Non Transplantable Recurrence After Percutaneous Thermal Ablation of ≤3cm HCC: Predictors and Implications for Treatment Allocation

Consecutive patients undergoing PTA for HCC between January 2015 and December 2020 were included. Data were collected from our prospective database. This study was approved by our institutional review board (NCT03428321 [www.clinicaltrials.gov\]) and written informed consent was obtained from all patients. Inclusion criteria were: HCC diagnosed by histopathology or by EASL imaging criteria, HCC ≤30mm, 1 - 3 tumor nodules, follow-up<3 months, no prior or combined treatment with intra-arterial therapy, potentially transplantable patient (ie, ≤70yr, AFP-score≤2 (7), no macroscopic portal vein invasion or extra-hepatic metastasis, no major comorbidity precluding LT).

Patient's and liver's characteristics were collected including: age, sex, HCC-naïve status, body mass index (BMI), diabetes mellitus, liver steatosis, cirrhosis, cause for hepatopathy, AFP serum level, Child-Pugh, MELD and Albumin-Bilirubin (ALBI) scores and preablative biological data.

Occurrence of NTR after PTA will be analyzed in a competing risks framework, with transplantation and death as competing events. Covariates associated with NTR were analyzed using Fine-Gray proportional sub-distribution hazards models.

Recurrence-free survival (RFS) will be defined as the time from PTA until the first recurrence, death, or last follow-up. OS will be defined as the interval between PTA and death (any cause) or last follow-up. Survival curves will be estimated using the Kaplan-Meier method and compared with the log-rank test.