Systematic Review of Image-guided Thermal Ablation for Treatment of High-Risk Patients with Stage I Non-Small Cell Lung Cancer.

Image-guided thermal ablation (IGTA) applied to pulmonary pathology is an alternative to surgery in high-risk patients with stage I non-small cell lung cancer (NSCLC). Its application to lung neoplasm was first introduced in 2001 and has been implemented to treat metastatic disease to the lung or in select medically inoperable patients with peripheral stage I NSCLC. IGTA may also be an alternative to treat stage I NSCLC in non-operable patients with interstitial lung disease in whom a radiation modality is deemed too high risk. There are 3 methods of delivery: radiofrequency ablation (RFA), microwave ablation and cryoablation. Observational series and some prospective trials have shown safety and efficacy across all three modalities. Despite accumulating experience, there are no large randomized clinical trials comparing the outcomes of lung IGTA to alternative locoregional therapies (e.g. stereotactic body radiotherapy or sublobar pulmonary resection) for the treatment of stage I NSCLC. Because IGTA is a local therapy, a higher risk of locoregional recurrence is inherently understood as compared with anatomic resection. In the literature, primary tumor control after RFA ranges from 47-90% and is dependent on tumor size and proximity to bronchovascular structures. Local failure ranges from 10-47%, and tumors ≥ 3 cm have the highest rate of local recurrence. The most prevalent side effects are pneumothorax and reactive pleural effusion; hemorrhage is uncommon. Of note, observational series show no significant loss of lung function after IGTA. This expert review contextualizes limitations, complications and outcomes of IGTA in patients with stage I NSCLC.