The Impact of F-FDG PET/CT and Related Parameters on Staging, Disease Management and Prognosis in Patients with Cholangiocarcinoma.

OBJECTIVES

We aimed to evaluate the relationship of Fluorine-fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) parameters with diagnostic efficacy, disease management and prognosis in patients with cholangiocarcinoma (CCA). The prognostic value of the spleen/liver F-FDG uptake ratio was also investigated.

METHODS

The clinical and imaging findings of 39 patients who met the diagnostic criteria and underwent F-FDG PET/CT imaging for staging between 2013 and 2023 were retrospectively analysed.

RESULTS

The tumour was intrahepatic in 34 patients and extrahepatic in 5 patients. PET/CT detected nodal involvement in 21 patients (53.8%) and distant metastases in 35 patients (89.7%). Fourteen cases (35.9%) had regional-distant metastases detected by PET/CT but not by magnetic resonance imaging/CT, and the stage of the disease changed accordingly. SUV, SUV, metabolic tumor volume, tumour lesion glycolysis, tumor-to-liver ratio (tumour/liver parenchyma SUV), tumor-to-background ratio (tumour/blood pool SUV), tumor-stroma ratio (tumour/spleen parenchyma SUV), and standardized liver ratio (SLR) (spleen/liver SUV) did not differ based on tumour location. Recurrence occurred in 14 patients (35.9%), and 2 patients survived. When the cut-off values for the parameters were determined by the Youden index, progression-free survival (PFS) was significantly shorter in patients with an SLR value of less than 0.94 compared to the others (p=0.04). Nodal involvement, metastatic location, and other PET/CT parameters had no significant effect on PFS and overall survival.

CONCLUSION

Our results highlight the efficacy of F-FDG PET/CT in staging nodal and distant metastases, similar to several studies in patients with CCA. Although SLR was found to have significant efficacy in PFS among the parameters we analysed, it is appropriate to evaluate the prognostic significance of these parameters in larger patient groups.