RFA expands applications through liver, lung, and kidney therapy data

December 28, 2005

Researchers continue to build the case for RFA with new data showing the procedure to be an effective alternative to surgery for the treatment of liver, lung, and kidney malignancies. Results were presented at the Interventional Oncology Symposium in December.

Researchers continue to build the case for RFA with new data showing the procedure to be an effective alternative to surgery for the treatment of liver, lung, and kidney malignancies. Results were presented at the Interventional Oncology Symposium in December.

LIVER TREATMENT

RFA is as effective as resection for treatment of both hepatocellular carcinoma and metastatic colorectal tumors in the liver, according to two studies presented at the RSNA/SIR joint symposium. The key factor in both cases was RFA's ability to easily repeat treatment on recurring tumors in a much less destructive fashion than surgery.

Three-year survival rates for patients with HCC who were treated with RFA were virtually identical to those treated with resection, according to a study presented by Professor Riccardo Lencioni of the University of Pisa in Italy.

Lencioni and his team compared 38 resections with 124 RFA treatments for patients with single lesions of 5 cm or less. The case-controlled investigation of overall survival rates, tumor progression, and tumor recurrence found a 72% three-year survival rate for patients treated with RFA versus 65% for those treated with resection. The difference is not statistically significant.

Patients treated with RFA experienced a 19% rate of local tumor progression compared with no local tumor progression for those treated with resection. Lencioni attributed some recurrence to tumors that had not been fully ablated on the first treatment. About 50% of both RFA and resection patients experienced tumor recurrence at the three-year mark.

Similarly, three- and five-year survival rates for patients whose small, solitary colorectal metastases were treated with RFA are competitive with survival rates from resection, according to a study presented by Dr. Alice Gillams of the University College London. These findings contradict studies in the surgical literature that suggest four-year survival rates for patients treated with RFA were as low as 22%.

In Gillams' study of 35 patients treated with RFA, three- and five-year survival rates from the time of first ablation were 65% and 43%, respectively. About 40% of patients developed new metastases in the liver, which is consistent with the tumor biology of colorectal cancer. New extrahepatic disease occurred in 41% of patients, and 38% of patients experienced local recurrence. A quarter of patients are tumor-free.

LUNG TREATMENT

Updated data from a multicenter lung cancer trial found cancer-specific two-year survival rates of 92% in patients treated with RFA. It also provided effective local control for both nonresectable non-small cell lung cancers and lung metastases, according to new data from the Radiofrequency Ablation of Pulmonary Tumors Response Evaluation (RAPTURE) Trial.

The prospective multicenter trial is designed to evaluate the feasibility, safety, and effectiveness of RFA for treating lung malignancies in patients who are not eligible for surgery or other anticancer treatments. RFA was used to treat NSCLC and metastatic lesions of no more than 3.5 cm in diameter in 107 patients.

RFA achieved local tumor control in 88% of cases. The 12% of patients who experienced tumor progression at the ablated site were successfully treated again, and the residual tumor was destroyed, said Professor Riccardo Lencioni of the University of Pisa.

The procedure proved most effective for patients with colorectal metastases, Lencioni said. The overall two-year survival rate for the 53 patients in this category was 62%, and median survival time was 29 months. The cancer-specific two-year survival rate was 82%.

The study also evaluated 33 patients with stage 1, 2, 3, and 4 NSCLC. The two-year survival rate for all patients with NSCLC was 48%, and median survival time was 21 months. A separate analysis of 14 patients with stage 1A NSCLC found patients treated with RFA had a 92% two-year cancer-specific survival rate.

Complete tumor ablation occurred in 86% of stage 1A NSCLC patients. One patient experienced local tumor progression after the second ablation.

KIDNEY TREATMENT

Dr. Debra Gervais, an assistant professor of radiology at Harvard University and director of abdominal intervention at Massachusetts General Hospital, found that RFA of renal masses is a safe option for patients with solitary kidneys compared with surgical removal. In addition, RFA preserves renal function sufficient to avoid dialysis in most cases.

The retrospective review of 141 tumors ablated in 125 patients revealed 25 tumors (median 3.1 cm) in 21 patients with solitary or functionally solitary kidneys. Complete ablation was achieved in 92% of tumors. Follow up ranged from one to 75 months, with no local recurrences following complete necrosis.