Preoperative PET/CT (18)F-FDG Standardized Uptake by Lymph Nodes as a Significant Prognostic Factor in Patients with Colorectal Cancer

PURPOSE: We evaluated the prognostic value of preoperative (18)F-FDG uptake by suspected lymph nodes (LNs) using (18)F-FDG PET/CT in colorectal cancer patients. METHODS: Patients with CRC underwent (18)F-FDG PET/CT before radical surgery. We used Cox proportional hazards regression to examine the relationship between recurrence and the (18)F-FDG maximum standardized uptake value (SUVmax) in the suspected LNs (SUV(LN)) on (18)F-FDG PET/CT. RESULTS: Clinical data, treatment modalities, and results from 90 CR C patients were reviewed. The median follow-up was 19 months (range 3 to 72 months). Receiver operating characteristic analysis identified SUV(LN) 1.15 was the optimal cut-off value for predicting recurrence. SUV(LN) correlated with tumour size (P=0.045), lymph node metastasis (P=0.03), and recurrence (P < 0.0001). Univariate analysis showed significant associations between recurrence and SUV(LN) (P=0.017), and tumour grade (P=0.013). Multivariate analysis identified SUV(LN) (P < 0.0001), and tumour grade (P=0.005) as independent risk factors for recurrence. Patients with SUV(LN) ≤ 1.15 and SUV(LN) > 0.15 differed significantly in terms of recurrence (P < 0.0001). CONCLUSION: Preoperative SUV(LN) measured by (18)F-FDG PET/CT was significantly associated with recurrence and had significant prognostic value for recurrence-free survival in patients with colorectal cancer.