Microspheres should only be administered by doctors who are experienced in the treatment of liver tumours using this technology. You will need to attend a pre-treatment day when the medical team will conduct a series of tests to allow them to plan the optimum treatment for you (this is sometimes called work-up). You will then be invited back usually 1-2 weeks later, for treatment using the Selective Internal Radiation Therapy (SIRT) procedure.
The pre-treatment day
On the pre-treatment day, you will usually have a number of tests including: an angiogram, a scintigraphy scan (called a lung-shunting or MAA scan) and possibly, a special CT scan called a CT-hepatic angiogram. (Further explanation of these tests is outlined below). After these tests, you can usually go home on the same day.
Occasionally, these tests reveal that treatment using the SIRT is not achievable because the microspheres cannot be safely delivered to liver tumours without damaging other sensitive tissue.
The angiogram provides a detailed picture of the blood supply to the liver, which can vary between people.
Before the angiogram, the groin area is numbed with a local anaesthetic and a small cut is made. A soft, flexible catheter (tube) is then inserted through the cut and directed into the hepatic artery via the femoral artery (so the catheter is sometimes called a femoral catheter).
Once the catheter is in place, a contrast medium (dye) is injected through the tube and images of blood vessels are captured using x-rays.
The procedure usually takes about 60-90 minutes but may take longer in some cases.
It usually involves little discomfort and you may have a feeling of warmth or a slight burning sensation when the contrast material is injected. The most difficult part may be lying flat for the procedure. After the procedure, you can resume a normal diet and all normal activities within 8 to 10 hours.
2. Scintigraphy (lung-shunting scan or MAA scan)
Scintigraphy is an imaging method that uses radioactive materials called radiopharmaceuticals or radiotracers as a dye.
In an MAA scan, the radiotracer MAA is injected into the catheter that has been positioned in your hepatic artery. This radiotracer imitates the SIR-Spheres® Y-90 resin microspheres and allows the medical team to predict where they will lodge on the day of treatment.
A gamma camera and a computer are used to determine the amount and location of radiotracer absorbed by your body (by detecting gamma radiation from MAA). Sometimes some of the radiotracer will pass through the liver into the lung. Your doctor needs to know how much passes through to determine a safe dose of SIR-Spheres Y-90 resin microspheres for you.
You will need to remain still for the brief periods of time while the images are taken.
3. CT-hepatic angiogram
Sometimes the information given in an angiogram is not sufficient. Your doctor might decide to do an additional test called a CT-hepatic angiogram. Contrast medium is injected through the catheters in the groin, while the CT scan is performed to show the blood vessels in the liver.
The treatment day
Usually, you can have SIRT as an outpatient or you may need to stay in hospital overnight.
On the treatment day you will have another angiogram.
This angiogram is usually quicker than the pre-treatment angiogram because the doctor has already identified the best place for the positioning of the catheter.
Once the catheter placement is confirmed, the SIRT can be given. This takes about 15-20 minutes and the entire procedure lasts approximately 1 hour from beginning to end.
You will not need an anaesthetic, but you will be given a sedative to help you relax as well as pain relief and anti-sickness medication if you need it.
After the SIRT procedure and the SIR-Spheres Y-90 resin microspheres have been delivered, the catheter is removed. You will have a small dressing placed over the cut in the groin and pressure will be applied to the site for 10-15 minutes.
You will be asked to lie still for about 4 hours to prevent bleeding.
Sometimes you will have another scintigraphy scan after the treatment to confirm the placement of the microspheres. (This scan is sometimes called a "Bremsstrahlung" scan). You only need to lie under the gamma camera for about 20 minutes and there are no further injections or treatments.
After the procedure, you will be monitored for a few hours and most people are discharged within 24 hours.