Preoperative Assessment of Perceived Glioma Resectability between International Experts

This is the authors' abstract. We don't add key points for this paper.

Tumor resection is a prerequisite in many studies of new glioblastoma therapeutics; however, no clear parameters for "resectability" exist.We evaluated inter-rater variability in assessing tumor resectability and potential associations between resectability and survival in a clinical trial cohort of glioblastoma recurrence.Methods: DIRECTOR (NCT00941460; 9/2009-6/2012) evaluated two dosedense temozolomide regimens for first recurrent glioblastoma, yielding similar outcomes between arms.Re-resection was allowed before initiation of systemic therapy by institutional decision.Eleven surgical neuro-oncologists (blinded to final outcomes) rated whether a 'meaningful resection' was achievable for each recurrent IDH-wildtype glioblastoma based on imaging and clinical data.Results: MRI scans from 69 patients were available (median age:58.2±1.1 years, median survival:10.0months).40 patients underwent re-resection (median age:56.4±1.7 years, median survival:10.8months).Surgical decisionmaking markedly varied between raters, ranging from 30-58 of 69 cases being classified as 'resectable' (κ=0.405).In patients who received re-resection, a 'meaningful resection' was deemed feasible by >80% of raters in 30/40 cases (75.0%).For patients without re-resection, unanimous agreement on nonresectability occurred in only 3/29 cases (10.4%); and 5/29 tumors (17.2%) were considered resectable by >80% of raters.Knowledge of additional clinical factors virtually never changed MRI-based judgments.While patients who had a complete resection of contrast-enhancing tumor had favorable outcomes, a consensus on resectability by >80% of the raters was not associated with prolonged overall survival (11.9vs.9.1 months, p=0.326).Conclusions: Feasibility assessment for re-resection is heterogenous among neurosurgeons, challenging single-surgeon evaluation of "resectability" for trials.Efforts to develop selection criteria for re-resections should be intensified.