Tumor-Zapping Technique Fights Kidney Cancer

Mar. 23 -- FRIDAY, Aug. 3 (HealthDay News) -- A heat-based technique called "CT-guided radiofrequency ablation" was almost 100 percent successful in destroying small malignant kidney tumors in a study of more than 100 patients, new research shows.

Radiofrequency ablation has been used successful in liver tumors since the early 1990s. A needle-like treatment probe, guided by computer tomography (CT), is inserted into the tumor where it emits a high-frequency alternating current. The current heats the tumor tissue and destroys it. Radiofrequency ablation is an outpatient procedure in which the patient is sedated but conscious, and a local anesthetic is used at the puncture site.

The technique targeted tumors ranging in size from 0.6 centimeters to 8.8 centimeters in size. A total of 125 tumors in 104 patients were treated between 2000 and 2006. Of the 95 tumors that were smaller than 3.7 cm, all were completely eradicated by a single treatment, the researchers reported in the August issue of the American Journal of Roentgenology.

Seven of the remaining tumors were eradicated after a second treatment, the team added, for a total 93 percent success rate for all 125 tumors. The tumors were still gone 14 months after treatment. Of the 104 patients in the study, 101 went home the same day.

"This is the largest treatment group to date of patients with biopsy-proven renal malignancies," lead author Dr. Ronald J. Zagoria, of Wake Forest University Baptist Medical Center in Wnston-Salem, N.C., said in a prepared statement. "The results, a high cure rate and low complication rate, establish that at institutions with experience doing this procedure, this is an alternative method for treating small renal malignancies in patients who are not good surgical candidates," he said.

His team noted that the technique is best used for small tumors. Although it can be effective in larger tumors, there is always the risk of incomplete destruction. Further, tumors located near the middle of the kidney pose a particular challenge, because they are close to large blood vessels or the ureter, the tubes that transport urine from the kidney to the bladder.