Beneficial impact of high-field intraoperative magnetic resonance imaging on the efficacy of pediatric low-grade glioma surgery

Abstract

<jats:sec> <jats:title>OBJECTIVE</jats:title> <jats:p>Intraoperative MRI (iMRI) is assumed to safely improve the extent of resection (EOR) in patients with gliomas. This study focuses on advantages of this imaging technology in elective low-grade glioma (LGG) surgery in pediatric patients.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>The surgical results of conventional and 1.5-T iMRI-guided elective LGG surgery in pediatric patients were retrospectively compared. Tumor volumes, general clinical data, EOR according to reference radiology assessment, and progression-free survival (PFS) were analyzed.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>Sixty-five patients were included in the study, of whom 34 had undergone conventional surgery before the iMRI unit opened (pre-iMRI period) and 31 had undergone surgery with iMRI guidance (iMRI period). Perioperative data were comparable between the 2 cohorts, apart from larger preoperative tumor volumes in the pre-iMRI period, a difference without statistical significance, and (as expected) significantly longer surgeries in the iMRI group. According to 3-month postoperative MRI studies, an intended complete resection (CR) was achieved in 41% (12 of 29) of the patients in the pre-iMRI period and in 71% (17 of 24) of those in the iMRI period (p = 0.05). Of those cases in which the surgeon was postoperatively convinced that he had successfully achieved CR, this proved to be true in only 50% of cases in the pre-iMRI period but in 81% of cases in the iMRI period (p = 0.055). Residual tumor volumes on 3-month postoperative MRI were significantly smaller in the iMRI cohort (p &lt; 0.03). By continuing the resection of residual tumor after the intraoperative scan (when the surgeon assumed that he had achieved CR), the rate of CR was increased from 30% at the time of the scan to 85% at the 3-month postoperative MRI.</jats:p> <jats:p>The mean follow-up for the entire study cohort was 36.9 months (3–79 months). Progression-free survival after surgery was noticeably better for the entire iMRI cohort and in iMRI patients with postoperatively assumed CR, but did not quite reach statistical significance. Moreover, PFS was highly significantly better in patients with CRs than in those with incomplete resections (p &lt; 0.001).</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>Significantly better surgical results (CR) and PFS were achieved after using iMRI in patients in whom total resections were intended. Therefore, the use of high-field iMRI is strongly recommended for electively planned LGG resections in pediatric patients.</jats:p></jats:sec>

Intraoperative MRI-guided Resection in Pediatric Brain Tumor Surgery: A Meta-analysis of Extent of Resection and Safety Outcomes

“…Analysis of the rate of GTR of iMRI-guided resections of low-grade gliomas (WHO grades I and II) was performed. 19,24,26,29 The iMRI-guided rate of GTR in low-grade glioma surgery (WHO grades I and II) was 74.3% (35/47) in the included studies (95% CI: 61.1-85.5, p ¼ 0.76; ►Fig. 4).…”

“…All superficial (cutis and subcutis) and deep (abscess, subdural empyema, meningitis) wound infections after intracranial procedures were analyzed. 19,[23][24][25][26][27][28][29][30] All intracranial tumor resections as well as epilepsy and neurovascular surgery by craniotomy were analyzed with regard to SSI. The overall rate of SSI was 1.6% (6/482) of the analyzed studies (95% CI: 0.7-2.9; ►Fig.…”

Safeness and Utility of Concomitant Intraoperative Monitoring with Intraoperative Magnetic Resonance Imaging in Children: A Pilot Study

“…This takes up a special relevance in pediatric oncological neurosurgery. In the particular case of low-grade gliomas, children operated electively with ioMRI achieved a significant better surgical outcome and progression free survival, when a complete resection was aimed for [25].…”

High-resolution wide-field human brain tumor margin detection and in vivo murine neuroimaging

“…However, maximal safe resection is often limited by an inability to distinguish tumor from normal brain. To address this problem, a variety of intraoperative imaging modalities have been investigated, including magnetic resonance imaging (MRI) [12][13][14][15] , wide-field fluorescence 7 , highresolution fluorescence microscopy (confocal and multiphoton imaging) 16 , and optical coherence tomography (OCT) [17][18][19][20][21] .…”

“…Intraoperative MRI (iMRI) allows for the reliable identification of macroscopic residual tumor and has been shown to increase the extent of resection in glioma surgery 14,15,22,23 , however, iMRI has several limitations. iMRI systems are expensive and require the use of specialized non-ferromagnetic surgical equipment.…”