Prognostic Significance of ¹⁸F-FDG PET/CT in Patients with Distal Bile Duct Cancer undergoing Curative Surgery

Objectives: As there were few previous studies with a small number of subjects (Anticancer Res 2015;6985-6992), we evaluated the prognostic significance of ¹⁸F-FDG PET/CT in patients with distal bile duct cancer undergoing curative surgery.

Methods: Subjects were 43 consecutive patients (M:F = 27:16; age, 28.1 ± 7.8 years) who underwent preoperative ¹⁸F-FDG PET/CT followed by curative surgical resection. As clinicopathological variables for predicting overall survival, age, sex, baseline serum CA19-9 level, pathological tumor size, pathological stage, pathological tumor grade, R0 resection, and adjuvant therapy were included. As PET/CT variables, the maximum standardized uptake value (SUV_max), average SUV (SUV_avg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumor were measured with the liver activity (2 cm³ rectangular volume of interest, SUV_avg + 2 sd) as a cutoff for the tumor segmentation. The Kaplan-Meyer method and Cox proportional hazards model were used for the survival analysis.

Results: During following up, death occurred in the 11 of 43 patients (25.6%). In univariate analysis, low SUV_max (≤ 2.9, p = 0.008), low SUV_avg (≤ 2.4, p = 0.036), and elevated serum CA19-9 level (>25 U/ml, p = 0.027) were significant predictors for poor overall survival. In multivariate analyses, both low SUV_max (HR = 0.251, 95% C.I. 0.071-0.886, p = 0.032) and elevated serum CA19-9 level (HR = 6.314, 95% C.I. 0.801-49.785, p = 0.080) were independent prognostic factors associated with poor overall survival.

Conclusion: The SUV_max of primary tumor measured by ¹⁸F-FDG PET/CT is an independent significant prognostic factor for overall survival in patients with distal bile duct cancer along with serum CA19-9 level. However, different results from a previous study warrant further large-sized study. Research Support: None.