Abstract:

Objective

To investigate the correlation and consistency of computed tomography（CT） and bioelectrical impedance analysis （BIA） in the determination of skeletal muscle mass in presurgery patients with gastric cancer.

Methods

170 patients diagnosed as gastric cancer and treated with radical surgery from December 2022 to December 2023 in the Department of General Surgery of the Second Hospital of Lanzhou University were continuously enrolled， and their muscle mass was measured by CT and BIA respectively， the interval between the two checks should not exceed 1 month.According to the skeletal muscle mass index at the level of the third lumbar vertebra （L3-SMI）， they were divided into muscle mass reduction group and normal group， and the differences in general data and appendicular skeletal muscle mass index （ASMI） between the two groups were compared and stratified by gender and body mass index （BMI），for analysis of diagnosis relevance and consistency of the two methods.

Results

Among the 170 patients，there were 114 males （67.06%） and 56 females （32.94%） with an average age of （58.72±12.60） years.There were 70 cases （41.18%） of reduced muscle mass diagnosed by CT， and significant differences existed in L3-SMI， age， BMI and NRS2002 score， ASA， HU between the muscle mass reduction group and the normal group （P＜0.001）.80 patients （47.06%） were diagnosed with decreased muscle mass by BIA.There was no significant difference in the incidence of muscle mass reduction rate in the total population measured by the two instruments （χ²=1.913，P=0.275）.The correlation model between L3-SMI and ASMI， gender， BMI and age showed high liner correlation （R²=0.724， P＜0.001）.Stratified analysis showed a stronger correlation between the two measurements in the BMI range of ［18.5-24.0） kg/m² （R²=0.715， P＜0.05）.In male patients，the correlation between the two measures was stronger than that in female patients （R²=0.613， P＜0.05）.There was moderate consistency between the two measures （k=0.643， P＜0.001）.

Conclusion

There is good correlation between CT and BIA in the diagnosis of muscle mass loss in gastric cancer patients， especially in BMI ［18.5-24.0） kg/m² and male patients， while the two diagnostic results are moderately consistent， which may be related to the different influencing factors of measuring L3-SMI and ASMI.

Key words: Tomography, X-ray computed, Electric impedance, Stomach neoplasms, Appendicular sketal muscle mass, Sarcopenia