Y-90 radioembolization for liver cancer (TARE, transarterial radioembolization) is an interventional radiology (IVR) procedure in which tiny beads carrying the radioactive isotope yttrium-90 are released into the hepatic artery, so the tumor is irradiated from the inside. In the United States, a glass-bead product (2021) and a resin-bead product (2025) were approved by the FDA for hepatocellular carcinoma, and in the LEGACY study of 162 patients with a single unresectable liver cancer of 8 cm or less, 88.3% had an objective tumor response.
Based on FDA approval documents, peer-reviewed papers and patient information from US academic hospitals, this guide explains how radioembolization works, how it differs from chemoembolization (TACE) and radiofrequency ablation, who is a candidate, what happens from the mapping test to discharge, and what recovery and side effects look like.
Treatment status · An FDA-approved treatment in the US (TheraSphere glass microspheres in 2021; SIR-Spheres resin microspheres for HCC in 2025). It is used in Europe under CE marking, and a clinical trial for introduction in Japan (NCT07377487) is under way. This article is general information, not a recommendation.
What Y-90 radioembolization is
The liver has a dual blood supply. Normal liver tissue is fed mainly by the portal vein, while liver tumors draw most of their blood from the hepatic artery. Radioembolization uses this difference. A thin catheter is passed from an artery in the groin (or wrist) up to the hepatic artery, and millions of radioactive beads are released into the branch feeding the tumor. The beads lodge in the tumor's small vessels and deliver radiation right where they stop.
According to the FDA, about 95% of the Y-90 radiation is absorbed in the tumor region within 12 days, and the beads stay in the liver permanently. Because the radiation travels only a short distance, a high dose can be concentrated on the tumor compared with external beam radiation. Two products are currently approved in the US for hepatocellular carcinoma (HCC).
| Product | Bead type | US approval | Pivotal study |
|---|---|---|---|
| TheraSphere | Glass microspheres | March 17, 2021, for unresectable HCC 1–8 cm | LEGACY (162 patients) |
| SIR-Spheres | Resin microspheres | Approved in 2002 for colorectal liver metastases; HCC without macrovascular invasion added July 1, 2025 | DOORwaY90 (28 US hospitals) |
Both use the same principle (Y-90 beads delivered through an artery); the hospital and care team choose the product.
For the basics of catheter-based treatment see our IVR (interventional radiology) guide, and for needle-based heat treatment see the RFA (radiofrequency ablation) guide.
How it differs from TACE and RFA
Searches for liver cancer local therapy bring up TACE, RFA and TARE together. All three target liver tumors without open surgery, but the route and mechanism differ.
| Item | Radioembolization (TARE, Y-90) | Chemoembolization (TACE) | Radiofrequency ablation (RFA) |
|---|---|---|---|
| Route | Arterial catheter | Arterial catheter | Needle through the skin |
| How the tumor is treated | Radiation from the beads | Chemotherapy plus vessel-blocking material | Heat at the needle tip |
| Number of sessions | One mapping + one treatment (a second lobe may follow weeks later) | Often repeated according to response | Usually one |
| Typical tumors | Tumors hard to reach with a needle, single tumors up to 8 cm, etc. | Multiple or intermediate-stage tumors | Usually small tumors up to 3 cm |
| Hospital stay | US hospitals describe a few hours of rest and same-day discharge | Varies by hospital | Same day to a few days |
A general comparison; the actual choice depends on tumor number, size, location and liver function.
These procedures complement rather than compete with each other. For example, adding RFA after TACE in intermediate liver cancer is covered in the TORCH phase 3 trial of TACE plus RFA, and the RFA process itself in liver cancer RFA procedure and recovery.
Who is a candidate
According to FDA documents, radioembolization is mainly for patients with HCC that cannot be removed surgically and relatively well-preserved liver function.
- Tumor size: TheraSphere is for HCC of 1–8 cm; DOORwaY90 required a largest tumor of 8 cm or less and a sum of diameters of 12 cm or less.
- Liver function: no cirrhosis or mild cirrhosis (Child-Pugh A). In DOORwaY90, 79% were A5 and 21% A6.
- General condition: able to carry out daily activities (ECOG 0–1). In DOORwaY90, 80% were ECOG 0.
- Patients awaiting transplant or resection: in LEGACY, 21.0% received the procedure before liver transplantation and 6.8% before surgical resection.
The FDA advises against use when tests show beads would flow outside the liver (lungs, stomach or bowel), when a catheter cannot be placed safely in the hepatic artery, with poor liver function, with certain types of portal vein blockage, when the tumor occupies more than 70% of the liver, or during pregnancy. That is why a mapping test always comes first.
The procedure: from mapping to discharge
This general flow follows UCLA Health's patient information. Radioembolization is usually done in two sessions.
- Pre-procedure tests: CT or MRI to see tumor location and size, and blood tests for liver function.
- Step 1 – mapping angiogram: a catheter is passed through the groin to map the hepatic arteries. Branches to the stomach or bowel can be closed with small coils so beads do not go astray. A test also checks how much blood shunts to the lungs.
- Step 2 – treatment: on another day a microcatheter is guided into the branch feeding the tumor, its position is confirmed, and the Y-90 beads are injected under conscious sedation.
- Discharge: UCLA describes 2–6 hours of bed rest followed by going home. If both lobes have tumors, the other lobe may be treated several weeks later.
- Follow-up: tumor cells die over the next 1–3 months; imaging and clinic visits are usually at 1, 3 and 6 months.
Because the effect builds gradually, it is normal to review later scans with the care team even if the first scan does not show the tumor gone.
Results: how much did tumors shrink
These are the two studies behind the US approvals. Figures are as reported in the sources.
| Study | Patients | Main results |
|---|---|---|
| LEGACY (3 US hospitals, Hepatology 2021) | 162 patients with solitary unresectable HCC (≤8 cm, median size 2.7 cm) | Objective response rate 88.3%. Response lasting ≥6 months 62.2%. 3-year overall survival 86.6%; 92.8% in patients who went on to transplant or resection |
| DOORwaY90 (28 US hospitals, FDA document 2025) | 100 patients for safety, 65 for effectiveness; unresectable HCC without macrovascular invasion | Localized objective response through 9 months 98.5% (64 of 65), confirmed response 90.8%. 76.6% of responders kept the response ≥6 months (median duration 300.5 days) |
Both are single-arm studies without a comparison group. "Objective response" means the tumor shrank by a defined amount on imaging.
Put simply, about 9 in 10 patients with a single liver cancer of 8 cm or less saw the treated tumor shrink, and 8 to 9 in 10 were alive at three years. Between 15% (DOORwaY90) and 21.0% (LEGACY) of patients went on to liver transplantation after the procedure bought them time. This bridge to transplant or surgery role is one reason radioembolization draws attention.
Side effects and recovery time
Most reported side effects were temporary symptoms such as fatigue or abdominal discomfort, within what the care team can manage.
| Symptom | Rate in DOORwaY90 (100 patients) | Management |
|---|---|---|
| Fatigue | 39.0% | Rest for days to weeks and build activity gradually |
| Abdominal pain or discomfort | 24.0% | Prescribed pain relief |
| Decreased appetite | 19.0% | Small frequent meals, nutrition advice |
| Nausea | 17.0% | Anti-nausea medication |
| Constipation | 15.0% | Fluids, laxatives if needed |
From the FDA Summary of Safety and Effectiveness Data. No deaths were attributed to the device or procedure.
UCLA notes that post-embolization symptoms such as fatigue, pain and nausea can last several days or longer, and MD Anderson Cancer Center says most patients return to regular activities within two days. Remaining radioactivity in the body is minimal, but the doctor may give precautions for the first days, which should be followed. Liver function is checked with regular blood tests; persistent fever, abdominal swelling or yellowing of the eyes or skin should be reported promptly.
Where it is available
| Region | Status | Basis |
|---|---|---|
| United States | Glass beads (2021) and resin beads (2025) both FDA-approved for HCC; offered at academic hospitals and cancer centers | FDA documents, UCLA and MD Anderson information |
| Europe | Used under CE marking. In September 2025 the resin-bead indications were expanded to unresectable HCC, colorectal liver metastases, intrahepatic cholangiocarcinoma, neuroendocrine liver metastases and others | Sirtex announcement (September 8, 2025) |
| Japan | A pre-market clinical trial in Japanese patients (TheraSphere Japan Pre-Market Study) is registered and under way. Currently TACE and RFA are widely provided under insurance for liver cancer | ClinicalTrials.gov NCT07377487 |
International patients are often not covered by public insurance, so confirm cost and availability directly with the hospital.
Once the Japanese trial is completed, radioembolization is expected to become an option for patients in Japan. Until then, liver cancer local therapy in Japan centers on TACE and RFA, which are often combined.
Questions to ask your doctor
- Which suits my liver cancer best – radioembolization, TACE or RFA – and why?
- How will the mapping test check lung shunting and vessels to the stomach or bowel?
- Will you use glass or resin beads, and how much experience does this hospital have?
- Could transplant or surgery be a goal in my situation?
- What precautions should I follow afterward, and when is the first scan?
To prepare for a consultation, see also five questions before an RFA consultation.
Frequently asked questions
Is radioembolization painful?
It is done under conscious sedation through an arterial catheter, without a large incision. Abdominal discomfort can follow but is controlled with prescribed pain relief; in DOORwaY90, abdominal pain was reported in 24.0%.
How long is the hospital stay?
UCLA Health describes 2–6 hours of rest after the procedure and going home the same day. Some hospitals and countries keep patients overnight, so check the schedule with the treating hospital.
Can I have radioembolization after previous TACE?
In some cases, yes. Radioembolization uses the same arterial route as TACE but works differently, so it can be considered if liver function and vessel anatomy meet the criteria. The mapping test determines whether it is possible.
When will I know if it worked?
Tumor cells die over 1–3 months, so imaging is usually done at 1, 3 and 6 months. Tumor response was reported in 88.3% of patients in LEGACY and 98.5% in DOORwaY90.
This article summarizes official overseas sources and papers as general information and is not medical advice. Please discuss treatment choices with doctors who have examined the patient.
Sources (checked October 21, 2026)
- U.S. FDA. TheraSphere – P200029 (Recently-Approved Devices). 2021.
- U.S. FDA. Summary of Safety and Effectiveness Data: SIR-Spheres Y-90 resin microspheres, P990065/S014 (DOORwaY90). 2025.
- Salem R, Johnson GE, Kim E, et al. Yttrium-90 Radioembolization for the Treatment of Solitary, Unresectable HCC: The LEGACY Study. Hepatology. 2021;74(5):2342-2352.
- UCLA Health. Radioembolization (Y90)
- MD Anderson Cancer Center. Y90-radioembolization radiation therapy for liver cancer patients
- Sirtex Medical (September 8, 2025). Sirtex Receives Expanded CE Mark Approval for SIR-Spheres Y-90 Resin Microspheres
- ClinicalTrials.gov. TheraSphere Japan Pre-Market Study (NCT07377487)