[Use of a microcomputer system in radiotherapy (author's transl)]. / Zum Einsatz eines Microcomputersystems in der Strahlentherapie.

The authors report their experiences with the successful use of a microcomputers system in radiotherapy. A self-developed programme allowing the calculation of depth dose and irradiation times in telecobalt therapy is given as an example for the application of this system. The authors put stress on a simple handling (video dialogue) and a written documentation. The programme can easily be modified for the use of other telecobalt devices.

[Carcinomas of the Nasopharynx. Clinical aspects--treatment results--therapeutical improvements (author's transl)]. / Karzinome des Nasenrachens. Klinische Aspekte--Behandlungsergebnisse--Optimierungskriterien.

In the years from 1968-1977 to 44 out of 63 patients with carcinomas of the nasopharynx and to 15 out of 19 patients with malignant lymphomas of the nasopharynx curative radiation therapy was applied. The survival-rates for all carcinomas amount to 63,2% after 3 years, and to 46,5% after 5 years. Half of the patients live up to only 9% of their mean, age- and sex-dependent life expectancy. The prognosis differs with the histological type. Patients with transitional-cell-carcinomas had the smallest chance of survival; half of them did not survive. 0.08% of their age-dependent life expectancy. Skeletal infiltration and metastases of the cervical lymph nodes have a bad influence on the therapeutic results. Local recurrences developed in 20% of the patients. Using the examples of 3 patients, who don't belong to the analyzed collective, we shall discuss and optimize the radiotherapeutic management. As a result it is found out, that the megavoltage irradiation therapy (42 MeV X-rays) makes a better dose distribution in tumour-volume than cobalt 60 rays.

[Computer-assisted irradiation planning by means of computed tomography (author's transl)]. / Rechnergestützte Bestrahlungsplanung mit Hilfe des Computertomographen.

Operation of the computer tomograph combined with a computer for irradiation planning leads to an optimization of radiotherapeutic efforts. By means of a careful carrying-over of computed tomographic data into the computing system the demanded homogeneous dose distribution with a deviation rate of +/- 10% may be accomplished to a large extent for any given target volume. At the same time this method achieves an optimal sparing of the sound or else critical organs. An evaluation unit independent of the diagnostics ought to be available, as this renders possible the adaptation of the CT cross-sections of interest under individual aspects.

[Importance of computed tomography in irradiation planning for the thoracic region (author's transl)]. / Bedeutung der Computer-tomographie für die Bestrahlungsplanung im Thoraxbereich.

The target volumes, anatomical distances and isodose curves in 62 patients undergoing irradiation of the thoracic region have been defined and compared for treatment planning, using an idealized transversal body section on the one hand, and computed tomograms on the other hand. 74% revealed nonconformance of the target volumes, and correction on the radiation field was therefore necessary in 62%, according to the CT-findings. Computed tomograms are superior to conventional treatment planning because they present individual body sections. Thus, deviations of the peak doses amounted to more than 10%: in the region of the mediastinum 7%, in the region of th lungs 29%, and in the region of the spinal cord 13% of the cases.

[Radioactivity in dismantling a betatron]. / Radioaktivität beim Abbau eines Betatrons.

The authors report on the specific radioactivity of construction components of a 42 MeV betatron measured 28 days after the last run by means of a Ge spectrometer (ultra-pure germanium detector employed in a semiconductor spectroscopic method) recording the gamma spectra of various components of the betatron. This examination served to find out which components would have to be considered as radioactive waste requiring special treatment in accordance with Federal German legislation on radioactive waste disposal (section 47 of the Radiation Protection Ordinance). The examination showed that such special treatment would be required only for the target (main material: platinum) and the Platness-filter (chief constituent: lead) of the decommissioned electron accelerator.