Transarterial Radioembolisation

WHAT IS TRANSARTERIAL RADIOEMBOLISATION?

Transarterial Radioembolisation (TARE) consists of the delivering particles loaded with a radioactive compound directly into the liver. This is done by placing these particles superselectively into the artery supplying the liver. The hepatic artery is accessed through an angiography catheter inserted per cutaneously through a puncture in the groin. Radioactive compounds such as yttrium-90 microspheres or iodine131 or rhenium188 labelled Lipiodol may then be injected through this catheter, into the tumour in the liver

WHO ARE THE PATIENTS WHO MAY BENEFIT FROM TARE?

TARE is used in the treatment of primary and metastatic HCC and cholangiocarcinoma. TARE in combination with chemotherapy is also a very effective therapy in the treatment of colon cancer with secondaries in the liver.

IS TARE THE SAME AS TACE?

TACE is Transarterial Chemoembolisation where chemotherapy loaded particles into the liver. TACE is effective only in small liver tumours or where there are only one or two secondaries in the liver while TARE can be used even in situations where there is a large tumour in the liver or multiple tumours in the liver. While TACE is less expensive than TARE, the post procedure side effects of TACE may be slightly more severe than TARE.

WHAT ARE THE SIDE EFFECTS OF TARE?

Typically TARE is well tolerated. There may be some transient pain in the upper abdomen. In very few cases where there is extensive liver involvement there may be a worsening of the liver function tests and in rare instances an acute liver failure. However complications are extremely rare, with the incidence of serious complications being less than 1% .

WHY SHOULD I CHOOSE FMRI FOR THE PROCEDURE?

Having an experience of more than 14 years, the team at FMRI is adept at performing TARE procedures with response and complication rates at par with the best centres of the world. Also due to the vibrant technological support to the team, they have access to both Y90 Sirspheres as well as I-131 lipiodol. While Y90 Sirspheres is commercially available, is imported from Australia. Iodine 131 lipiodol is labelled in house using extremely strict quality assurance protocols. While the efficacy and adverse effects of both tracers is similar, Iodine 131 lipiodol is far cheaper than Y90 Sirspheres. Iodine Lipiodol is available at very select centres across the world, FMRI being one of them, as it requires a high degree of technical expertise to label and administer.

WHAT ABOUT RESPONSE RATES OF TARE?

Response rates depend of multiple factors, whether the tumours are primary cancers of the liver or secondaries from another cancer. How big are the tumours, how much of the liver is involved by the tumour, the tumour biology and the general condition of the patient. Treatments are personalised based on all these factors. Each case is discussed in a multidisciplinary tumour board consisting of medical oncologists, radiation oncologists and surgeons to ensure that best clinical practice protocols are followed.

HOW IS THE PROCEDURE DONE?

The interventional radiologist and the nuclear medicine expert first study the triple phase CT scan of the patient to ascertain feasibility of performing TARE. Then the patient is admitted for a day or in the day care for a hepatic angiography. Hepatic angiography involves inserting an angiographic catheter through a puncture in the groin to visualise the arterian anatomy of the patients liver. Some vessels may also need coiling to ensure that the radioactive particles are delivered specifically to site of the tumour and do not run off into the other organs due to any errant vessels. The interventional radiologist while doing the angiography injects a radioactive substance called Tc99m MAA which helps him simulate the exact distribution of the TARE particles in the liver even before the actual injection of TARE particle. The patient is subsequently discharged from the hospital while the interventional radiologist and the nuclear medicine expert study the patients images to plan the procedure and calculate the dose which needs to be delivered. It typically takes about a week to order the dose. In a second round the patient is admitted again, an angiography catheter is again placed in the liver artery and this time the actual TARE pharmaceutical is injected. The TARE particle finds its way to the tumours in the liver and get trapped there, emitting radiation to the tumour and killing it slowly

WHAT HAPPENS AFTER THE PROCEDURE?

The patient usually needs to stay in the hospital for 2-3 days after the TARE procedure, primarily because the radioactive material administered to the patient renders the patient radioactive for some time and he needs to be kept in relative isolation to protect the attendants and the general population from uneccesary radiation exposure.