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Freezing kidney tumors should be the gold standard or first treatment option for all individuals with tumors that are 4 centimeters in size or smaller. And, this treatment, interventional cryoablation, is a viable option for people with larger tumors, according to two studies presented at the Society of Interventional Radiology's 34th Annual Scientific Meeting.

Interventional cryoablation is as effective as laparoscopic surgery ( partial nephrectomy ), the current gold standard treatment, and laparoscopic cryoablation surgery for treating renal cell carcinoma.

Approximately 54,000 people are diagnosed with kidney cancer each year, with nearly 13,000 dying from it annually, according to recent statistics. Most people with this cancer are older, and the overall lifetime risk of getting kidney cancer is about 1 in 75, with men at higher risk than women. More than 75 percent of individuals who are diagnosed with kidney cancer have small tumors that are discovered incidentally.

The Hopkins studies have examined the safety and efficacy of percutaneous cryoablation, show the treatment's powerful results.
Based on the results of three-year study, Researchers have shown that interventional cryoablation for kidney cancer should be the gold standard or the first treatment option for all patients whose tumors are 4 centimeters or smaller. It should be a viable option for patients whose cancer is even larger than that. And, ablation ( or freezing ) is a very effective option for patients who cannot or do not want to have surgery.
Cryoablation's efficacy rate ( the ratio of how many patients' renal cell carcinoma was destroyed completely for localized tumors by size ) is 100 percent up to 4 centimeters and nearly 100 percent up to 7 centimeters. Three localized 10-centimeter tumors ( large tumors that are typically removed surgically ) were treated; in two cases the tumor was successfully killed.

This finding is especially significant for individuals with small tumors, since more than 75 percent of patients who are diagnosed with kidney cancer have tumors that are 4 centimeters or less in size. These individuals can have their tumors treated completely, effectively, without surgery, with quicker recovery and mostly on an outpatient basis.
At Hopkins, interventional cryoablation is the first-line treatment for small tumors. Most of our patients go home the same day they receive treatment with minimal limitation on regular activities. With laparoscopic kidney surgery, a patient remains in the hospital for several days and recovery time can be from two to four weeks.

Researchers followed kidney cancer patients who had received cryoablation for three years.

In studying cryoablation's efficacy, Researchers looked at 90 tumors in 84 patients. Efficacy was determined based on a tumor's size at 3-, 6- and 12-month clinic visits and then yearly, with follow-up imaging with CT or MRI scans. Both efficacy and three-year survival rates approach 100 percent overall.

In studying cryoablation's safety, Researchers studied the results of 101 percutaneous cryoablations on 91 patients who either couldn't undergo surgery or elected the interventional radiology treatment. Using computed tomography ( CT ) imaging, researchers could view tumors and probes in real time.

Cryoablation is typically performed under light anesthesia, known as sedation, by an interventional radiologist who has consulted with the patient's urologist. One or more hollow needles are inserted through the skin directly into a tumor. Interventional radiologists can observe and guide the insertion by combined use of ultrasound and CT. The needle, or cryoprobe, is filled with argon gas, which creates an ice ball, which rapidly freezes the tumor. The tumor is then thawed by replacing the argon with helium. The procedure consists of two freezing and one thawing cycle, seeking a frozen margin beyond the tumor edge to ensure death of the entire tumor. After the cryoprobe is removed, a small bandage is placed over the skin puncture site. Cryoablation is approved by the FDA ( Food and Drug Administration ) for treating soft tissue tumors, such as renal cell cancer.

Source: Society of Interventional Radiology, 2009


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