ESTRO meets Asia 2024 - Abstract Book

S387

RTT – Treatment planning, OAR and target definitions

ESTRO meets Asia 2024

RT combined with anti-angiogenic therapy and immunotherapy brings new hope to HCC patients with PVTT

jianing Ma, Lihua Dong, Xin Jiang, Lijuan Ding

Department of Radiation Oncology and Therapy, The First Hospital of Jilin University, Changchun, China

Purpose/Objective:

An increasing number of hepatocellular carcinoma (HCC) patients are experiencing concomitant portal vein tumor thrombosis (PVTT). However, the current therapeutic outcomes for such patients are suboptimal. Therefore, our study aims to assess the efficacy and safety of a combined approach involving radiotherapy(RT), programmed cell death-1 (PD-1) inhibitors, and tyrosine kinase inhibitors (TKIs) in the treatment of HCC with PVTT.

Material/Methods:

From March 2019 to March 2023, a total of 72 patients with HCC and concurrent portal vein tumor thrombosis (PVTT) were included in the study. Among them, 32 patients received combined therapy involving TKIs and PD-1 inhibitors along with radiotherapy, while 40 patients underwent PD-1 inhibitors and TKIs combination therapy. Propensity score matching (PSM) was employed to identify baseline-matched groups. Comparative analyses were conducted for the entire cohort and the PSM cohort, evaluating overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR).

Results:

Propensity score matching (PSM) analysis established 32 pairs of matched patients, demonstrating comparable baseline characteristics between those who received radiotherapy and those who did not. In the PSM cohort, patients who underwent radiotherapy exhibited superior median overall survival (mOS) (15.60 months vs. 8.23 months, P=0.008) and median progression-free survival (mPFS) (8.13 months vs. 5.2 months, P=0.011) compared to those who did not receive radiotherapy. Following adjustment for other confounding factors in multivariate analysis, RT+PD-1+TKIs remained independently associated with favorable OS (HR: 0.391; 95% CI: 0.173-0.882; P=0.024) and PFS (HR: 0.487; 95% CI: 0.276-0.857; P=0.013). Subgroup analysis revealed that patients with tumor thrombosis involving the portal vein, classified as type III/IV and with liver function grade child A, derived greater survival benefits from TKI+PD-1+RT treatment.Adverse reactions were predominantly graded as I-II.

Conclusion:

This real-world observational study suggests that the combination of radiotherapy with PD-1 inhibitors and TKIs for the treatment of HCC with PVTT holds considerable promise.

Keywords: HCC ， PVTT

111

Digital Poster

Clinical case: Radiotherapy treatment planning of right breast with three glands and boost with VMAT