4 - Clinical applications of thermal ablation

Abstract

Thermal ablation modalities achieve practical success due to their minimally invasive nature, which increases their clinical impact in oncology treatment. They are mostly employed for the treatment of several organs, including the musculoskeletal system, lung, breast, brain, prostate, kidney, and mainly the liver, as an effective alternative to surgical operations which have disadvantages. They are also being explored for other types of malignancies, such as adrenal neoplasms, thyroid carcinomas, primary breast tumors, and skin carcinomas. Currently, both hyperthermic and hypothermic devices are used widely for the treatment of several tumor types. The major advantage in using thermal ablation in tumor treatment is its capability to treat tumors with known volumes in the site, while surgical operations face some difficulties in such a scenario, or where it is desirable to keep the organ to preserve its function. However, thermal ablative modalities have a minor role in the treatment of large bulky tumors (i.e., neck nodules, bones), and superficial disease (i.e., skin). This chapter highlights the role of clinical trials in confirming the selection of the used thermal ablation modality based on the tumor characteristics and the modality qualities. The treatment of tumors in different organs is discussed from a clinical point of view. Furthermore, the advantages and limitations of the most well-known thermal ablation modalities are introduced. For example, the clinical observations recommended using radiofrequency ablation (RFA) and laser ablation (LA) in the treatment of small tumors, such as in the liver, with consideration given to the existence or not of blood vessels owing to their perfusion effects. Microwave ablation (MWA) is adequate for the treatment of large tumors which RFA can treat, along with tumors in tissues with high perfusion, such as the kidney, high impedance, such as bone, and the lung. In addition, high-intensity focused ultrasound (HIFU) is considered a completely noninvasive ablation choice, nevertheless there is inadequate clinical information to support its use. Generally, additional studies are still required to confirm its treatment efficiency and for proper treatment guidelines for each thermal ablation modality for safe use in humans.