Cure Alveolar Soft Part Sarcoma International (iCureASPS)

Abstract

Image-guided tumor ablation is a rapidly evolving technique for treatment of benign and malignant tumors, but optimization of performance and patient outcomes requires using the most appropriate modality for each patient; this article will help provide a rationale for choosing an appropriate modality for a given clinical scenario.

Abstract

Image-guided thermal ablation is an evolving and growing treatment option for patients with malignant disease of multiple organ systems. Treatment indications have been expanding to include benign tumors as well. Specifically, the most prevalent indications to date have been in the liver (primary and metastatic disease, as well as benign tumors such as hemangiomas and adenomas), kidney (primarily renal cell carcinoma, but also benign tumors such as angiomyolipomas and oncocytomas), lung (primary and metastatic disease), and soft tissue and/or bone (primarily metastatic disease and osteoid osteomas). Each organ system has different underlying tissue characteristics, which can have profound effects on the resulting thermal changes and ablation zone. Understanding these issues is important for optimizing clinical results. In addition, thermal ablation technology has evolved rapidly during the past several decades, with substantial technical and procedural improvements that can help improve clinical outcomes and safety profiles. Staying up to date on these developments is challenging but critical because the physical properties underlying the different ablation modalities and the appropriate use of adjuncts will have a tremendous effect on treatment results. Ultimately, combining an understanding of the physical properties of the ablation modalities with an understanding of the thermal kinetics in tissue and using the most appropriate ablation modality for each patient are key to optimizing clinical outcomes. Suggested algorithms are described that will help physicians choose among the various ablation modalities for individual patients.

©RSNA, 2014

SA-CME LEARNING OBJECTIVES

After completing this journal-based SA-CME activity, participants will be able to:

■ Describe the physical properties of the most commonly used thermal ablation modalities.

■ Discuss the potential advantages and disadvantages of each thermal ablation modality.

■ Apply decision-making algorithms to select an appropriate thermal ablation modality for common clinical indications.


https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4319523/

Introduction

Image-guided thermal ablation is becoming increasingly accepted for the treatment of certain benign and malignant tumors of the lungs, liver, kidneys, bone, and soft tissues (1–6). Numerous thermal and nonthermal ablation modalities are available, including radiofrequency (RF) ablation, microwave ablation, cryoablation, high-intensity focused ultrasonography (US), laser ablation, irreversible electroporation, chemical ablation (with ethanol and acetic acid), and brachytherapy. This article focuses on the thermal ablation devices used most frequently in the United States: RF ablation, microwave ablation, and cryoablation devices. The number of available ablation modalities, the rapid changes in the associated technology (especially recently), the relative lack of randomized controlled or comparative trials, the wide discrepancies in published results (with associated difficulties in interpreting the results), and the variability of practice in different centers have led to confusion about best practice in patients. In this article, some of the issues are elucidated, and the present and future of image-guided tumor ablation are clarified.

The mechanisms of action of various ablation modalities are at the center of many of the relative advantages, disadvantages, and limitations encountered in clinical practice. A basic understanding of the underlying physical processes is critical to determining the most advantageous modality. Therefore, we start by discussing the physical properties of the various modalities and then address the reasons why particular technologies may succeed or fail when applied clinically.