title: The value of intraoperative ultrasonography during the resection of relapsed irradiated malignant gliomas in the brain.
abstract: OBJECTIVE
  The aim of this study was to investigate whether intraoperative ultrasonography (IOUS) helped the surgeon navigate towards the tumor as seen in preoperative magnetic resonance imaging and whether IOUS was able to distinguish between tumor margins and the surrounding tissue.
  
  
  METHODS
  Twenty-five patients suffering from high-grade gliomas who were previously treated by surgery and radiotherapy were included. Intraoperatively, two histopathologic samples were obtained a sample of unequivocal tumor tissue (according to anatomical landmarks and the surgeon's visual and tactile impressions) and a small tissue sample obtained using a navigated needle when the surgeon decided to stop the resection. This specimen was considered to be a boundary specimen, where no tumor tissue was apparent. The decision to take the second sample was not influenced by IOUS. The effect of IOUS was analyzed semi-quantitatively.
  
  
  RESULTS
  All 25 samples of unequivocal tumor tissue were histopathologically classified as tumor tissue and were hyperechoic on IOUS. Of the boundary specimens, eight were hypoechoic. Only one harbored tumor tissue (P=0.150). Seventeen boundaries were moderately hyperechoic, and these samples contained all possible histological results (i.e., tumor, infiltration, or no tumor).
  
  
  CONCLUSIONS
  During surgery performed on relapsed, irradiated, high-grade gliomas, IOUS provided a reliable method of navigating towards the core of the tumor. At borders, it did not reliably distinguish between remnants or tumor-free tissue, but hypoechoic areas seldom contained tumor tissue.
authors: Department of Neurosurgery, Zentralklinik, Bad Berka, Germany.
authors: Kay
authors: 0000-0001-9818-292X
authors: K
authors: Mursch
authors: Department of Neurosurgery, Klinikum Duisburg, Duisburg, Germany.
authors: Martin
authors: M
authors: Scholz
authors: Department of Neuropathology, Georg August Universität, Göttingen, Germany.
authors: Wolfgang
authors: W
authors: Brück
authors: Department of Neurosurgery, Zentralklinik, Bad Berka, Germany.
authors: Julianne
authors: J
authors: Behnke-Mursch
keywords: Glioblastoma; Glioma; Interventional ultrasonography; Neoplasms, residual; Neurosurgical procedure