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Biomedical subjects

F Brix

Publications and source records attributed to F Brix.

35 records · Page 2Linked to original sources
PubMed1987

[Presentation of a new partial-field blocker for breast-preserving therapy of breast carcinoma].

A combination of conservative surgery and locoregional radiotherapy is a promising conception for conservative treatment of the so-called little mammary carcinoma. As a further increase of the longterm healing rate is probably almost impossible to achieve, changes of the irradiation technique aim at present only to improve the irradiation quality. With this background, the authors have developed a partial field blocker considering the anatomic and topographic radiophysical features of this therapy method and making possible furthermore various individual treatment modalities. The construction, function and clinical importance of this partial field blocker are described in detail and the physical parameters changing with respect to open field irradiation are discussed.

Breast Neoplasms↗
PubMed1986

General and specific aspects of experimental dose measurement in total body irradiation (TBI).

In magna-field irradiation using high energy bremsstrahlung (photons), i.e. total body irradiation, it is desirable to achieve a homogeneous dose distribution or to realize a planned modification in dose deposition within the target volume. In the Department of Radiology, University of Kiel, for this purpose individually constructed compensators are in routine use for about three years. Some physical and dosimetric aspects of this irradiation technique are described briefly and the experimental test procedure for TBI-compensators is highlighted by several details, for example transmission measurements, radiographies of the compensators and determination of actual dose rates in the midplane of the patient.

Humans↗
PubMed1985

[Allogeneic bone marrow transplantation after fractionated whole body irradiation. Results at the Kiel transplantation center].

Allogeneic bone marrow transplantations were carried out between March 1983 and July 1985 in 31 patients aged 7 to 45 years (median 18 years). Acute lymphoblastic leukaemia in 1st to 5th remission was present in 8 patients, acute myeloblastic leukaemia in 1st and 2nd remission in 4 patients, chronic myeloid leukaemia, with various remission status, in 6 patients, 3 patients had severe aplastic anaemia and there were single cases of myelodysplasia and immature cell megakaryocytic myelosis. Transplantation was carried out during relapse in 8 patients with either acute myeloid or lymphoblastic leukaemia. Phenotypic HLA-identical mothers (n = 2) as well as genotypic HLA-identical siblings (n = 27), and in two cases HLA-non-identical mothers, served as bone marrow donors. In leukaemia patients the conditioning treatment consisted of fractionated total body irradiation and high dose cyclophosphamide or etoposide. Patients with severe aplastic anaemia received cyclophosphamide (4 X 50 mg/kg) and fractionated total nodal irradiation (total dose 8 Gy). 19 patients (61%) survived 14 to 605 days after bone marrow transplantation. 15 patients (48%) continue to remain in complete remission with Karnofsky indices of greater than or equal to 90%. Causes for death were infection (n = 3), interstitial pneumonia (n = 3), relapse (n = 3) as well as single cases involving acute graft-versus-host-disease, non-engraftment of donor marrow and veno-occlusive disease of the liver.

Acyclovir↗
PubMed1985

[Fractionated homogeneous whole body irradiation prior to bone marrow transplantation].

At the University of Kiel, myeloid and acute lymphatic leukemia is treated since 1983 by total-body irradiation applied prior to bone marrow transplantation. Dose deviations in the midplane caused by the irregular surface and tissue inhomogeneities of the patient are reduced down to +/- 3.5% compared to the central ray, with the help of CT-based individual compensators. This method prevents above all an excessive dose to the lungs. The radiobiologic advantages of fractionated irradiation have been employed for all patients treated hitherto (n = 9). At present, a total body dose of 12 Gy in six fractions is applied within three days. There were no undesired acute radiogenic reactions except a mild acute mucositis found in all patients. Chronic side effects, especially in the lungs, were not demonstrated, too. However, the average follow-up time of 149 days has been rather short. One patient died from relapse of leukemia after a total dose of 10 Gy, another patient died because the transplanted bone marrow was rejected, and a third died from catheter sepsis. Six out of nine patients are in complete remission with a maximum index of Karnofsky. The limited experiences gained hitherto show that the homogenous accelerated-fractionated total-body irradiation offers essential advantages compared to non-compensated single dose irradiation with respect to the prevention of undesired radiogenic effects in sound tissues and that its therapeutic efficacy is at least the same.

Adolescent↗
PubMed1984

[Optimization of dose distribution in whole body irradiation by means of compensators].

In case of whole-body irradiation prior to bone marrow graft, an undesired irregular dose deposition in the median body plane is caused by the irregular body shape and the tissue inhomogeneities of the patient, which can amount up to 50% of the planned focal dose in case of laterally opposing irradiation. A procedure is proposed allowing to modify the dose distribution in the irradiated body systematically by means of compensators. Such compensators are produced with the aid of an adequate number of serial CT scans, a programme system considering these data and the individual irradiation geometry, and a computer-controlled cutter working in three dimensions. First a casting mould is manufactured which is then filled up with an adequate compensation material. The actual compensation data and the planned irradiation geometry are controlled before and during the treatment. Taking into consideration the individual shapes and the different tissue densities, it is not only possible to prevent the dose inhomogeneities mentioned above but also to introduce by means of a special programme part regions with a higher or lower dose deposition at any point of the irradiation field, at the therapeutist 's discretion.

Bone Marrow Transplantation↗
PubMed1984

[Presentation of a new shutter and compensator table for radiotherapy].

A shutter and compensator table for radiotherapy is presented which is moved by a motor and adjusted to a fixed position with respect to the irradiation unit. It is equipped with removable rotation plates, each possessing six trays for shutters and compensators. By hydraulic and infinitely variable regulation, these plates can be brought into different distances from the source to the lower edge of the shutter, one of the trays always lying precisely within the vertical axis of the central tray. The application of this equipment allows a very good reproduction of the geometric irradiation parameters and is easily operable in common practice.

Radiotherapy↗
PubMed1981

[A device for cutting and milling of styrodur for the use in radiation therapy (author's transl)].

A device for the hand-operated or numerically programmed cutting and milling of styrodur-molds has been designed in order to cast diaphragms and compensation bodies for radiation therapy. This process is quickly performed, reproducible and accomplished with maximal precision. The technique employed for cutting and milling is functioning without susceptibility to trouble, is nearly independent of attendance and distinctly reduces the risk of lesions.

Radiation Protection↗
PubMed1980

[Presentation of a diaphragm carriage for radiation therapy with irregularly shaped fields (author's transl)].

This paper describes the technical difficulties in irradiation of irregularly shaped target volumes. A diaphragm carriage that allows depositing and simple handling of up to eight diaphragms is presented. The diaphragms can be brought into a well reproducible position towards the patient and the radiation source. Thus, from different aspects, an improvement of radiation therapy with irregularly shaped fields is obtained.

Radiotherapy↗