[Ablation Treatment for Peripheral Lung Cancers]

Ablation therapy is a minimally invasive local treatment that destroys tumor tissue. It has attracted attention as a treatment option for early-stage lung cancer and metastatic lung tumors. In this review, we provide an overview of the current status of treatment, technical characteristics, indications, and treatment results for three ablation methods for peripheral lung lesions: radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (PCT). RFA is relatively simple to perform, but its therapeutic effect is limited in tumors near blood vessels due to the influence of heat diffusion by blood vessels and bronchi. MWA enables wide-range ablation in a short time compared to RFA and has the advantage of being less affected by blood vessels and bronchi. PCT enables easy confirmation of the ablation range because it can be visualized as an ice ball on computed tomography (CT) fluoroscopy and is less painful for the patient. It is characterized by the induction of tumor cell death by apoptosis and the preservation of tissue structure. The indications for ablation therapy are mainly early-stage non-small cell lung cancer (NSCLC) that is difficult to surgically resect. Patients with high surgical risk, such as elderly patients and patients with serious complications, are targeted. The combination of ablation therapy and immunotherapy is expected to have a therapeutic effect, and systemic antitumor effects through the release of tumor-associated antigens can be expected. In the future, further expansion of treatment options for lung cancer is expected with the development of optimal combination methods with immunotherapy and the development of transbronchial approaches.