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Biomedical subjects

P Wöllgens

Publications and source records attributed to P Wöllgens.

At least 19 recordsLinked to original sources
PubMed1988

[Dosimetry on a rotating phantom in remote electron irradiation].

The Therac-20 Saturne produces a high dose rate electron radiation allowing a whole-skin electron irradiation. The problem of producing large fields enclosing the whole patient has been solved by superposition of two tilted stationary fields. The angle regulations are optimized by a computer program fed with the TLD values of transverse dose distributions. A homogeneous irradiation is obtained by the patient's rotation on a turntable within the radiation field. In case of a distance of 3 m between focus and skin, the irradiation times are only 5 min for a body surface dose of 1 Gy.

Humans↗
PubMed1983

[Value of radiotherapy in metastases of hypernephroid carcinoma].

52 own cases are retrospectively evaluated in order to investigate the importance of radiotherapy for the treatment of the metastasizing hypernephroma. The treatment is above all indicated in case of painful osseous metastases, but the success is retarded and often appears only after a focal dose of more than 30 Gy. Furthermore, radiotherapy of brain metastases and lymph node metastases within the mediastinum is often successful, whereas the irradiation of pulmonary metastases has to be judged less favorably. In most of all cases, surgical interventions are not an alternative, but a complementary treatment to radiotherapy. In default of promising systemic therapy methods, radiotherapy of metastases of the hypernephroma are a possibility to achieve a real palliative effect.

Adenocarcinoma↗
PubMed1980

[Serum iron and serum copper balance in the early diagnosis of metastases of breast cancer].

In a study made in the follow-up clinic on 684 patients with mammary carcinoma it was found that there were 64 cases of local recurrence and 244 cases of distant metastases. In both groups the serum iron and the serum copper balance in blood tests, in relation to the clinical proof of local recurrence and/or distant metastases, was investigated. It was found that there were 43.7% pathological serum iron and serum copper findings with local recurrences and 62.7% with distant metastases. The drift apart tendency of the blood serum values in patients with distant metastases could be proved in 78.7% of the cases and in 77.5% of the cases before any clinical proof. Thus, these observations allow the statement that the blood serum iron and serum copper imbalance in blood tests is of very real value in the early diagnosis of distant metastases.

Breast Neoplasms↗
PubMed1978

[Linear accelerators in oncoradiology. Comparison of the effciency of four clinically utilized electron linear accelerators with energies up to 20 MeV (author's transl)].

Further development of linear accelerators for medical purposes results in leaving off the principle of circular acceleration. The present investigation, comparing four clinically utilized electron linear accelerators with different constructional systems, reveals a large scale of clinical applicability, advantages and disadvantages partly compensating one another. None of the four machines examined offers a total of decisive advantages as compared to the other ones. Some essential data from the side of radiation exit are tested: depth dose data and photon contamination during operation with electrons, field sizes and homogeneity, penumbral width and penetration power for electron and X radiations. The appreciation of electron therapy by the radiologist may be a factor as well the handling of the machine, but in many cases the space available in an existing locality or the confidence in the ready service of a contracting firm, considerations concerning failure periods, estimate of repair and subsequent costs are influencing the decision for a certain type of equipment.

Electrons↗
PubMed1977

[Contribution to the radiation therapy of cerebral tumors (author's transl)].

Postoperative radiation therapy chiefly has to be regarded under the aspects of prevention or delay of recurrences. Primary radiation therapy without surgical extirpation of the principal mass of the tumor generally represents a palliative measure. As the radiosensitivity of a cerebral tumor is not exclusively dependent on the histological picture, histology should not influence the indication for radiotherapy. A diagnosis however, based on all clinical means, being reliable to a high degree, is a condition of the radiation therapy of brain tumors without a clear histologic determination. In this paper are reported the results of treatment from 132 intracranial tumors, and compared with data from literature.

Adenoma↗
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↗
PubMed1975

[Results of ortho- and megavolt therapy of inoperable bronchial carcinoma].

Survival rates of patients with inoperable, histologically verified bronchial carcinoma are compared as to orthovoltage or megavoltage radiation therapy. With megavoltage therapy, better survival rates are obtained after one or two years; later on, an approximation of the comparison groups is to be observed with regard to life expectancy. The improvement in one-year and two-year survival rates does justify the application of megavoltage therapy.

Adult↗