Prediction of the wall-invasion pattern of advanced gallbladder carcinoma using extracellular volume fraction

TL;DR

This study shows that extracellular volume fraction can predict aggressive growth patterns in advanced gallbladder cancer, which may help guide treatment decisions.

Contribution

The study introduces extracellular volume fraction as a novel imaging biomarker for predicting gallbladder cancer invasion patterns.

Findings

ECV fraction was significantly higher in destructive growth type of gallbladder carcinoma.

ECV values showed strong diagnostic ability with high ROC curve areas.

Destructive growth type had significantly shorter recurrence-free survival.

Abstract

This study aimed to evaluate the utility of extracellular volume (ECV) fraction for predicting wall-invasion patterns in advanced gallbladder carcinoma (GBCA).

Patients who had surgically resected GBCA at a single institution were retrospectively evaluated. All patients underwent computed tomography (CT) before the surgery. Based on pathological examinations, the wall-invasion pattern of GBCA was classified into two groups: infiltrative growth (IG, n = 19) and destructive growth (DG, n = 11).

ECV map was generated by inputting the patients’ hematocrit values and subtraction algorithms using pre-contrast and equilibrium phase images. CT parameters were evaluated by two radiologists (Rad1 and Rad2). The Mann–Whitney U test was performed to identify significant CT parameters for differentiating between the two groups. The diagnostic ability was measured using receiver operating characteristic (ROC) curve analysis. Recurrence-free survival (RFS) was estimated using the Kaplan–Meier method, and differences between the two groups were compared using the log-rank test.

Thirty patients (mean age, 75.5 years; 20 men) were evaluated. Mean ECV fraction of the DG-type (Rad1, 34.5%; Rad2, 34.1%) was significantly higher than that of the IG-type (Rad1, 28.5%; Rad2, 28.8%) (p < 0.05). The ECV values of the two radiologists indicated that the areas under the ROC curves for differentiation between the two groups were Rad1, 0.91 and Rad2, 0.84 (p < 0.05). Medium RFS of the DG-type (970 days) was significantly shorter than that of the IG-type (2200 days) (p < 0.05).

ECV fraction demonstrates potential as the most valuable predictor of the DG type of GBCA, which has a higher recurrence rate compared with the IG type. However, further large-scale multi-center studies are required to validate these findings.

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