Radiofrequency Lung Ablation in ILD

Radiofrequency Ablation in Patients with Interstitial Lung Disease and Lung Neoplasm: A Retrospective Multicenter Study

Clinical Question

Is percutaneous radiofrequency ablation safe and effective against lung neoplasms in patients with interstitial lung diseases?

Take Away Point

Radiofrequency ablation is a feasible technique in combating lung neoplasms in patients with interstitial lung diseases but there are risks of post-procedural acute exacerbations which has a relatively high mortality rate of 45%.

Reference

Yamamoto A, Hiraki T, Ikeda O, et al. Radiofrequency ablation in patients with interstitial lung disease and lung neoplasm: A retrospective multicenter study. Journal of Vascular and Interventional Radiology. 2024;35(9):1305-1312. doi:10.1016/j.jvir.2024.06.010

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Study Design

Retrospective, observation, cohort study

Funding Source

No reported funding

Setting

Academic, Osaka Metropolitan University, et al, Japan

Figure

Summary

Interstitial lung diseases are generally irreversible with poor prognosis. There is no optimal therapeutic approach for concomitant lung neoplasms, which has a frequency of 10-20%. Radiofrequency ablation is a safe and effective treatment strategy for inoperable primary and metastatic lung lesions. The authors of this paper decided to investigate the safety and efficacy of radiofrequency ablation in combating lung tumors in patients with interstitial lung diseases due to lack of pertinent data.

The authors performed a multi-institutional retrospective observational study acquiring data of all the patients diagnosed with lung neoplasm and interstitial lung disease from April 2002 and October 2017 who underwent radiofrequency ablation, with their respective images reassessed by radiologic review. After central radiologic review excluded patients who did not have interstitial lung disease, 49 patients remained in the sample, 43 men and 6 women. Within the 49 patients, there were 64 tumors—34 of which were primary neoplasms and 30 of which were metastatic—with 66 treatment sessions.

Technical success was defined as completion of the radiofrequency procedure. Adverse events were based on the parameters set by the modified definitions of Society of Interventional Radiology, including unexpected increase in the level of care, prolonged hospital stay, or death. The following variables were also included in the study: local tumor progression, overall survival, and acute exacerbation of interstitial lung disease after ablation. Acute exacerbation diagnosis was based on radiologic or clinical diagnosis.

Technical success rate was 100%. While no adverse events occurred during the procedure, multiple events occurred after the procedure, the most frequent being pneumothorax in 53% (35/66 treatment sessions). The rest of the listed adverse events are summarized in Table 3 provided in this article. Acute exacerbations occurred in 8% of the study (5 patients). Among these 5 patients, 3 passed away despite initiation of steroid treatment (60%). The events of acute exacerbations did not differ significantly between patients with UIP (8%) and those without UIP (7%). Additionally, onset of acute exacerbation always occurred at least 8 days after radiofrequency ablation. Univariate analysis determined that pleural effusion and fever were statistically significant risk factors for development of acute exacerbations. Local tumor progression rate was 43% at one year. The overall survival rate at one, three, and five-years were 83%, 62%, and 36%, respectively.

While the results have demonstrated that radiofrequency ablation can be feasible for treating lung neoplasm in patients with interstitial lung disease, the results do not provide consensus recommendations. With regards to procedural safety, prior literature has demonstrated that ablation for lung neoplasms is safe, with mortality rate <1%, which is significantly lower than the mortality rate in patients with interstitial lung disease reported in this series, at 5% per session. The rate of 8% for acute exacerbation and an associated mortality rate of 45% may seem alarming at first. However, the rate of acute exacerbation after surgery was similar to that of ablation at 9.3%, with a similar mortality rate at 43.9%. Similarly, acute exacerbation can occur after thoracic radiotherapy and pharmacotherapy. After all, patients with idiopathic pulmonary fibrosis and non-idiopathic pulmonary fibrosis interstitial lung diseases develop acute exacerbations at a rate of 10-20%, and 3-5%, respectively annually during the natural course. The safety profile of radiofrequency ablation for lung neoplasm should be considered within this specific patient population and not taken out-of-context.

With regards to the local tumor progression rates, various factors may have contributed, both from the operator and from the lesion pathology. The operator may not have had sufficient margin, partly due to the intention to minimize adverse events. Additionally, patients with severe emphysema or UIP may present challenges to the accurate identification of the overall tumor burden, complicating the assessment of local tumor progression. Furthermore, fibrotic changes such as those seen in usual interstitial pneumonia may reduce the ablation’s electrical and thermal conductivity, limiting the tumoricidal effect of radiofrequency ablation.

This study had several limitations apart from its retrospective design. Firstly, interstitial lung disease diagnosis was not based on pathological findings. Secondly, central reading to evaluate interstitial lung disease was only applied to those that were already diagnosed as such, making the study prone to additional selection bias. Multivariate analysis to identify independent risk factors for acute exacerbations could improve the quality of the study. Sub-analyses, which may require a larger study, focusing on patients with primary neoplasms, and patients with metastatic lesions, separately, will provide further clinically relevant information and guidance.

Commentary

Despite several limitations, this article assessing radiofrequency ablation for the treatment of lung neoplasms in patients with concomitant pulmonary pathologies like interstitial lung disease is of significant clinical relevance. Risk factors that predispose patients to interstitial lung disease such as smoking are very prevalent, especially in certain countries like Japan. Referring and treatment physicians of patients with interstitial lung disease need information specific to the patient population. Clinical guidelines and treatment algorithms also require such information for development and refinement. In conclusion, radiofrequency ablation appears feasible in patients with interstitial lung disease with a risk of post-procedural acute exacerbation grossly similar to other treatment modalities.

Post author
Naeem Patel, DO
Radiology Resident, PGY4
Department of Radiology, Interventional Radiology Division
Hartford Hospital, Hartford, CT
@Naeemp7Patel