Abstract
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Objectives: Radioembolization (RE) using Yttrium-90-Resin microspheres is an emerging option for loco-regional treatment in patients suffering from non-resectable and chemotherapy-resistant intrahepatic cholangiocarcinoma (ICC). Aim of the current study was the development and implementation of a prognostic risk model to stratify patients who will most likely benefit from RE.
Methods: The retrospective study comprised of 33 patients (f 22; m 11; 61 [32-80] yrs) with ICC prior to RE (median activity 1.8 [0.4-2.5] GBq). Uni- and multivariate Cox regression as well as Kaplan-Meier (KM) analyses were conducted for clinical (ECOG performance status >1, extrahepatic metastasis, hepatic tumor burden, ascites), laboratory parameters (gamma-GT, AP, bilirubin, ALT, AST, albumin) and the necessity for dose-reduction (DR; 0, 20 and 40%) due to high hepato-pulmonary shunt fractions (>10 or 15%). The risk model combined variables with equal weights, based on Cox regression tests.
Results: Median overall survival (OS) after RE was 8 [1.3-33] months. 31 patients died. In univariate Cox regression analysis AP (p=0.018; Hazard Ratio [HR], 1.006 for one-unit increase), gamma-GT (p=0.011; HR, 1.002), ECOG >1 (p=0.047; HR, 3.76) and relative DR of 40% (p=0.007; HR, 5.65) were significant predictors of OS. A combined risk model of gamma-GT >750 U/l, AP >275 U/l and ECOG >1 subdivided the cohort into three groups according to their OS (Group I = 0 risk factors [RF], median OS 9.3 months; Groups II = 1 RF, 4.9 months; Group III 蠅 2 RF, 1.8 months; Figure 1). Median OS decreased dependent on the DR from 9.3 to 7.3 (DR of 20%) to 3.8 (DR of 40%) months, respectively.
Conclusion: In this explorative study, the combined prognostic risk model, based on gamma-GT, AP and ECOG performance status, identifies patients with ICC, which will most likely respond to RE. Notably, the indication for RE has to be scrutinized in patients with two or more risk factors. Research Support: No financial research support. $$graphic_5FBA5452-2FAD-4089-B42C-F823F53B14D0$$