Oncologic efficacy of CT-guided percutaneous radiofrequency ablation of renal cell carcinomas.
OBJECTIVE
A single institution's experience with CT-guided percutaneous radiofrequency ablation of biopsy-proven renal cell carcinomas (RCCs) was studied to determine the disease-free survival and complication rate.


METHODS
Data from 125 RCCs in 104 patients treated with curative intent was reviewed. Radiofrequency ablation treatments were performed using conscious sedation and local anesthesia. Patients were followed with contrast-enhanced CT or MRI. Tumor control was defined as the absence of contrast enhancement in the tumor on CT or MRI.


RESULTS
Tumor size ranged from 0.6 to 8.8 cm (mean, 2.7 cm; SD, 1.5 cm). Of the 125 treated tumors, 116 (93%) were completely ablated (109 in a single ablation session, seven after a second ablation session) with a mean follow-up interval of 13.8 months. All 95 RCCs smaller than 3.7 cm were completely ablated, and 21 (70%) of 30 larger tumors were completely ablated, with nine showing evidence of residual viable tumor on follow-up scans. Tumor size smaller than 3.7 cm was significantly associated with achieving complete tumor eradication (p < 0.001). With each 1-cm increase in tumor diameter over 3.6 cm, the likelihood of tumor-free survival decreased by a factor of 2.19 (p < 0.001). There were 8 (8%) complications, none of which resulted in long-term morbidity.


CONCLUSIONS
CT-guided percutaneous radiofrequency ablation is a safe method to treat small RCCs. This study indicates that radiofrequency ablation can reliably eradicate RCCs smaller than 3.7 cm. Treatment of larger RCCs will result in an increased risk of residual RCC.
Zagoria
Ronald J
RJ
Department of Radiology, Wake Forest University Health Sciences, Medical Center Blvd., Winston-Salem, NC 27157-1008, USA.
Traver
Michael A
MA
Werle
David M
DM
Perini
Molly
M
Hayasaka
Satoru
S
Clark
Peter E
PE
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation; D015897:Comorbidity; D016292:Procedural Sedation; D003287:Contrast Media; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D015641:Radiography, Interventional; D012189:Retrospective Studies; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D003287:Contrast Media