Validation of skeletal muscle mass assessment at the level of the third cervical vertebra in patients with head and neck cancer

S.I Bril,N Chargi,A.W Wendrich,I Wegner,G.H Bol,E.J Smid,P.A De Jong,L.A Devriese,R De Bree

doi:10.1016/j.oraloncology.2021.105617

Abstract

BackgroundLow skeletal muscle mass (SMM) is associated with adverse outcomes. SMM is often assessed at the third lumbar vertebra (L3) on abdominal imaging. Abdominal imaging is not routinely performed in patients with head and neck cancer (HNC). We aim to validate SMM measurement at the level of the third cervical vertebra (C3) on head and neck imaging. Material and methodsPatients with pre-treatment whole-body computed tomography (CT) between 2010 and 2018 were included. Cross-sectional muscle area (CSMA) was manually delineated at the level of C3 and L3. Correlation coefficients and intraclass correlation coefficients (ICCs) were calculated. Cohen’s kappa was used to assess the reliability of identifying a patient with low SMM. ResultsTwo hundred patients were included. Correlation between CSMA at the level of C3 and L3 was good (r = 0.75, p < 0.01). Using a multivariate formula to estimate CSMA at L3, including gender, age, and weight, correlation improved (r = 0.82, p < 0.01). The agreement between estimated and actual CSMA at L3 was good (ICC 0.78, p < 0.01). There was moderate agreement in the identification of patients with low SMM based on the estimated lumbar skeletal muscle mass index (LSMI) and actual LSMI (Cohen’s κ: 0.57, 95%CI 0.45–0.69). ConclusionsCSMA at C3 correlates well with CSMA at L3. There is moderate agreement in the identification of patients with low SMM based on the estimated lumbar SMI (based on measurement at C3) and actual LSMI.

Highlights

Over the last decade, research into the specific body composition of cancer patients and its relationship with clinical outcomes has tremen dously increased due to the use of diagnostically performed imaging for quantification of different body compartments, including skeletal mus cle mass (SMM) and adipose tissue mass [1,2]
The cross-sectional skeletal muscle area (CSMA) at the level of L3 is most commonly normalized for stature, to calculate the lumbar skeletal muscle index [5]
Our current study shows that measurement of Cross-sectional muscle area (CSMA) at the level of C3 provides a good estimation of CSMA at the level of L3

Summary

Introduction

Research into the specific body composition of cancer patients and its relationship with clinical outcomes has tremen dously increased due to the use of diagnostically performed imaging for quantification of different body compartments, including skeletal mus cle mass (SMM) and adipose tissue mass [1,2]. In head and neck cancer (HNC), abdominal CT imaging is not commonly performed as part of the routine diagnostic work-up. A measurement method for SMM at the level of the third cervical vertebra (C3), which is featured on standard CT imaging of the head and neck area, was published by Swartz et al [7]. Abdominal imaging is not routinely performed in patients with head and neck cancer (HNC). There was moderate agreement in the identification of patients with low SMM based on the estimated lumbar skeletal muscle mass index (LSMI) and actual LSMI (Cohen’s κ: 0.57, 95%CI 0.45–0.69). There is moderate agreement in the identification of patients with low SMM based on the estimated lumbar SMI (based on measurement at C3) and actual LSMI

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Conclusion