France Builds a Real-World Registry for Y-90 Radioembolization in Liver Cancer
France has launched a prospective phase IV registry to measure how yttrium-90 glass microspheres perform outside the controlled environment of a trial. The PROACTIF study follows patients treated in routine practice for hepatocellular carcinoma, intrahepatic cholangiocarcinoma, and metastatic colorectal cancer, three settings in which liver-directed therapy often carries major weight in the treatment plan.
The registry exists because reimbursement has already moved this technology into everyday care. Once a therapy enters routine use, questions change: not whether it can be delivered, but how durable the benefit is, which patients do best, and how treatment affects daily functioning when the patient population is broader than a registration trial.
Why This Registry Matters for Liver-Directed Cancer Therapy
Selective internal radiation therapy delivers radiation directly into the hepatic tumor vasculature. In practical terms, the appeal is obvious: concentrated tumor dosing with limited exposure to the rest of the body. Yet the patients treated in real life rarely resemble a narrowly selected trial cohort. They arrive with different liver tumor burdens, variable performance status, unilobar or bilobar disease, and differing prior treatment histories.
PROACTIF was built to capture that heterogeneity. It is an open registry with no fixed sample size, and 115 patients had already been enrolled at the time of the protocol publication. Recruitment covers patients treated with a commercial vial of Y-90 glass microspheres between 1 January 2019 and 31 December 2024. The study includes only patients whose treatment was reimbursed in France and who do not object to the use of their medical data.
A single sentence explains the clinical urgency here: reimbursement without systematic follow-up can outpace the evidence base.
Survival and Quality of Life Sit at the Center of the Protocol
The registry’s primary outcome is overall survival from the time of Y-90 glass microsphere treatment. That endpoint is clinically meaningful because liver malignancies often fail through a combination of intrahepatic progression, declining hepatic reserve, and systemic cancer burden. A therapy that controls liver disease but shortens neither symptom burden nor survival may still have limited value in practice, especially when it is used in older patients or in those with advanced disease.
Quality of life is tracked with the Functional Assessment of Cancer Therapy-Hepatobiliary questionnaire. This choice reflects the central tension in liver cancer care: local control matters, but so does the patient’s ability to eat, move, think clearly, and tolerate ongoing therapy. In liver-directed treatment, symptom preservation can be as clinically important as tumor shrinkage, particularly when treatment is being used in patients who may already have compromised hepatic function or heavy prior treatment exposure.
The registry therefore examines not only whether patients live longer, but how they live during and after treatment.
Disease-Specific Analyses Will Separate Three Distinct Clinical Populations
The protocol stratifies analyses by disease state: HCC, iCC, and mCRC. That separation is essential. These cancers differ in biology, treatment sequencing, and liver-dominant behavior. Hepatocellular carcinoma often develops in a cirrhotic liver, where preserving residual liver function is just as important as treating the tumor. Intrahepatic cholangiocarcinoma tends to behave aggressively and may be treated with a mix of systemic and locoregional approaches. Metastatic colorectal cancer represents a different therapeutic ecosystem entirely, often with liver metastases arising in the context of broader systemic disease.
Mixing those populations into a single outcome stream would blur the interpretation. Separating them gives the registry a chance to answer a more useful question: where does this liver-directed radiation strategy appear most effective in daily care?
Subgroup Work May Clarify Which Patients Benefit Most
The planned subgroup analyses are clinically relevant because response to radioembolization is rarely uniform. Investigators intend to examine age group, unilobar versus bilobar disease at baseline, ECOG performance status, liver tumor burden, target lesion size, and whether treatment used standard or multi-compartment personalized dosimetry.
Personalized dosimetry deserves particular attention. Radiation biology is dose-dependent, and the liver is an organ where both undertreatment and overtreatment can carry consequences. A more tailored distribution strategy could theoretically improve tumor coverage while limiting unnecessary injury to healthy parenchyma. In a registry setting, those patterns may help identify whether dosimetry refinement translates into better survival or better tolerance in routine practice.
Performance status and tumor burden will likely be equally important. Patients with preserved function and lower disease burden often do better in oncology, but registries are especially valuable because they reveal where real-world boundaries lie. A treatment may look strong in selected candidates and far less robust when used in patients with extensive liver involvement or reduced functional reserve.
Safety Will Be Interpreted in the Context of Routine Practice
Because PROACTIF is a phase IV registry, its value depends on capturing the everyday consequences of treatment rather than only idealized efficacy. Safety data matter here for a simple reason: liver-directed radiation can only be adopted broadly if clinicians can identify who tolerates it well and who does not.
Real-world treatment also carries operational complexity. Reimbursed therapy may be delivered across centers with differing workflows, imaging resources, and dosimetry practices. Those variations can affect outcomes, and a national registry is one of the few ways to observe those differences at scale without forcing practice into a single experimental model.
A French Registry With Wider Relevance for Oncology Practice
Although the study is rooted in the French reimbursement setting, its clinical implications extend beyond one health system. Many countries face the same dilemma once an expensive locoregional therapy becomes commercially available: use expands quickly, while the evidence linking it to patient-centered outcomes often lags behind.
PROACTIF offers a structured way to close that gap. Its open design, broad inclusion across liver malignancies, and focus on survival and quality of life make it a practical observational framework for assessing whether Y-90 glass microspheres deliver consistent benefit across heterogeneous patients in routine care.
The main limitation is already visible in the protocol itself: this is not a randomized comparison, and interpretation will depend on how well the registry captures baseline disease severity, treatment selection, and post-treatment follow-up. The study can map outcomes in the real world, but it cannot by itself prove causality between radioembolization and survival. Even so, the registry is positioned to answer a crucial clinical question that randomized trials often cannot resolve on their own: how this treatment performs after it leaves the trial setting and enters everyday oncology practice.