The prognostic utility of temporalis muscle thickness measured on magnetic resonance scans in patients with intra-axial malignant brain tumours: A systematic review and meta-analysis

Abstract

Introduction: Sarcopenia is associated with worsened outcomes in solid cancers. Temporalis muscle thickness (TMT) has emerged as a measure of sarcopenia. Hence, this study aims to evaluate the relationship between TMT and outcome measures in patients with malignant intra-axial neoplasms.

Method: We searched Medline, Embase, Scopus and Cochrane databases for relevant studies. Event ratios with 95% confidence intervals (CI) were analysed using the RevMan 5.4 software. Where meta-analysis was impossible, vote counting was used to determine the effect of TMT on outcomes. The GRADE framework was used to determine the certainty of the evidence.

Results: Four outcomes were reported for three conditions across 17 studies involving 4430 patients. Glioblastoma: thicker TMT was protective for overall survival (OS) (HR 0.59; 95% CI 0.46-0.76) (GRADE low), progression free survival (PFS) (HR 0.40; 95% CI 0.26-0.62) (GRADE high), and early discontinuation of treatment (OR 0.408; 95% CI 0.168-0.989) (GRADE high); no association with complications (HR 0.82; 95% CI 0.60-1.10) (GRADE low). Brain Metastases: thicker TMT was protective for OS (HR 0.73; 95% CI 0.67-0.78) (GRADE moderate); no association with PFS (GRADE low). Primary CNS Lymphoma: TMT was protective for overall survival (HR 0.34; 95% CI 0.19-0.60) (GRADE moderate) and progression free survival (HR 0.23; 95% CI 0.09-0.56) (GRADE high).

Conclusion: TMT has significant prognostic potential in intra-axial malignant neoplasms, showing a moderate to high certainty for its association with outcomes following GRADE evaluation. This will enable shared decision making between patients and clinicians.

Keywords: Brain metastases; Glioblastoma (GBM); Primary CNS lymphoma; Prognosis; Sarcopenia; Temporalis muscle thickness (TMT).

Fig. 1

Quality assessment of each full text article for inclusion using the Quality in Prognosis Studies (QUIPS) tool. Orange circle = moderate risk of bias, green circle = low risk of bias. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

The flowchart of the selection process of studies according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA).

Fig. 3a

Harvest plot showing the association between thicker TMT and Outcomes in Glioblastoma. Fig. 3b: Harvest plot showing the association between thicker TMT and Outcomes in Brain Metastasis. Fig. 3c: Harvest plot showing the association between thicker TMT and Outcomes in Primary CNS Lymphoma.

Fig. 4a

Forest plot of included studies evaluating the association between TMT and Overall Survival in Glioblastoma. Fig. 4b: Forest plot of included studies evaluating the association between TMT and Progression Free Survival in Glioblastoma. Fig. 4c: Forest plot of included studies evaluating the association between TMT and Overall Survival in Brain Metastases. Fig. 4d: Forest plot of included studies evaluating the association between TMT and Overall Survival in Primary CNS Lymphoma.