Application of 18F-FDG PET/CT metabolic parameters in the prediction of perineural invasion in non-metastatic rectal cancer / 中华核医学与分子影像杂志

ABSTRACT

Objective:To investigate the value of 18F-FDG PET/CT metabolic parameters in predicting perineural invasion (PNI) in patients with non-metastatic rectal cancer. Methods:From August 2012 to April 2020, 81 patients (51 males, 30 females, median age 63 years) who received PET/CT examination and pathologically confirmed as rectal cancer in the Affiliated Hospital of Qingdao University were retrospectively analyzed. The 18F-FDG PET/CT metabolic parameters including SUV max, metabolic tumor volume (MTV) and total lesion glycolysis (TLG), and clinicopathological factors including gender, age, carcinoembryonic antigen (CEA), carbohydrate antigen (CA)19-9, maximum tumor diameter, degree of differentiation, T stage, lymph node metastasis, and TNM stage were recorded. Mann-Whitney U test and χ2 test were used to compare the differences of each parameter between PNI positive group and PNI negative group. Multivariate logistic regression was used to analyze the independent predictor of positive PNI. ROC curve was used to analyze its predictive efficacy. Results:Of 81 patients, 32(39.51%) were PNI positive and 49(60.49%) were PNI negative. There were significant differences of T stage ( χ2=10.73, P=0.010), lymph node metastasis ( χ2=6.21, P=0.013), TNM stage ( χ2=7.61, P=0.022), MTV (14.6(10.4, 24.7)and 9.0(5.4, 14.5) cm 3; U=-3.48, P=0.001) and TLG (108.588(72.749, 182.707) and 65.365(35.593, 117.682) g; U=-2.79, P=0.005) between PNI positive group and PNI negative group. Multivariate logistic regression analysis showed that MTV was the independent predictor of positive PNI in non-metastatic rectal cancer patients (odds ratio ( OR)=1.130, 95% CI 1.025-1.245, P=0.014). The optimal threshold of MTV was 9.53 cm 3 and AUC was 0.73 with the sensitivity of 81.82%(27/33) and the specificity of 59.18%(29/49). Conclusion:18F-FDG PET/CT metabolic parameter MTV can predict PNI in non-metastatic rectal cancer with high sensitivity.