Direct navigated 3D ultrasound for resection of brain tumors: a useful tool for intraoperative image guidance

Abstract

<jats:sec> <jats:title>OBJECTIVE</jats:title> <jats:p>Navigated 3D ultrasound is a novel intraoperative imaging adjunct permitting quick real-time updates to facilitate tumor resection. Image quality continues to improve and is currently sufficient to allow use of navigated ultrasound (NUS) as a stand-alone modality for intraoperative guidance without the need for preoperative MRI.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>The authors retrospectively analyzed cases involving operations performed at their institution in which a 3D ultrasound navigation system was used for control of resection of brain tumors in a “direct” 3D ultrasound mode, without preoperative MRI guidance. The usefulness of the ultrasound and its correlation with postoperative imaging were evaluated.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>Ultrasound was used for resection control in 81 cases. In 53 of these 81 cases, at least 1 intermediate scan (range 1–3 intermediate scans) was obtained during the course of the resection, and in 50 of these 53 cases, the result prompted further resection. In the remaining 28 cases, intermediate scans were not performed either because the first ultrasound scan performed after resection was interpreted as showing no residual tumor (n = 18) and resection was terminated or because the surgeon intentionally terminated the resection prematurely due to the infiltrative nature of the tumor and extension of disease into eloquent areas (n = 10) and the final ultrasound scan was interpreted as showing residual disease. In an additional 20 cases, ultrasound navigation was used primarily for localization and not for resection control, making the total number of NUS cases where radical resection was planned 101. Gross-total resection (GTR) was planned in 68 of these 101 cases and cytoreduction in 33. Ultrasound-defined GTR was achieved in 51 (75%) of the cases in which GTR was planned. In the remaining 17, further resection had to be terminated (despite evidence of residual tumor on ultrasound) because of diffuse infiltration or proximity to eloquent areas. Of the 33 cases planned for cytoreduction, NUS guidance facilitated ultrasound-defined GTR in 4 cases. Overall, ultrasound-defined GTR was achieved in 50% of cases (55 of 111). Based on the postoperative imaging (MRI in most cases), GTR was achieved in 58 cases (53%). Final (postresection) ultrasonography was documented in 78 cases. The findings were compared with the postoperative imaging to ascertain concordance in detecting residual tumor. Overall concordance was seen in 64 cases (82.5%), positive concordance was seen in 33 (42.5%), and negative in 31 (40%). Discordance was seen in 14 cases—with ultrasound yielding false-positive results in 7 cases and false-negative results in 7 cases. Postoperative neurological worsening occurred in 15 cases (13.5%), and in most of these cases, it was reversible by the time of discharge.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>The results of this study demonstrate that 3D ultrasound can be effectively used as a stand-alone navigation modality during the resection of brain tumors. The ability to provide repeated, high-quality intraoperative updates is useful for guiding resection. Attention to image acquisition technique and experience can significantly increase the quality of images, thereby improving the overall utility of this modality.</jats:p></jats:sec>

Intraoperative ultrasound use in intracranial lesion surgery: An initial institution experience

“…As it provides instant visualization, USG is not affected by this change and is advantageous than neuronavigation [2,3,7]. USG is not affected by the location changes of tissues during surgery and after resection and this is an important advantage of USG but if craniotomy cannot be made in lesion border, a clear image cannot be provided as the prob movement would be limited [5].…”

“…In another study on a pediatric patient group, it was shown that the use of intraoperative USG was a faster and more affordable method compared to MRI [14]. The use of USG in residual tissue evaluation due to the imaging quality deficiency was limited before, but today it can prove optimal evaluation in residual tissue with the technological developments and imaging quality improvements [7]. Information can be provided on the vascularity of the present lesion with Doppler USG through instant visualization, and thus surgical area coagulation can be provided more easily during surgery [5].…”

Fusion of Intraoperative 3D B-mode and Contrast-Enhanced Ultrasound Data for Automatic Identification of Residual Brain Tumors

“…Second, highlighted structures are extracted in both imaging modalities by applying the Otsu multi-level thresholding method. Third, segmented structures are combined via a fused rule defined by Equation (1). Finally, a post-processing stage is performed to remove small structures detected that are in general false positives.…”

“…This intraoperative modality is routinely used to guide brain tumor operations. Particularly, iUS aims at identifying the presence of possible tumor residuals at the end of the operation, in order to remove as much tumor tissue as possible [1,2]. This is a crucial aspect since several studies showed that a gross-total resection has a positive impact on the progression-free survival of patients.…”

Optical coherence tomography for precision brain imaging, neurosurgical guidance and minimally invasive theranostics

“…Furthermore, many advanced technologies are widely used in intraoperative brain tumor detection and neurosurgical guidance, including computer tomography (CT) (13), diffusion-weighted magnetic resonance imaging (MRI) (14), fluorescence (15,16) and fluorescence spectral analysis (17), Raman spectroscope (18,19), ultrasound (20), photoacoustic imaging (21), biomarkers (22), and evaporative ionization mass spectrometry (23) etc. OCT can visualize sub-surface tissue structure non-invasively, the micro-meter depth microstructure of tissue also has an intuitive demonstration for neurosurgeons, and the research of neurosurgical OCT are launching gradually in neurosurgical diagnostics and guidance.…”