Abstract
Imaging-guided percutaneous ablative treatments, such as radiofrequency ablation (RFA), cryoablation and microwave ablation (MWA), have been developed for the treatment of unresectable primary and secondary lung tumors in patients with advanced-stage disease or comorbidities contraindicating surgery. Among these therapies, MWA has recently shown promising results in the treatment of pulmonary neoplasms. The potential advantages of MWA over RFA include faster ablation times, higher intra-tumoral temperatures, larger ablation zones and lower susceptibility to the heat sink effect, resulting in greater efficacy in proximity to vascular structures. Despite encouraging results supporting its efficacy, there is a relative paucity of data in the literature regarding the role of computer tomography (CT) to monitor MWA-treated lesions, and the CT appearance of their morphologic evolution and complications. For both interventional and non-interventional radiologists, it is crucial to be familiar with the CT features of such treated lesions in order to detect incomplete therapy or recurrent disease at early stage, as well as to recognize initial signs of complications. The aim of this pictorial essay is to describe the typical CT features during follow-up of lung lesions treated with percutaneous MWA and how to interpret and differentiate them from other radiological findings, such as recurrence and complications, that are commonly encountered in this setting.
Highlights
The treatment of lung tumors, both primary and metastatic, has undergone substantial diversification in the last two decades [1–5]
Among the different ablation therapies, microwave ablation (MWA) is a relatively new technique, whose effectiveness and safety were demonstrated for the first time in a large study of 50 patients with lung cancer in 2008 by Wolf et al [7]
MWA can be applied to different types of tumors and has recently shown promising results, especially in the treatment of pulmonary neoplasms [9]
Summary
The treatment of lung tumors, both primary and metastatic, has undergone substantial diversification in the last two decades [1–5]. Since the ablated tumor and the surrounding ablated lung tissue remain in place during MWA, the direct histopathologic verification of complete tumor ablation is not possible [13] In this scenario, post-procedural cross-sectional imaging represents the most reliable and feasible means of evaluating and ensuring treatment success, both immediately after the procedure and during follow-up. Despite the well-established role of CT in this scenario, there is currently no unanimous consensus regarding the best imaging modality or the optimal timing to assess success or failure of treatment [10] The purpose of this pictorial essay is to describe a potential timing for post-MWA imaging surveillance using CT by reviewing the expected and typical radiological appearance of post-ablation lung lesions during a predetermined follow-up (1–3–6 months), in order to differentiate them from radiological signs of recurrence or complications
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
