Change in total lesion glycolysis and clinical outcome after 90Y radioembolization in intrahepatic cholangiocarcinoma

IntroductionOur aim was to assess the prognostic value of post-treatment decrease in total lesion glycolysis (ΔTLG) assessed by 2-[18 F]-fluorodeoxyglucose ([18 F] FDG) PET-CT performed 6 weeks after 90Y radioembolization (90Y RE) in patients affected by intrahepatic cholangiocarcinoma (ICC).MethodsA total of 18 patients were accepted into our department for 90Y RE. Before the procedure, all patients underwent [18 F] FDG PET-CT, and total lesion glycolysis was calculated. Six weeks after 90Y administration, PET scan was performed, and ΔTLG was determined. Patients underwent follow up by imaging and laboratory at quarterly intervals until death or for at least 24 months from 90Y RE. Furthermore, subjects were divided in 2 groups (group 1: 6 weeks ΔTLG > 50%, group 2: ΔTLG < 50%). Kaplan–Meier method was used to achieve time to progression (TTP) and overall survival (OS) curves for each group. TTP and OS curves were compared to demonstrate eventual relevant differences between the 2 groups.ResultsSeventeen patients underwent 90Y RE, and one subject was considered ineligible. According to PET Response Criteria in Solid Tumors, partial response was found in 14 patients (82.4%), stable disease in 3 (17.6%). No patient showed complete metabolic response. The mean OS for all patients was 64.5 ± 5.0 weeks. Subjects with a ΔTLG > 50% and ΔTLG < 50% had a mean OS of 79.6 ± 3.6 and 43.1 ± 2.0 weeks, respectively (p < 0.001). TTP resulted of 28.9 ± 3.8 weeks for the whole cohort. Patients with ΔTLG > 50% had a significantly longer TTP (mean 36.9 ± 3.6 weeks) than those with ΔTLG < 50% (mean 13.7 ± 1.7 weeks, p =