Mikhail AS, Pritchard WF, Negussie AH, Inkiyad G, Long DJ, Mauda-Havakuk M, Wakim PG, van der Sterren W, Levy EB, Lewis AL, Karanian JW, and Wood BJ
Objectives: The aims of this study were to develop a model to estimate drug dose delivered to tumors after transarterial chemoembolization (TACE) with radiopaque drug-eluting beads (DEBs) based on DEB density on cone-beam computed tomography (CT) and to evaluate drug penetration into tissue in a woodchuck hepatoma model., Materials and Methods: Transarterial chemoembolization was performed in woodchucks with hepatocellular carcinoma (N = 5) using DEBs (70-150 μm, LC Bead LUMI) loaded with doxorubicin. Livers were resected 45 minutes after embolization, immediately frozen, and cut using liver-specific, 3D-printed sectioning molds. Doxorubicin levels in tumor specimens were measured by high-performance liquid chromatography and correlated with DEB iodine content that was measured using prototype cone-beam CT-based embolization treatment planning software. Doxorubicin penetration into tissue surrounding DEBs was assessed by fluorescence microscopy of tumor sections. Fluorescence intensity was converted into doxorubicin concentration using calibration standards. Intensity-thresholded color heatmaps were generated representing extravascular drug penetration., Results: Consistent segmentation of DEBs on cone-beam CT was achieved using a semiautomated intensity thresholding method. A positive linear correlation (0.96) was found between DEB iodine content measured on cone-beam CT and the amount of doxorubicin measured in tumor specimens. Prediction of doxorubicin levels in tumor sections that were not included in model development was accurate, with a root-mean-square error of 0.08 mg of doxorubicin. Tumor penetration of eluted doxorubicin resulted in concentration gradients where drug content decreased with increasing distance from blood vessels containing DEBs. Drug penetration was greater for blood vessels containing DEB clusters compared with single DEB, with higher doxorubicin concentrations extending further away from the vessels., Conclusions: Estimation of drug dose delivered during transarterial chemoembolization in a woodchuck hepatocellular carcinoma model was possible using DEB radiopacity on cone-beam CT as a surrogate marker. Doxorubicin penetration was greatest adjacent to vessels containing DEB clusters compared with single DEB. Intraprocedural estimation of the spatial distribution of drug dose within the tumor could enable real-time adjustments to DEB delivery, to maximize treatment coverage or identify regions of tumor at risk for undertreatment., Competing Interests: Conflicts of interest and sources of funding: This work was supported by the Center for Interventional Oncology in the Intramural Research Program of the National Institutes of Health (NIH) by intramural NIH grants NIH Z01 1ZID BC011242 and CL040015. M.M.-H. is supported by the Clinical Translational Fellowship Program of the NIH Clinical Center and the Intramural Research Program of the National Institute of Biomedical Imaging and Bioengineering. The NIH has a Materials Transfer Agreement with Northeastern Wildlife. The NIH has Cooperative Research and Development Agreements with Biocompatibles UK Ltd–Boston Scientific Corporation and Philips that provide support for this research. The NIH had control over the conduct of the study, the inclusion of any data, data analysis and interpretation, manuscript preparation, and decisions on submission for publication. The content of this manuscript does not necessarily reflect the views or policies of the US Department of Health and Human Services. The mention of commercial products, their source, or their use in connection with material reported herein is not to be construed as an actual or implied endorsement of such products by the US government. W.v.d.S. is an employee of Philips. A.L.L. was an employee of Biocompatibles UK Ltd, the company sponsoring the study. B.J.W. is the principal investigator for Cooperative Research & Development Agreements between NIH and the following: BTG Biocompatibles/Boston Scientific, Siemens, Philips, NVIDIA, Celsion Corp, Canon Medical, and XAct Robotics. B.J.W. and NIH are party to Material Transfer or Collaboration Agreements with Angiodynamics, 3T Technologies, Profound Medical, Exact Imaging, Johnson and Johnson, Endocare/Healthtronics, and Medtronic. Outside the submitted work, B.J.W. is primary inventor on 47 issued patents owned by the NIH (list available upon request), a portion of which have been licensed by NIH to Philips. B.J.W. and NIH report a licensing agreement with Canon Medical on algorithm software with no patent. B.J.W. is joint inventor (assigned to the Department of Health and Human Services NIH US government) for patents and pending patents related to drug-eluting bead technology, some of which have joint inventorships with BTG Biocompatibles/Boston Scientific. B.J.W. is primary inventor on patents owned by NIH in the space of drug-eluting embolic beads. The authors report no other conflicts of interest in this work. This manuscript discusses the use of an investigational device, software for iodine quantification in Emboguide, a Philips product., (Copyright © 2022 Written work prepared by employees of the Federal Government as part of their official duties is, under the U.S. Copyright Act, a “work of the United States Government” for which copyright protection under Title 17 of the United States Code is not available. As such, copyright does not extend to the contributions of employees of the Federal Government.)