Multi-Operational Selective Computer-Assisted Targeting of hepatocellular carcinoma—Evaluation of a novel approach for navigated tumor ablation

Abstract

ObjectiveTo facilitate precise local ablation of hepatocellular carcinoma (HCC) in a setting of combined ablation and transarterial chemoembolization (TACE), we evaluated accuracy and efficiency of a novel technique for navigated positioning of ablation probes using intrahepatic tumor referencing and electromagnetic (EM) guidance, in a porcine model.MethodsAn angiographic wire with integrated EM reference sensor at its tip was inserted via a transarterial femoral access and positioned in the vicinity of artificial liver tumors. The resulting offset distance between the tumor center and the intrahepatic endovascular EM reference was calculated. Subsequently, EM tracked ablation probes were inserted percutaneously and navigated toward the tumor center, relying on continuous EM guidance via the intrahepatic reference. Targeting accuracy was assessed as the Euclidean distance between the tip of the ablation probe and the tumor center (Target Positioning Error, TPE). Procedural efficiency was assessed as time efforts for tumor referencing and tumor targeting.ResultsIn 6 animals, 124 targeting measurements were performed with an offset distance < 30 mm (clinically most feasible position), resulting in a mean TPE of 2.9 ± 1.6 mm. No significant correlation between the TPE and different intrahepatic offset distances (range 21 to 61 mm, n = 365) was shown as long as the EM reference was placed within the liver. However, the mean TPE increased when placing the EM reference externally on the animal skin (p < 0.01). TPE was similar when targeting under continuous ventilation or in apnea (p = 0.50). Mean time for tumor referencing and navigated targeting was 6.5 ± 3.8 minutes and 14 ± 8 seconds, respectively.ConclusionThe proposed technique allows precise and efficient navigated positioning of ablation probes into liver tumors in the animal model. We introduce a simple approach suitable for combined ablation and TACE of HCC in a single treatment session.

Stereotactic Image-Guided Microwave Ablation for Malignant Liver Tumors—A Multivariable Accuracy and Efficacy Analysis

“…This explains the significantly higher TPE when targeting lesions in cirrhotic livers, as the associated liver stiffness leads to organ distortion when ablation probes are introduced. The influence of targeting trajectory length on TPE can be explained by the bending of ablation probe shafts when applying longer probes, which represents a known challenge when tracking instruments at their extracorporal end rather than the tip (37). Hence, when targeting tumors in cirrhotic livers or when using long targeting trajectories, giving particular attention to control of the ablation probe position is advocated.…”

Evaluation of a New CT-Guided Robotic System for Percutaneous Needle Insertion for Thermal Ablation of Liver Tumors: A Prospective Pilot Study

“…It is lower than rates from other reports of robotic needle placement with manual repositioning required in 48.7% to 60% of the interventions, and a mean number of adjustment from 0.8 (± 0.8) to 1.1 (± 0.7) per lesion [ 7 , 17 ]. Needle placement has a major impact on the treatment outcomes since any adjustment may increase radiation dose, procedure time, tissue trauma, and possibly the risk of bleeding and tumor seeding; but moreover approximative needle placement will decrease the probability of local tumor control [ 20 , 22 , 24 , 25 ].…”

Leberchirurgie 4.0 - OP-Planung, Volumetrie, Navigation und Virtuelle Realität

“…Beide Verfahren geben jedoch (bislang) keine Orientierungshilfe in Bezug auf die intrahepatisch laufenden Gefäße. Die intraoperative Navigation auf der Basis der 3-D-Modelle ist bei Ablationen insbesondere bei der stereotaktischen Ablation eine wertvolle Unterstützung, sodass die Erfolgsrate deutlich gesteigert werden kann [33,46,55,56,57]. Ein weiteres Einsatzgebiet bieten Metastasen, die durch eine durchgeführte Chemotherapie in der präoperativen Bildgebung nicht mehr abgegrenzt werden können.…”