AUTHOR=Xu Ying , Yang Yi , Li Lu , Ye Feng , Zhao Xinming TITLE=The α-RECIST (RECIST 1.1 Combined With Alpha Fetoprotein): A Novel Tool for Identifying Tumor Response of Conversion-Radiotherapy for Unresectable Hepatocellular Carcinoma Before Hepatectomy JOURNAL=Frontiers in Oncology VOLUME=Volume 12 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.905260 DOI=10.3389/fonc.2022.905260 ISSN=2234-943X ABSTRACT=Purpose: To develop a novel criterion based on the response evaluation criteria in solid tumors (RECIST) 1.1 and alpha fetoprotein (AFP) and evaluate its performance in tumor response for patients with unresectable hepatocellular carcinoma (uHCC) receiving conversion-radiotherapy before hepatectomy. Method: From June 2012 to December 2020, a total of 39 patients with uHCC who received intensity-modulated radiotherapy (IMRT) before hepatectomy were retrospectively included in this study. Pre- and post-treatment contrast-enhanced magnetic resonance imaging (CE-MRI) scans were performed in all patients. Eight modified criteria were developed with the combination of RECIST 1.1, modified RECIST (mRECIST) and the percentage change of AFP, baseline AFP. The endpoint events were recurrence-free survival (RFS) and overall survival (OS). Results: The median RFS and OS was 26.5 (IQR, 15.7-43.1), 38.8 months (IQR, 18.4-53.6). An optimal revised evaluation criterion named -RECIST (alpha fetoprotein-RECIST 1.1) was developed by combining the RECIST 1.1 with the AFP (cut-off value, 76%). Patients defined as responders by -RECIST showed significantly better RFS and OS than those defined as non-responders (p=0.035, 0.048). The other criteria (RECIST 1.1, mRECIST, -mRECIST, &-RECIST, &-mRECIST, BL-RECIST, BL-mRECIST, &BL-RECIST, &BL-mRECIST) all failed to identify responders from non-responders (p=0.405, 0.201, 0.773, 0.424, 0.266, 0.060, 0.721, 0.644, 0.910, respectively). Responders according to -RECIST showed significant better RFS compared to non-responders (HR, 0.31 [95% CI: 0.10, 0.98]; p=0.046); but OS without statistical significance [HR, 0.33 (95% CI: 0.11, 1.05); p=0.06]. RFS or OS between responders and non-responders according to RECIST 1.1 showed no significant difference [RFS: HR, 0.59 (95% CI: 0.17, 2.11), p= 0.419; OS: HR, 0.65 (95% CI: 0.18, 2.33), p=0.512]. Conclusions: Patients identified as responders by -RECIST provided significant better RFS and OS. The -RECIST criteria might be a user-friendly and reliable tool for identifying tumor response of conversion-radiotherapy for unresectable hepatocellular carcinoma before hepatectomy.