Does tumor type affect local control by radiofrequency ablation in the lungs?

Objective: To retrospectively evaluate the effect of tumor type on local control by radiofrequency ablation in the lungs.Materials and methods: This study included 252 lung tumors (mean size, 13.5 mm) in 105 patients (73 men and 32 women; mean age, 66.6 years) who underwent radiofrequency ablation with a multitined expandable electrode. Those tumors comprised five tumor types: primary lung cancer (n = 35) and pulmonary metastases from colorectal cancer (n = 117), lung cancer (n = 23), renal cell carcinoma (n = 49), and hepatocellular carcinoma (n = 28). Local control was evaluated with contrast-enhanced computed tomography. The overall local control rates were estimated as well as those for each tumor type using the Kaplan-Meier analysis. Local control rates for a given tumor type were compared with those for the four other types. Then, multivariate multilevel analysis was performed using the variables of tumor type, tumor size, contact with a vessel or bronchus, and procedure period.Results: The overall local control rates were 97%, 86%, 81%, and 76% at 6, 12, 18, and 24 months, respectively. Local control rates varied among the tumor types, and metastatic colorectal cancer showed significantly (P = .023) higher local control rates than those of the four other types. However, multivariate analysis indicated that the relative risk of local progression for a given tumor type was comparable to the risks for the four other types.Conclusion: Tumor type per se did not significantly influence local control.