Percutaneous radiofrequency ablation yields high proportions of sustained complete responses in properly selected patients with pulmonary malignancies, and is associated with acceptable morbidity, according to a trial published in the July issue of Lancet Oncology.
Riccardo Lencioni, MD, from the division of diagnostic and interventional radiology, department of oncology and advanced technologies in medicine at the University of Pisa in Italy, and colleagues said that the purpose of the study was to identify the feasibility, safety and effectiveness of percutaneous radiofrequency ablation of malignant lung tumors.
Between July 1, 2001, and Dec. 10, 2005, the researchers enrolled 106 patients with 183 lung tumors that were 3.5 cm in diameter or smaller (mean 1.7 cm) in a prospective, intention-to-treat, single-arm, multicenter clinical trial from seven centers in Europe, the United States and Australia.
Diagnoses included non-small-cell lung cancer (NSCLC) in 33 patients, metastasis from colorectal carcinoma in 53 patients and metastasis from other primary malignancies in 20 patients, the authors wrote.
All patients were considered by the treating physician to be unsuitable for surgery and unfit for radiotherapy or chemotherapy. Patients underwent radiofrequency ablation in accordance with standard rules for CT-guided lung biopsy and were then followed for up to two years, according to the researchers.
Lencioni said that the primary endpoints were technical success (defined as correct placement of the ablation device into all tumor targets with completion of the planned ablation protocol), safety (including identification of treatment-related complications and changes in pulmonary function) and confirmed complete response of tumors. The secondary endpoints were overall survival, cancer-specific survival and quality of life.
Lencioni and colleagues found that correct placement of the ablation device into the target tumor with completion of the planned treatment protocol was feasible in 105 (99 percent) of 106 patients. The technical failure in one patient was caused by the inability to place the device inside a small tumor, according to the researchers.
The authors wrote that no procedure-related deaths occurred in any of the 137 ablation procedures. Major complications consisted of pneumothorax (27 cases) or pleural effusion (4 cases), which needed drainage. No significant worsening of pulmonary function was noted.
The investigators also reported a confirmed complete response of target tumors, lasting at least one year was shown in 75 (88 percent) of 85 assessable patients. No differences in response were noted between patients with NSCLC or lung metastases. The authors wrote that the overall survival was 70 percent at one year and 48 percent at two years in patients with NSCLC; 89 percent at one year and 66 percent at two years in patients with colorectal metastases; and 92 percent at one year and 64 percent at two years in patients with other metastases.
Lencioni and colleagues said that cancer-specific survival was 92 percent at one year and 73 percent at two years in patients with NSCLC 91 percent at one year; 68 percent at two years in patients with colorectal metastases; and 93 percent at one year and 67 percent at two years in patients with other metastases. Patients with stage I NSCLC (13 cases) had a two-year overall survival of 75 percent and a two-year cancer-specific survival of 92 percent.
Based on their findings, the researchers recommended that randomized controlled trials comparing radiofrequency ablation with standard non-surgical treatment options are warranted.