Quantitative liver SPECT/CT is a novel tool to assess liver function, prognosis, and response to treatment in cirrhosis

BackgroundFunctional liver reserve is an important determinant of survival in cirrhosis. The traditional indocyanine green test (ICG) is cumbersome. Hence, we developed and validated a novel liver imaging, a hybrid of SPECT and CT (Q-SPECT/CT), for evaluating disease severity, outcomes, and response to treatment in decompensated cirrhosis (DC).MethodsWe recruited a cohort of DC patients at a tertiary institute between 2016–2019. First, we standardized the Q-SPECT/CT across a predefined range of volumes through phantom experiments. Then we performed clinical and laboratory evaluations, ICG test (retention at 15 min), and Q-SPECT/CT at baseline and 12 months of granulocyte colony-stimulating factor (G-CSF) and standard medical treatment (SMT).ResultsIn 109 DC patients, 87.1% males, aged 51 ± 10 years, MELD: 14 (7–21), the percent quantitative liver uptake (%QLU) on Q-SPECT/CT exhibited a strong correlation with CTP (r = −0.728, p < 0.001), MELD (r = −0.743; p < 0.001) and ICG-R-15 (r = −0.720, p < 0.001) at baseline. %QLU had the maximum discrimination (AUC: 0.890–0.920), sensitivity (88.9–90.3%), specificity (81.2–90.7%), and accuracy (85.8–89.4%) than liver volumes on Q-SPECT/CT or ICG test for classifying patients in CTP/MELD based prognostic categories. A significant increase in %QLU (26.09 ± 10.06 to 31.2 ± 12.19, p = 0.001) and improvement in CTP/MELD correlated with better survival of G-CSF treated DC patients (p < 0.05). SMT did not show any improvement in Q-SPECT/CT or clinical severity scores (p > 0.05). %QLU > 25 (adj.H.R.: 0.234, p = 0.003) and G-CSF treatment (adj.H.R.: 0.414, p = 0.009) were independent predictors of better 12-months survival in DC.ConclusionQ-SPECT/CT (%QLU) is a novel non-invasive, diagnostic, prognostic, and theragnostic marker of liver reserve and its functions in cirrhosis patients.Clinical trial registrationClinicaltrials.gov, NCT02451033 and NCT03415698.