Introduction: The aim of glioblastoma surgery is to maximize the extent of resection, while preserving functional integrity. Standards are lacking for surgical decision-making and consequently surgical strategies may differ between neurosurgical teams. In this study we quantitated and compared surgical decision-making throughout the brain between neurosurgical teams for patients with a glioblastoma using probability maps.
Methods: All adults with first-time glioblastoma surgery in 2012-2013 from ten tertiary referral centres for neuro-oncological care were included in this study. For each patient, pre- and postoperative tumor were manually segmented on MRI and aligned to standard brain space. Resection probability maps and biopsy probability maps were constructed in 1 mm resolution for each team's cohort. Brain regions with differential biopsy and resection results between teams were identified.
Results: The study cohort consisted of 931 patients of whom 293 received a biopsy and 638 a resection. Biopsy probability maps demonstrated differences between teams in biopsy rate per brain location, such as for the left precuneus and superior parietal lobule, indicating variation in biopsy decisions (Fig1). Resection probability maps demonstrated differences between teams in residual tumor rate per brain location, such as for the left saggital striatum and neighboring posterior corpus callosum, indicating variation in resection decisions (Fig2).
Conclusions: Biopsy and resection probability maps indicate treatment variation between teams for patients with a glioblastoma. This conveys useful objective arguments for quality of care discussions between surgical teams for these patients.
Patient Care: In this study we present for the first time that surgical decision-making in glioblastoma can be quantitated and compared between surgical teams using a new volumetric MRI analysis. We identified variation in biopsy and resection decisions. These biopsy and resection probability maps therefore convey useful objective information for quality of care discussions between surgical teams. This standardization of quality assessment could improve decision-making in glioma surgery and ultimately improve quality of care for the individual patient with a glioblastoma.
Learning Objectives: By the conclusion of this session, participants should be able to 1) acknowledge that treatment variation occurs in surgical-decision making for patients with a glioblastoma and this might lead to differential results; 2) understand that these treatment results can be made explicit using probability maps of tumor and residual tumor; 3) use this new knowledge for self-evaluation and quality of care discussions with other surgical teams, which could improve future decision-making.