The Role of Ablative Techniques in Treatment of Lung Metastasis: Our Interventional Radiology Experience

Objectives: To evaluate retrospectively efficacy and safety of two percutaneous thermal ablation techniques, radiofrequency ablation (RFA) and microwave ablation (MWA), in unresectable lung malignancies, focusing on local tumor progression and survival outcomes. Methods: Data regarding patients with lung metastasis and factors precluding resection who underwent RFA or MWA from July 2008 to December 2019 were reviewed retrospectively. The follow-up computed tomographic scans were performed immediately after procedure and at 1, 3, 6, and 12 months. The primary study objectives such as technical success, primary and secondary technique efficacy rates, local tumor progression (LTP) rate, LPT-free survival (LTPFS), cancer-specific survival (CSS), and overall survival (OS) were assessed. The secondary study objectives included assessment of side effects and complication rate. Predictive factors of LTPFS and OS were analyzed using Mann–Whitney U-test. Results: A total of 118 patients, with an average age of 73 years, underwent 74 RFA (46%) and 85 MWA (53%) for a total of 159 ablations. The histological survey revealed a prevalence of colon and rectum cancer origin, with an average diameter of 17 mm (5–76 mm). Technical success rate was 157/159 (98.7%). Primary and secondary technique efficacy rates were 151/159 (95%) and 150/159 (94%), respectively. During the entire study follow-up, 26 cases experienced disease progression (16%) of which 15 underwent repeat ablation (9%). Residual unablated tumor happened in eight cases (5%), while LTP occurred in 18 cases (11%) after 2–37 months after initial treatment. One-, 3-, and 5-year LTPFS was, respectively, 91%, 89%, and 89%. One-, 3-, and 5-year OS and CSS were 94%, 89%, and 86% and 99%, 98%, and 96%, respectively. Minor and major complications' rate was 51/159 (39%) and 23/159 (14%), respectively. In bivariate analysis, the only factors associated with higher recurrence rate and then with poorer LTPFS were lesion dimensions (P = 0.031) and the technique (P = 0.003), with a higher recurrence percentage in MWA. The technique influenced only LTP and not the survival. In univariate analysis, COPD comorbidity was the only factor associated with poorer OS, but the association did not reach statistical significance (P = 0.094). Conclusion: The findings of this study confirm the appropriateness of percutaneous RFA and MWA for lung metastasis treatment, in terms of good tolerability, safety, and efficacy at follow-up.

Publication History

Article published online:
26 April 2021