Comparison of sodium fluorescein and intraoperative ultrasonography in brain tumor resection

Various intraoperative neuroimaging modalities are available to the neurosurgeon during brain tumor surgery. There remains no consensus on which modalities are superior. This retrospective, single-center cohort study directly compares sodium fluorescein (SF) and intraoperative ultrasonography (IOUS) as intraoperative imaging modalities in a sample of patients with glioblastoma isocitrate dehydrogenase 1 wildtype (GBM). Adult patients with GBM who underwent surgical resection using SF or IOUS guidance between 2010 and 2020 were included. Primary outcomes included extent of resection (EOR), post-operative residual tumor volume, gross total resection (GTR) rate, false negative assessments, and the incidence of new post-operative neurologic deficits. Additionally, pre-and post-test probabilities were calculated to assess each modality's ability to identify residual tumor. 98 patients met inclusion criteria (34 SF and 64 IOUS). Mean EOR was significantly higher for SF (94 +/- 11 %) when compared to IOUS (87 +/- 20 %; p = 0.032). Mean post-operative residual tumor was significantly higher for IOUS (197 +/- 358 mm2) when compared to SF (81 +/- 161mm2; p = 0.038). GTR was more frequent with SF (62 % vs 46 %, p = 0.12). False negative assessments for residual tumor were more common with IOUS (22 % vs 15 %, p = 0.53). One patient in each group suffered a new neurologic deficit post-operatively (p = 0.58). Sensitivity, specificity, positive predictive value, and negative predictive value were 62 %, 100 %, 100 %, and 81 % for SF and 59 %, 100 %, 100 %, and 67 % for IOUS, respectively. Taken together, SF may be superior to IOUS in maximizing EOR in patients with GBM, however, both modalities appear to have good efficacy.