Results of this study confirm that RF ablation is a relatively low-risk procedure for the treatment of focal liver tumors.

RF ablation results in a higher rate of complete necrosis and requires fewer treatment sessions than percutaneous ethanol injection. However, the complication rate is higher with RF ablation than with percutaneous ethanol injection. RF ablation is the treatment of choice for most patients with HCC.

RF ablation appears to be an effective, safe, and relatively simple procedure for the treatment of medium and large HCCs.

Percutaneous image-guided ablative therapies using thermal energy sources such as radiofrequency, microwave, high intensity focused ultrasound (HIFU), and laser have received much recent attention as minimally-invasive strategies for the treatment of focal malignant disease. Potential benefits of these techniques include the ability to ablate tumor in non-surgical candidates, reduced morbidity as compared to surgery, and the potential to perform the procedure on an outpatient basis. This manuscript proposes a unified framework using the "Bioheat equation" for discussing aspects of thermal ablation therapies as they relate to the treatment of focal malignancies. Briefly, these include an understanding of under which conditions heat induces cellular damage, the types of energy sources which can supply this heat, and tissue properties such as perfusion mediated cooling which modify tissue response to the heat deposited. Additionally, the various facets of diagnostic imaging which are required to direct thermal ablation therapy are discussed. These include modalities which can be used for targeting of the lesion to be treated, determination of an optimal treatment plan, and assessment of results at long term follow-up.

Background It is unclear whether an evaluation incorporating coronary computed tomographic angiography (CCTA) is more effective than standard evaluation in the emergency department in patients with symptoms suggestive of acute coronary syndromes. Methods In this multicenter trial, we randomly assigned patients 40 to 74 years of age with symptoms suggestive of acute coronary syndromes but without ischemic electrocardiographic changes or an initial positive troponin test to early CCTA or to standard evaluation in the emergency department on weekdays during daylight hours between April 2010 and January 2012. The primary end point was length of stay in the hospital. Secondary end points included rates of discharge from the emergency department, major adverse cardiovascular events at 28 days, and cumulative costs. Safety end points were undetected acute coronary syndromes. Results The rate of acute coronary syndromes among 1000 patients with a mean (±SD) age of 54±8 years (47% women) was 8%. After early CCTA, as compared with standard evaluation, the mean length of stay in the hospital was reduced by 7.6 hours (P<0.001) and more patients were discharged directly from the emergency department (47% vs. 12%, P<0.001). There were no undetected acute coronary syndromes and no significant differences in major adverse cardiovascular events at 28 days. After CCTA, there was more downstream testing and higher radiation exposure. The cumulative mean cost of care was similar in the CCTA group and the standard-evaluation group ($4,289 and $4,060, respectively; P=0.65). Conclusions In patients in the emergency department with symptoms suggestive of acute coronary syndromes, incorporating CCTA into a triage strategy improved the efficiency of clinical decision making, as compared with a standard evaluation in the emergency department, but it resulted in an increase in downstream testing and radiation exposure with no decrease in the overall costs of care. (Funded by the National Heart, Lung, and Blood Institute; ROMICAT-II ClinicalTrials.gov number, NCT01084239.)