Value of computed tomography-based lipiodol retention pattern in the assessment of hepatocellular carcinoma complete response following conventional transarterial chemoembolization

Abstract

Abstract Background Conventional transarterial chemoembolization (cTACE) has emerged as a major treatment modality for unresectable hepatocellular carcinoma (HCC). Efforts have recently been made to identify biomarkers of HCCs that can potentially predict the response of lesions to transarterial chemoembolization (TACE) therapy. The goal of these efforts is to simplify the decision-making process on whether a patient should choose cTACE or pursue other treatment options. Among these, computed tomography (CT) based lipiodol retention analysis has shown promise in providing valuable insights into post-TACE outcomes. This study aimed to investigate the value of CT-based lipiodol retention pattern in predicting recurrence after a state of complete response (CR) according to modified Response Evaluation Criteria in Solid Tumors (mRECIST) guideline post-cTACE. Methods From January 2022 to June 2023, a cohort of 30 patients with 40 HCCs who received a primary cTACE session were identified. The study included patients who underwent 1st cTACE session with no more than three HCCs. Ten HCC lesions were eliminated owing to different reasons (illustrated in the flow chart). Tumor response was evaluated based on mRECIST on 1st follow-up CT with a particular focus on tumors demonstrating a complete response. Patterns of lipiodol retention within these tumors were categorized as complete lipiodol retention pattern (C-Lip), covering the whole tumor, or incomplete lipiodol retention pattern (I-Lip). Recurrence was defined when reappearance of enhancement on arterial-phase images of the treated lesion with subsequent washout on portal/delayed phase images occurred corresponding to findings of restricted diffusion on follow-ups DCE-MRI. Results A total of 30 HCCs with a CR were classified into 21 (70%) with C-Lip and 9 (30%) with I-Lip. After a median follow-up of 6.00 ± 2.27 months (3–9 months), 8/9 (88.9%) I-Lip and 5/21 (23.8%) C-Lip showed recurrence on follow-up (DCE-MRI), (p < 0.01), with no significant difference in the time of progression (mean 5.57 ± 2.69 for C-Lip vs. 6.00 ± 2.27 months for I-Lip, with (p < 0.5). Conclusions HCCs exhibit complete lipiodol retention alongside mRECIST CR possess a reduced susceptibility of recurrence, thereby potentially benefiting from MRI during subsequent evaluations. Conversely, the presence of incomplete lipiodol retention in conjunction with mRECIST CR is an indication of a high risk of recurrence and may require further treatment.