Preoperative prediction model of microvascular invasion in intrahepatic cholangiocarcinoma patients based on CT radiomics can assist clinical surgical decision-making: a multicenter study.

Objectives: We developed and validated a combined CT-based model to predict microvascular invasion (MVI) in patients with intrahepatic cholangiocarcinoma (ICC) for surgical resection decision-making.

Materials And Methods: This retrospective study included 292 patients with pathologically confirmed ICC between January 2012 and May 2023 at four institutions. The patients were divided into training (n = 141), test (n = 60), and external validation (n = 91) cohorts. The radiomics features were extracted from arterial and portal venous phases, and a combined model incorporating a CT radiomics signature and clinicoradiological features was developed and validated. The 2-year recurrence-free survival (RFS) of the MVI risk stratification was analyzed using the Kaplan-Meier method with a log-rank test and compared between anatomical and non-anatomical, or major and minor resections.

Results: The combined model incorporating 20 radiomics features and 3 clinicoradiological features achieved areas under the curve of 0.938, 0.889, and 0.844 in the training, test, and external validation cohorts, respectively. In the high MVI risk group, the 2-year RFS was significantly higher in patients who underwent major hepatectomy than in those who underwent minor hepatectomy (log-rank p = 0.007), especially for tumors located subcapsularly (log-rank p = 0.005). In the low MVI risk group, the 2-year RFS was significantly lower in patients who underwent major hepatectomy than in those who underwent minor hepatectomy (log-rank p = 0.033), particularly for tumors ≤ 5 cm (log-rank p = 0.011).

Conclusions: We developed and validated a robust combined CT-based model that accurately identified the MVI status of ICC and assisted in surgical decision-making.

Key Points: Question An effective preoperative MVI prediction model for ICC patients should consider its implications for different surgical resection strategies. Findings We developed and validated a combined model integrating CT radiomics and clinicoradiological features to accurately identify preoperative MVI status for surgical guidance. Clinical relevance For ICC patients, minor hepatectomy is recommended for those with low-risk MVI, particularly for tumors ≤ 5 cm, while major hepatectomy is advised for those with high-risk MVI, especially for tumors located subcapsularly.