basis for not advocating routinely total radiation of the lymphatic pathways in the early tumour stages.

Adult↗
PubMed1978

[Radiotherapy of testicle tumors--results and consequences (author's transl)].

A report is given on 113 patients who had been irradiated because of testicle tumors and a part of whom had been submitted to an anterior lymphadenectomy. The five-year survival rate of the seminomas of all stages was 81% (n = 61) and that of the non-seminomas of all stages was 54% (n = 52). It has to be mentioned that the group of patients with seminomas of the stages T1-2N0M0 had a five-year survival rate of 100%, and those with embryonic teratomas of all stages had a five-year survival rate of 69%. With regard to these therapy results, it is recommended to carry out the radiotherapy of testicle tumors in conformity to the individual stage. A therapy scheme is presented.

Adult↗
PubMed1976

[Results of radiotherapy of bronchial carcinoma (author's transl)].

In a joint retrospective study by 17 radiotherapy clinics in German-speaking countries the results of treatment of bronchial carcinoma after radiotherapy were analysed in 7503 cases. The age peak was between the 60th and 70th year. Squamous-cell carcinoma was the most frequent histological type, followed by anaplastic carcinoma, with adenocarcinoma being rare. There was a high proportion of histologically not clearly identified cases (27% in central and 35% in peripheral carcinomas). Survival rate at one year was 31% for central (3662 patients) and peripheral (961 patients) tumours, but only 2% at five years. Prognostically there was no difference between histological types and kind of radiotherapy or technique, but total dose affected survival rate. At a total dose of less than 5000 rd the survival rate at five years was minimal. The prognosis of combined surgical and radiotherapeutic measures was slightly better than with a radiotherapy alone, but results were unpredictable for the individual case. It is concluded that radiotherapy aiming at cure should be used in imoperable bronchial carcinoma if the tumour state and general condition of the patient appear to make a cure possible. But if this is not the case, radiotherapy should be used only palliatively, i.e. only to ameliorate symptoms.

Adenocarcinoma↗
PubMed1975

[Variations in kidney location and consequences for the radiotherapy of kidney neoplasms in the optimization of irradiation planning].

Related to the discussion of optimal radiotherapy planning for the treatment of intrathoracal and intraabdominal tumors being located near the diaphragm, the question arises all over again, if the tumor or the former tumor-bed really are completely encompassed by treatment fields if the patient's topography has changed during a series of irradiations. Using a therapy simulator, the variations of the situs of kidneys are investigated in 20 patients. Changes of the location, which ought to be considered for radiotherapy treatment planning, are observed while changing from dorsal to abdominal position or due to exspiration and inspiration. Hence, consequences result concerning the precision of irradiation planning especially with regard to the sound kidney to be spared. Altogether, a better adjustment to individual features of the topographical correlations is realized. The accurate encompassment of the target volume and the careful sparing of the sound kidney resulting therefrom are justifying that much time must be spent on irradiation planning.

Cobalt Radioisotopes↗