4:03 PM Abstract No. 297 True three-dimensional holographic visualization for performance of percutaneous thermal ablation of solid liver tumors: an update on in-human evaluation

Abstract

Earlier work has demonstrated bench targeting accuracy, usability, and first-in-human feasibility of an augmented-reality platform developed for 3D-HPA. The purpose of this study is to further evaluate the clinical feasibility of this novel technology. Five patients clinically indicated for microwave liver tumor ablation were enrolled in an IRB-approved protocol. Preprocedural multiphasic CT angiography (CTA) was acquired in all patients with the addition of fiducial skin markers for intraprocedural registration. 3D HPA integrates HoloLens (Microsoft, WA, USA) guidance with electromagnetic tracking of instruments to generate, register, and project holograms directly to the operative site as the instrument is navigated. Holograms are based on structures segmented from CTA (e.g., liver, vessels, tumor, bone) and a holographic light ray (HLR) co-axially extending from the tracked instrument. As standard of care, ultrasound was used for percutaneous placement of the trocar and all surgical decisions; for minimal risk to the patient at this early stage of development, holograms were only visible prior to percutaneous access and after the trocar was placed. Following ablation, images and video from postprocedural sonography, cone-beam and multidetector row CT, and HoloLens recordings were evaluated. Five patients were treated during this evaluation of 3D-HPA. In all five cases, intraprocedural holographic guidance, including HLR navigation, was in agreement with ultrasound-based guidance, as defined by (1) visualization of the guidance track relative to critical structures and (2) placement of the ablation probe within the targeted tumor. Postprocedural imaging showed adequate tumor ablation coverage. There was no recurrence at 3-month follow-up in patients who had this imaging available for review. This first clinical series further demonstrated feasibility of 3D-HPA and its potential to improve the performance of PTA, which could lead to improved quality of patient care as well as benefits for the global health care system. Further development and evaluation for tumor ablation guidance, along with other IR applications, is ongoing.