IMAGE-GUIDED
CRYOABLATION
LIVER METASTASIS
Frequently Asked Questions
about Treating Liver Metastases with Cryotherapy
What are liver metastases?
When it is said that cancer has metastasized, it means that it has spread to a location outside of its original, or primary, site. In this case, it refers to cancer that has spread to the liver from another site. Cancer may spread from any part of the body to the liver. The most common source of metastatic liver cancer is from tumors of the colon and rectum. About 140,000 people in the United States are diagnosed with colon cancer each year, and roughly half of these patients will develop tumors in their liver at some time. Only about one in 10 of these patients will have a chance for a cure by having the liver tumors removed surgically.
How is cryoablation used to treat liver metastases?
For inoperable liver tumors, cryoablation offers a nonsurgical, localized treatment that kills the tumor cells by freezing them, while sparing the healthy liver tissue. Thus, this treatment is much easier on the patient than any type of systemic therapy. Cryoablation can be performed without affecting the patient's overall health and most people can resume their usual activities in a few days. This technique has been used for many years by surgeons in the operating room, but in the last few years, the needles have become small enough to be used by interventional radiologists directly through the skin, without the need for an operation.
When might liver metastases cryoablation be recommended?
Currently, most patients who undergo liver cryotherapy are those whose disease is considered medically or technically inoperable or who refuse surgery. It is generally limited to patients whose lesions are 5cm or smaller, and no more than 4 lesions are usually treated per session. Most studies have included patients with secondary liver involvement from colorectal carcinoma. Cryoablation may also be an option for patients with metastatic disease from less common primary sites such as neuroendocrine, small intestine and ovarian tumors. Cryoablation may also be recommended as a palliative treatment for advanced metastatic liver cancer.
When is cryoablation for treatment of liver metastases not recommended?
The decisions required to determine the optimal treatment plan for any given patient are complex. Literature suggests that patients should be free of active infection, be hemodynamically stable, and that coagulation factors be corrected prior to cryoablation treatment to the liver. In general, lesions larger than 5cm, or that lie so close to adjacent structures that it is impossible to gain a 1 cm margin are not treated by cryoablation. Extra-hepatic metastases may also contraindicate cryotherapy. However, physicians consider many of these contraindications to be relative, especially when performing the procedure for palliative rather than curative treatment.
What type of anesthesia is used for cryoablation of liver metastases?
When liver cryoablation is performed surgically, whether open or laparoscopic, general anesthesia is almost always used. When image-guided percutaneous cryoablation is being performed by an I.R. doctor, it may be possible to perform the procedure under conscious sedation and local anesthesia. Again, the patient’s general health is considered, as well as the location of the tumor within the liver, since the patient must remain completely still during treatment, and the required body position may be uncomfortable.
What can be expected after the procedure?
In the case of percutaneous image-guided cryoablation, a post-procedure imaging scan is usually obtained to assure that there is no bleeding. Patients will generally be observed and have their vital signs monitored in a post-anesthesia recovery area. The patient may be moved from the recovery area when anesthesia has sufficiently worn off and pain is manageable. Generally, patients remain in the recovery area from 2-6 hours and are typically not released from the hospital until it can be ascertained that they have no complications from the procedure and it can be documented that they are hemodynamically stable.
What kind of follow-up care is usually performed?
Currently, definitions of the appropriate length of follow-up and timing of post-procedure testing and imaging are not well established. Ongoing surveillance will be carefully planned so as to evaluate the efficacy of treatment as well as monitor for disease recurrence. A typical follow-up imaging schedule follows, but may be revised at the discretion of the Interventionalist and/or other care team member(s). per institution protocol.
• First scan (MRI or CT) at 24-hours post-ablation or at 7-10 day post-procedure office visit.
• Scan at 1, 3, 6, 9 and 12 months post-procedure.
• Scan at 6 month intervals during the second year post-procedure.
• Yearly scans performed thereafter. |
