Percutaneous radio frequency ablation of small renal tumors: initial results.
OBJECTIVE
Thermal tissue ablation with radio frequency energy is an experimental treatment of renal tumor. We report early results of an ongoing trial of percutaneous radio frequency ablation for small renal tumors.


METHODS
Patients with percutaneously accessible renal tumors were evaluated for radio frequency ablation. Tumors were solid on computerized tomography (CT), 3 cm. or less in diameter and enlarging during at least 1 year. Ablation was performed at the Interventional Radiology suite under ultrasound and/or CT guidance. A 50 W., 460 kHz. electrosurgical generator delivered radio frequency energy via a percutaneously placed 15 gauge coaxial probe. At least 2, 10 to 12-minute ablation cycles were applied to each lesion. Patients were observed overnight before discharge from hospital and reevaluated 2 months later.


RESULTS
A total of 24 ablations were performed in 21 patients with renal tumor, including solid von Hippel-Lindau clear cell tumor in 19 and hereditary papillary renal cancer 2. Most (22 of 24) procedures were performed with patients under conscious sedation. At 2 months postoperatively mean tumor diameter plus or minus standard deviation decreased from 2.4 +/- 0.4 to 2.0 +/- 0.5 cm. (p = 0.001), and a majority of tumors (19 of 24, 79%) ceased to be enhanced on contrast CT. Mean serum creatinine plus or minus standard deviation was unchanged during this interval (1.0 +/- 0.2 mg./dl.). No major and 4 minor complications were encountered, including 2 episodes each of transient psoas pain and flank skin numbness.


CONCLUSIONS
Percutaneous radio frequency ablation of small renal tumor is well tolerated and minimally invasive. It will remain experimental until procedural and imaging parameters that correlate with tumor destruction are validated.
Pavlovich
Christian P
CP
Urologic Oncology Branch, National Cancer Institute and Division of Radiology, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland.
Walther
McClellan  M
M
Choyke
Peter L
PL
Pautler
Stephen E
SE
Chang
Richard
R
Linehan
W Marston
WM
Wood
Bradford J
BJ
D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000601:surgery; D017115:Catheter Ablation / Q000379:methods; D003404:Creatinine / Q000097:blood; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D006623:von Hippel-Lindau Disease / Q000601:surgery
D003404:Creatinine