Temporal muscle measurements as predictor for outcome in a cohort of IDH-wildtype glioblastoma patients

Purpose. Temporal muscle thickness has been suggested as an independent prognostic marker for glioblastoma patient outcome. Various cohort studies show however conflicting results. This study therefore aims to reevaluate the prognostic value of different types of temporal muscle measurements in glioblastoma patients. Methods. A retrospective cohort study was performed including 137 patients diagnosed with IDH-wildtype glioblastoma. Temporal muscle thickness (TMT) and volume (TMV) were measured on preoperative MR-imaging. Next, these measurements were thereafter used in a multivariate Cox survival analysis to identify their possible prognostic value. These results were compared to the literature after systematic review of the Medline database. Results. TMT has a moderate to strong linear correlation with total muscle volume (Pearson r = 0,6; P < 0,001). Glioblastoma patients “at risk for sarcopenia” show similar outcome compared to controls (median overall survival time: 13 months vs 11 months; P = 0,775). In a covariate Cox regression model, none of the temporal muscle measurements (TMT, TMV or sex-specific cut-off points) showed prognostic value for outcome in glioblastoma patients. Conclusion. Temporal muscle measurements show no independent relation to clinical outcome in IDH-wildtype glioblastoma patients. There seems adequate linear correlation of temporal muscle thickness and overall muscle volume. The literature on temporal muscle measurements was found to be severely flawed and should be interpreted with caution.