Using The L3 Skeletal Muscle Index To Evaluate The Nutritional Status And Prognosis Of Patients With Oral Squamous Cell Carcinoma

ObjectivesIn recent years,the Skeletal Muscle Index of the Third Lumbar Vertebra(L3 SMI)has been used as a new and effective nutritional assessment Index.However,patients with head and neck carcinoma often lack of images of lumbar skeletal muscle.Therefore,L3 SMI cannot be directly used to evaluate the nutritional status in those patients.The Cross-Sectional Area of the Third Cervical Vertebra(C3 CSA)can be easily obtained by head and neck CT and MRI that patients with head and neck carcinoma usually performed.And it was reported that C3 CSA may be closely correlated with L3 CSA.Therefore,this study aims to explore the correlation between C3 CSA and L3 CSA,so as to construct a prediction formula and screen out the diagnostic threshold of L3 SMI.This study provides a new idea for the nutritional status assessment of OSCC patients and a new basis for the prognosis judgment in OSCC.Materials and MethodsA retrospective analysis was performed on 220 OSCC patients admitted to Southern Medical University Nanfang Hospital from April 2012 to June 2020.Patients were divided into two groups:the training set(n=100)and the validation set(n=120).Patients in the training set were performed the preoperative whole-body positron emission tomography/computed tomography(PET/CT)scans,and patients in the validation set received preoperative head-and-neck computed tomography(CT)scans before the radical resection.C3 CSA and L3 CSA were delineated in CT images respectively.The predictive formula was established by regression of training set data.L3 CSA was corrected by height to obtain the L3 SMI(cm2/m2),and X-tile software was used to screen the threshold with gender specificity for diagnosis of malnutrition.Finally,the formula and cutoff values were validated combined with clinical parameters.ResultsThe predictive formula was successfully established as follows:L3 CSA(cm2)=-6.310+1.845 × C3 CSA(cm2)+1.101 × Weight(kg)+4.923 × Gender(gender value:female=-1,male=1).The gender-specific cutoff values for L3 SMI were 55.0 cm2/m2 for men and 36.6 cm2/m2 for women.There were no differences between the overall survival(OS)of patients diagnosed with malnutrition and that of patients who are not malnutrition.ConclusionsC3 CSA is closely related to L3 CSA in OSCC,which can be used to assess the nutritional status quickly.Malnutrition is not an independent predictor of overall survival in OSCC.