2163 - Stereotactic Body Radiation Therapy Combined with Immune Checkpoint Inhibitors in Unresectable Hepatocellular Carcinoma: A Comprehensive Meta-Analysis

03:00pm - 04:00pm ET

Poster Hall - Exhibit Hall A

Screen: 29

POSTER

Presenter(s)

Neil Newman, MD, MS - Home, San Antonio , TX

J. T. Dreyer¹, R. M. Narasimhan², A. R. Dias Neto³, L. Nagal³, B. Spieler⁴, W. Jin⁴, J. M. Bryant³, J. B. Bell⁵, and N. B. Newman³; ¹University of Miami, Miami, FL, United States, ²University of Miami Miller School of Medicine, Miami, FL, ³University of Miami, Miami, FL, ⁴Department of Radiation Oncology, University of Miami/Sylvester Comprehensive Cancer Center, Miami, FL, ⁵Department of Radiation Oncology, Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL

Purpose/Objective(s):

In locally advanced hepatocellular carcinoma (HCC), immune checkpoint inhibitors (ICI) is the frontline regimen, but the benefit of additional stereotactic body radiation therapy (SBRT) is unclear. Given randomized evidence for survival benefit with SBRT with sorafenib, we performed a systematic review and meta-analysis to assess whether the combination of SBRT and ICI would improve survival and response outcomes with acceptable toxicity.

Materials/Methods:

Per PRISMA guidelines, we performed a systematic review and meta-analysis of studies published from 2020 onward evaluating adults with intermediate or advanced stage HCC treated with SBRT plus ICI. Eligible studies included phase II-III randomized control trials (RCTs), prospective cohorts, prospective single-arm studies with =20 patients, and retrospective comparative cohort studies with =20 patients with adjustment for confounding. Primary outcomes were overall survival (OS) and progression free survival (PFS), reported with 95% confidence intervals (CIs) or derived from Kaplan-Meier curves. Secondary endpoints included objective response rate (ORR), disease control rate (DCR), and grade 3+ treatment-related adverse events (toxicity). The DerSimonian-Laird method was employed. For proportions (DCR, ORR, toxicity), logit transformation was applied. Heterogeneity was assessed via I² statistics and Q-test.

Results:

We screened 1120 studies from PubMed and Embase using Covidence software. Six studies of 264 patients met inclusion criteria with results in table 1. Median OS was 20.2 months (95% CI: 12-33 months; I²=73.9%, p=0.009) across 4 studies with 206 patients. Median PFS was 9.2 months (95% CI: 6-14 months; I²=91.3%, p<0.001) across 6 studies with 264 patients. Pooled DCR was 96.2% (95% CI:63-99%; I²=89.2%, p<.001) across 5 studies with 239 patients and 215 disease control events. Pooled ORR was 63% (95% CI: 54-71%; I²=41.1%, p=0.15) across 5 studies with 239 patients and 151 objective responses. Grade =3 toxicity events were reported in 11.1% of patients (95% CI: 6.2–19.1%) across 5 studies with significant heterogeneity (I² = 82.7%, p<.001).

Conclusion:

SBRT plus ICI demonstrated meaningful clinical benefit, with median OS >20 months and acceptable toxicity (11.1%). Despite limitations including single-arm design and lack of randomized comparisons, findings support the biological rationale for SBRT-mediated immune potentiation pending results of activated phase three studies.

Outcome	k	N	Pooled Estimate (95% CI)	I²	t²	Q (p-value)	Heterogeneity
Overall Survival (OS)	4	205	20.2 months (12.4–33.0)	73.9%	0.158	11.51 (p=0.009)	High
Progression-Free Survival (PFS)	6	263	9.2 months (5.9–14.5)	91.3%	0.266	57.42 (p=<0.001)	High
Disease Control Rate (DCR)	5	238	96.2% (63.3–99.7%)	89.2%	8.516	37.20 (p=<0.001)	High
Objective Response Rate (ORR)	5	238	63.0% (53.8–71.3%)	41.1%	0.049	6.80 (p=0.147)	Moderate
Grade =3 Toxicity Events	5	238	11.1% (6.2–19.1%)	82.7%	0.386	23.19 (p=<0.001)	High