Percutaneous Image-Guided Ablation of Lung Tumors

Abstract

Tumors of the lung, including primary cancer and metastases, are notoriously common and difficult to treat. Although surgical resection of lung lesions is often indicated, many conditions disqualify patients from being surgical candidates. Percutaneous image-guided lung ablation is a relatively new set of techniques that offers a promising treatment option for a variety of lung tumors. Although there have been no clinical trials to definitively compare its efficacy to those of traditional treatments, lung ablation is widely practiced and generally accepted to be safe and effective. Especially encouraging results have recently emerged for cryoablation, one of the newer ablative techniques. This article reviews the indications, techniques, contraindications, and complications of percutaneous image-guided ablation of lung tumors with special attention to cryoablation and its recent developments in protocol optimization.

Image-Guided Percutaneous Ablation for Primary and Metastatic Tumors

“…RFA ( Figure 2 ) works by delivering radiofrequency waves in the 375–500 kHz range to an area surrounding a generator-coupled electrode, causing an oscillating electric field that creates frictional energy by electron collision. This collision generates heat that leads to eventual tumor destruction by coagulation necrosis from temperatures above 60 °C [ 19 , 24 , 25 ].…”

“…Cryoablation ( Figure 4 ) destroys tumors by applying freezing temperatures or alternating freeze–thaw cycles [ 29 ]. This technique works by utilizing the Joule–Thomson effect by which certain gases such as nitrogen, nitrous oxide, or argon drop in temperature when going from high pressure to low pressure [ 24 , 30 ]. Once the target region reaches temperature of −40 °C, ice crystals form in the extracellular space that leads to increased tonicity and osmotic damage to cells in the area [ 24 , 31 , 32 ].…”

“…This technique works by utilizing the Joule–Thomson effect by which certain gases such as nitrogen, nitrous oxide, or argon drop in temperature when going from high pressure to low pressure [ 24 , 30 ]. Once the target region reaches temperature of −40 °C, ice crystals form in the extracellular space that leads to increased tonicity and osmotic damage to cells in the area [ 24 , 31 , 32 ]. Eventually, intracellular ice forms, rupturing the plasma and organelle membranes, followed by indirect cell death by thrombosis of damaged blood vessels that lead to ischemia and inflammation [ 24 , 33 ].…”

“…Once the target region reaches temperature of −40 °C, ice crystals form in the extracellular space that leads to increased tonicity and osmotic damage to cells in the area [ 24 , 31 , 32 ]. Eventually, intracellular ice forms, rupturing the plasma and organelle membranes, followed by indirect cell death by thrombosis of damaged blood vessels that lead to ischemia and inflammation [ 24 , 33 ].…”

Clinical application status and prospect of the combined anti-tumor strategy of ablation and immunotherapy

“…In a palliative treatment of bronchial cancer, cryoablation also effectively relieved the severe pain and hemoptysis which caused by bronchus blockage, and restored the bronchial ventilation again ( 24 ). Cryoablation has been widely used in the treatment of patients with early hepatocellular carcinoma (HCC), non-small cell lung cancer (NSCLC), pleural lesions, palliative treatment of lung metastatic foci, which achieved good clinical outcome ( 25 , 26 ). A phase I clinical study enrolled 160 patients with NSCLC after cryoablation therapy.…”