Friedrich Wilhelm Kreth

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Treatment and prognosis of gliomas depend on their histological tumour grade. The aim of the study was to evaluate the potential of [18F]fluoroethyltyrosine (FET) PET for non-invasive tumour grading in untreated patients. Dynamic FET PET studies were performed in 54 patients who, based on MRI, were estimated to have low grade (LG; n = 20), intermediate (WHO(More)
Hypermethylation of the DNA repair gene O(6)-methyl-guanine DNA methyltransferase (MGMT) has been linked to prolonged survival in glioblastoma patients treated with alkylating agents. It was aimed to analyze prospectively whether the MGMT status of malignant gliomas could be determined from small-sized stereotactic biopsies (maximum volume: 1 mm(3)).(More)
Epigenetic silencing of the O(6) -methylguanine-DNA methyltransferase (MGMT) gene promoter is associated with prolonged survival in glioblastoma patients treated with temozolomide (TMZ). We investigated whether glioblastoma recurrence is associated with changes in the promoter methylation status and the expression of MGMT and the DNA mismatch repair (MMR)(More)
Background Is Gamma Knife surgery alone as effective as surgery plus whole brain irradiation (WBRT) for patients with a single, small-sized brain metastasis? Methods Patients aged between 18 and 80 years harboring a single, resectable metastasis ≤3 cm in diameter, a Karnofsky performance score (KPS) ≥70, and a stable systemic disease were randomly assigned(More)
UNLABELLED The aim of the present study was to evaluate whether extended analyses of O-(2-18F-fluoroethyl)-L-tyrosine (FET) uptake kinetics provide results superior to those of standard tumor-to-background ratios in predicting tumor grade in patients with pretreated gliomas. METHODS Dynamic 18F-FET PET studies (0-40 min after injection of 180 MBq of(More)
PURPOSE The purpose of this study was to analyze retrospectively timing, frequency, and prognostic impact of TP53 mutations and P53 protein accumulation in supratentorial WHO grade II astrocytomas and oligoastrocytomas of adult patients. EXPERIMENTAL DESIGN We included 159 consecutively treated patients (1991-1998), and each tumor was screened for TP53(More)
BACKGROUND Detailed long-term outcome data are not available for adult patients with World Health Organization (WHO) Grade 2 astrocytoma or oligoastrocytoma. METHODS A previously published short-term data set of 239 adult patients with circumscribed de novo supratentorial astrocytoma (187 patients) and oligoastrocytoma (52 patients) treated with(More)
Favorable outcome after chemotherapy of glioblastomas cannot unequivocally be linked to promoter hypermethylation of the O 6-methylguanine-DNA methyltransferase (MGMT) gene encoding a DNA repair enzyme associated with resistance to alkylating agents. This indicates that molecular mechanisms determining MGMT expression have not yet been fully elucidated. We(More)
Since differentiation between low-grade glioma (LGG) and high-grade glioma (HGG) remains challenging according to MRI criteria alone, we investigated the discriminative value of additional dynamic FET PET in patients with MRI-suspected LGG. Included in this retrospective study were 127 patients with newly diagnosed MRI-suspected LGG and dynamic FET PET(More)
Glioblastoma multiforme continues to be a devastating disease despite modest improvements in survival achieved at present, and there is an urgent need for innovative treatment concepts. Five-aminolevulinic acid (ALA) is a drug which induces protoporphyrin IX accumulation in malignant gliomas and has been explored for fluorescence-guided resections of these(More)