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Purpose: To evaluate an integrated liver biopsy platform that combined CT image fusion, electromagnetic (EM) tracking, and optical molecular imaging (OMI) of indocyanine green (ICG) to target hepatocellular carcinoma (HCC) lesions and a point-of-care (POC) OMI to assess biopsy cores, all based on tumor retention of ICG compared to normal liver, in phantom and animal model., Material: A custom CT image fusion and EM-tracked guidance platform was modified to integrate the measurement of ICG fluorescence intensity signals in targeted liver tissue with an OMI stylet or a POC OMI system. Accuracy was evaluated in phantom and a woodchuck with HCC, 1 day after administration of ICG. Fresh biopsy cores and paraffin-embedded formalin-fixed liver tissue blocks were evaluated with the OMI stylet or POC system to identify ICG fluorescence signal and ICG peak intensity., Results: The mean distance between the initial guided needle delivery location and the peak ICG signal was 5.0 ± 4.7 mm in the phantom. There was complete agreement between the reviewers of the POC-acquired ICG images, cytology, and histopathology in differentiating HCC-positive from HCC-negative biopsy cores. The peak ICG fluorescence intensity signal in the ex vivo liver blocks was 39 ± 12 and 281 ± 150 for HCC negative and HCC positive, respectively., Conclusion: Biopsy guidance with fused CT imaging, EM tracking, and ICG tracking with an OMI stylet to detect HCC is feasible. Immediate assessment of ICG uptake in biopsy cores with the POC OMI system is feasible and correlates with the presence of HCC in the tissue., (© 2021. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)

Purpose: To compare needle placement performance using an augmented reality (AR) navigation platform implemented on smartphone or smartglasses devices to that of CBCT-guided fluoroscopy in a phantom., Materials and Methods: An AR application was developed to display a planned percutaneous needle trajectory on the smartphone (iPhone7) and smartglasses (HoloLens1) devices in real time. Two AR-guided needle placement systems and CBCT-guided fluoroscopy with navigation software (XperGuide, Philips) were compared using an anthropomorphic phantom (CIRS, Norfolk, VA). Six interventional radiologists each performed 18 independent needle placements using smartphone (n = 6), smartglasses (n = 6), and XperGuide (n = 6) guidance. Placement error was defined as the distance from the needle tip to the target center. Placement time was recorded. For XperGuide, dose-area product (DAP, mGy*cm 2 ) and fluoroscopy time (sec) were recorded. Statistical comparisons were made using a two-way repeated measures ANOVA., Results: The placement error using the smartphone, smartglasses, or XperGuide was similar (3.98 ± 1.68 mm, 5.18 ± 3.84 mm, 4.13 ± 2.38 mm, respectively, p = 0.11). Compared to CBCT-guided fluoroscopy, the smartphone and smartglasses reduced placement time by 38% (p = 0.02) and 55% (p = 0.001), respectively. The DAP for insertion using XperGuide was 3086 ± 2920 mGy*cm 2 , and no intra-procedural radiation was required for augmented reality., Conclusions: Smartphone- and smartglasses-based augmented reality reduced needle placement time and radiation exposure while maintaining placement accuracy compared to a clinically validated needle navigation platform.

Purpose: Topotecan is a camptothecin analogue with potential advantages over irinotecan for transarterial chemoembolization (TACE) of hepatic colorectal metastases including greater anti-neoplastic activity without enzymatic activation. The purpose of this study was to assess safety and tolerability of topotecan-loaded radiopaque microspheres (ROMTOP) administered by TACE in a rabbit model and to compare the in vitro elution of topotecan from microspheres to irinotecan., Materials and Methods: Topotecan was loaded into radiopaque microspheres (70-150 µm, DC Bead LUMI™, Biocompatibles UK Ltd-Boston Scientific Corporation) to the maximum capacity of 80 mg/mL of microspheres. Six healthy New Zealand White rabbits underwent hepatic TACE with ROMTOP under fluoroscopic guidance until angiographic stasis. Assessment of toxicities included regular liver function tests and complete blood counts until euthanasia 28 days post-TACE. In vitro topotecan elution from the microspheres was assessed using an open-loop flow-through system and compared to irinotecan., Results: The mean bead volume and topotecan dose delivered were 0.086 mL (0.076-0.105 mL) and 1.99 mg/kg (1.51-2.55 mg/kg), respectively. Aspartate aminotransferase and alanine aminotransferase were elevated post-embolization but resolved within 2 weeks. One rabbit died two days after TACE with pyloric duodenal perforation observed at necropsy, potentially due to non-target embolization. In vitro elution of topotecan from ROMTOP was complete in 10 h compared to 3 h for irinotecan-loaded microspheres., Conclusion: Selective embolization with ROMTOP was tolerated at a dose of 2 mg/kg (24 mg/m 2 ) in rabbits. In vitro topotecan elution from microspheres was more prolonged compared to irinotecan.

Objective: To develop and assess the accuracy of an augmented reality (AR) needle guidance smartphone application., Methods: A needle guidance AR smartphone application was developed using Unity and Vuforia SDK platforms, enabling real-time displays of planned and actual needle trajectories. To assess the application's accuracy in a phantom, eleven operators (including interventional radiologists, non-interventional radiology physicians, and non-physicians) performed single-pass needle insertions using AR guidance (n = 8) and CT-guided freehand (n = 8). Placement errors were measured on post-placement CT scans. Two interventional radiologists then used AR guidance (n = 3) and CT-guided freehand (n = 3) to navigate needles to within 5 mm of targets with intermediate CT scans permitted to mimic clinical use. The total time and number of intermediate CT scans required for successful navigation were recorded., Results: In the first experiment, the average operator insertion error for AR-guided needles was 78% less than that for CT-guided freehand (2.69 ± 2.61 mm vs. 12.51 ± 8.39 mm, respectively, p < 0.001). In the task-based experiment, interventional radiologists achieved successful needle insertions on each first attempt when using AR guidance, thereby eliminating the need for intraoperative CT scans. This contrasted with 2 ± 0.9 intermediate CT scans when using CT-guided freehand. Additionally, average procedural times were reduced from 13.1 ± 6.6 min with CT-guided freehand to 4.5 ± 1.3 min with AR guidance, reflecting a 66% reduction., Conclusions: All operators exhibited superior needle insertion accuracy when using the smartphone-based AR guidance application compared to CT-guided freehand. This AR platform can potentially facilitate percutaneous biopsies and ablations by improving needle insertion accuracy, expediting procedural times, and reducing radiation exposures.