Hepatocellular Carcinoma with Vascular Invasion Treated with Resin Yttrium-90 Transarterial Radioembolization Using Single Compartment Dosimetry.

Purpose: To report outcomes in hepatocellular carcinoma (HCC) patients with lobar and segmental vascular invasion treated with resin Yttrium-90 transarterial radioembolization (Y90-TARE) with single-compartment MIRD (Medical Internal Radiation Dose) model.

Materials and methods: This was a retrospective IRB approved study of patients with a diagnosis of HCC with vascular invasion undergoing resin Y90-TARE from 2014 to 2022 (n = 61). Patients with Body Surface Area dosimetry (n = 20), main portal vein invasion (n = 6) and patients with an ECOG of > 2 were excluded (n = 1) with a final cohort of 34 patients.

Results: Study population consisted of 34 patients, median age 62 years [60-71], tumor size 4.2 (2.8-7.4) cm, and 82% male. The median prescribed dose was 170 (126-200) Gy. The objective response rate at 6 months was 67% and disease control rate was 72%. The median survival was 18 months, median progression-free survival was 9.8 months. The 1- and 3-year survival rates were 76% and 57% in patients prescribed > 180 Gy, compared to 29% and 15% in patients with < 180 Gy (p = 0.01). Five of 15 Childs-Pugh A, ECOG < 1 patients (33%) were downstaged to resection, with complete pathologic necrosis in 40%, and 1 and 3-year survival rates of 100%. Grade-3 adverse events were seen in only 5/34 (15%), with no grade-4 or 5 adverse events.

Conclusion: Resin Y90-TARE using single compartment MIRD model for HCC with segmental and lobar vascular invasion can result in downstaging to resection in 33% of patients and higher prescribed doses (> 180 Gy) result in improved survival.