-Original-

Intraoperative Low-Field Magnetic Resonance Imaging-Guided Tumor Resection in Glioma Surgery: Pros and Cons

Yu Fujii¹, Toshihiro Ogiwara¹, Gen Watanabe¹, Yoshiki Hanaoka¹, Tetsuya Goto², Kazuhiro Hongo^1,3 and Tetsuyoshi Horiuchi¹

¹Department of Neurosurgery, Shinshu University School of Medicine, Nagano, Japan
²Department of Neurosurgery, Saint Marianna University School of Medicine, Kanagawa, Japan
³Department of Neurosurgery, Ina Central Hospital, Nagano, Japan

Background: Intraoperative magnetic resonance imaging (MRI) is useful for identifying residual tumors during surgery. It can improve the resection rate; however, complications related to prolonged operating time may be increased. We assessed the advantages and disadvantages of using low-field intraoperative MRI and compared them with non-use of iMRI during glioma surgery.
Methods: The study included 22 consecutive patients who underwent total tumor resection at Shinshu University Hospital between September 2017 and October 2020. Patients were divided into two groups (before and after introducing 0.4-T low-field open intraoperative MRI at the hospital). Patient demographics, gross total resection (GTR) rate, postoperative neurological deficits, need for reoperation, and operating time were compared between the groups.
Results: No significant differences were observed in patient demographics. While GTR of the tumor was achieved in 8/11 cases (73%) with intraoperative MRI, 2/11 cases (18%) of the control group achieved GTR (p=0.033). Seven patients had transient neurological deficits: 3 in the intraoperative MRI group and 4 in the control group, without significant differences between groups. There was no unintended reoperation in the intraoperative MRI group, except for one case in the control group. Mean operating time (465.8 vs. 483.6 minutes for the intraoperative MRI and control groups, respectively) did not differ.
Conclusions: Low-field intraoperative MRI improves the GTR rate and reduces unintentional reoperation incidence compared to the conventional technique. Our findings showed no operating time prolongation in the MRI group despite intraoperative imaging, which considered that intraoperative MRI helped reduce decision-making time and procedural hesitation during surgery.

J Nippon Med Sch 2022; 89: 269-276

Keywords
glioma, gross total resection, intraoperative MRI, residual tumors

Correspondence to
Toshihiro Ogiwara, MD, Department of Neurosurgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
togiwara@shinshu-u.ac.jp

Received, April 30, 2021
Accepted, August 4, 2021