Elevated Lung Shunt Fraction as a Prognostic Indicator for Disease Progression and Metastasis in Hepatocellular Carcinoma

Abstract

Purpose To evaluate lung shunt fraction (LSF) as an early predictor for local disease progression or the development of metastatic disease. Materials and Methods Retrospective analysis was performed on 52 patients with hepatocellular carcinoma who underwent preradioembolization assessment, including the calculation of LSF. Comparison of preprocedural and postprocedural surveillance imaging was performed. Mean patient age was 67 years (range, 50-88 y), with a mean surveillance of 245 days (range, 24-871 d). Statistical analysis was conducted to assess the relationship between LSF and local disease progression or development of new metastatic disease. Results In patients in whom metastatic disease developed during routine surveillance, the mean LSF was almost double that in patients in whom no metastasis developed (18.3% vs 9.3%; P =.001). Patients with elevated LSFs were also more likely to show intrahepatic disease progression (15.6% vs 8.5%; P =.003). LSFs < 8% corresponded to negative predictive values of 74% for local disease progression and 95% for development of metastasis, signaling a better prognosis. Of pretreatment variables examined (age, sex, previous treatment with disease progression, lesion size, lesion number, LSF, α-fetoprotein level, and portal vein thrombus), only LSF was an independent predictor for new metastasis (odds ratio [OR] = 1.2; P =.01). LSF (OR = 1.2; P =.03) and progression after previous treatment (OR = 4.7; P =.04) were independent predictors for local progression. Conclusions As local disease progression and metastatic disease were more likely to occur in patients with elevated LSFs, LSF may be the most sensitive predictor for local disease progression and new metastatic disease.