Concordance of Extent of Resection Between Intraoperative Ultrasound and Postoperative MRI in Brain and Spine Tumor Resection

Abstract

Objective Evaluate the utility of intraoperative ultrasound (IOUS) in brain and spinal tumor resections and the concordance of the extent of resection between IOUS and postoperative magnetic resonance imaging (MRI). Methods A retrospective analysis of prospectively collected data was performed. Thirty-nine lesions (36 patients) in the brain and spine were operated on for resection using IOUS between May 2020 and December 2022. All patients who underwent brain or spinal tumor resection were included, and who underwent IOUS during tumor resection and postoperative MRI was done within 48 hours of surgery. The Cohen's kappa coefficient was performed to the concordance of resection by IOUS and postoperative MRI. Results Forty-one patients underwent surgery, of which 36 met the inclusion criteria and five were excluded due to incomplete clinical records. Of the 36 patients included, two presented lesions in different locations, one with frontal and parietal metastases and the other with extradural and intradural spinal lesions, and one patient had a recurrence of glioblastoma, for which 39 procedures were included. Of the 36 patients, 36% were women, and the average age was 51.4 years with an age range of one year and two months to 94 years. The concordance of the degree of resection by ultrasound and the degree of resection by postoperative magnetic resonance is high. Conclusions The higher degree of concordance between IOUS and postoperative MRI would suggest that IOUS is a reliable tool for assessing the extent of tumor resection during surgery and provides real-time information to make decisions to adjust surgery plans based on the benefit/risk ratio.

Keywords: brain tumor; intraoperative ultrasound; magnetic resonance image; neurosurgery; oncology; spine tumor; tumor resection.

Figure 1. Left frontal low-grade glioma

(A) Preoperative T2 MRI shows hyperintense intra-axial tumor (white arrow). (B) Intraoperative ultrasound shows hyperechoic intra-axial tumor with well-defined edges (white arrowhead). (C) Postoperative intraoperative ultrasound image shows total resection of tumor (white arrowhead). (D) Postoperative T2 MRI shows total resection of intra-axial tumor (white arrow).

Figure 2. Right temporal high-grade glioma

(A) Pre-operative T1 gadolinium-enhanced MRI shows intra-axial tumor with contrast enhancement in the periphery and perilesional edema (white arrow). (B) Intraoperative ultrasound shows intra-axial tumor with central hypoechoic and hyperechoic portions in the periphery, the edges are well defined (white arrowhead). (C) Post-operative intraoperative ultrasound image shows total resection of tumor (white arrowhead). (D) Post-operative T1 gadolinium-enhanced MRI shows total resection of tumor (white arrow).