gms | German Medical Science

67th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Korean Neurosurgical Society (KNS)

German Society of Neurosurgery (DGNC)

12 - 15 June 2016, Frankfurt am Main

The value of intraoperative and early postoperative MRI in low-grade glioma surgery

Meeting Abstract

  • Andrej Pala - Department of Neurosurgery, University of Ulm, Günzburg, Germany
  • Michal Hlavac - Department of Neurosurgery, University of Ulm, Günzburg, Germany
  • Christian Rainer Wirtz - Department of Neurosurgery, University of Ulm, Günzburg, Germany
  • Ralph König - Department of Neurosurgery, University of Ulm, Günzburg, Germany
  • Jan Coburger - Department of Neurosurgery, University of Ulm, Günzburg, Germany

Deutsche Gesellschaft für Neurochirurgie. 67. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 1. Joint Meeting mit der Koreanischen Gesellschaft für Neurochirurgie (KNS). Frankfurt am Main, 12.-15.06.2016. Düsseldorf: German Medical Science GMS Publishing House; 2016. DocMI.22.03

doi: 10.3205/16dgnc372, urn:nbn:de:0183-16dgnc3722

Published: June 8, 2016

© 2016 Pala et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at



Objective: Early postoperative MRI (within 48 hours) is considered as reference imaging to assess the grade of resection or tumor remnants in neuro-oncology. There are hints, that in low grade gliomas (LGG) early postoperative MRI (FLAIR and T2) may overestimate residual tumor due to postoperative signal intensification. In a setting with routine use of intraoperative MRI (iMRI) the final iMRI scan without subsequent resection may assess the amount of residual tumor more adequately. To evaluate the utility of postoperative imaging in LGG we volumetrically analyzed intraoperative, early and late postoperative MRI (FLAIR and T2) in LGG.

Method: A total of 33 patients with LGG were assessed retrospectively. Residual tumor was defined as signal enhanced tissue in T2 and FLAIR. Volumetric assessment was performed using intraoperative, early and late (3 months) postoperative MRI (FLAIR and T2) of the same patient using Brainlab iPlan 3.0. Furthermore demographic data and complications were collected.

Results: A significant difference of FLAIR and T2 abnormalities was found in intraoperative (FLAIR mean volume=5,433cm3, T2 mean volume=3,374 cm3) and early postoperative MRI (FLAIR mean volume=14,090 cm3, p=0,028, T2 mean volume=7,597 cm3, p=0,030; Paired T-test). On the contrary, there was no significant difference between intraoperative and late postoperative FLAIR and T2 abnormalities 3 months after the surgery (late postoperative FLAIR and T2 mean volume=5,560 cm3 and 2,370 cm3, p=0,833, p=0,477). Moreover, significant difference was detected between early and late postoperative images (p=0,001, p=0,004). Recurrent tumor was treated in 12,1% (N=4). The most of the patients were treated for diffuse astrocytoma (45,5%, N=15). In 51,5% (N=17) cases additional resection after iMRI was necessary. In 12,1% (N=4) cases mild neurological deficit was persistent 3 months after surgery (3x quadtranaopia and 1 mild aphasia).

Conclusions: iMRI seems to reflect the actual volume of residual tumor in LGG more precisely compared to early postoperative MRI and therefore seems to be more useful regarding decisions for adjuvant therapy. Early postoperative MRI overestimates the amount of residual tumor. Therefore, in a setting with iMRI final imaging without subsequent resection or alternatively late postoperative MRI at 3 months should be considered as a reference to evaluate residual tumor in LGG.