200 DWI and ADC Changes in Patients With Glioblastoma IDH-Wild Type Following Surgical Tumor Resection

INTRODUCTION: Current standard of care for glioblastoma (GBM) entails maximal tumor resection to achieve better outcomes while preserving neurological function. Early postoperative DWI has elucidated that peritumoral ischemia is common following glioma resection, but radiographic characteristics, risk factors, and outcomes have not been well described. METHODS: This retrospective cohort included 324 patients (18-86 years) who underwent surgical resection for glioblastoma IDH-wildtype between 2005 and 2022. All patients had structural MRI and DWI acquired preoperatively and within 72 hrs after resection. Areas of restricted diffusion on postoperative DWI were classified as rim, sector, mixed, or remote. RESULTS: Areas of restricted diffusion on postoperative DWI were found in 173 (53%) patients. 55 (32%) were rim-shaped, 103 (59%) sector-shaped, 10 (6%) mixed, and 5 (3%) remote. Preoperative tumor volume was positively correlated with areas of ischemia (p = 0.048), but peritumoral DWI was not correlated with decreased overall survival (OS) or Karnofsky Performance Score (KPS). In the full cohort analysis, gross total resection (GTR) correlated with improved OS compared to subtotal total resection (STR) (p = 0.016); however, subgroup analysis revealed that this survival benefit was exclusively found in patients without peritumoral infarction on DWI (21 months vs. 13 months, p = 0.043). CONCLUSIONS: Larger tumor volume was a risk factor for larger peritumoral infarction. The survival benefit of GTR was only seen in patients who did not experience postoperative peritumoral infarction, underscoring the importance of maximal safe tumor resection. Future study on specific causes of postoperative peritumoral infarctions may improve surgical management and outcomes in glioblastoma patients.