Janna C. Welleweerd

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Spontaneous intracranial artery dissection is an uncommon and probably underdiagnosed cause of stroke that is defined by the occurrence of a haematoma in the wall of an intracranial artery. Patients can present with headache, ischaemic stroke, subarachnoid haemorrhage, or symptoms associated with mass effect, mostly on the brainstem. Although intracranial(More)
Chinese hamster M3-1 cells were irradiated with several doses of X rays or alpha particles from 238Pu. Propidium iodide-stained chromosome suspensions were prepared at different times after irradiation; cells were also assayed for survival. The DNA histograms of these chromosomes showed increased background counts with increased doses of radiation. This(More)
OBJECTIVES Aneurysms of the extracranial carotid artery (ECAA) are rare. Although most ECAA are identified in asymptomatic patients, serious neurological complications may occur. Current literature on treatment outcome contains mainly case reports and small case series with incomplete data and lack of long--term follow--up. There is clear lack on natural(More)
INTRODUCTION Extracranial carotid artery aneurysms (ECAA) are rare but may be accompanied with significant morbidity. Previous studies mostly focused on diagnostic imaging and treatment. In contrast, the pathophysiological mechanisms and natural course of ECAA are largely unknown. Understanding the pathophysiological background may add to prediction of risk(More)
INTRODUCTION Aneurysms of the extracranial carotid artery (ECAA) are rare. Several treatments have been developed over the last 20 years, yet the preferred method to treat ECAA remains unknown. This paper is a review of all available literature on the risk of complications and long-term outcome after conservative or invasive treatment of patients with ECAA.(More)
To do calculations for wedged photon beams with the NRC Monte Carlo simulation package BEAM, a new Component Module for wedges called WEDGE has been designed and built. After an initial series of benchmarks using monoenergetic photon beams as well as realistic 6 MV and 10 MV beams, it was found, that the new CM did work fine for the large wedge (maximum(More)
Experiments were performed to verify the finding of others that prolonged irradiation caused sudden death of cells. Continuous irradiation (dose rate 0.09 Gy/h) was applied to the R-1, RUC-2, V79 and T-1g cells for up to 140 days. End points were: population growth rate, plating efficiency and radiosensitivity. The population doubling times were increased(More)
IMRT treatments using multi-leaf collimators may involve a large number of segments in order to spare the organs at risk. When a large proportion of these segments are small, leaf positioning errors may become relevant and have therapeutic consequences. The performance of four head and neck IMRT treatments under eight different cases of leaf positioning(More)
57Co-bleomycin is useful in the detection and staging of lung cancer, but the long half-life of 57Co (270 days) has discouraged its widespread acceptance. We investigated the shorter living positron emitting 55Co (half-life 18.2 h) as a label for bleomycin. In eleven patients with proven lung cancer scintigraphy with 55Co-bleomycin, using a positron camera,(More)
The measured electron spectra of linear accelerators from several manufacturers differ in comparison to the spectral form and width. As part of our investigations of linac performance and stability, we analyzed the electron spectra of our linacs. After building a spectrometer the electron spectra were measured. The measured spectral widths were comparable(More)