Electromagnetic navigation system combined with High-Frequency-Jet-Ventilation for CT-guided hepatic ablation of small US-Undetectable and difficult to access lesions

Abstract

Objectives: To report the feasibility and efficacy of percutaneous ablation of small hepatic malignant tumors that are invisible on ultrasound and inaccessible using in-plane CT guidance, using a combination of high-frequency jet-ventilation (HFJV) and electromagnetic (EM) needle tracking. Methods: This study reviewed 27 percutaneous ablations of small hepatic tumors (<2 cm) performed using EM navigation-based probe placement and HFJV. All lesions were invisible on ultrasound and difficult to reach on CT requiring a double-oblique approach. The primary outcome was technical efficacy, defined as complete lesion coverage, and evaluated on contrast enhanced MRI after 3 and 6 months. Needle placement accuracy, the number of control CT acquisitions, procedure time, complications and radiation doses were assessed.Results: Twenty-one patients with 27 treated lesions (14 hepatocellular carcinomas and 13 metastases) were included in this study. Mean tumor size was 12 ± 5.7 mm. Thirty-three percent of the lesions were located on the hepatic dome. Complete ablation was obtained in 100% at the 3-and 6-month MRI follow-up. The ablation probe was correctly placed on the first pass in 96%, with a mean path-to-tumor angle of 7 ± 4 degrees and a mean tip-to-tumor distance of 22 ± 19mm. A readjustment for additional overlapping application resulted in complete treatment in 4 patients. Needle placement took a mean 23 ± 12 min with mean radiation doses of 558 mGy à cm. No major complications were reported. Conclusion: Percutaneous liver ablation of lesions that cannot be seen on US and requiring out-ofplane CT access can be successfully and safely treated using electromagnetic-based navigation and jet-ventilation.

Stereotactic and Robotic Minimally Invasive Thermal Ablation of Malignant Liver Tumours - A Systematic Review and Meta-Analysis

“…Two studies reported results using a laparoscopic treatment access (44,55), the other 32 reporting on thermal ablations using a percutaneous approach. Six studies applied robotic targeting using mechanical tracking (31,47,48,51,60,62), 7 an electromagnetic (EM)-tracked dynamic technique (35,42,50,55,57,59,61) and the other 21 an optically tracked stereotactic aiming device. Baseline study, patient and lesion characteristics, applied ablation and navigation techniques and reported outcomes of the included works are shown in Table 2.…”

“…All of the 34 included works were single-centre studies, of which 26 were retrospective studies (29,30,(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)31,(49)(50)(51)(52)(53)(54)(32)(33)(34)(35)(36)(37)(38), 3 prospective case series(55-57), 3 prospective cohort studies(58-60) and 2 randomised controlled trials (61,62). Two studies reported results using a laparoscopic treatment access (44,55), the other 32 reporting on thermal ablations using a percutaneous approach.…”

Computed Tomography-Navigation™ Electromagnetic System Compared to Conventional Computed Tomography Guidance for Percutaneous Lung Biopsy: A Single-Center Experience

“…This is particularly true for small lung lesions, but also lesions localized in the lower lobes, more sensitive to respiratory motions. Studies have shown that this kind of drawback can possibly be overcome by the use of fusion systems with ultrasound images [ 1 , 14 , 26 ]. However, this kind of system is not applicable in the specific field of lung biopsies.…”

“…In order to improve accuracy and limit X-ray exposure, a series of navigational guidance tools have been developed, based on the principle of “augmented reality” [ 1 , 9 ]. These new systems allow electromagnetic [ 2 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ], or optical tracking of devices [ 19 , 20 , 21 , 22 , 23 ], that are used for interventional radiology or surgical procedures. Data from a previous patient’s scan can be used in a model to perform virtual real time navigation.…”

Augmented reality improves procedural efficiency and reduces radiation dose for CT-guided lesion targeting: a phantom study using HoloLens 2

“…As with any navigation system, patient motion, respiratory breathing, soft tissue deformation, and needle bending are important factors that can affect navigational performance. Breathing can be compensated by techniques such as simple respiratory gating 20 or high frequency jet ventilation under general anesthesia 21 . Soft tissue deformation can be compensated by deformable modeling 9 , and needle bending can be extrapolated using a shape sensing needle 22 .…”