Article
The benefit of an ultra-early postoperative MRI in low grade glioma surgery
Der Vorteil der ultra-frühen frühen postoperativen MRT-Bildgebung bei der Resektion niedriggradiger Gliome
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Published: | May 8, 2019 |
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Objective: Decision of adjuvant treatment in low grade glioma (LGG) is often based on the presence of residual tumor after surgery. However, differentiation of tumor remnants and surgically induced artifacts can be challenging. MRI imaging immediately after surgical resection might be more appropriate for the assessment of the extent of resection (EoR). The aim of our study was to perform a detailed volumetric analysis of patients recruited for the Log-Glio LGG registry at our department
Methods: The Log-Glio database of patients treated at our clinic from 2016 to 2018 was searched for patients >18 years, no recurrent surgery and diagnosis of LGG. 29 patients matched the inclusion criteria. Based on the study protocol, all patients received an intraoperative scan after complete tumor removal, an ultra-early postoperative scan after skin closure, and a routine early MRI within 48 hours and a late follow up MRI after 3 months. Detailed volumetric analyses of FLAIR and T2 abnormalities on ultra-early, early and late postoperative MRI scans were done using Brainlab iPlan 3.0. Demographic data and basic characteristics were analyzed as well. Wilcoxon test was used for the analysis.
Results: Most common gliomas were diffuse astrocytomas (48.3%) followed by oligodendrogliomas (34.5%). 48.3% of patients had WHO°II and 31% WHO°III glioma, mean age was 43 years. Males were more common (55.2%). Mutated IDH was identified in 68.2%. Ultra-early postoperative MRI was performed 20–60 minutes after skin closure and showed significantly lower FLAIR (p=0.003, mean=0.80 cm3vs 7.65 cm3) and T2 (p=0.001, mean=0.28 cm3vs 4.20 cm3) abnormalities compared to the early postoperative MRI (18–89 hours after surgery), while no significant difference was found between ultra-early and late postoperative FLAIR (p=0.687, mean=0.80 cm3vs 1.36 cm3) and T2 (p=0.959, mean=0.28 cm3vs 0.49 cm3) images. Simultaneously, significant differences were calculated between early and late postoperative T2 (p<0.001) and FLAIR (p=0.001) MRI scans. Ischemic lesions were seen in 4 patients (13.8%).
Conclusion: MRI performed 24 or 48 hours after the surgery overestimates tumor borders and shows false positive results. Potentially, a false stratification as high-risk patients may occur resulting in application of adjuvant treatment after surgery. Ultra-early postoperative MRI might be more appropriate for delineation of tumor remnants in LGGs.