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Biomedical subjects

A R Fischedick

Publications and source records attributed to A R Fischedick.

At least 19 recordsLinked to original sources
PubMed2000

Effect of distortions and asymmetry in MR images on radiotherapeutic treatment planning.

Before using MR-images for radiotherapeutic treatment planning, it is necessary to check whether geometrical distortions influence the calculated dose distribution. In this study, 27 MRI units from different manufacturers and with different magnetic field strengths were investigated. First, all geometrical distortions and asymmetry were determined by specially defined parameters. Virtual planning target volume and organ of risk were drawn into MR images from different units and optimized dose distributions were calculated. The resulting field parameters were then transferred to the reference geometry. Geometric distortions caused small variations of the dose maximum (+/-0.5%). Twenty-five percent of the investigated calculated dose distributions showed an increase of the 95% isodose volume, 60% a decrease. The dose deviations in the organ of risk were comparable with the dose deviations in the planning target volume (PTV). This study has shown that measurements of geometrical distortions and asymmetry are necessary for MR-assisted treatment planning. For evaluation, we recommend dose calculations with hypothetical PTV's and organs of risk. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 46-50 (2000).

Electromagnetic Fields↗
PubMed1996

Epirubicin and ifosfamide in metastatic breast cancer.

In a randomized, phase II trial, we evaluated the effectiveness of continued chemotherapy with epirubicin/ ifosfamide versus unmaintained treatment interruption in advanced metastatic breast cancer. Three hundred fifty-seven patients were enrolled and 331 were evaluable for response. Complete response was achieved in 25 patients (8%) and partial response in 121 patients (37%). Pretreatment status correlated significantly with response (complete and partial response). While 54% of unpretreated patients responded, only 42% of the patients responded who had been pretreated with adjuvant chemotherapy and 33% who had been pretreated in the metastatic stage of disease; 69 patients (21%) had disease progression. Of 11 patients pretreated in both the adjuvant and metastatic setting, only two responded. Toxicity of treatment was mild, with leukopenia being the treatment-limiting factor. Thrombocyte levels were not altered significantly by treatment. Thus, there seems to be room for dose escalation using granulocyte colony-stimulating factor. There was no considerable cardiotoxicity, central nervous system toxicity, or cystitis observed. The low rate of cardiotoxicity appeared to be related to dose fractionation of epirubicin. After randomization of patients to treatment interruption versus continuation of chemotherapy, a longer relapse-free survival was observed for patients who continued chemotherapy (mean relapse-free survival, 2+ months); however, this did not translate into prolonged survival. The cumulative scores of toxicity and quality of life parameters showed increasing superiority for treatment interruption. Therefore, a strategy of treatment until maximum response and subsequent treatment interruption seems to be superior to treatment continuation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

[Neurofibromatosis and multiple nonossifying bone fibromas].

Three patients with a combination of neurofibromatosis and multiple non-ossifying fibromas are presented. All patients possessed multiple osteolytic lesions with sclerotic margins, resembling non-ossifying fibromas. Two patients showed similar lesions in additional localizations. In two patients, non-ossifying fibroma was histologically verified. The simultaneous occurrence of neurofibromatosis and multiple non-ossifying fibromas can possibly be put down to a generalized mesodermal dysplasia. However, the definite explanation is unknown.

Adolescent↗
PubMed1987

[Microabscesses of the spleen in patients with acute leukemia].

Eight patients with acute myelogenous leukemia in complete remission after induction chemotherapy developed septic fever. Fever was unresponsive to broad-spectrum antibiotic therapy. Ultrasonography showed multiple 0.5-2 cm in diameter, anechoic densities and some 1-3 cm "target" appearances in spleen and liver. Computed tomography demonstrated multiple, round, 0.5-2 cm areas of diminished attenuation in spleen and liver, which did not enhance like the surrounding parenchyma. These microabscesses increased in size and number without equivalent antifungal therapy and decreased or disappeared after specific treatment. Candida-infection was confirmed by histologically from liver specimens in four patients, fungal organisms were seen microscopically an liver-biopsy in one patient and at autopsy one patient was found to have candida disseminated to the spleen, liver, kidneys, lung and CNS.

Abscess↗
PubMed1986

[Candida abscesses in the liver and spleen. The sonographic and computed tomographic morphology].

In three patients with acute leukemia candidal abscesses occurred. In spite of ready response to induction chemotherapy, septic fever as well as hepatic and splenic enlargement were observed. Broad-spectrum antibiotics did not improve the patients' condition either. Ultrasonography of liver and spleen revealed multiple, small echolucent foci and target lesions. Computed tomography detected multiple, hypodense foci 1-2 cm in diameter; after contrast medium application there was no enhancement. Candidal septicaemia was demonstrated in all three patients.

Abscess↗
PubMed1986

[CT studies following ethanol embolization of malignant kidney tumors].

CT studies were carried out in 25 patients after alcohol embolisation. It was shown that the embolisation reaches the very periphery of the renal capsule. Nevertheless, contrast enhancement in renal tumours persists, due to capsular and collateral vessels. These subsequently permit further tumour growth. Intratumoral gas could be demonstrated in all patients. In the absence of symptoms, this must be regarded as a normal post-embolic event.

Embolization, Therapeutic↗
PubMed1986

[Acute focal bacterial nephritis].

Acute focal bacterial nephritis is a very rare type of infective nephritis. It is characterised by groups of abscesses of 1 to 5 mm. situated in the renal cortex with pus tracking to the papillae. Urography is normal or suggests a non-specific enlargement. On sonography, non-homogeneous foci with reduced echogenicity are observed. Unenhanced CT shows indefinite lesions of reduced density, which do not enhance as much as the surrounding parenchyma after contrast injection. On angiography these areas appear as hypovascular lesions. The disease must be differentiated from a malignant renal tumour and from an acute renal abscess. The clinical findings and the results of sonographic and radiological observations on five patients with acute focal bacterial nephritis are described.

Acute Disease↗
PubMed1986

[X-ray diagnosis of foot deformities].

In order to analyze foot deformities, the foot is divided into three compartments. Their normal and pathological positions are defined by the alignment of the bones' axes. The various foot deformities can be put down to a malalignment of the particular compartments. X-ray analysis of the malalignment allows a diagnosis to be made. The most important congenital and acquired foot deformities are discussed.

Calcaneus↗
PubMed1985

[Diagnostic possibilities of computer tomography in spinal and paraspinal space-occupying lesions].

Characteristic CT findings of intramedullary, intradural and epidural as well as of vertebragenic and paraspinal tumours are described, basing on literature and on the authors patient material. The value of CT is discussed and compared with that of other imaging modalities. Attention is also drawn to the value of i.v. application of contrast medium and of primary or secondary CT myelography.

Brain Neoplasms↗
PubMed1984

["Intensive lungs"--possibilities for quality improvement].

X-ray lung diagnosis in an intensive-care unit makes special demands on technique, imaging and on the physician's experience. The quality of image interpretation and evaluation is considerably improved by superimposing the technical data on the x-ray image and by using an antiscatter grid cassette. Proper evaluation of the parameters important for diagnosis is improved by registration of the data on the x-ray film; taking a maximum possible score of 100 as reference value, quality of evaluation is improved from 66.5 points to 71.8 points by data registration on the film itself, whereas the simultaneous use of an antiscatter grid cassette improves the score still further, namely, to 84.3 points. The importance of the clinical condition of the patient, and of the type of breathing chosen, for assessing the chest x-ray, is emphasised.

Humans↗
PubMed1983

[Significance of computed tomography in the staging of renal pelvic tumors].

The computer tomographic appearances of space-occupying lesions in the renal pelvis in 15 patients are described, and the place of CT in the radiological diagnosis is discussed. The clinical symptoms of renal tumours are often not characteristic, and conventional radiological methods frequently produce nonspecific appearances. Computed tomography, which is non-invasive, is therefore a suitable method for diagnosing space-occupying lesions in the renal pelvis at an early stage. Prognosis depends greatly on extra-pelvic spread, which can be demonstrated by CT alone.

Adult↗