TARE – Y-90 Radioembolization for Liver Cancer
TARE (Transarterial Radioembolization), commonly known as Y-90 or SIRT (Selective Internal Radiation Therapy), delivers internal radiation directly into liver tumours through millions of microscopic spheres loaded with Yttrium-90. Unlike TACE, TARE does not completely obstruct tumour blood flow – it delivers a sustained, targeted radiation dose over 14 days. This makes it a powerful option for tumours involving portal vein branches, where TACE carries higher risk, and for achieving tumour downstaging prior to transplant. I am Dr Chetan Kalal, DM Hepatologist at Gleneagles Hospital Mumbai. TARE decisions are made through our multidisciplinary tumour board.
What Is TARE / Y-90?
Yttrium-90 (Y-90) is a radioactive isotope that emits beta radiation – high-energy electrons that travel only 2.5 mm in tissue, creating a highly localised radiation effect. Millions of tiny Y-90 microspheres (20-60 microns in diameter, the size of fine sand grains) are injected via catheter into the hepatic artery. The microspheres lodge in the tumour’s small vessels and emit continuous radiation for approximately 14 days as Y-90 decays to stable Zirconium-90.
Two types of microspheres are available: TheraSphere (glass microspheres, higher activity per sphere, used in smaller volumes) and SIR-Spheres (resin microspheres, lower activity per sphere, used in larger volumes). Both are effective; the choice depends on tumour size, target dose, and institutional preference.
When Is TARE Used?
HCC with Portal Vein Involvement
Portal vein tumour thrombosis (PVTT) is a relative contraindication to TACE but not necessarily to TARE. Y-90 can be used in carefully selected patients with segmental or lobar PVTT where liver function remains preserved.
TACE-Refractory or TACE-Unsuitable
Intermediate HCC that has not responded to TACE, or where TACE is technically difficult due to tumour vascularity, can be treated with TARE.
Downstaging to Transplant
TARE achieves deep tumour responses in HCC beyond Milan criteria, enabling downstaging to transplant eligibility – with some evidence of more durable responses than TACE in larger tumours.
Radiation Segmentectomy / Lobectomy
High-dose TARE to a single liver segment (radiation segmentectomy) achieves ablative tumour control for small HCC – comparable to RFA – while also inducing contralateral hypertrophy, potentially enabling future resection.
Pre-Treatment Planning
TARE requires a planning procedure before treatment. A mapping study using 99mTc-MAA (macroaggregated albumin, a particle that mimics the microspheres) is performed by nuclear medicine: the MAA is injected into the hepatic artery and a nuclear scan assesses how much radioactivity shunts to the lung (lung shunt fraction). If >20% of the particles shunt to the lungs, TARE carries radiation pneumonitis risk and may be contraindicated or require dose reduction. The mapping study also identifies any hepatoduodenal or gastric artery branches that require coil embolisation to prevent non-target radiation.
Treatment is scheduled 1-2 weeks after the mapping study. The actual TARE procedure takes 1-2 hours. Radiation safety precautions for approximately 7 days post-treatment are advised (limiting close contact with pregnant women and young children).
How TARE Differs from TACE
TACE works primarily by ischaemia (cutting off blood supply) with added local chemotherapy. TARE works primarily by radiation, with partial ischaemia. TARE causes significantly less post-embolization syndrome – patients typically feel well 1-2 days after treatment rather than the 5-7 days of fatigue and pain common after TACE. This makes TARE preferable in patients with borderline liver function where a major inflammatory response after TACE is risky. On the other hand, TARE availability requires a nuclear medicine facility with Y-90 licensing, which limits it to specialist centres.
Discuss Y-90 Radioembolization at Gleneagles Hospital
If you have been diagnosed with intermediate or advanced HCC and want to understand whether TARE is an option – particularly if TACE has been tried, is unsuitable, or portal vein involvement is present – contact us to schedule a multidisciplinary tumour board review.