Combined analysis of imaging tumor capsule with imaging tumor size guides the width of resection margin for solitary hepatocellular carcinoma

Background: The optimal width of resection margin（RM） for hepatocellular carcinoma（HCC） remains controversial. This study aimed to investigate the value of imaging tumor capsule（ITC） and imaging tumor size（ITS） in guiding RM width for patients with HCC. Methods: Patients who underwent hepatectomy for HCC in our center were retrospectively reviewed. ITC（complete/incomplete） and ITS（ ≤ 3 cm/＞ 3 cm） were assessed by preoperative magnetic resonance imaging（MRI）. Using subgroup analyses based on ITC and ITS, the impact of RM width [narrow RM（ ＜ 5 mm）/wide RM（ ≥ 5 mm）] on recurrence-free survival（RFS）, overall survival（OS）, and RM recurrence was analyzed. Results: A total of 247 patients with solitary HCC were included. ITC and ITS were independent predictors for RFS and OS in the entire cohort. In patients with ITS ≤ 3 cm, neither ITC nor RM width showed a significant impact on prognosis, and the incidence of RM recurrence was comparable between the narrow RM and wide RM groups（15.6% vs. 4.3%, P = 0.337）. In patients with ITS ＞ 3 cm and complete ITC, the narrow RM group exhibited comparable RFS, OS, and incidence of RM recurrence with the wide RM group（ P = 0.606, 0.916, and 0.649, respectively）. However, in patients with ITS ＞ 3 cm and incomplete ITC, the wide RM group showed better RFS and OS and a lower incidence of RM recurrence compared with the narrow RM group（ P = 0.037, 0.018, and 0.046, respectively）. Conclusions: As MRI-based preoperative markers, conjoint analysis of ITC with ITS aids in determining RM width for solitary HCC patients. Narrow RM is applicable in patients with ITS ≤ 3 cm regardless of ITC status and in those with ITS ＞ 3 cm and complete ITC. Wide RM is preferred in those with ITS ＞ 3 cm and incomplete ITC.