Thermal Protection Techniques for Image-guided Musculoskeletal Ablation

Percutaneous image-guided thermal ablation has gained wide acceptance among physicians for the treatment of benign and malignant tumors of the musculoskeletal system. Increasing evidence to support the efficacy of thermal ablation techniques in primary and adjuvant treatment of soft-tissue sarcomas, treatment of oligometastatic disease to bone and soft tissue, and metastatic pain palliation has positioned interventional oncology alongside surgery, systemic therapies, and radiation therapy as the fourth pillar of modern comprehensive cancer care. Despite the expanding indications and increasing use in clinical practice, thermal ablation carries a significant risk of injury to the adjacent vulnerable structures, predominantly the skin, bowel, and neural structures. Knowledge of the mechanism of action of each thermal ablation modality informs the physician of the attendant risks associated with a particular modality. Thermal ablation mechanisms can be divided into hypothermic (cryoablation) and hyperthermic (radiofrequency ablation, microwave ablation, high-intensity focused US, or laser). Active thermal protection techniques include hydrodissection, pneumodissection, direct skin thermal protection, and physical displacement techniques. Passive thermal protection techniques include temperature monitoring, biofeedback, and neurophysiologic monitoring. The authors provide an overview of the mechanism of action of the most commonly used thermal ablation modalities, review the thermal injury risks associated with these modalities, and introduce the active and passive thermal protective techniques critical to safe and effective musculoskeletal ablative therapy.