Predictive value of intratumoral heterogeneity measured by preoperative 18F-FDG PET/CT for regional lymph node metastasis of cN0 colorectal cancer / 中华核医学与分子影像杂志

ABSTRACT

Objective:To investigate whether the intratumoral heterogeneity measured by preoperative 18F-fluorodeoxyglucose (FDG) PET/CT could predict regional lymph node metastasis (LNM) in patients with clinical (c)N0 colorectal cancer. Methods:A total of 70 patients with cN0 colorectal cancer were consecutively enrolled from January 2012 to December 2019. All patients underwent 18F-FDG PET/CT followed by radical resection of colorectal cancer within one month. Whether the regional LNM existed was confirmed pathologically. Volume of interest (VOI) was drawn with the threshold of the standardized uptake value (SUV) of 2.5. The area under the cumulative SUV histograms curve (AUC-CSH) of the primary lesion was calculated by PMOD software, as well as the maximum SUV (SUV max), metabolic tumor volume (MTV) and total lesion glycolysis (TLG). Differences of AUC-CSH and metabolic parameters between groups were compared by using independent-sample t test and Mann-Whitney U test. Whether AUC-CSH was the independent predictor of regional LNM was analyzed with multivariate logistic regression model. The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of AUC-CSH. Results:Among 70 patients with cN0 colorectal cancer, 16(22.9%) patients were pathologically confirmed to have regional LNM. The AUC-CSH of metastasis group was significantly lower than that of non-metastasis group (0.372±0.089 vs 0.464±0.121; t=2.831, P=0.006). There were no significant differences in SUV max(21.0±9.6 vs 23.9±10.9), MTV (33.0(20.8, 50.2) vs 28.3(16.0, 47.1) cm 3) and TLG (203.3(117.2, 467.5) vs 184.5(105.6, 434.3) g) of the primary tumor between those two groups( t=0.980, U values 0.517, 0.028, all P>0.05). The multivariate logistic regression analysis showed AUC-CSH was the independent predictor of regional lymph node matastasis (odds ratios ( OR)=5.04, 95% CI 1.37-18.60, P=0.015). The ROC curve analysis showed the area under the curve of AUC-CSH was 0.73 (95% CI 0.59-0.86, P=0.006). When the cut-off value of AUC-CSH was 0.409, the sensitivity and specificity of predicting regional LNM was 12/16 and 66.7%(36/54), respectively. Conclusions:The intratumoral heterogeneity of primary tumor is strongly associated with regional LNM in cN0 colorectal cancer. AUC-CSH measured by preoperative 18F-FDG PET/CT has a potential in prediction of regional LNM in patients with cN0 colorectal cancer.