Pulmonary radiofrequency ablation (Part 1): current state

Endoscopic radiofrequency biliary ablation treatment: A comprehensive review

Radiofrequency ablation (RFA) functions by delivering thermal energy within tissue, the result of a high-frequency alternating current released from an active electrode, leading to coagulative necrosis and cellular death. Recently, a biliary catheter working on a guidewire has been developed and a number of studies have so far been carried out. The present article provides a comprehensive review of the literature on the results of the use of RFA for the clinical management of patients with unresectable malignant biliary strictures, benign biliary strictures, and residual adenomatous tissue in the bile duct after endoscopic papillectomy. Available data show that biliary RFA treatment is a promising adjuvant therapy in patients with unresectable malignant biliary obstruction. The procedure is safe, well tolerated and improves stent patency and survival, even though more studies are warranted. In patients with residual endobiliary adenomatous tissue after endoscopic papillectomy, a significant rate of neoplasia eradication after a single RFA session has been reported, thus favoring this treatment over surgical intervention. In these patients, as well as in those with benign biliary strictures, dedicated probes with a short electrode able to focus the RF current on the short stenosis are needed to expand RFA treatment for these indications.

Contrast-Enhanced Ultrasound-Guided Radiofrequency Ablation of Renal Tumors

Although only limited long-term studies evaluating thermal ablation of renal masses have been performed, it appears that thermal ablation has a comparable 5-year success rate to that of partial or total nephrectomy. This technique is often used in patients who are not good candidates for partial or total nephrectomy. Contrast-enhanced ultrasound (CEUS) has been recently approved by the Food and Drug Administration for characterization of focal liver lesions in adults and pediatric patients. CEUS can be used off label for renal applications and has been used for years in Europe and Asia. It has several advantages over contrast-enhanced computed tomography for use as the technique to guide and evaluate efficacy of thermal ablation of renal masses. These include the ability to visualize small amounts of enhancement, repeat dosing to evaluate efficacy of an ablation during a procedure, thin slice thickness, and real-time visualization. Ultrasound contrast is also non-nephrotoxic and non-hepatotoxic, allowing evaluation of patients with renal insufficiency. This article reviews the use of CEUS for the guidance and follow-up of thermal ablative procedures of renal masses.

Interventional procedures in the chest

Many thoracic conditions will require an interventional procedure for diagnosis and/or treatment. For this reason, radiologists need to know the indications and the technique for each procedure. In this article, we review the various interventional procedures that radiologists should know and the indications for each procedure. We place special emphasis on the potential differences in the diagnostic results and complications between fine-needle aspiration and biopsy. We also discuss the indications for radiofrequency ablation of lung tumors and review the concepts related to the drainage of pulmonary abscesses. We devote special attention to the management of pleural effusion, covering the indications for thoracocentesis and when to use imaging guidance, and to the protocol for pleural drainage. We also discuss the indications for percutaneous treatment of pericardial effusion and the possible complications of this treatment. Finally, we discuss the interventional management of mediastinal lesions and provide practical advice about how to approach these lesions to avoid serious complications.