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Interventional Radiology Clinic |
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Cancer
Treatment
Medical DisclaimerThe information on this web site is for general informational purposes only. It is not a substitute for a medical evaluation. If you feel that medical interventions are necessary, please check with your physician. |
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Selective Internal Radiation Therapy (SIRT) Radiation therapy for the liver has generally been limited in multifocal disease because the high radiation doses delivered to normal liver tissue can lead to liver failure. Selective internal radiation therapy takes advantage of the general principle that tumor metastases in the liver generally have an increased blood supply. A new FDA approved therapy involving radioactive microspheres (yttrium-90) can be used to safely irradiate liver cancers. SIR-spheres delivered into the arterial circulation of the liver will congregate in highest concentration within areas of increased blood flow (tumors) delivering lethal doses of radiation to these areas while sparing more normal areas of liver. Thus widely multifocal disease can be treated without causing liver failure. Do I qualify for this therapy? Most patients are candidates for this therapy. Three things will determine which patients are appropriate candidates. First, liver function has to be normal. Generally this means that the total bilirubin is less than 2 and that there are no other signs of liver damage. Second, multifocal disease that cannot be treated with surgical resection or appropriately with RF-ablation should be present. The best responses occur with complete removal of the tumor if possible. Some patients may have disease that could be resected or treated with RF-ablation, but for other medical reasons cannot have these procedures done. These patients would also be considered for Selective Internal Radiation Therapy. Third, the arterial supply to the liver has to be appropriate and there cannot be too much shunting of particles thru the liver to the lungs. These factors can only be known after completion of a liver angiogram and liver/lung shunt study. These are performed as a last step prior to scheduling the actual embolization using the yttrium-90 labeled microspheres into the liver. I want to be evaluated what do I do? Schedule an appointment to discuss your case. We will answer your questions and describe the complete process. If it looks like you will be a good candidate and you want to proceed we will schedule an outpatient angiogram and go on from there. Out-of-town patients will be evaluated in a single day and can submit copies of imaging and lab reports prior to visiting. Pre-procedure evaluation. This occurs as an outpatient and takes generally a full day. We begin with a review of your imaging studies (CT, MRI, ultrasound, PET) and medical history with lab work. Then you will undergo a planning arteriogram to evaluate the blood supply to your liver. You will also undergo CT liver imaging with hepatic arterial injection of contrast. Liver/lung shunt evaluation will be performed with injection of Technetium 99m labeled MAA into the hepatic artery. This in essence simulates the actual deliver of the yttrium-90 microspheres demonstrating the expected distribution of the microspheres within the liver and to make sure that too many spheres don't end up outside of the liver in the gut or within the lungs. If the hepatic arterial anatomy is appropriate and there is no evidence of significant shunt of spheres to the lungs or intestine then we will schedule a date for the actual implantation of the yttrium labeled microspheres. Yttrium 90 microsphere treatment of the liver: Once
it has been determined that you are an appropriate candidate for the therapy
a dose will be ordered from Sirtex Medical.
This will take 1-2 weeks to arrive and you will be scheduled to come in the
morning the dose arrives. You will receive intravenous fluids and
pre-medications to help control nausea/pain and to limit acid production in
the stomach. You will undergo a second angiogram (very much similar to the
planning angiogram) during which the spheres will be instilled into half of
your liver. Once the treatment is complete the catheters will be removed and
you will be observed in the hospital. More imaging will be performed to
confirm that the dose went to the liver and the liver only. If you do well,
you will be discharged before 24 hours have passed such that this will be
considered an outpatient procedure. If you have any complications like fever,
vomiting or significant pain then you will stay in the hospital until these
have resolved. Most patients tolerate the procedure quite well and are
discharged as outpatients. Post procedure handout.
Only half of the liver is treated at a time to limit toxicities and
complications. Follow-up will occur 1-2 weeks post procedure and then you
will return to treat the other half of your liver 4 weeks after the initial
treatment. Total time to treat the whole liver therefore takes one month.
FDA Approval Summary: Safety and Effectiveness of SIR Spheres Alternative Liver treatments. Other therapies such as RF-ablation and chemoembolization (TACE) are also performed to treat metastatic disease to the liver. More information.
Affiliated Hospitals Where the Procedure Can be Performed Methodist Specialty and Transplant
Hospital 210 575-8155 Radiology Southwest Texas Methodist Hospital |
