Long-Term Overall Survival After Selective Internal Radiation Therapy for Locally Advanced Hepatocellular Carcinomas: Updated Analysis of DOSISPHERE-01 Trial.

Interim analysis of the DOSISPHERE-01 study demonstrated a strong improvement in response and overall survival (OS) on using 90Y-loaded glass microspheres with personalized dosimetry compared with standard dosimetry in patients with nonoperable locally advanced hepatocellular carcinoma. This report sought to provide a long-term analysis of OS. Methods: In this phase II study (ClinicalTrials.gov identifier NCT02582034), treatment was randomly assigned (1:1) with the goal to deliver either at least 205 Gy (if possible >250-300 Gy) to the index lesion in the personalized dosimetry approach (PDA) or 120 ± 20 Gy to the treated volume in the standard dosimetry approach (SDA). The 3-mo response of the index lesion was the primary endpoint, with OS being one of the secondary endpoints. This report is a post hoc long-term analysis of OS. Results: Overall, 60 hepatocellular carcinoma patients with at least 1 lesion larger than 7 cm and more than 30% of hepatic reserve were randomized (intent-to-treat population: PDA, n = 31; SDA, n = 29), with 56 actually treated (modified intent-to-treat population: n = 28 in each arm). The median follow-up for long-term analysis was 65.8 mo (range, 2.1-73.1 mo). Median OS was 24.8 mo and 10.7 mo (hazard ratio [HR], 0.51; 95% CI, 0.29-0.9; P = 0.02) for PDA and SDA, respectively, in the modified intent-to-treat population. Median OS was 22.9 mo for patients with a tumor dose of at least 205 Gy, versus 10.3 mo for those with a tumor dose of less than 205 Gy (HR, 0.42; 95% CI, 0.22-0.81; P = 0.0095), and was 22.9 mo for patients with a perfused liver dose of 150 Gy or higher, versus 10.3 mo for those with a perfused liver dose of less than 150 Gy (HR, 0.42; 95% CI, 0.23-0.75; P = 0.0033). Lastly, median OS was not reached in patients who were secondarily resected (n = 11, 10 in the PDA group and 1 in the SDA group), versus 10.8 mo in those without secondary resection (n = 45) (HR, 0.17; 95% CI, 0.065-0.43; P = 0.0002). Only resected patients displayed favorable long-term OS rates, meaning an OS of more than 50% at 5 y. Conclusion: After longer follow-up, personalized dosimetry sustained a meaningful improvement in OS, which was dramatically improved for patients who were accurately downstaged toward resection, including most portal vein thrombosis patients.

Large, multifocal or portal vein-invading hepatocellular carcinoma (HCC) downstaged by Y90 using personalized dosimetry: safety, pathological results and outcomes after surgery.

Background: Transarterial radioembolization (TARE) has recently been recognized as a bridging/downstaging therapy to surgery for early hepatocellular carcinomas (HCCs) with high rates of complete pathological necrosis (CPN) on liver explants. In patients with portal vein tumoral thrombus (PVTT), multifocal or large tumors, TARE has mainly a palliative role and surgery remains controversial in this poor-prognosis population. Personalized dosimetry recently proved to outperform standard dosimetry used in prior negative Y90 randomized-controlled trials. Methods: In this retrospective study, we evaluated safety, radiological and pathological response and outcomes in HCC patients with PVTT, multifocal or large tumors, who underwent surgery after downstaging using TARE with Y90-loaded glass microspheres with personalized dosimetry. Results: Between December 2015 and October 2021, 18 unresectable patients (14/18 with PVTT) had surgery (16 resections, 2 liver transplantations) 6.2 months (range, 2-14.6 months) after a single Y90 treatment. No 90-day mortality was reported. Objective modified response criteria in solid tumors (mRECIST) response were noted in all but one patient. Complete and extensive (50-99%) necrosis was observed in 36% and 45% of tumors, respectively. The post-treatment tumor-absorbed dose significantly differed depending on the extent of pathological necrosis (P=0.045). Median overall survival and progression-free survival (PFS) were respectively of 61.8 months [95% CI: 31.4 months-not reached (NR)] and 49.3 months (95% CI: 14 months-NR). PFS was longer in patients with complete imaging response [median NR (none recurred or died) vs. 21.5 months (95% CI: 10.1 months-NR), P<0.001] and in those with complete pathological response [median NR vs. 22.5 months (95% CI: 10.1 months-NR), P<0.001]. Conclusions: Y90 TARE using personalized dosimetry can provide high rates of imaging and pathological response in patients with PVTT, large or multifocal HCC. Subsequent surgery is safe and leads to outcomes far exceeding expectations in an otherwise poor prognosis population with no chance for cure. Trial Registration: Clinical trial number: NCT05045573.