[A storage and transport system for the shielding blocks in radiotherapy].
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Equipment Design↗
Biomedical subjects
B Kober
Publications and source records attributed to B Kober.
[Results of palliative chemotherapy in advanced small cell bronchial carcinoma].
Results of chemotherapy for small cell bronchial carcinoma were analysed retrospectively on 36 of 40 consecutive patients with the disease, admitted to an oncology unit between January 1985 and December 1987. The survival curves indicated a highly significant trend (log-rank p = 0.001). Patients with extensive disease and Karnofsky index of 40-50% had a median survival of four months, but for those with Karnofsky index greater than 50% it was 15 months. There was virtually no age difference between the two groups, but there were significant differences regarding additional diseases (e.g. coronary heart disease, arteriosclerosis, etc.) frequency of liver and CNS metastases, rates of complete or partial remission, number of early deaths, haematological toxicity, and severe weight loss (greater than 5 kg). These results suggest that aggressive chemotherapy (primary designed for patients with limited disease) failed to improve the grave prognosis of patients with distant metastases and a low Karnofsky index (less than 50%). Supportive care should be intensified for these patients.
Adult↗
[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↗
Effects of local irradiation and i.v. methotrexate on brain morphology in rabbits: early changes.
Brain damage following cranial radiation therapy can be crippling or even life-threatening and has been studied in both patients and animals. An additional toxic effect of chemotherapy has been found in children, who died following brain irradiation and systemic chemotherapy for the treatment of acute lymphoblastic leukemia. To study the interaction of radiation and drugs on brain tissue, we treated rabbits with brain irradiation and/or i.v. methotrexate. For a period of up to 3 months following radiation therapy, brain morphology was compared in seven treatment groups. Weekly doses of methotrexate administered i.v. produced no brain damage. Histological examination showed myelin swelling and beading 14 weeks after fractionated brain irradiation with 24 Gy. Combination of brain irradiation and methotrexate produced additional hypertrophy of microglia and pyknosis of adventitial cells. In none of these groups, even after doses of 48 Gy brain irradiation, was calcification or brain necrosis observed during the first 14 weeks following irradiation.
Animals↗
Stereotactic percutaneous single dose irradiation of brain metastases with a linear accelerator.
The effectivity of stereotactic percutaneous single dose irradiations in the treatment of solitary brain metastases has been assessed in a series of 12 consecutive patients. Only radioresistant deeply localized metastases have been treated. Photon-irradiation was carried out with the convergent beam technique using stereotactic localization methods, in a linear accelerator facility. In 11 of the 12 patients no side effects occurred. The first 7 patients, who could be observed 3 months or longer, have been studied in detail. In each of these cases single dose irradiation with 20-30 Gy yielded arrest of tumor growth. In one case a marked decrease in contrast enhancement and in four cases shrinkage of the metastasis as well as a marked decrease of the edema occurred. In every patient a marked, sometimes dramatic improvement of the clinical condition was achieved, beginning a few days after irradiation. Stereotactic radiosurgery is a valuable tool in the treatment of inoperable, radioresistant brain metastases, the major advantage being high efficacy and smoothness of the procedure, as well as extremely short hospitalization times (2-3 days).
Adult↗
[Results of radiation therapy in brain metastases with reference to computerized tomography].
Between 1979 and 1985, 193 patients were submitted to radiotherapy of the brain for formation of metastases. A primary irradiation was performed in 159 patients, 34 patients had been treated by surgery. The median survival time after diagnosis of all irradiated patients (40 to 60 Gy within four to six weeks) was 4.9 months, 22% of the patients survived one year. Patients with mammary carcinomas and patients with bronchial carcinomas showed marked differences in median survival times (4.2 and 6.9 months, respectively) and one-year survival rate (11% and 32%, respectively). In histologic examination, the extent of extracerebral formation of metastases was the decisive parameter for survival. At the end of radiotherapy, 47% of patients showed an amelioration in neurologic deficiency, 16% deteriorated. A follow-up by computed tomography with observation periods between four and 34 months was possible in 84 patients. Most of these patients showed improvement in computed tomography during a period of four to twenty weeks after the beginning of radiotherapy. Later on, about two thirds of the controlled patients had again deterioration with local progression or new formation of metastases in spite of total brain irradiation. A long-term normalization (greater than one year) was observed only in patients with mammary carcinomas.
Brain Neoplasms↗
[Functional heterogeneity of liver metastases in 3-phase computerized tomograms].
Ninety patients with liver metastases (68 colorectal carcinomas, 22 breast carcinomas) were examined by triphasic angio-CT. This included demonstration of the entire liver after a bolus-like injection of contrast. Originally, the metastases were hypodense, but showed four patterns of contrast enhancement. Quantitative evaluation of the mammary carcinomas showed a marked increase in density during the bolus phase, with similar contrast values in the liver and at the centre and edge of the metastasis at ten minutes after the injection. Colorectal carcinomas showed only slight increase in density after contrast injection. The difference in density between the centre and the periphery of the metastasis was still present on later images. This finding indicates that there are differences in the vascularisation of these metastases.
Breast Neoplasms↗
[Intra-arterial dynamic computed tomography in characterizing liver metastases of colorectal cancer].
Locoregional chemotherapy of liver metastases from colorectal tumours is a promising new approach. The results of CT in fifteen patients after intravenous and intra-arterial contrast injection are compared. The liver metastases are supplied mainly by the arterial route and this permits a means of assessing therapy. Contrast injections through a hepatic catheter may result in flow phenomena which limits the value of this investigation. It is unknown whether such flow phenomena may influence the result of intra-arterial chemotherapy. Although the margins of the metastases were more clearly defined, diagnostic accuracy was not increased, as compared with intravenous CT enhancement.
Colonic Neoplasms↗
[Nuclear magnetic resonance tomographic staging of tumors of the oral cavity, oro- and hypopharynx and the larynx. A comparison with computed tomography and sonography].
Thirty-six patients with tumours of the mouth, the oropharynx and hypopharynx and the larynx were examined by nuclear resonance tomography. The results were compared with the clinical findings of inspection and palpation and with CT and sonography, with respect to T and N classification. In seven patients the classification could be confirmed at operation. NMR provides very good anatomical detail and marked contrast between tumour and the surrounding tissues, particularly on T2 weighted images. NMR showed the best correlation with the clinical findings as regards the T classification and was the most accurate method, as confirmed by surgery. It is superior to CT and sonography for diseases in the oropharynx and hypopharynx. For the examination of the cervical lymphatics, sonography remains the recommended method.
Adult↗
[Radiotherapy of pathological fractures and skeletal lesions in danger of fractures].
Radiotherapy is of great importance in the treatment of pathologic fractures and skeletal lesions bearing the risk of fracture which are induced by malignomas, especially if these are in an advanced stage. In dependence on site and extent of skeletal destruction as well as on the general tumor dissemination, it can be distinguished between palliative radiotherapy and curative radiotherapy aiming at analgesia and remineralization. A retrospective analysis of 27 pathologic fractures and 56 skeletal lesions bearing the risk of fracture in malignoma patients showed an analgetic effect obtained by radiotherapy in 67% of pathological fractures and in 80% of skeletal lesions bearing the risk of fracture, whereas a remineralization could be demonstrated for 33% of pathological fractures and 50% of destructions bearing the risk of fracture. A stabilization of destructions progressing before therapy was found in 55% of pathological fractures and 40% of skeletal lesions bearing the risk of fracture. Thus a partial loading, supported by orthopedic prostheses, was possible for more than 50% of all patients.
Adult↗
[Nuclear magnetic resonance tomography in the diagnosis of head and neck tumors. A comparison of methods].
36 patients with carcinomas of different ENT regions were investigated by means of MRI, CT and B-mode ultrasonography (US). The images were evaluated by parameters of clinical importance: tumour detectability marginal appearance, internal architecture, regional extension, and artifact degradation. The results were compared with the clinical tumour staging in accordance with the TNM system. In MRI, a multiplanar imaging of tumour extension with horizontal, frontal and sagittal sections is possible. Together with a good contrasting of the tumour against the surrounding structures, these are major advantages over CT in the imaging of carcinomas of the tonsils, the hypopharynx and the larynx. For both methods, tumours of the tongue base and the floor of the mouth are a real challenge. Lymph node metastases can be visualised with MRI, but US is the method of choice for the evaluation of cervical lymph nodes.
Carcinoma, Squamous Cell↗
[Diagnosis of lesions in the area of the facial skull--indications and effectiveness of the conventional roentgen technic in comparison with computer tomography].
The substantial information conveyed by conventional radiodiagnostics of pathological alterations of the facial skull is shown in 243 patients examined by conventional radiodiagnostic means and by computerised tomography. Except in case of special demands, conventional tomography has to be preferred in routine diagnostics of the facial skull as a primary method supplying an answer to the most important questions at a lower cost and in a shorter time.
Diagnosis, Differential↗
Cerebral radiation surgery using moving field irradiation at a linear accelerator facility.
A modified irradiation technique at a linear accelerator facility for radiation surgery within the brain is described consisting of several moving field irradiations in non-coplanar planes. Using collimated narrow beams, a localization system and special computer programs for precise patient positioning, a high concentration of dose within small, well circumscribed volumes is obtained. Resulting dose distributions were studied experimentally and by calculations. A simple algorithm for treatment planning was developed and based on CT images. Radiation surgery within the brain is now technically feasible at our linear accelerator. Seventeen patients have now been treated.
Brain↗
[Dosimetry in computerized tomography].
During CT, the surface dose increases towards the centre of the axis of rotation. Measurements on 35 patients and theoretical considerations indicate a hyperbolic relationship between the axis of rotation and the surface dose.
Adult↗
[Angio-CT in the diagnosis of liver metastases of colorectal tumors].
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Angiography↗
[Ultrasound in the diagnosis of malignant lymphomas].
Optimal treatment of a malignant lymphoma demands accurate staging at the time of first diagnosis. In addition, it is mandatory to perform reproducible therapy control and closely meshed follow-up care. In this connection, sonography occupies an unrivalled place as a non-invasive, relatively uncomplicated and economical examination method. The ranking depends in individual cases on the diagnostic importance and informative value of rival methods, such as lymphography and computed tomography.
Hepatomegaly↗
[The significance of computer tomography in the diagnosis, planning, therapy planning and control of the therapy of malignant lymphomas].
Staging of malignant lymphomas is significantly improved by computed tomography. This method not only visualizes enlarged lymph nodes, but also enables the assessment of organs which could also be affected within the overall underlying disease. Accuracy of diagnosis of computed tomography is between 80 and 95%, depending upon the examined area. The distance between the cuts, as well as contrast enhancement of the intestine and the vessels are major factors in promoting the accuracy of diagnosis. In addition, computed tomography represents a safe and non-invasive tool in therapy planning and control.
Combined Modality Therapy↗
[Angio-CT: an improvement in the diagnosis of malignant liver diseases].
Dynamic contrast studies of the liver make it possible to evaluate the vascularity of liver metastases. Up to the present, the examination has only been carried out in single planes, whereas studies of the whole of the liver during one examination have not yet been published. This can be obtained by performing sequential CT (angio-CT), using special software. A clinical study of the value of the procedure has been undertaken on 64 patients with suspected liver metastases. In addition to the plain scans, the examination was repeated during the early phase of a bolus injection and subsequently ten minutes after injection (enhancement). The various structures which can be seen are described and the changes in density patterns have been interpreted according to contrast kinetics derived from nephrographic examinations. The advantages of angio-CT as compared with plain films and with scans after normal contrast infusions are described. The improved sensitivity and specificity obtained by using the three modes of examination, as compared with a single examination, is stressed.
Breast Neoplasms↗