Radiofrequency Ablation Called Safe and Effective in NSCLC

PROVIDENCE, R.I., March 27 -- Radiofrequency (RF) ablation is a safe and effective option for treating patients with early-stage but inoperable non-small cell lung cancer, according to researchers here.

RF ablation offers outcomes as good as or better than external beam radiation, the current approach when surgery is refused or contraindicated, said Damian Dupuy, M.D., of Rhode Island Hospital and Brown Medical School.

The finding came from a retrospective review of 153 consecutive patients with 189 primary or metastatic inoperable lung cancers who had percutaneous fluoroscopic CT-guided RF ablation, Dr. Dupuy and colleagues reported in the April issue of Radiology.

"In our study, (radiofrequency) ablation produced meaningful results in terms of both survival and tumor control," Dr. Dupuy said. For example, he said, "the best two-year survival rate for early-stage lung cancer using (external beam radiation) is 51%, compared with 57% for ablation."

The 153 patients were stratified according to the intention of treatment -- 21 considered as palliative care only and the remainder in the "local control group."

In the latter group, there were 80 Stage I non-small cell tumors and 82 Stage IV cancers, including some that had metastasized from other malignancies. All told, 602 radiofrequency ablations were performed in 183 sessions.

Initial technical success -- defined as no detectable residual tumor on the first CT scan after the procedure -- was seen in 159 (or 98.1%) of the 162 tumors in the local control group.

Symptoms also improved in the palliation group in all but one of the lesions, but between 25% and 67% of lesions had a recurrence of symptoms, the researchers reported.

The analysis found that:

• For Stage I NSCLC, the one-, two, three-, four- and five-year survival rates, respectively, were 78%, 57%, 36%, 27%, and 27%.
• The rates for colorectal pulmonary metastasis were 87%, 78%, 57%, 57%, and 57%.
• For tumors 3 cm in diameter or smaller, the one-, two, three-, four- and five-year local tumor progression-free rates, respectively, were 83%, 64%, 57%, 47%, and 47%.
• For larger tumors, the rates were 45%, 25%, 25%, 25%, and 25% and the difference between the survival curves for small and large tumors was significant at P<0.002.

The pneumothorax rate was 28.4% of the 183 ablation sessions and a chest tube was required in 9.8%. Six of 153 patients died within 30 days, and four were considered to be related to the procedure, for a 2.6% procedure-specific mortality rate.

The survival curves for Stage I non-small cell tumors compare favorably to those seen in external beam radiation therapy, Dr. Dupuy and colleagues said, where in a representative study had survival rates one, two, and three years of 57%, 36%, and 21%, respectively.

"Ablation is not without risks," the researchers said. "However, we believe our safety profile is acceptable, especially given that the majority of our patients were not candidates for surgery and were treated against backgrounds of severe cardiopulmonary disease."

"Conventional (external beam radiation) therapy involves 33 treatments over a six-week period and can often lead to side effects including radiation pneumonia and the permanent loss of lung tissue," Dr. Dupuy said.

RF ablation "is performed in a single day as an outpatient procedure, is minimally invasive, and has few side effects," he said.

"It's important for physicians to know that ablation is a treatment option for their sickest and elderly patients," Dr. Dupuy said.