Benign and malignant tumors or neoplastic disease have traditionally been approached systemically with chemotherapy or radiotherapy, or locally with surgery. Recent advancements in minimally invasive therapies now permit the use of techniques to heat tumors to the point of cell death. This form of killing tumors is called thermal ablation. We currently perform thermal ablation using radio frequency and with magnetic resonance-guided high-intensity focused ultrasound. Radiofrequency ablation (RFA) has emerged as a safe, easy and predictable technology for thermal ablation in bone, lung, liver, kidney, prostate, lymph nodes and other soft tissues. It has also been used to treat uterine fibroids, breast tumors and bony metastases. RFA is also being used to treat pain due to soft tissue neoplasms. This technique relies on needles that are used as electrodes and placed with imaging guidance provided by CT, ultrasound or MRI.