The Value Of ¹⁸F-FDG PET/CT Imaging In The Colorectal Cancer

Objective:This study retrospectively analyzed the imaging and clinicopathological data of patients with colorectal cancer who underwent ¹⁸F-FDG PET/CT examination before operation to explore the relationship between ¹⁸F-FDG PET/CT metabolic parameters and clinicopathological characteristics and studied the role of ¹⁸F-FDG PET/CT in the prognosis of colorectal cancer through follow-up of these patients.Methods:?1?A retrospective analysis was made on 123 patients who underwent operation after ¹⁸F-FDG PET/CT examination in Tianjin Medical University Tumor Hospital from January 2014 to December 2018.All patients met the admission criteria and had complete imaging and clinicopathological data.The maximum standard uptake value?SUVmax?,metabolic tumor volume?MTV?and total lesion glycolysis?TLG?of primary lesion were measured by PET VCAR software.Mann-Whitney U nonparametric test and Kruskal-Wallis rank sum test were used to analyze the relationship between location,size,differentiation degree,TNM stage and other clinicopathological features of tumor and above metabolic parameters.The ability of metabolic parameters to predict regional lymph node metastasis was analyzed by ROC curve.?2?Patients with colorectal cancer from January 2014 to June 2018 were followed up.The neutrophil-to-lymphocyte ratio?NLR?,lymphocyte-to-monocyte?LMR?and platelet-to-lymphocyte ratio?PLR?were calculated using the absolute value of platelet,neutrophil,lymphocyte and monocyte from preoperative blood routine examination.90 patients with complete imaging,hematology,clinico-pathology and follow-up data were finally included.The best cut-off value of SUVmax,MTV,TLG,NLR,LMR and PLR in predicting disease progression were calculated by ROC curve.If the P value was more than 0.05 and the area under the curve was small,the median was selected as the corresponding cut-off value.Univariate COX regression analysis was carried out after the binary classification transformation of each parameter.Multivariate COX analysis was carried out by selecting the indicators with statistical significance.Kaplan-Meier survival analysis was used to study the relationship between indicators and the progression-free survival of patients with colorectal cancer after operation.Results:SUVmax,MTV and TLG of primary colorectal cancer increased with the increase of tumor size.MTV was related to N and M stage of colorectal cancer,while TLG was only related to M stage.ROC curve analysis showed that the sensitivity and specificity of MTV in predicting regional lymph node metastasis were 76.2%and45.0%respectively.The cut-off values of MTV,TLG and NLR were 10.73,155.48and 2.13 respectively?P<0.05?,while the median values of SUVmax,LMR and PLR were 14.96,4.43 and 149.43 respectively because P values were more than0.05.Univariate COX regression analysis showed that gender,N stage,M stage,MTV,TLG,NLR,LMR,CEA and CA199 were associated with progression-free survival after colorectal cancer surgery.Multivariate COX regression analysis showed that M stage,MTV and CEA were independent risk factors for the prognosis of colorectal cancer.Kaplan-Meier survival analysis showed that the progression-free survival of patients with distant metastasis was significantly shorter than patients without metastasis.The progression-free survival of patients with primary MTV?10.73 was significantly longer than that of patients with MTV>10.73 and patients with CEA?5 was significantly longer than that of patients with CEA>5.Conclusion:?1?SUVmax,MTV and TLG of primary colorectal cancer patients were all related to the length of tumor.In addition,MTV was related to the N and M stage of the tumor,and TLG was related to the M stage of the tumor.The sensitivity and specificity of MTV in predicting regional lymph node metastasis patients were 76.2%and 45.0%respectively.?2?Gender,N stage,M stage,MTV,TLG,hematological parameters NLR,LMR,CEA and CA199 were the influencing factors of progression-free survival in patients with colorectal cancer.M stage,MTV and CEA were independent risk factors affecting the prognosis of patients with colorectal cancer.Colorectal cancer patients without distant metastasis had longer progression-free survival than those with distant metastasis,patitents with MTV?10.73 had longer progression-free survival than those with MTV>10.73 and patients with CEA?5 had longer progression-free survival than those with CEA>5.