Roland Schröder

11C-METHIONINE AND 18F-2-FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY :A TOOL FOR DIAGNOSIS OF CEREBRAL GLIOMA AND MONITORING AFTER BRACHYTHERAPY WITH 125I SEEDS

Forty-six patients with suspected brain tumors were investigated by positron emission tomography (PET). Using 11C-methionine PET, the spatial extent of increased uptake in gliomas was larger than that of contrast enhancement on CT/MR images in 67% or the same in 33%. Ten of 46 patients treated with brachytherapy for low-grade gliomas were also investigated with 18F-2-fluorodeoxyglucose (FDG)-PET. One year after seed implantation, the glucose metabolism had not changed, but the decline of methionine uptake was significant. In conclusion, 11C-methionine PET may improve tumor delineation and, following brachytherapy, provides more information on the therapeutic effects than FDG.

CT-Guided and Computer Assisted Stereotactic Biopsy Technique, Results, Indications

SummaryOn the base of a stereotactic device originally described by Riechert and Mundinger a three-dimensional localization and treatment planning system for CT-guided computer assisted stereotactic procedures has been developed. The experience with 338 patients, in which image guided stereotaxy has been used for the assessment of various intracerebral lesions, is presented. In 54 of these patients the cannula was introduced with a 20 MHz Doppler-probe positioned at the tip of the needle. A comparison of tissue specimens taken stereotactically with tissue material after tumour resection and/or autopsy was performed in 35 patients. The accuracy of the histological diagnosis was 88%. Bleeding as a complication due to the stereotactic intervention occurred in 8 patients (2.4%). Two of these patients had a fatal outcome (mortality: 0.6%). The morbidity (transient and permanent deterioration of the clinical status) was 1.2%.

Prognostic relevance of localization and grading in intracranial ependymomas of childhood.

Intracranial ependymomas represent one of the most frequent brain tumors in childhood. Their preferred midline localization and their often controversially discussed classification prompted the present study of 67 intracranial ependymomas in children less than 15 years of age who were operated on from 1951 to 1990. Clinical data and follow-up of all children were retrospectively analyzed by calculation and statistical comparison of progression-free survival (PFS). According to the WHO classification as revised in 1993, 1 grade I subependymoma, 38 grade II ependymomas, and 28 grade III anaplastic (malignant) ependymomas were differentiated. Grade II ependymomas were predominantly located in the IV ventricle and in the supratentorial midline, which often made complete tumor resection impossible. In contrast, the majority of grade III tumors, most often situated in the cerebral hemispheres, could be totally removed. Operative mortality was higher in grade II than in grade III tumors. After recovery from operation, PFS was mainly determined by the histological grading. Median postoperative PFS was 120 months in grade II, but only 18 months in grade III ependymomas (P = 0.1417). Thus, despite varying therapeutic concepts, analysis of this 40-year collective study confirms the prognostic relevance of localization and WHO grading in the case of intracranial ependymoma in children.

Supratentorial ependymomas in childhood: clinicopathological findings and prognosis.

SummaryOut of 29 supratentorial ependymomas in children under 10 years of age, operated on between 1951 and 1989, 18 were situated in the hemispheres and 11 in the midline.15 of the 18 hemispheric tumours, but only 4 of the 11 intra- or paraventricular ependymomas allowed complete removal. The operative mortality within the observation period of nearly 40 years was 27% for tumours in the midline and 11% for those in the hemispheres.The grade of malignancy rose with increasing distance from the ventricular level. 5-year survival without recurrence was 75% in grade 2 and 31% in grade 3 ependymomas. The total rate of recurrence was 58%.New tumour growth can be delayed by postoperative irradiation, at least in grade 2 ependymomas. It can be prevented, if at all, only by total resection of the primary tumour.

The growth potential of ependymomas with varying grades of malignancy measured by the Ki-67 labelling index and mitotic index

The prognostic significance of histopathological grade for postoperative outcome is not yet known for ependymomas. Data on proliferation kinetics of these tumors are few.In our study, the growth fraction was immunohistochemically determined by labelling cell nuclei with the monoclonal antibody Ki-67 in 24 tumors of the ependymoma group (2 malignant ependymomas grade III, 11 ependymomas grade II, 8 spinal ependymomas, and 3 subependymomas). The results were compared with the mitotic index in the same tumor areas. Both growth parameters are related to the grade of malignancy. The differences between the results of spinal ependymomas (grade I) and of intracranial tumors (grade II) were statistically signifcant. Malignant ependymomas had the highest values. Variable growth potentials could be demonstrated in a few tumors. A non-linear relationship between growth fraction and mitotic index was found, indicating a variable generation time in ependymomas (as in astrocytomas). Thus, with rising grade of malignancy the growth fraction increases and the generation time decreases.

Cerebrovascular involvement in systemic AA and AL amyloidosis: a clear haematogenic pattern.

Abstract Amyloid deposits in cerebral vessels are common in β-amyloid diseases (Alzheimer’s disease, congophilic amyloid angiopathy, Down’s syndrome and hereditary cerebral amyloidosis with haemorrhage of the Dutch type). We report of 20 autopsies on patients who had died with systemic amyloidosis of the AA, Aλ and Aκ types: the brains were examined for the occurrence of amyloid. Vascular amyloid was detected in choroid plexus (in 17 of 20 cases), infundibulum (5 of 8), area postrema (6 of 11), pineal body (3 of 7) and subfornical organ (2 of 3), but not in cortical and leptomeningeal vessels. Immunohistochemical classification of the cerebral amyloid and the systemic amyloid syndrome showed identity proving the same origin of both. The distribution is indicative of a haematogenic pattern of amyloid deposition in systemic amyloidosis and is different from that in Alzheimer’s, prion, ATTR and cystatin C diseases. It corresponds to areas of the brain with a ”leaky” blood–brain barrier. Additionally, all the cases with AA amyloidosis exhibited an Aβ coreactivity in choroid plexus vessels. In one exceptional case, Aβ reactivity of AA amyloid also occurred outside of the brain.

Intracranial ependymomas: Prognostic aspects

According to the grading of brain tumors as proposed by the WHO in 1976, out of 128 ependymomas 83 tumors could be classified as grade II and 38 as grade III Only seven subependymomas were benign and could be assigned to grade I.In contrast to most series known from the literature, 73 ependymomas were located above the tentorium and only 55 in the posterior cranial fossa. The grade of malignancy rised with an increased distance from the ventricular level.Macroscopically complete exstirpations were usually possible in hemispheric ependymomas, whereas tumors arising from the floor of the fourth ventricle often allowed only a partial removal. The operative mortality in the infratentorial group was more than twice as that in the supratentorial group.Postoperative survival was predominantly dependent on the histologic grade of malignancy. The five year survival rate without recurrence was 57.4% in grade II ependymomas as compared to 24.1% in grade III ependymomas. It could be improved by postoperative radiation therapy in both groups of malignancy. The almost identical longterm results indicate that even in less malignant ependymomas new tumor growth will occur later on.

Histological Study of Lumbar Intervertebral Disc Herniation in Adolescents

Summary¶ Herniated intervertebral discs are rare in children and adolescents constituting approximately 1–5% of all patients undergoing surgery for lumbar and lumbosacral intervertebral disc herniation. Preceding traumata and congenital anomalities have been reported as important factors for the pathogenesis of intervertebral disc prolapses in young patients. The present histological study is based upon 15 patients with lumbar disc herniation within an age range from 14 to 19 years. Only in one case, was adequate trauma reported. All patients exhibited degenerative changes of the disc, similiar to those observed in adults. These changes were marked in 11 patients (73%). Thus, as known from adults, also in isolated traumatic disc herniation of adolescence, pre-existing degeneration of the disc has to be considered. If such changes are present, trauma has the significance of only transitory deterioration of the previous disc degeneration.

Ganglioside profiles in human gliomas: quantification by microbore high performance liquid chromatography and correlation to histomorphology and grading.

Summary¶ The composition and the content of gangliosides changes during physiological growth and differentiation as well as in neoplastic cell transformation. In order to determine if ganglioside profiles correlate with brain tumour malignancy, the ganglioside distribution was determined in 31 gliomas of astrocytic origin and in non-tumour tissue by a recently developed microbore high performance liquid chromatography (HPLC) method. Glioma malignancy was graded according to the grading system proposed by the World Health Organization (WHO) in 1993. In general, an increase of GD3 and a decrease of normal brain gangliosides correlated with a higher grade of malignancy. Pilocytic astrocytomas Grade I had a distinctive ganglioside profile, histologically as well as biochemically. Although they are low-grade gliomas, the pilocytic astrocytomas exhibited a GD3 content comparable to anaplastic gliomas and could only be biochemically distinguished from other tumour grades by relatively high type “b” ganglioside levels. Thus, ganglioside composition not only reflects anaplasia but can also be used to indicate biological characteristics of tumours of different histogenetic origin.

Gene expression of the nicotinic acetylcholine receptor α4 subunit in the frontal cortex in Parkinson's disease patients

Cognitive impairment in Parkinsons disease is accompanied by a marked decrease of cerebrocortical nicotinic receptors. To study the putative site of impaired receptor synthesis, frontal cortices of Parkinson patients with cognitive dysfunction have been screened for the expression of the nicotinic receptor alpha 4 subunit gene. Quantitative assessment of alpha 4 mRNA-expressing neurons did not show significant differences between patients and controls. Therefore, decreased nicotinic receptor sites cannot be attributed to alterations at the transcriptional level of the alpha 4 gene. Alternative causes have to be searched for at the translational and/or postranslational level.