495 Background: Transarterial Radioembolization (TARE) is an emerging modality for hepatocellular carcinoma (HCC). Understanding early imaging responses may help guide downstream treatment decisions ranging from active surveillance to additional systemic or local therapies. In this study, we evaluated the prognostic value of the response noted in the first post-TARE imaging in our institute. Methods: A single center retrospective review was conducted evaluating patients with HCC who underwent TARE between 1/2015 and 8/2022. Patients’ clinical and pathological characteristics were elucidated. Descriptive statistics, Kaplan-Meier curves, and log-rank test were used to estimate overall survival (OS; from diagnosis to death or loss of follow-up) and TARE-specific OS (OS-TARE; from TARE procedure to death or loss to follow-up). Reports of the first available imaging (magnetic resonance imaging (MRI) or computerized tomography (CT)) to assess the treatment response were reviewed. Patients were divided into four groups, complete response (CR), partial response or residual disease (PR), progressive disease (PD), and unclear response (UR). Modified RECIST criteria was used in most of the cases to assess the response. Patients who died before the first imaging, lost to follow-up after the procedure, and had TARE-related complications were excluded. Results: Of the 141 patients evaluated, 126 met the eligibility criteria. The median time for the first imaging (> 80% had MRI) was 3 months (1-11). The outcome analysis is reported in the table below. Conclusions: PR on first post-TARE imaging correlated with the best outcomes in both OS-TARE and overall survival, likely reflecting more frequent administration of post-TARE systemic therapy. CR did not predict superior survival in the absence of additional therapy. UR group outcomes were comparable to PD, supporting a similar clinical approach and need for aggressive post-TARE treatment strategies. A multimodal approach to assess the TARE response in HCC may be needed, and future research is warranted to elucidate optimal post-TARE surveillance approaches. Response Category N Median OS-TARE (months)* Median OS (months)# Additional Therapy Post-TARE % Deceased at the time of analysis CR 22 17 29 1 TKI 64% PR 37 22 33 7 ICI, 6 TKI, 8 both 81% PD 39 4 22 7 ICI, 4 TKI, 1 both 87% UR 28 6 20 2 ICI, 3 TKI 89% *p=0.002; #p=0.04. ICI - immune-checkpoint inhibitor, TKI - tyrosine-kinase inhibitors.
Sherpally et al. (Sat,) studied this question.