Biomedical subjects

K Schnabel

Publications and source records attributed to K Schnabel.

At least 109 records · Page 6Linked to original sources

PubMed1978

[The computed tomography of the malignant thoracic space-occupying process under special consideration of radiotherapeutic points of view (author's transl)].

The data of 70 patients with a malignant thoracic space-occupying process were compared in order to find out the differences between computed tomography and conventional X-ray diagnosis (thorax radiography, hilum tomography), the radiotherapeutic aspects of these methods being taken under special consideration. Computed tomography is excellently suited for the establishment of therapeutic schemes because it is the only technique producing individual cross-sectional views of the thorax which are in correct scale and have a high resolving power. Contrary to thorax radiography and hilum shadow, the computed tomography offers some additional diagnostic information in several special fields.

Bronchial Neoplasms↗

PubMed1977

[Whole body computer tomography in the planning and follow-up of radiation therapy (author's transl)].

Whole body computer tomography provides accurate transverse sections of the areas to be irradiated in the position used for irradiation. The method has been used in 167 patients with malignant tumours in various parts of the body on a routine basis. Actual-size cuts allowed accurate delineation of the tumour or of the area to be irradiated with its neighbouring organs in 135 patients; in 66 patients CT scanning probided additional information regarding the extent of the tumour. Follow-up examinations carried out in 29 patients proved effective in showing the results of treatment. The introduction of the whole body scanner into radiation therapy has improbed radiation planning when compared with conventional methods because of the more accurate delineation of the area to be irradiated and of the surrounding organs.

Bone Neoplasms↗

PubMed1977

[Pendulum irradiation of the middle part of the esophagus with rapid electrons and ultrahard X-rays (author's transl)].

In order to find out whether the moving field irradiation with rapid electrons and ultrahard X-rays of a 42 MeV betatron is suitable for the radiotherapy of the esophagus carcinoma, we took measurements on the Alderson phantom. By both methods--irradiation with rapid electrons as well as mono-axial pendulum irradiatin with ultra-hard X-rays--we did not achieve a satisfactory dose distribution, because lung segments of different sizes or the spinal marrow were reached by a relative dose which was too high. The bisegmental pendulum irradiation is the only one which leads to a dose distribution producing a good concentration in the target volume and sparing the surrounding tissues.

Electrons↗

PubMed1977

[Computed tomography of the whole body as a means of radiation planning (author's transl)].

Computed tomography of the whole body offers the first possibility to obtain individual tomographs with high resolution and in correct scale from all regions of the body. Using the "Sicograph", large-sized copies are obtained, which are therefore particularly useful for radiation planning. The size and location of tumors relative to critical organs can be determined exactly. The efficacy of radiation therapy in every individual case may be estimated on the basis of the controlled course (radiobiological information), [2,4,6,11,16,17,18,24,30], and the necessary modifications of the therapeutic schedule can be adopted early, allowing the complete utilization of the advantages of the shrinking field technique [8,19,26]. Since ultrasonic tomographs in many cases furnish additional information, we regard the combination of computed and ultrasonic tomography as the best way to obtain an accuracy of radiation planning previously unknown.

Humans↗

PubMed1977

[Depth therapy with electrons in the thoracic region. V. Dosimetric studies with telecentric small-angle pendulous irradiation (author's transl)].

The conditions of dose distribution in telecentric small-angle pendulous electron irradiation of the thoracic region are reported on the basis of isodoses experimentally found using a phantom. Electron energies from 20 to 42 MeV were used, the axial depth amounted to 20 to 30 cm, the pendulous angles to 30 degrees, 40 degrees, or 60 degrees and the field breadth was 3 or 4 cm. Irradiations were performed monaxially as well as biaxially. The influences of single variables upon the dose distribution and especially on the radiation load to skin, lung and spinal cord are discussed.

Humans↗

PubMed1977

[Comparative examination by means of radiograms and computer tomograms on body-like phantoms with equivalent tissues (author's transl)].

A comparative examination of three Alderson phantoms by means of radiograms and computer tomograms shows that there are significant differences between the individual phantoms. Phantom I, for example, is inferior to phantom II because of the bad insertion of the bones into the surrounding plastic material (covered by air bubbles) and the inclusions of air in the soft parts. All phantoms have a rather strong osteoporosis of the skeleton which is most probably due to the production method [1,2]. Furthermore, the average absorption coefficients of the soft tissues show remarkable differences from one phantom to another.

Absorption↗

PubMed1975