A clinical study of thermal monitoring techniques of ultrasound-guided microwave ablation for hepatocellular carcinoma in high-risk locations

Abstract

To confirm the safety and effectiveness of the minimally invasive thermal monitor technique on percutaneous ultrasound-guided microwave ablation (MWA) for hepatocellular carcinoma (HCC) in high-risk locations, a total of 189 patients with 226 HCC nodules in high-risk locations were treated with MWA. The real-time temperature of the tissue between the lesion margin and the vital structures was monitored by inserting a 21G thermal monitoring needle. The major indexes of technical success, technique effectiveness, local tumour progression and complications were observed during the follow-up period. Technical success was acquired in all patients. Technique effectiveness was achieved with one session in 119 lesions based on contrast-enhanced ultrasound (CEUS) 3–5 days after treatment. An additional 95 lesions achieved technique effectiveness at the second session. Within the follow–up period of 6–58 months (median 38 months), the 1-, 2-, 3-, and 4-year local tumour progression rate was 11.1%, 18.1%, 19.1%, and 19.9%, respectively. There were no major complications in all the patients except for the common side effects. These results indicate that the thermal monitor technique can be applied to prevent major complications in vulnerable structures and allow percutaneous MWA to achieve satisfactory technique effectiveness in the treatment of HCC in high-risk locations.

Ultrasound-guided percutaneous microwave ablation for hepatocellular carcinoma adjacent to large vessels: a propensity score matching analysis

“…With larger zones of necrosis, MWA may increase the risk of potential collateral injury to adjacent non-target organs such as gastrointestinal tract, diaphragm, gallbladder, etc [9,24,28]. Furthermore, the higher energy might cause injury to surrounding bile ducts and vessels, leading to cholangiectasis, bile leakage, thrombosis, occlusion of blood vessels and segmental liver infarction [8,11,24,29]. In this study, no related biliary tract damage and vascular injury were observed in the Vessel group.…”

3D visualization ablation planning system assisted microwave ablation for hepatocellular carcinoma (Diameter >3): a precise clinical application

“…Microwave ablation (MWA) is an acceptable therapeutic efficiency option for hepatocellular carcinoma (HCC) with several advantages, such as produce larger ablation volume rapidly, less affected by heat-sink effect and less dependence on the electrical conductivities compared to radiofrequency ablation (RFA) [1][2][3][4]. However, high local tumor recurrence rates seriously restrict the long-term survival of HCC, especially for larger tumors or challenging locations ones [5][6][7][8]. A possible reason is the inability to determine the optimal permutation of ablations spheres and the exact location of antennae placement to completely destroy target tumors based on traditional two-dimensional (2D) preoperative treatment planning, which is mainly dependent on spatial awareness and highly subjective experience of radiologists.…”

Monitoring Thermal Ablation via Microwave Tomography: An Ex Vivo Experimental Assessment

“…Before the treatment, to help targeting the applicator in the center of the tumor to be treated, clinicians use image-guidance techniques such as ultrasounds (US), computerized tomography (CT), or magnetic resonance imaging (MRI). During the treatment, temperature is monitored by temperature sensors (usually thermocouples), whose positions are carefully chosen to assure safe temperatures in critical organs close to the tumor to be treated [14,15,16,17,18,19,20,21,22,23,24]. Techniques which could be used to monitor the evolution of the thermally ablated area during the treatment include US, CT, and MRI.…”

“…In particular, US would be the most natural choice for MTA real-time monitoring, due to its widespread availability, low cost, and real-time imaging up to sub-millimeter resolutions [17]. However, US can be scarcely effective for the real-time monitoring of MTA procedures, because it is blinded by a hyper-echogenic cloud caused by water vaporization in the heated tissue, which conceals the applicator and the tumor [1,18].…”

“…MRI is potentially the most accurate and safe technique to perform real-time thermometry during the procedure [14,23], since temperature can be obtained from T1 relaxation time or proton resonance frequency (PRF) shift [24]. However, MRI use is limited by technical difficulties related to (unavoidable) motion artefacts, electromagnetic compatibility issues with the microwave antenna, and, last but not least, the high cost of the MRI equipment, which entails a significant impact in terms of economical sustainability for health systems [18].…”