Image-Guided Ablation a Viable Treatment for Small Renal Tumors
Roger Williams, DO
SAN FRANCISCO—Image-guided ablation of primary renal cancers smaller than 4.8 cm may be performed with minimal morbidity and produce excellent results in terms of long-term survival, according to a new study presented at the 37th Annual Scientific Meeting of the Society of Interventional Radiology.
“The outcomes are comparable to partial nephrectomy,” said study investigator Roger Williams, DO, Assistant Professor of Radiology at Emory University in Atlanta. “Image-guided percutaneous cryoablation is similar to partial nephrectomy, in that the ablation zone can be sculpted to cause tumor destruction, while preserving adjacent renal parenchyma and therein renal function. There is also lower morbidity.”
Dr. Williams, who presented the study findings, said percutaneous image-guided ablation is an accepted treatment for nonsurgical candidates with limited renal tumor burden and appropriate tumor location. He and his colleagues investigated four-year survival rates among patients with biopsy-proven malignant renal neoplasms at their institution.
A total of 50 ablations of biopsy-proven renal cell carcinoma (RCC) were performed on 43 patients from December of 2004 to July 2011. The study included 30 males and 13 females, and the mean age was 65 years (range 47-89 years). In this group of patients, extrarenal disease was identified in 22 patients. Four patients had treated contralateral RCC and four received chemotherapy. Among the four chemotherapy patients, three received adjutant therapy and one received immunosuppression for a renal transplant.
Dr. Williams said 46 lesions (92%) were treated under moderate sedation and four (8%) under general anesthesia. Treatment modalities included radiofrequency ablation for 39 ablations and cryoablation for 11 ablations. The mean tumor diameter was 2.4 cm (range 0.9 – 4.8 cm).
The three and four-year survival rates following ablation were 82% and 71%, respectively.
Survival rates did not differ by gender, treatment modality, or tumor number. Pre-and post-ablation creatinine levels and glomerular filtration rate also had no significant effects on survival.
For patients with stage 1 disease, the three- and four-year survival rates were both 85%. For stage 4 patients, the three- and four-year survival rates were 76% and 66%, respectively.
“These are important findings,” Dr. Williams told Renal & Urology News. The four-year survival is above 90% for stage 1 patients, so that shows that this is a viable treatment modality. The percutaneous treatment of neoplasms has benefits for the patients. In the majority of cases there is no general anesthesia. It is outpatient and it is important to know we can reach surgical standards using percutaneous methods.”