BACKGROUND
Hepatocellular carcinoma (HCC) is one of the most common cancers and the second leading cause of cancer-related death globally. Recurrence rates range from 50% to 70% within 5 years after radical hepatectomy, with most recurrences occurring during the first 2 postoperative years. Hence, precise identification of recurrent lesions is essential to optimize patient outcomes. Conventional ultrasound (US) and contrast-enhanced magnetic resonance imaging (CE-MRI), each with distinct advantages and limitations, are the main imaging modalities used for surveillance. However, the combined diagnostic performance of these modalities in a systematic post-hepatectomy surveillance program remains uncharacterized.
AIM
To assess the complementary diagnostic efficacy of conventional US and CE-MRI in early recurrence surveillance following radical hepatectomy for HCC. Specifically, we evaluated the diagnostic performance of each modality alone and in combination for detecting early recurrent lesions, as well as their respective strengths and weaknesses, to identify an optimal imaging follow-up strategy.
METHODS
We performed a retrospective study of 186 patients with HCC who underwent radical hepatectomy in the Department of Hepatobiliary Surgery at Fengjie County People’s Hospital from January 2020 to December 2024. All patients underwent regular surveillance with conventional US and CE-MRI during the first 2 years after surgery. The study protocol was approved by the hospital ethics committee. Patients were categorized into recurrence and non-recurrence groups based on clinical follow-up and confirmation of recurrent lesions by pathological examination (where biopsy or surgical re-exploration was performed) or by multidisciplinary clinical-imaging consensus using Liver Imaging Reporting and Data System criteria on sequential imaging in conjunction with alpha-fetoprotein trajectory and clinical progression. Detection rate, diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were compared among US alone, CE-MRI alone, and the combined US-MRI approach. We also examined the size distribution, location patterns, and imaging features of recurrent lesions detected by each modality.
RESULTS
Early recurrence occurred in 68 (36.6%) of 186 patients within 24 months after surgery. US detected 42 of the 68 recurrent cases (detection rate, 61.8%), whereas CE-MRI detected 63 cases (detection rate 92.6%). The combined US-MRI approach achieved a detection rate of 97.1% (66/68). For lesions measuring ≥ 2 cm, US demonstrated a sensitivity of 85.7% and specificity of 93.2%, compared with a sensitivity of 97.1% and specificity of 95.8% for CE-MRI. However, for lesions measuring < 1 cm, US sensitivity was only 38.5%, compared with 84.6% for CE-MRI (P < 0.001). Compared with CE-MRI, US had significantly higher sensitivity for detecting superficial subcapsular recurrences (88.9% vs 72.2%, P = 0.032) and provided real-time assessment. CE-MRI showed superior performance in detecting deep parenchymal lesions (sensitivity 95.2% vs 52.4% for US, P < 0.001), portal vein tumor thrombus, and lesion vascularity patterns. The combined approach achieved an overall sensitivity, specificity, positive predictive value, and negative predictive value of 97.1%, 96.6%, 94.3%, and 98.3%, respectively, outperforming each modality alone (all P < 0.05). The greatest benefit of complementary diagnostic testing was observed for 1- to 2-cm lesions and lesions in difficult-to-visualize locations.
CONCLUSION
The findings of this study provide compelling preliminary evidence supporting a complementary role for a dual-modality strategy in post-hepatectomy HCC surveillance. However, the combined detection rate of 97.1% did not achieve absolute sensitivity because 2 subcentimeter hepatic dome lesions were not detected even with the combined approach. These findings warrant consideration for incorporation into clinical practice, pending confirmation in larger multicenter prospective trials.
Core Tip: Postoperative recurrence remains a major challenge in the management of hepatocellular carcinoma. This study evaluated the complementary diagnostic value of conventional ultrasound and contrast-enhanced magnetic resonance imaging for detecting early recurrence after radical hepatectomy. Contrast-enhanced magnetic resonance imaging demonstrated superior sensitivity for detecting small and deep lesions and vascular invasion, whereas ultrasound showed advantages in detecting superficial lesions and facilitating frequent surveillance. The combined use of ultrasound and contrast-enhanced magnetic resonance imaging significantly improved diagnostic accuracy and detection rates. An integrated surveillance strategy using both modalities may enhance early detection and facilitate timely therapeutic intervention.
