Radioembolization / Y-90 Therapy

Introduction

If your doctor has recommended radioembolization — also called Y-90 therapy, Y-90 radioembolization, or transarterial radioembolization (TARE) — you are likely facing a diagnosis involving a tumour in the liver. This may be primary liver cancer (cancer that started in the liver) or cancer that has spread to the liver from somewhere else, such as the colon, breast, or a neuroendocrine tumour.

Y-90 therapy is a form of targeted internal radiation. Tiny radioactive beads are delivered directly into the blood vessels that feed a liver tumour, so that the radiation acts on the cancer from inside while sparing most of the healthy liver. It sits at the intersection of interventional radiology and radiation oncology, and it is usually planned by a team of specialists working together.

This guide explains what radioembolization is, how it is done, who it is suited for, what the mapping appointment and the treatment day involve, what recovery looks like, and what side effects and outcomes you can expect. It is written for patients who have already been diagnosed and are now weighing or preparing for treatment. It does not replace the conversation with your own oncology team, but it should help you walk into that conversation with the right questions.

What Is Radioembolization (Y-90 Therapy)?

Radioembolization is a procedure in which millions of microscopic beads loaded with a radioactive substance called yttrium-90 (Y-90) are injected through a thin catheter into the artery that supplies blood to a liver tumour. The beads lodge in the small blood vessels around and inside the tumour and emit radiation over a short distance for a limited time, killing tumour cells.

Two ideas make this approach possible.

The first is that liver tumours, unlike normal liver tissue, get most of their blood supply from the hepatic artery rather than from the portal vein. Healthy liver cells survive mostly on portal vein blood. This means that a treatment delivered through the hepatic artery concentrates in tumour tissue and largely spares the normal liver.

The second is that yttrium-90 emits beta radiation that travels only a few millimetres in tissue. Once the beads are placed inside the tumour’s blood supply, the radiation stays local. It does not spread through the body the way external beam radiation might if it were used on the same area, and it does not make the patient broadly radioactive in a way that endangers others.

Y-90 therapy is described as a locoregional treatment, meaning it acts on a specific region of the body rather than on the whole body. It is different from systemic chemotherapy (which travels through the bloodstream to all organs) and different from external radiation (which is delivered from a machine outside the body). It is also different from chemoembolization (TACE), which uses chemotherapy drugs and blocking particles rather than radiation, although the two procedures share some technical similarities.

The treatment is generally given on an outpatient or short-stay basis. Most patients go home the same day or the day after.

Why Is Radioembolization Performed?

Radioembolization is used when a tumour or tumours are confined mainly to the liver, or when liver disease is the dominant problem even if cancer is present elsewhere. The most common situations include:

• Hepatocellular carcinoma (HCC) — the most common type of primary liver cancer, often arising in a liver already affected by cirrhosis or chronic hepatitis. Major guidelines from groups such as the NCCN and ESMO describe radioembolization as one option for intermediate-stage and selected advanced HCC, particularly when the tumour cannot be surgically removed and when other locoregional treatments are not suitable.
• Intrahepatic cholangiocarcinoma — a cancer of the bile ducts inside the liver. Radioembolization is one of several locoregional options doctors may consider, often combined with systemic chemotherapy.
• Liver metastases from colorectal cancer — cancer that started in the colon or rectum and has spread to the liver. Y-90 is generally considered after systemic chemotherapy options have been used, when liver disease is the main driver of illness.
• Liver metastases from neuroendocrine tumours — these tumours, which often spread to the liver, can be slow-growing but symptom-causing. Radioembolization is used to shrink tumours and reduce hormone-related symptoms.
• Other liver metastases — in selected cases of breast cancer, melanoma (including ocular melanoma), and other cancers that have spread to the liver and are not controlled by other treatments.
• Bridge or downstaging to transplant or resection — in some patients with HCC, Y-90 is used to control tumours while waiting for a liver transplant, or to shrink them enough that surgery becomes possible.

The goal of the treatment varies. Sometimes the aim is to cure (in the rare cases where tumour can be completely destroyed), sometimes to downstage for surgery or transplant, and sometimes to slow disease, relieve symptoms, and extend life with good quality. Your oncology team should be explicit about which of these is the goal in your case.

Who Is a Candidate?

Whether Y-90 therapy is suitable is a clinical decision made by a multidisciplinary team — typically an interventional radiologist, a medical oncologist, a hepatologist or surgeon, and a nuclear medicine specialist. Several factors are weighed.

Factors that generally support candidacy

• Cancer involvement is mostly in the liver, or liver disease is the most significant problem driving symptoms or prognosis.
• Liver function is preserved enough to tolerate the treatment. This is often measured using clinical scores and blood tests of liver function.
• The patient is well enough to undergo a catheter-based procedure under conscious sedation.
• The tumour’s blood supply, mapped during a preliminary angiogram, is suitable for directing beads selectively into the tumour.
• Other treatments (surgery, ablation, transplant) are not currently feasible, or Y-90 is being used as a bridge to one of these.

Factors that may make Y-90 less suitable

• Severely impaired liver function or advanced cirrhosis with complications.
• Significant cancer spread outside the liver that is not controlled by other treatments and is the main threat to the patient.
• An unfavourable pattern of blood flow that cannot be safely managed during the mapping angiogram — for example, when too many beads would travel to the stomach, intestine, or lungs.
• A blocked or compromised portal vein in some situations, although this is not always an absolute exclusion and depends on the details.
• Active infection, uncontrolled bleeding, or significant kidney problems that make contrast dye use risky.

Pregnancy is a contraindication. The treatment is generally not used during pregnancy because of radiation exposure to the foetus.

Alternatives to Radioembolization

Y-90 is one of several tools for treating liver tumours. Depending on the type and stage of cancer, the alternatives your team may discuss include:

Surgical resection

Removing the part of the liver containing the tumour is the option most likely to be curative when feasible. It requires that the tumour is in a location that can be removed and that enough healthy liver will remain.

Liver transplant

For some patients with HCC who meet specific criteria, replacing the diseased liver removes both the tumour and the underlying liver disease. Availability of donor organs is limited, and waiting times vary.

Thermal ablation

Radiofrequency ablation (RFA) and microwave ablation (MWA) use heat delivered through a needle placed into the tumour to destroy it. These are usually best for smaller tumours (typically under 3 cm). They are sometimes combined with other treatments.

Transarterial chemoembolization (TACE)

TACE is the closest cousin of radioembolization. Instead of radioactive beads, TACE delivers chemotherapy drugs along with particles that block blood flow to the tumour. Both are catheter-based, both are locoregional, and both are used for similar indications. The choice between TACE and Y-90 depends on tumour size and number, blood flow patterns, liver function, prior treatments, and team experience.

External beam radiation therapy

Stereotactic body radiation therapy (SBRT) delivers focused external radiation to a tumour from outside the body. It is one option for selected liver tumours when ablation or surgery is not feasible.

Systemic therapy

Drug treatments — chemotherapy, targeted therapies, and immunotherapy — act throughout the body. For HCC, combinations involving immunotherapy and targeted drugs have become important first-line options in advanced disease. For colorectal liver metastases, chemotherapy is usually the starting point. Systemic treatment is often used alongside or before locoregional treatments like Y-90.

Best supportive care

When active cancer treatment is no longer expected to help — or when the burden of treatment outweighs its benefits — supportive care focuses on symptom control, comfort, and quality of life. This is a legitimate choice that should be discussed openly when relevant.

Radioembolization is a single concept, but it is delivered using different devices and different strategies.

Glass microspheres vs resin microspheres

Two main types of Y-90 microspheres are in clinical use:

• Glass microspheres — the radioactive yttrium is built into a glass bead. Each bead carries a higher dose of radiation, so fewer beads are needed to deliver the prescribed dose. They are often used for HCC.
• Resin microspheres — the radioactive yttrium is bound to the surface of a small resin bead. Each bead carries less radiation, so more beads are needed. They are commonly used for liver metastases and are sometimes preferred when broader coverage of tumour blood supply is desired.

Both types have been used for many years and both are accepted by major guidelines. The choice depends on the cancer type, the tumour’s features, and the interventional radiologist’s judgment.

Lobar, segmental, and radiation segmentectomy approaches

The catheter can be advanced to different points in the liver’s arterial tree:

• Lobar treatment treats a whole lobe of the liver (left or right). This is used when tumours are spread across one lobe.
• Segmental treatment targets a smaller portion of the liver, usually one or two of the eight liver segments.
• Radiation segmentectomy is a high-dose, very localised treatment of a small segment containing a single tumour, with the intent of destroying it completely — sometimes considered when surgery or ablation is not feasible.
• Radiation lobectomy is a strategy of treating one lobe to both treat tumour and cause the untreated lobe to grow larger, which can sometimes allow later surgery on the diseased side.

The strategy is mapped out in advance and confirmed during the procedure.

Preparing for Radioembolization

Preparation for Y-90 therapy is more involved than for many outpatient procedures because it requires a separate planning step, called the mapping angiogram or work-up angiogram, before the actual treatment.

Initial workup and imaging

Before treatment is approved, your team will typically arrange:

• Detailed imaging of the liver — usually a multi-phase CT scan or MRI — to characterise the tumour or tumours and the surrounding anatomy.
• Blood tests to check liver function, kidney function, blood counts, and clotting.
• Tumour markers where relevant (for example, AFP for HCC, CEA for colorectal cancer, chromogranin A for neuroendocrine tumours).
• An assessment of overall fitness and other medical conditions.
• A multidisciplinary discussion of all treatment options.

The mapping angiogram

The mapping angiogram is typically done one to four weeks before the actual Y-90 treatment. During this procedure, an interventional radiologist:

• Inserts a thin catheter, usually through the artery at the top of the leg (femoral artery) or the wrist (radial artery).
• Guides the catheter under X-ray imaging up into the hepatic artery and its branches.
• Maps the exact blood vessels supplying the tumour and the rest of the liver.
• Identifies and, if needed, blocks (“coils off”) small arteries that might carry beads to unwanted places, such as the stomach or duodenum.
• Injects a small amount of a radioactive tracer (technetium-99m macroaggregated albumin, or MAA), which mimics how the Y-90 beads will distribute.

After this, a nuclear medicine scan checks where the tracer went. The team measures how much of the test dose travels through the liver into the lungs — called the lung shunt fraction — because too much shunting to the lungs can cause radiation injury there. They also check that no significant amount has gone to the stomach or intestines.

Based on all this information, the team calculates the personalised Y-90 dose for your treatment day. This is one of the reasons radioembolization is described as a precisely planned therapy rather than a one-size-fits-all procedure.

Practical preparation before the treatment day

Your team will give you specific instructions, which usually include:

• Not eating for a number of hours before the procedure (often from midnight the night before).
• Adjusting blood-thinning medications under medical guidance if you take them.
• Arranging someone to accompany you home afterwards.
• Continuing essential medications with small sips of water as advised.
• Telling the team about any allergies, particularly to iodine contrast dye, and about any kidney problems.

Some teams prescribe a short course of acid-reducing medication (a proton pump inhibitor) and sometimes anti-inflammatory or steroid medication around the time of treatment to reduce the chance of stomach irritation and side effects.

What Happens During Radioembolization

The treatment day itself is similar in feel to the mapping angiogram. You will usually arrive in the morning, change into a gown, and have an IV line placed.

Before the procedure starts

• The team confirms your identity, the planned procedure, and the calculated dose.
• Vital signs are monitored.
• Light sedation is usually given through the IV to keep you relaxed and comfortable. Most patients are awake but drowsy. General anaesthesia is not usually required.
• The skin over the access site (groin or wrist) is cleaned and numbed with local anaesthetic.

During the procedure

• The interventional radiologist inserts a small tube into the artery and threads a thin catheter up into the hepatic artery, guided by real-time X-ray.
• The catheter is positioned in the same branch identified during the mapping study.
• The Y-90 microspheres, prepared in shielded containers by nuclear medicine staff, are slowly injected through the catheter into the tumour’s blood supply.
• The beads travel into the small vessels feeding the tumour and lodge there. They begin emitting radiation immediately.
• The catheter is removed and pressure is applied to the access site to stop bleeding. A closure device may also be used.

The active treatment portion typically takes about 30 to 90 minutes, although total time in the procedure room can be longer because of positioning, imaging, and dose checks.

After the injection, the team may take additional imaging to confirm where the beads have lodged. Some centres perform a PET or SPECT scan within a day of treatment to map the actual distribution of radiation.

Recovery and Healing

Recovery from radioembolization has two parts: recovery from the catheter procedure itself, and recovery from the effects of the radiation on the tumour and liver.

The first few hours and the first day

After the procedure, you will rest in a recovery area for several hours, lying flat if the femoral artery was used so that the artery seals properly. Staff will check the access site, monitor vital signs, and watch for bleeding.

Most patients are discharged the same day or after one night in hospital. You will be given:

• Instructions on caring for the access site.
• A list of medications, often including a proton pump inhibitor and sometimes a short course of steroids or anti-nausea medication.
• Advice on radiation safety (described below).
• A follow-up appointment, usually a few weeks later.

The first one to two weeks: post-radioembolization syndrome

Many patients experience a constellation of symptoms in the first one to two weeks after treatment, known as post-radioembolization syndrome. This is not a complication so much as an expected reaction. It can include:

• Fatigue, which is often the most prominent symptom and can last several weeks.
• A dull pain or discomfort in the upper right abdomen.
• Mild fever.
• Nausea, sometimes with vomiting.
• Reduced appetite.

These symptoms are usually managed with rest, fluids, pain relief, and anti-nausea medication. They generally improve over one to three weeks. Your team will tell you which symptoms warrant a phone call or visit (for example, high fever, worsening pain, jaundice, or bleeding).

Radiation safety after treatment

Because yttrium-90 emits beta radiation that travels only a short distance in tissue, the radiation does not project far outside the body. Most external exposure to others is very low. Still, centres usually advise simple precautions for the first few days, such as:

• Avoiding prolonged close contact, especially with pregnant women and young children, for a short period as advised.
• Sleeping in a separate bed for a small number of nights if your team recommends it.
• Good handwashing, since small amounts of activity can be excreted in urine and stool early on.

The specific instructions vary by country, centre, and device. Your team will give you the exact precautions that apply to your case.

Activity and return to normal life

Most patients can resume light activity within a few days. Walking and gentle movement are encouraged. Heavy lifting and strenuous exercise are usually avoided for about a week after a femoral artery access. Driving is usually possible within a few days, depending on how you feel.

Return to work depends on your role and how you feel. Many patients with sedentary work return within one to two weeks; those with physical work or significant fatigue may need longer.

Follow-up imaging and assessment

• A clinic visit a few weeks after treatment to check on recovery.
• Imaging (usually CT or MRI) at one to three months, and then at regular intervals afterwards, to assess tumour response.
• Blood tests including liver function tests and relevant tumour markers.

In some cases, a second Y-90 treatment is planned for the other lobe of the liver or for new disease. Some patients have only one session; others have repeat treatments over time.

Risks and Complications

Radioembolization is generally well tolerated, but every treatment has risks. Your interventional radiologist should review these with you in detail. They include:

Common and expected effects

• Post-radioembolization syndrome (described above).
• Temporary worsening of liver blood tests.
• Mild bruising or soreness at the catheter access site.

Less common but recognised complications

• Radiation-induced liver disease — injury to the healthy liver, more likely in patients with already-impaired liver function. Careful patient selection and dose planning aim to keep this risk low.
• Gastrointestinal ulcers — if beads inadvertently travel to the stomach or duodenum, they can cause radiation injury and painful, slow-healing ulcers. The mapping angiogram is designed to prevent this.
• Cholecystitis — inflammation of the gallbladder if beads reach the cystic artery.
• Pneumonitis — lung inflammation if too much radioactive material shunts to the lungs. The lung shunt fraction measured during mapping is used to avoid this.
• Bile duct injury — rare but can lead to bile leaks or strictures.
• Infection — including liver abscess, particularly in patients with prior bile duct surgery or stents.
• Bleeding or vessel injury at the catheter site.
• Contrast-related kidney injury — particularly in patients with pre-existing kidney problems.
• Allergic reactions to contrast or medications.

Serious complications are uncommon when treatment is performed by experienced teams with careful pre-treatment planning. Centres that perform radioembolization regularly tend to have established protocols for prevention, early detection, and management of these problems.

Life After Radioembolization

What life looks like after Y-90 therapy depends largely on the underlying cancer, how the treatment has worked, and what other treatments you may receive. Some general patterns are worth understanding.

Tumour response and disease control

In clinical studies of well-selected patients with HCC, neuroendocrine liver metastases, and colorectal liver metastases, radioembolization has been shown to shrink tumours, slow disease progression, relieve symptoms, and in some cases extend survival. Response rates and outcomes vary widely depending on cancer type, stage, liver function, and what other treatments are combined. Your own oncology team can give you a personalised picture based on your specific situation.

Tumour response is usually assessed not just by size on imaging but also by changes in how active the tumour looks — for example, less enhancement with contrast on CT or MRI, or reduced uptake on PET. A tumour that has stopped growing or is no longer active is often considered a meaningful response, even if it has not disappeared.

Combining with other treatments

Y-90 is often part of a longer treatment plan that may include:

• Systemic therapy — chemotherapy, targeted drugs, or immunotherapy — before, after, or alongside.
• Repeat locoregional treatments such as ablation or another Y-90 session.
• Surgery, if Y-90 has shrunk the tumour enough to make removal possible.
• Liver transplant, when Y-90 has been used as a bridge.

Sequencing of treatments is a clinical decision that depends on response, side effects, and overall health.

Ongoing surveillance

After Y-90, you will be on long-term follow-up that typically involves imaging every few months in the first year or two, with the schedule tailored to your cancer type. Blood tests, including liver function and tumour markers, are usually repeated at the same intervals.

Lifestyle and liver health

Because Y-90 acts on the liver, your team will likely encourage habits that protect liver function, including:

• Avoiding alcohol or strictly limiting it, particularly if you have underlying liver disease.
• Managing hepatitis B or C if relevant, with antiviral treatment under specialist care.
• Reviewing medications and supplements that can stress the liver.
• Maintaining good nutrition; a dietitian may be helpful, especially if appetite has been affected.
• Vaccinations against hepatitis A and B where appropriate.

Emotional adjustment is part of life after a major cancer treatment. Fatigue can linger longer than expected. Many people benefit from talking with a counsellor, joining a support group, or working with a palliative care or supportive care team alongside their oncology team — even when the goal of treatment is still active disease control.

Frequently Asked Questions

Will I be radioactive after Y-90 therapy?

Only to a very limited extent, and only for a short period. Yttrium-90 emits beta radiation that travels only a few millimetres in tissue, so it stays mostly inside the treated part of the liver. External exposure to others is low. Your team will give you specific safety advice for the first few days, which usually includes simple precautions around pregnant women and young children.

How is Y-90 different from chemotherapy?

Chemotherapy is usually a systemic treatment that travels through the bloodstream to all parts of the body, killing fast-dividing cells wherever it goes. Y-90 is a locoregional treatment delivered through a catheter directly into the blood supply of a liver tumour. Its effect is concentrated on the tumour and the surrounding small area of liver. The two treatments work in different ways and are sometimes used together.

How is Y-90 different from TACE?

Both Y-90 and transarterial chemoembolization (TACE) are delivered through a catheter in the hepatic artery, and both target liver tumours. TACE uses chemotherapy drugs and blocking particles; Y-90 uses radioactive beads. The two have different side-effect profiles and different patterns of use. The choice depends on tumour features, liver function, prior treatments, and team experience. Major guidelines describe both as accepted locoregional options for liver tumours.

Is Y-90 a cure?

For most patients, Y-90 is not given with the goal of cure. It is used to control disease, shrink tumours, relieve symptoms, or bridge to other treatments. In some carefully selected cases — for example, radiation segmentectomy of a small single tumour — it can produce results that look similar to ablation or surgery. Whether cure is a realistic aim in your case is something to discuss directly with your oncologist.

Will I lose my hair?

No. Y-90 is not chemotherapy and does not cause the kind of hair loss commonly associated with chemotherapy drugs.

How many Y-90 treatments will I need?

It varies. Some patients have a single session that covers their disease. Others have two sessions, often treating the right and left lobes separately a few weeks apart. Some patients have repeat treatments months or years later if new disease appears. The plan is individual.

How soon will I know if it worked?

The full effect of Y-90 unfolds over months. The first imaging scan, typically at one to three months, gives an early picture of response. Tumour size may not change dramatically on the first scan, but changes in tumour activity (such as reduced contrast enhancement) are meaningful. Continued monitoring over six to twelve months gives the clearer picture.

Can I have Y-90 if I have had a previous TACE or ablation?

Often yes. Prior locoregional treatments do not automatically rule out Y-90. The interventional radiologist will reassess your blood vessel anatomy and liver function during the mapping angiogram.

Can Y-90 be used if cancer has spread outside the liver?

Y-90 acts only on the liver. If significant cancer is also present outside the liver, the team will weigh whether treating the liver disease will meaningfully help, and whether systemic therapy is more important. In some cases — particularly with neuroendocrine tumours — Y-90 to the liver can be very useful even when limited disease is present elsewhere, because the liver disease drives most symptoms.

What does the procedure feel like?

With sedation, most patients feel relaxed and drowsy. You may feel some pressure when the catheter is inserted, but pain is usually minimal because of the local anaesthetic. You will not feel the beads being delivered. After the procedure, some patients have mild discomfort over the liver, which is treated with simple pain relief.

Are there any long-term effects on the liver?

The treated part of the liver shrinks over time and develops fibrosis (scarring). In most patients this is well tolerated because the healthy parts of the liver compensate. In patients with already-impaired liver function, the team is especially careful with dose planning to protect remaining liver tissue.

Can Y-90 be combined with immunotherapy?

This is an active area of research and clinical practice. Combinations of locoregional treatments such as Y-90 with immunotherapy are being studied and used in selected patients with HCC. Whether such a combination is appropriate in your case depends on the specific cancer, current evidence, and your oncology team’s assessment.

Conclusion

Radioembolization with yttrium-90 is a targeted, catheter-based way of delivering radiation directly to liver tumours from inside the blood vessels that feed them. It is part of a broader toolkit for liver cancer and liver metastases that also includes surgery, transplant, ablation, chemoembolization, external radiation, and systemic therapies. For many patients with disease that is mostly confined to the liver and not suitable for surgery, Y-90 is one of the options doctors may consider, sometimes on its own and often alongside other treatments.

The path through Y-90 therapy is well defined: careful imaging and laboratory workup, a mapping angiogram to plan the treatment safely, the treatment day itself, and a recovery period that mostly unfolds over the first few weeks while the radiation does its work over the months that follow. Side effects are usually manageable, and serious complications are uncommon in experienced hands.

If you are preparing for Y-90 therapy, the most useful conversations with your oncology team will focus on what the treatment is intended to achieve in your specific case, how it fits with other treatments you have had or may have, what the team expects in terms of recovery, and how response will be measured. Walking into those conversations with a clear understanding of how the treatment works, and what to expect along the way, makes the whole process feel less unfamiliar and more navigable.