Abstract
INTRODUCTION: The use of intraoperative 3D navigational ultrasound (Sonowand) offers a relatively inexpensive method of obtaining imaging of intrinsic brain tumours during resection which takes in account brain shift during surgery and also allows better visualisation of the tumour margin to help control resection. We designed a study to measure the volume of tumour resection in 25 consecutive Sonowand cases compared to 25 matched non-ultrasound guided controls. METHOD: A retrospective consecutive case series of 50 patients who underwent resection of an intrinsic tumour was collected, comprising 25 cases using neuronavigational intraoperative 3D ultrasound and 25 with standard neuronavigation without intraoperative ultrasound. The volume of the tumour was calculated both pre- and post-operatively using volumetric analysis software based on T1 contrast sequences from MRI scans. The mean percentage resection of the Sonowand group was compared to that of the control. RESULTS: The percentage resection in the Sonowand group was significantly greater (p < 0.0005) than the control group. The Sonowand group had a percentage resection of 97.7% (95% CI 96.9%- 98.5%) and the non-Sonowand group had a percentage resection of 93.5% (95% CI of 92.1%-94.9%). There was no significant difference in the pre-op volume or tumour location between the two groups. CONCLUSION: The experience in our unit is that Sonowand guided resection results in a greater volume of tumour resection when compared to cases in which intraoperative ultrasound guidance was not used. Further studies are required to show if this results in reduced recurrence and improved survival in patients with intrinsic brain tumours.