Prognostic Value of Intratumor Metabolic Heterogeneity Parameters on <sup>18</sup>F‐FDG PET/CT for Patients with Colorectal Cancer
Xin Liu, Kun Xiang, Guang-Yong Geng, Shi‐Cun Wang, Ming Ni, Yifan Zhang, Hai‐Feng Pan, Weifu Lv
Abstract
Purpose . Intratumor metabolic heterogeneity parameters on 18 F‐2‐fluoro‐2‐deoxy‐D‐glucose ( 18 F‐FDG) positron emission tomography‐computed tomography (PET‐CT) have been proven to be predictors of the clinical prognosis of cancer patients. The study aimed to examine the correlation between 18 F‐FDG PET‐CT‐defined heterogeneity parameters and the prognostic significance in patients with colorectal cancer. Methods . The study included 188 patients with colorectal cancer who received surgery and 18 F‐FDG PET/CT examinations. Preoperative 18 F‐FDG PET/CT conventional and metabolic heterogeneity parameters were collected, including maximum, peak, and mean standardized uptake value (SUVmax, SUVpeak, and SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), heterogeneity index‐1 (HI‐1) and heterogeneity index‐2 (HI‐2), and clinicopathological information. Correlations between these parameters and patient survival outcomes were inferred. Results . The associations between 18 F‐FDG PET/CT parameters and clinical outcomes were analyzed. Tumor thrombus ( P < 0.001), tumor stage ( P = 0.001), MTV ( P = 0.003), HI‐1 ( P = 0.032), and HI‐2 ( P = 0.001) differed between the two groups with and without recurrence. Multivariate analysis showed that, in the radical surgery group, HI‐2 (HR = 1.10, 95% CI: 1.04–1.17, P = 0.001), tumor stage (HR = 20.65, 95% CI: 4.81–88.62, P < 0.001), and regional lymph nodes status (HR = 0.16, 95% CI: 0.04–0.57, P = 0.005) were independent variables significantly correlated with progression‐free survival (PFS) and HI‐2 (HR = 1.16, 95% CI: 1.07–1.26, P < 0.001) was an independent variable affecting overall survival (OS). In the palliative surgery group, HI‐2 (HR = 1.03, 95% CI: 1.01–1.06, P = 0.020) was an independent variable affecting PFS, and all the parameters were not statistically significant for OS. Conclusion . HI‐2, tumor stage, and regional lymph nodes status might predict the outcomes of colorectal cancer more effectively than other 18 F‐FDG PET/CT defined parameters.