Predicting Clinical Success of CT-based Functional Drained Liver Volume Assessment in Malignant Biliary Obstruction

Purpose To compare the predictive accuracy of subjective versus objective assessment of three-dimensional functional drained liver volume (fDLV) for clinical success after percutaneous transhepatic biliary drainage (PTBD). Materials and Methods This retrospective study included patients with malignant biliary obstruction and hyperbilirubinemia who underwent de novo PTBD between January 2016 and February 2017. Clinical success was defined as achieving total bilirubin level less than 1.8 mg/dL (30.8 μmol/L) within 30 days after PTBD. Seven interventional radiologists independently categorized subjective fDLV into four groups: less than 30%, 30%-50%, 51%-75%, and greater than 75% of the total liver volume. Objective fDLV was calculated using imaging software and expressed as volume, percentage, and categorical groups. Interobserver agreement was assessed using the intraclass correlation coefficient (ICC). Predictive accuracy was analyzed via univariate and multivariate logistic regression and receiver operating characteristic curves. Results This study included 35 consecutive patients (median [IQR], 66 years [57, 71]; 23 men). Clinical success was achieved in 17 of 35 patients (49%). Interobserver agreement for subjective fDLV was low (ICC, 0.29 [95% CI: 0.12, 0.48]). Objective fDLV expressed as volume (odds ratio [OR], 1.34 [95% CI: 1.13, 1.70]; P = .004), percentage (OR, 1.06 [95% CI: 1.02, 1.10]; P = .002), and category (OR, 3.46 [95% CI: 1.64, 9.68]; P = .005) were associated with clinical success; subjective consensus category was not (OR, 2.08 [95% CI: 0.94, 4.99]; P = .081). Objective fDLV percentage demonstrated higher predictive accuracy (area under the receiver operating characteristic curve [AUC], 0.84 [95% CI: 0.69, 0.99]) than individual subjective estimates (AUC range, 0.56-0.74) and group consensus (AUC, 0.67 [95% CI: 0.49, 0.84]). A threshold of at least 76.1% objective fDLV yielded a sensitivity of 88% and specificity of 83% and remained independently associated with clinical success (OR, 1.10; P = .013). Conclusion Objective fDLV assessment outperformed subjective evaluation and more accurately helped predict short-term clinical success after PTBD. Keywords: Percutaneous Transhepatic Biliary Drainage, Functional Drained Liver Volume, Hyperbilirubinemia, Malignant Biliary Obstruction, Objective Measurement © RSNA, 2025.