As the management of breast cancer evolves toward less invasive treatments, the next step is the possibility of removing the primary tumor without surgery. The most promising of the noninvasive ablation techniques is radiofrequency ablation, which uses frictional heating that is caused when ions in the tissue attempt to follow the changing directions of a high-frequency alternating current. Three pilot studies, including an ongoing study at M.D. Anderson Cancer Center, have demonstrated that radiofrequency ablation is effective for the destruction of small primary breast cancers. The most important factorfor successful radiofrequency ablation is accuracy of the ultrasound evaluation, which is used to estimate tumor size, localize the tumor for treatment, and monitor the progress of the ablation. A study in preparation at M.D. Anderson will determine whether the use of radiofrequency ablation alone for the local treatment of primary breast cancer will result in outcomes equivalent to those obtained with breast conservation therapy.