gms | German Medical Science

Objective: A convincing intraoperative resection control in surgery of malignant brain tumors is associated with a longer overall survival of the patients. B-mode ultrasound (BUS) is a well known intraoperative imaging application in neurosurgical procedure but it's limited in the differentiation of tumor, tumor borders, edema or tumor remnants.

The aim of this clinical study is the investigation of contrast enhanced and 3D-reconstructed ultrasound (CEUS) in surgery of glioblastoma regarding the uptake of the contrast agent after tumor resection, imaging quality and comparison with the postoperative MRi.

Method: We investigated prospectively 20 patients suffering from a glioblastoma multiforme (GBM). All have undergone surgery with the support of neuronavigation in our Department of Neurosurgery. The median age was 61 years (range from 27 to 79 years).

Ultrasound imaging for resection control was acquired at the end of tumor resection defined by the neurosurgeon. A high end ultrasound (US) device (Toshiba Aplio XG^®) with linear probes for B-Mode and contrast mode was used. The navigation and 3D reconstruction was performed with the LOCALITE SonoNavigator^® and the images were transferred digitally. The used contrast agent was SonoVue^® by Bracco^®. Subsequently the ultrasound images were segmented with itk-Snap^® and compared to the corresponding postoperative MR data.

Results: In 17 of the 20 tumors we noticed a high contrast uptake while in 3 patients the uptake was slightly and not sufficient. In five of these 17 patients the postoperative MRi as well as the intraoperative CEUS for resection control showed tumor remnants. No further resection was performed because of eloquent location of these tumors. In the remaining 12 patients a gross total resection was planned preoperatively. In all patients the postoperative MRi demonstrated complete resection. 6/12 showed a small contrast enhancement lower than 0.175 cm³. In four of these six patients the resection control with CEUS could visualized also small contrast enhancement (mean size 0,85 ml).

Conclusions: 3D-contrast enhanced intraoperative ultrasound (CEUS) is a save and convincing intraoperative imaging modality. High resolution images in real time 3D could be acquired in 5 to 10 minutes. Gross total resection and incomplete resection of glioblastoma were sufficient demonstrated with CEUS intraoperatively. The application of US contrast agent could be a helpful imaging tool for resection control.in glioblastoma.