Personalized Radiation Therapy Achieves 100% Tumor Control, Redefining Liver Cancer Treatment

WOBURN, Mass. – April 13, 2026 – A groundbreaking study has delivered unprecedented results in the fight against unresectable hepatocellular carcinoma (HCC), the most common type of liver cancer. Sirtex Medical announced today that its pivotal DOORwaY90 clinical trial demonstrated 100% local tumor control in patients treated with SIR-Spheres® Y-90 resin microspheres using a personalized radiation dosing method. The findings, presented at the Society of Interventional Radiology (SIR) Annual Meeting in Toronto, signal a potential paradigm shift in how physicians approach this notoriously difficult-to-treat disease.

The study reported a staggering 99% overall response rate, with 90% of patients achieving a complete response, meaning the disappearance of all signs of cancer in response to treatment. These outcomes, assessed by a blinded independent central review, are among the highest ever reported for Y-90 selective internal radiation therapy (SIRT) and could establish a new benchmark for liver-directed therapies.

"These results raise the bar for what physicians should expect from Y-90 therapy," said Matt Schmidt, CEO of Sirtex Medical, in a statement. "DOORwaY90 demonstrates that personalized dosimetry with SIR-Spheres can deliver outcomes that challenge conventional approaches and expand what's possible in liver-directed therapy for patients with unresectable HCC."

The Power of Personalized Dosimetry

At the heart of the study's success is a technique called partition dosimetry. Unlike standard approaches that deliver a uniform dose of radiation to the liver lobe containing the tumor, partition dosimetry allows clinicians to calculate and deliver a highly targeted, specific radiation dose directly to the tumor itself while sparing surrounding healthy liver tissue. This precision is critical for patients with HCC, as many also suffer from underlying liver disease like cirrhosis, making the preservation of liver function paramount.

The DOORwaY90 study, the first pivotal, prospective U.S. trial to use this method for HCC, showed that this aggressive tumor targeting did not come at the cost of safety. Over 95% of patients maintained stable liver function at the 12-month follow-up mark. Furthermore, the responses were highly durable, with 75% lasting longer than six months and a median duration of 295 days.

"These 12-month results demonstrate the consistency of response achievable with personalized dosimetry," commented Dr. Armeen Mahvash, an Interventional Radiologist at MD Anderson Cancer Center and Co-Principal Investigator of the study. "The high complete response rates, durability and preservation of liver function observed in this study give physicians increased confidence in using radioembolization as a definitive, liver-directed treatment option."

A New Weapon in a Challenging Fight

The treatment landscape for unresectable HCC, where surgical removal is not an option, has historically been fraught with challenges, offering patients a poor prognosis. In recent years, the standard of care has shifted toward systemic therapies, particularly immunotherapy combinations like atezolizumab and bevacizumab, which have extended survival. However, not all patients are eligible for or respond to these treatments, creating a persistent need for effective alternatives.

Y-90 radioembolization, a minimally invasive procedure where microscopic radioactive beads are delivered to the tumor through the liver's blood supply, has long been a valuable locoregional therapy. The DOORwaY90 results elevate its potential from a palliative or bridging therapy to a definitive treatment capable of eliminating tumors entirely. The findings have already supported a new FDA approval for SIR-Spheres, making it the only radioembolization therapy in the U.S. indicated for both unresectable HCC and metastatic colorectal cancer that has spread to the liver.

This places Sirtex in a strong competitive position. Its primary rival, Boston Scientific's TheraSphere™, which uses glass microspheres, also holds an FDA approval for HCC. However, the remarkable efficacy and robust data from the DOORwaY90 trial provide Sirtex with a powerful new narrative centered on the superiority of personalized dosimetry. One expert reviewing the interim results called the 90% complete response rate "superb, regardless of methodology," underscoring the significance of the findings within the oncology community.

Market Impact and Patient Hope

The interventional oncology market, valued at nearly $3 billion in 2025, is projected to grow at over 8% annually, fueled by an aging population and a rising incidence of cancer. Liver cancer treatments represent a significant and growing segment of this market. Sirtex Medical, which was acquired by a Chinese consortium in 2018, is now poised to capture a larger share of this market, particularly in regions like China where liver cancer rates are high.

Beyond the market dynamics, the results offer a profound sense of hope for patients. For individuals diagnosed with unresectable HCC, treatment decisions often involve a difficult balance between extending life and maintaining its quality. Many patients prioritize avoiding the debilitating side effects that can accompany systemic therapies. A treatment that can eradicate tumors while preserving vital liver function directly addresses this crucial patient preference.

The strong safety profile and high efficacy seen in the DOORwaY90 study could also pave the way for broader insurance coverage and reimbursement. Cost-effectiveness studies in Europe have already suggested that SIRT can be a financially viable alternative to more expensive systemic drugs, partly by reducing the costs associated with managing severe adverse events. With the new FDA approval and compelling clinical evidence, payers in the U.S. will be under pressure to ensure patient access to this highly promising therapy, potentially making it a more accessible frontline option for a wider group of patients.