Boston Scientific TheraSphere Y90 Glass Microspheres Evaluated in PROACTIF Registry

April 22, 2026—Boston Scientific announced an analysis of 989 patients with hepatocellular carcinoma (HCC) from the PROACTIF prospective real-world registry. The findings demonstrated that targeted radiation therapy to treat liver tumors with the company’s TheraSphere Y90 glass microspheres achieved a significant survival benefit spanning all stages of disease.

The findings were published by Professor Boris Guiu, MD, et al in eClinical Medicine, a publication of The Lancet.

As summarized in Boston Scientific’s press release, the PROACTIF registry includes 5-year data and reflects the complexity of real-world practice. Approximately 78% of patients had intermediate or advanced disease, median tumor size was 6.8 cm, and > 35% of patients had portal vein tumor thrombus (PVT).

The company outlined the following key findings:

• Patients treated with TheraSphere across all Barcelona Clinic Liver Cancer stages had a median overall survival of 21.8 months. Patients with intermediate-stage disease had median overall survival of 27.0 months, and patients with advanced disease had a median overall survival of 21.1 months.
• Patients with tumors ≥ 5 cm who received high doses of radiation via TheraSphere (≥ 400 Gy) achieved median overall survival of 36.4 months compared to overall survival of 18.5 months in patients with the same-sized tumors who received lower doses of radiation (< 400 Gy). The dose-survival relationship is consistent with previous TheraSphere studies, noted Boston Scientific.
• Median overall survival among patients with localized PVT was 24.8 months (Vp1/Vp2; n = 179) compared to 23.1 months in patients without PVT. Approximately 26% of patients with PVT received subsequent curative-intent transplantation or resection surgeries.
• TheraSphere downstaged > 10% of patients (106) to curative-intent surgery, which doubled median overall survival (48.6 months vs 20.1 months).