gms | German Medical Science

Objective: Available data implies that gross total resection (GTR) improves progression free survival (PFS) in patients harboring a low-grade glioma (LGG). Intraoperative high-field magnetic resonance imaging (iMRI) is an established diagnostic tool that can detect residual tumor in LGG surgery. Yet, at time of writing, a direct comparison of iMRI and conventional surgery for LGG has not been published to best of our knowledge. Thus, we conducted a retrospective study to evaluate the extend of resection and clinical outcome in conventional and iMRI based LGG.

Method: A total of 83 patients were assessed. We compared two cohorts: 45 patients who had surgery using iMRI (2008-2013) and a historical cohort of 38 patients, who underwent surgery before introduction of iMRI at our center (2000-2008) Demographic data, EOR, complication rate and overall time of surgery were evaluated at first follow-up after 3 month.

Results: The majority of patients were treated for a diffuse astrocytoma in both cohorts (iMRI: 42%, conv.: 35%). Approximately one third of tumors were located in eloquent areas in both groups (iMRI: 31%, conv.: 34%). New neurological deficits after surgery were found in 11.1% (N=5) of iMRI group and in 26.3% (N=10) of conventional group. Time of surgery was significantly longer in the iMRI group (iMRI: 6.24 hours, conv.: 4.37 hours, p < 0.036). However, there was no significant increase of postoperative surgical complications. GTR was achieved in 68.9% (N=31) of iMRI patients while in the conventional group GTR rate was only 47.4% (N=18, p < 0.045).

Conclusions: Gross total resection rate was significantly higher using iMRI. Additionally, we have found fewer cases of new postoperative deficits in ioMRI group. Surgical time was significantly longer with iMRI which did not increase complication rates. Thus, from our data, patients with LGG did benefit from the introduction of iMRI. However, prospective trials have to be conducted whether this influences PFS.