Nonsurgical Candidates Do Well With Renal Cancer Ablation

Pam Harrison

March 21, 2013

VIENNA, Austria — Elderly patients with renal cancer and patients with comorbidities who are poor candidates for surgery do well after treatment with percutaneous radiofrequency ablation and have few complications and recurrences, according to a new study.

"Nearly half of all renal cancers are now diagnosed incidentally because of the increasing use of imaging. For these patients, a conservative surgery has been developed to preserve renal function," lead investigator Pierre Balageas, MD, from Saint-André Hospital in Bordeaux, France, told Medscape Medical News.

However, Dr. Balageas, who presented the results here at the European Congress of Radiology (ECR) 2013, pointed out that "there still are patients with small renal cancers who are poor candidates for surgery because of advanced age or comorbidities. For these patients, percutaneous radiofrequency ablation works well."

To evaluate the effectiveness of the approach, Dr. Balageas and his team retrospectively reviewed all T1a renal cancers treated with percutaneous radiofrequency ablation at a single centre from 2002 to 2009. A total of 93 patients (median age, 73.5 years) underwent the procedure.

The technique used depended on tumor size, morphology, and location. "Most patients were treated with computerized-tomography-guided ablation," but 2 were treated with ultrasound guidance, Dr. Balageas noted.

The survival analysis involved 62 patients (mean age, 69.5 years) with 71 tumors (mean size, 23.9 mm). Mean follow-up was 38.8 months.

After initial treatment of the tumors, the technical success rate was more than 95%. After the retreatment of recurrences, the secondary success rate was more than 98%.

There was no change in real function 2 and 6 months after the procedure. Rates of both tumor progression (~3%) and metastatic evolution (~10%) were relatively low, and median survival was 68 months, Dr. Balageas reported.

One year after radiofrequency ablation, more than 98% of patients were alive and free of disease; 3 years after, 92% were; and 5 years after, approximately 61% were.

"In our study, tumor site was the only independent factor predicting risk for residual tumor or in situ recurrence," Dr. Balageas said, "and all tumors less than 40 mm were completed ablated after 1 procedure."

Major complications occurred at a rate of 5.9% per session. Central location of the tumor was the only factor associated with an increased risk for complications.

"Our experience using radiofrequency for renal tumors is increasingly being helped, not only by our good results, but also by the treatment strategy established with members of our surgical team, who have become convinced of the benefits of this technique," Dr. Balageas observed.

Session chair Jurgen Fütterer, MD, from the Radboud University Nijmegen Medical Centre in the Netherlands, who was asked by Medscape Medical News to comment on this study, noted that both radiofrequency ablation and cryoablation can be used to treat small renal tumors with curative intent.

"Not every patient with renal cancer is a candidate for radiofrequency ablation, but patients with localized disease who have a high mortality risk with general anesthesia are," he said.

Dr. Fütterer noted that the literature suggests that radiofrequency ablation has a success rate of ~80%, so the success rate achieved by Dr. Balageas and colleagues is very good.

Factors Affecting Success

In another study presented during the same session, Vanessa Acosta-Ruiz, a medical student at Uppsala University in Sweden, reported that her team also found very high success rates in 44 patients treated with percutaneous radiofrequency ablation over a period of 4.5 years.

"After the first ablation, 75% of the tumors were completed ablated, 8 tumors were incompletely ablated, and 7 were retreated, so we ended up with a total success rate of 85%," Acosta-Ruiz said.

Correct positioning of the electrode over the tumor favorably affected results, as might be expected, she added.

However, a tumor smaller than 30 mm and a distance from the tumor to the collecting system of at least 10 cm were more likely to be associated with complete ablation, she added.

Dr. Balageas, Dr. Fütterer, and Ms. Acosta-Ruiz have disclosed no relevant financial relationships.

European Congress of Radiology (ECR) 2013: Abstracts B176 and B177. Presented March 7, 2013.