The application of thoracic vertebral cross section skeletal muscle index in the diagnosis and prognosisof sarcopenia in patients with advanced gastric cancer
1.Department of Gastrointestinal Surgery, the Second Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, China; 2.Department of Gastrointestinal Surgery, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325027, China
JIANG Zhixuan,LU Yangbin,HUANG Jianqiang, et al. The application of thoracic vertebral cross section skeletal muscle index in the diagnosis and prognosisof sarcopenia in patients with advanced gastric cancer[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2023, 53(11): 868-874.
Abstract：Objective: To investigate the feasibility of diagnosing sarcopenia with the skeletal muscle index
(SMI) of thoracic vertebra section under computed tomography (CT), with a comparison of abdominal CT of third lumbar vertebra cross section (L3) for routine diagnosis of sarcopenia, and to analyze the influence of these indexes on postoperative survival of gastric cancer patients. Methods: A total of 1 096 patients with gastric cancer who underwent radical gastrectomy in the First Affiliated Hospital of Wenzhou Medical University from July 2014 to March 2019 were enrolled. Skeletal muscle areas (SMA) at the twelfth thoracic vertebra (T12) and L3 levels were measured on cross-sectional CT images, and SMI corresponding to the two levels and the skeletal muscle truncation corresponding to the diagnosis of sarcopenia at the T12 level were calculated. The correlation of two levels of CT image parameters and the predictive value of sarcopenia diagnosed at two levels for postoperative survival
of gastric cancer were analyzed. Results: The cut-off value of SMI at the T12 level (SMI-T12) for the diagnosis of sarcopenia was 29.2 cm2/m2 in male patients with gastric cancer and 25.3 cm2/m2 in female patients. Thesensitivity, specificity, and area under the curve corresponding to the cut-off value in male patients were 79.3%,77.0% and 0.858, respectively, and for females, it was 71.0%, 61.8% and 0.737 correspondingly. Of all gastric cancer patients, 167 cases (15.2%) were diagnosed with sarcopenia at the T12 level [sarcopenia-T12 (+)] and 154 cases (14.1%) at the L3 level [sarcopenia-L3 (+)], with no statistical significant difference in the detection rate between the two groups of patients (P=0.188). COX regression analysis showed that sarcopenia-T12 (+) was an independent risk factor for overall survival (HR=1.502, 95%CI=1.159-1.948, P=0.002). Multiple linear regression analysis showed that both sarcopenia-T12 (+) and sarcopenia-L3 (+) were significantly associated with prolonged postoperative hospital stay (P=0.002, P=0.020). Conclusion: SMI at the T12 level can be applied to the diagnosis of sarcopenia, which is an independent risk factor for postoperative survival in patients with gastric cancer.
