CT after Lung Microwave Ablation: Normal Findings and Evolution Patterns of Treated Lesions

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

Prediction of Ablation Volume in Percutaneous Lung Microwave Ablation: A Single Centre Retrospective Study

Background: Percutaneous Microwave Ablation (MWA) of lung malignancies is a procedure with many technical challenges, among them the risk of residual disease. Recently, dedicated software able to predict the volume of the ablated area was introduced. Cone-beam computed tomography (CBCT) is the imaging guidance of choice for pulmonary ablation in our institution. The volumetric prediction software (VPS) has been installed and used in combination with CBCT to check the correct position of the device. Our study aimed to compare the results of MWA of pulmonary tumours performed using CBCT with and without VPS. Methods: We retrospectively reviewed 1-month follow-up enhanced contrast-enhanced computed tomography (CECT) scans of 10 patients who underwent ablation with the assistance of VPS (group 1) and of 10 patients who were treated without the assistance of VPS (group 2). All patients were treated for curative purposes, the maximum axial diameter of lesions ranged between 5 and 22 mm in group 1 and between 5 and 25 mm in group 2. We compared the presence of residual disease between the two groups. Results: In group 1 residual disease was seen in only 1 patient (10%) in which VPS had ensured complete coverage of the tumour. In group 2 residual disease was found in 3 patients (30%). Conclusions: Using this software during MWA of lung malignancies could improve the efficacy of the treatment compared to the conventional only CBCT guidance

A) Advances in extracorporeal detoxification by MARS dialysis in patients with liver failure

Although liver transplantation has become standard procedure for patients with liver failure, a number of issues in the management of these patients remains to be addressed. Alternative approaches have been tested, such as hepatocytes containing liver-support systems and filtration devices. However, the replacement of detoxification has been difficult, as the majority of toxins accumulating in liver failure is albumin-bound. Albumin dialysis (MARS system) is characterized by the specific removal of albumin-bound toxins through an innovative membrane transport. In particular, the albumin acts as a specific molecular adsorbent that is regenerated on line in a recycling system. Nowadays MARS represents the most frequently used liver support system. This treatment has been shown to remove albumin-bound molecules, such as bilirubin, bile acids, aromatic amino acids and copper. The removal of these toxins is clinically accompanied with an improvement of liver, cardiovascular and renal functions and hepatic encephalopathy. In several trials MARS was found to improve the clinical situation in patients with acute exacerbation of chronic liver failure and acute hepatic failure, but also in hepatorenal syndrome and primary graft non function or chronic rejection after liver transplantation. In summary, a critical analysis of the literature confirms that MARS device can be a safe therapeutic choice to achieve a better clinical outcome, and, sometimes, a survival advantage in patients with liver failure, even if a multi-center randomized trial is the only reliable way to enforce today's results. Further advances in the MARS components will definitively state whether albumin dialysis may represent the future in the field of artificial liver devices