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Biomedical subjects

L Voigtmann

Publications and source records attributed to L Voigtmann.

17 recordsLinked to original sources
PubMed1991

The hydroxyproline content in the lung tissue of young pigs after fractionated irradiation with photons or neutrons.

The radiation response of normal lung tissue was studied in 99 young pigs. Five fractions of Co-60-photons and of neutrons with an average energy of 6.2 MeV were applied during overall treatment times of five and 35 days respectively. The irradiation field comprised the whole of the right lung. At eight to ten weeks and at eight to 13 months animals were sacrificed and the removed lungs were investigated histopathologically and biochemically. Radiation induced fibrosis was evaluated by determining the ratio of hydroxyproline concentration of irradiated and non-irradiated lung in the same animal. Above a threshold there was a significant increase of the hydroxyproline ratio with increasing doses. Histopathological findings and hydroxyproline ratio were in close agreement. RBE values between 3.8 and 4.5 were calculated in accordance with the results using the other criteria of lung damage in our studies on pigs.

Animals↗
PubMed1990

[A universal verification and protocol system for teletherapy].

To increase the quality of radiotherapy a verify and record system (VPS) was developed for teletherapy equipments, that takes control of manually adjusted irradiation parameters and of recording all relevant data of radiotherapy. The VPS can be adapted to special wishes of the user and it lends itself to application on different irradiation equipments. In the represented paper especially the extent of efficiency of the system is shown which is characterized by high operating comfort, flexible reacting to exceptional cases and by high date and operating security. The testing phase on an accelerator model has been brought to a close, actually the system is installed to an electron linear accelerator "Neptun 10p" and led to clinical trial.

Humans↗
PubMed1990

[The determination of the RBE of neutrons based on the hydroxyproline concentration in the lung tissue of irradiated piglets].

To test the radiogenic reaction of normal lung tissue experiments were done in 99 young pigs altogether. The radiation field included the total right lobe of the lung, 5 fractions of photons or neutrons (mean energy 6.2 MeV) were applied in a total treatment of 5 or 35 days. After killing the animals and taking the lungs the examination of tissue samples and others has been done for contents of hydroxyproline (HP) that has been used to register radiogenic injuries where the relation of irradiated and non-irradiated half of the same animal was estimated as measuring value. Above a limit of 1.13 for the HP-quotient (estimated in non-irradiated controls) there was a significant correlation with dose. Between the results of HP-quotients and histopathological findings a very good correlation was found. Calculation of RBE was done from relation of the dose values of photons and neutrons on base of the same level of injuries. In the tested total dose limit (photons: 14.25-38 Gy, neutrons 3.0-8.5 Gy) RBE-values of 3.8-4.5 were reached that correlates well with other tested criteria of the study in young pigs.

Animals↗
PubMed1990

Application of a semi-phenomenological model to experimental data of radiation induced pneumopathy in pigs.

A semi-phenomenological model has been derived, which describes the inactivation effect on individual cells by survival curves. This model is applied to experimental data of pneumopathy in pigs. The corresponding survival curves as well as the relations between cell survival and complication probability are calculated and discussed. Furthermore, dose-response curves for single dose irradiation and different fractionation schemes are derived. The comparison between the response curve for single dose irradiation and similar curves from the literature shows a good agreement.

Animals↗
PubMed1979

[Application of the NSD-concept for the ascertainment of tolerance doses in the region of the lung (author's transl)].

A clinical application of the NSD-concept using iso-ret plans for the recording of radiation pneumonitis is reported. The conditions of an ascertainment of tolerance values for single organs by help of the Ellis formula are discussed. Of the examined patients with Hodgkin's disease who had been exposed to irradiation of the unaffected mediastinum, 42% suffered from radiogenic lung complications. The calculated iso-ret plans reveal a limitation of the pneumonitic shadow zone identical to the 1200-ret isoline. The data in literature are in accordance with these results.

Cobalt Radioisotopes↗