Scientific Research

ABK Biomedical Scientific Research

ABK Biomedical is committed to improving every aspect of Y90 radioembolization treatment and patient follow-up.

We are dedicated to improving patient outcomes; from engineering microsphere technology and delivery systems for optimal imaging and tumor targeting to ensuring physicians know the cutting-edge advantages of Eye90 microspheres Precision Dosimetry™.

Eye90 microspheres Precision Dosimetry™

Precision Dosimetry involves a CT-based approach to calculating the post-treatment absorbed dose. The benefits of Precision Dosimetry include significantly enhanced spatial resolution of the dose distribution and a more accurate estimation of dose heterogeneity.

Current Y90 microsphere technology lacks sufficient radiopacity for CT-based dosimetry to be feasible.

Eye90 microspheres® are engineered to be imageable, permitting Precision Dosimetry with CT-based imaging to be utilized. The clinical potential of Eye90 microspheres Precision Dosimetry™ has been demonstrated in a pre-clinical model and published in a well-respected peer-reviewed journal.

Y90 radioembolization

Eye90 microspheres Precision Dosimetry™ in a rabbit model. a–c Axial, sagittal, and coronal views of CT-based dose distribution.  d–f Axial, sagittal, and coronal views of traditional PET-based dose distribution showing inferior resolution.

From Henry et al. EJNMMI Physics (2022) 9:21

Podcast on Eye90 microspheres® on ResearchPod

Listen to ABK Biomedical’s Chief Medical Officer Aravind Arepally, M.D. and E. Courtney Henry, PhD, Medical Physics discuss Eye90 microspheres for the treatment of unresectable liver cancer on ResearchPod by clicking here.

Eye90 microspheres logo

Comparison of Glass Y90 Administration Systems in an in vitro model published in JVIR


ABK Biomedical and affiliated researchers at North Carolina State University recently published new data on the in vitro distribution and penetration of glass microspheres under different administration methods.

Specifically, an in vitro microvascular tumor model, replicating the human HCC condition, was developed and used to compare glass microsphere administration methods during Y90 procedures.

Eye90 microspheres® Dual Syringe administration was compared to standard glass microsphere Bolus Delivery administration. The same glass microspheres were used to test both administration approaches.

The investigators concluded that Eye90 microspheres administration technology achieved deeper microspheres penetration and greater deposition uniformity within the in vitro tumor microvasculature.



Y90 radioembolization

A schematic of the dual-syringe and bolus delivery administration methods.
BD = bolus delivery; DS = dual-syringe.

From Miller et al, J Vasc Interv Radiol 2023; 34:11–20

Scientific Presentations

2024 Presentations

Eye90 microspheres® – The Next Frontier in SIRT?

Nadine Abi-Jaoudeh, M.D. FSIR CCRP,  University of California Irvine

  • Patient personalized dosimetry is feasible
    o Ability to control volume and activity of microspheres.
  • Advanced administration technology enables in-procedure visualized tumor targeting
  • Post procedure precision CT-dosimetry is feasible
  •  Future Direction:
    o Real-time CT/CBCT Dosimetry
    o Imaging Biomarker with Radiomics
    o 3D Micro Dosimetry

2023 Presentations

Feasibility of CT Based Tumor Dosimetry Using Multimodal Imageable Glass Eye90 microspheres® in a FIH Clinical Trial

R J Abraham (1,2), A Verma (2), D Dobrowski (2), A Kulp (3),  A Holden (4), E C Henry (5), S C Kappadath (5), A Syme (6,7), A Arepally (2)

  • Investigational use of CT dosimetry in this study confirms feasibility of determining CT based tumor absorbed dose. Conventional CT provides reduced partial volume effects, reduced respiratory motion artifacts, and an improved depiction of dose heterogeneity which has not been described with usual post Y90 SPECT or PET modalities. These benefits may provide more accurate dose metrics and a better understanding of the dose-response relationship in 90Y therapy.

Liver and Spleen CT Volumetric Analysis after Selective Imageable Y90 Microspheres (Eye90 microspheres®) Administration

Robert Abraham MD FSIR FCIRSE FRCPC (1,2), Amit Verma DrPH, MPH (2), Robert Lewandowski MD FSIR (3), David Liu MD FSIR (4), David Dobrowski (2), Andrew Holden MD (5), Aravind Arepally MD FSIR (2)

• Volumetric analysis demonstrated significant contralateral and/or caudate hypertrophy approximately 3 months after selective (≤ 2 segments) Eye90 microsphere® radioembolization with no splenic hypertrophy or evidence of portal hypertension.
• Limitations: Small number of patients and 3-month time point (-> 12 mo.)
• Route 90 US IDE Study planned commencement later this year

Initial Clinical Experience with a Novel Glass Imageable Yttrium-90 Radioembolization Microsphere for Treating Malignant Liver Tumors

Principal Investigator and Presenter: Professor Andrew Holden (1)

  • Primary Endpoints Met
    • Eye90 microspheres treatment was well tolerated
    • No related SAEs have been reported
    • No reports of REILD or RILI
    • 5/6 Patients-CR, 1 patient pending
  • Secondary Endpoints
    • Multi-modality imaging of Y90 MS is feasible: PET, SPECT/CT and Conventional CT
    • Multi-modality dosimetry of Y90 MS is feasible: PET, SPECT/CT and Conventional CT
  • Bonus Endpoints
    • Growth of non treated contralateral liver segments noted- Pending Final Analysis
    • Potential Imaging Biomarker → Targeting and Tracking

Comparison of Bolus Versus Dual-Syringe Administration Systems on Glass Yttrium-90 Microsphere Deposition in an In Vitro Microvascular Hepatic Tumor Model

Samuel R. Miller, PhD, Shaphan R. Jernigan, MS, Robert J. Abraham, MD, and Gregory D. Buckner, PhD

  •  An in vitro microvascular hepatic tumor model was developed and used to evaluate and compare microsphere administration methods during radioembolization procedures. The transparent planar geometry of this model enables optical assessment of microsphere distributions, and its dynamic perfusion system maintains realistic hepatic pressures and flow rates.
  • The deposition characteristics of yttrium-90 glass microspheres were evaluated for 2 administration methods: conventional bolus delivery and dual-syringe delivery.
  • Administration using a dual-syringe delivery device was associated with more uniform deposition of the microspheres and a higher degree of distal deposition when compared with a bolus delivery device.

Understanding of Flow Allows Better Tumor Microsphere Coverage

Jorge Aramburu, PhD, Raúl Anton, PhD, Macarena Rodríguez-Fraile, MD, PhD, and Jose I. Bilbao, MD, PhD

In its current form, the in vitro platform allows for the analysis of the final microsphere distribution. Incorporating a system to record the dynamic deposition of microspheres would help us better understand how microspheres flow through the arteries and eventually deposit in the in vitro platform.

Clinical Use of Investigational Radiopaque Eye90 Microspheres™ for the Treatment of Unresectable Hepatocellular Carcinoma with 3-month Follow-Up

Robert Abraham, MD, FSIR, FRCPC; Amit Verma; David Dobrowski; Andrew Holden MBChB, FRANZCR, EBIR; Aravind Arepally , M.D., FSIR

• No Evidence of RILD/SAE
• Multimodality Imaging and Dosimetry is feasible
• Noted Contralateral Hypertrophy of Left Lobe
• RO may serve multiple roles

  1. Targeting
  2.  Surrogate marker
  3. Provide anatomic contour to monitor tumor morphology

2022 Presentations

Precision Dosimetry in Yttrium-90 Radioembolization through CT Imaging of Radiopaque Microspheres in a Rabbit Liver Model

Dr. E. Courtney Henry, MD Anderson Cancer Center

American Association of Physicists in Medicine Annual Meeting 2022
“Best in Physics”

  • Potential benefits of Eye90 microspheres Precision Dosimetry™ include reduced partial volume effects and respiratory motion artifacts, improved visualization of dose distribution, and accurate quantification of dose heterogeneity.
  • Post-treatment CT imaging of imageable microspheres provides the means to perform precision dosimetry and extract more accurate absorbed dose metrics.
  • The strong positive correlation between imageable microspheres and CT-based dosimetry may help physicians with dose-response relationships and improve future patient outcomes.

What’s new in microspheres: The next generation for radioembolization

Robert J. Abraham MD, Dalhousie University

Society of Interventional Radiology Annual Meeting 2022

  • Eye90 microspheres® are in clinical development and are the only imageable Y90 microspheres imageable using X-ray-based imaging technologies.
  • CT-based dosimetry depicts dose heterogeneity with increased accuracy relative to PET-based dosimetry.
  • This approach to dosimetry could provide clinicians with an opportunity to enhance their understanding of the dose-response relationship and improve patient outcomes.
  • The First-in-Human study with Eye90 microspheres® for mCRC and HCC was initiated November 2021 in Auckland, NZ.

Novel Radiopaque Y-90 Glass Microspheres (Eye90 microspheres) for Canine Hepatocellular Carcinoma: Correlation of Microsphere Radiopacity with TOF PET Radioactivity and mRECIST Tumor Response Determination

Robert J. Abraham MD, Dalhousie University

Society of Interventional Radiology Annual Meeting 2022

  • Eye90 microspheres® is being evaluated in a First-in-Dog HCC Study in partnership with The University of Missouri College of Veterinary Medicine.
  • Here, we describe a case study that evaluated tumor response after Eye90 microspheres administration in a dog patient with HCC.
  • Significant anti-tumor response was noted after six weeks, and the dog underwent a successful left lobectomy.
  • This case shows Eye90 microspheres treatment resulted in a beneficial tumor response, the ability to assess tumor targeting and coverage on CT, and inherent radiopacity correlated well with PET-based radioactivity and tissue histology.

Novel Hepatic Tumor Microvascular Model for Evaluating the Deposition Characteristics of Y-90 Microspheres

Robert J. Abraham MD, Dalhousie University

Global Embolization Symposium & Technologies Annual Meeting 2022

  • It is a known challenge to evaluate Y90 tumor microspheres deposition in vivo.
  • ABK Biomedical developed a standardized in vitro model, in partnership with NC State University, that captures hepatic vascular anatomy and matches physiologic pressures and flow rates.
  • In this model, the tumor is represented by a branched vascular structure which simulates HCC tumors down to the arteriole level (18µm).
  • Researchers compared in vitro microsphere distribution between the ABK dual-syringe delivery system (DS) and the typical glass Y90 bolus delivery system (BD).
  • The ABK DS system delivered a greater number of glass microspheres penetrating distally, and a more uniform distribution compared to BD.

2021 Presentations

Read the abstract!
Purpose :
Perform a comparison of PET- and CT-based approaches to dosimetry in Yttrium-90 (90Y) radioembolization (RE) following the administration of 90Y-infused radiopaque microspheres (MS) in a rabbit liver model.
Materials & Methods :
An experimental calibration phantom (Figure 1.A) containing multiple cylinders varying in diameter and MS concentration was designed to quantify the correlation between CT Hounsfield units (HU) and MS concentration. Mean HU were extracted from CT volumes-of-interest placed within 15 mm-diameter cylinders containing nominal MS concentrations of 0.5 mg/mL, 5.0 mg/mL, and 25.0 mg/mL. A calibration curve was determined through a linear least squares fit of the data (Figure 1.B). PET and CT imaging of a rabbit liver was performed following the intra-arterial administration of activated 90Y MS. CT voxel values [HU] were transformed into 90Y activity [Bq] through the application of the calibration curve and three scale factors: CT voxel volume [mL], MS number per milligram [MS/mg], and specific activity [Bq/MS]. PET and CT activity distributions were convolved with 90Y dose-voxel kernels generated with the GATE Monte Carlo toolkit to produce PET- and CT-based dose distributions, dd_PET and dd_CT, respectively. Within the liver, the mean dose ± standard deviation (Dµ ± σ) and dose maxima (Dmax) were compared between dd_PET and dd_CT.
Results :
The calibration curve demonstrated strong linearity (r2 > 0.999) between HU and MS concentration. Axial, sagittal, and coronal slices through a high-dose region in dd_CT and dd_PET are shown in Figure 2. In dd_PET, Dmax = 309 Gy and Dµ = 68 ± 63 Gy. In dd_CT, Dmax = 1230 Gy and Dµ = 45 ± 65 Gy. These statistics suggest that Dµ can be ascertained with reasonable confidence independent of the imaging modality while the true range of dose values is better characterized through CT-based dosimetry.
Conclusions :
CT imaging of radiopaque MS distributions in 90Y RE can provide increased confidence in characterizing the dose heterogeneity – relative to PET-based dosimetry – by capturing the true range of dose values within the tumour and healthy liver tissue. The accurate and precise knowledge of the dose distribution is essential in identifying undertreated tumour volumes, identifying radiation toxicity in adjacent liver tissue, and improving our estimates of dose metrics used in establishing a viable dose-response

CT-based Dosimetry in Yttrium-90 Radioembolization Performed in a Rabbit Liver Model

Dr. E. Courtney Henry, Dalhousie University

Global Embolization Symposium & Technologies Annual Meeting 2021

  • The poor spatial resolution encountered with Y90 PET and SPECT dosimetry underestimates the true dose heterogeneity following radioembolization.
  • Improved estimates of distribution can be obtained with higher resolution dosimetry to accurately quantify dose-response and identify areas at risk of recurrence.
  • The steep dose gradients observed with CT-based dosimetry are highly correlated with radioembolized vasculature because it is directly derived from the microspheres implanted distribution.
  • The strong positive correlation between imageable microspheres and CT-based dosimetry may help physicians with dose-response relationships and improve future patient outcomes.
Read the abstract!
Purpose :
The purpose of this study was to develop a novel hepatic tumor vascular model (TVM) for investigating the embolic characteristics of Y-90 microspheres (MS) during radioembolization (RE). The microscale features of this model enables quantification of attributes not practical in animal models, and may offer new perspectives on the mechanics of embolization.
Materials & Methods :
The TVM was designed to represent a 4.5cm (48cc) tumor in a 1400cc liver with a total hepatic flow of 160mL/min. The TVM flow rate was calculated to be 20mL/min using a two compartment model with a T/N ratio of 4. Thus with a mean inlet pressure of 90mmHg, the TVM must have a fluid resistance of 270PRU (mmHg·s/mL). The TVM was designed to branch from an inlet diameter of 1mm to four microfluidic trees which further branch down to a total of 6400 outlet arterioles. These arterioles were designed to be 180μm long and taper from 30μm to 18μm wide. Fabricated using a silicone soft-lithography technique, the TVM was attached to a 3D-printed hepatic vascular system consisting of a proper hepatic artery (PHA), left/right hepatic arteries (LHA/RHA), and 16 outlets 1mm in diameter; one of which feeds the TVM. The PHA was perfused with a glycerin-water mixture (3.5cP viscosity) at a pressure of 140/60mmHg and a rate of 160mL/min. A 2.9F Cook Cantata (0.027in ID) microcatheter (Cook Medical, Bloomington, IN) was placed distal to the RHA origin into a 2mm caliber artery feeding the TVM and two additional arteries. A syringe pump was used to inject glass MS (20-30μm diameter) through the catheter at a concentration of 50mg/mL and a rate of 0.3mL/s. MS were delivered in two 1.5mL aliquots separated by a pause of 180s. Following delivery, the TVM was disconnected from the vascular system and imaged.
Results :
The actual TVM flow rate measured was 23.5mL/min giving a resistance of 230PRU. Within 15% of the 270PRU target, this shows good agreement between the design methodology and fabrication. A series of 2 TVM were embolized and imaged. TVM flow rates measured after embolization revealed an 88% reduction to 2.5mL/min and 3.0mL/min for the two trials. Image analysis showed the glass MS penetrated a distance of 100μm (95th percentile) into the outlet arterioles.
Conclusions :
The TVM—through image analysis and flow measurements—can yield information about the MS deposition that would otherwise be difficult to obtain using animal models. This has demonstrated its potential to bring a new perspective to Y-90 technological development.

Novel Hepatic Tumor Microvascular Model for Evaluating the Microembolic Characteristics of Y-90 Microspheres

Dr. Sam Miller, North Carolina State University

Global Embolization Symposium & Technologies Annual Meeting 2021
“Best at GEST” Winner

  • Attributes of Y90 distribution in tumors are difficult to observe through in vivo models. This is the first published in vitro model simulating HCC tumors down to the arteriole level (18µm).
  • This study compared in vitro microsphere distribution between the ABK dual-syringe delivery system (DS) and a typical glass Y90 bolus delivery system (BD).
  • The use of the ABK DS system resulted in a greater number of microspheres penetrating distally compared to BD.
  • A more uniform distribution of microspheres was also observed with ABK DS vs BD.
  • This study demonstrated that the mode of microsphere delivery affects penetration and uniformity of deposition and may bring a new perspective to Y90 technology development.

Recent Peer-Reviewed Publications


Comparison of Bolus Versus Dual-Syringe Administration Systems on Glass Yttrium-90 Microsphere Deposition in an In Vitro Microvascular Hepatic Tumor Model

Miller et al. J Vasc Interv Radiol 2023; 34:11–20

Click to download the article


Quantification of the inherent radiopacity of glass microspheres for precision dosimetry in yttrium-90 radioembolization.

Henry et al 2019 Biomed. Phys. Eng. Express 5 055011

Click to read this abstract


Precision dosimetry in yttrium‑90 radioembolization through CT imaging of radiopaque microspheres in a rabbit liver model

Henry et al. EJNMMI Physics (2022) 9:21 

Click to download the article


Post-administration dosimetry in yttrium-90 radioembolization through micro-CT imaging of radiopaque microspheres in a porcine renal model

Henry et al 2021 Phys. Med. Biol. 66 095011

Click to read this abstract

ABK's Business Partners

ABK Biomedical is proud to partner with cutting-edge organizations and individuals with exceptional skills, scientific expertise, and the highest business ethics.

Research Partners

Development Partners

ABK Biomedical is ISO Certified


The ABK Biomedical Team

We are dedicated to encouraging a stimulating work environment offering an opportunity to significantly expand experience and skills by researching, developing, and commercializing cutting-edge medical device technologies with a mandate to effectively treat cancer.

ABK Biomedical is an equal opportunity employer offering competitive compensation packages.

Corporate Offices

Halifax Office (Main Office)
155 Chain Lake Drive
Unit 32
Halifax, NS B3S 1B3

T. 902.442.4009


Orange County Office
555 Corporate Drive 
Suite 105
Ladera Ranch, CA, 92694

ABK Biomedical Inc. provides and continues to provide accurate information on its website. However, ABK Biomedical Inc. assumes no responsibility for the accuracy and/or completeness, express or implied, as to the information contained or omitted and/or the products described. Furthermore, ABK Biomedical Inc. may change the products mentioned, and their stage in development, at any time without notice. ABK Biomedical Inc. is a clinical-stage company engaged in the research and development of new medical devices. Eye90 microspheres® is considered an investigational product and is NOT FDA-approved for use.

Copyright 2022 - All International Rights Reserved