BioXmark® improves target delineation and is suitable for Small Animal Image-Guided Radiation Therapy (SAIGRT)
15 September 2020
A recent publication of a study on BioXmark®, Nanovi’s liquid fiducial marker, concludes:
- Good marker safety, visibility and stability in vivo
- Significantly lower CBCT imaging artifacts compared to solid fiducial markers
- Potential to align SAIGRT protocols for better animal welfare in research
DK-Copenhagen, 14 September 2020 – Nanovi informs about the publication of a study, which compared image contrast performance and artifacts of BioXmark® with that of currently used solid fiducial markers for preclinical Cone Beam CT (CBCT) imaging applications. The study also evaluated the in vivo stability of BioXmark® and its impact on tumor radiation response.
The study was published by Kathryn Brown and colleagues from the Patrick G. Johnston Centre for Cancer Research at Queen’s University Belfast in the field of Small Animal Image-Guided Radiation Therapy (SAIGRT) that is the current state-of-the-art in experimental radiation biology. SAIGRT enables previously unachievable approaches in preclinical radiation research and allows close mimicking of clinical exposure scenarios for further understanding of tumor and normal tissue radiation responses. The use of onboard CBCT imaging to deliver volumetric imaging of soft tissues is however, challenging in small animals. The use of fiducial markers for more precise target delineation can help to overcome these challenges for improved animal welfare, and the study was supported by the National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs).
BioXmark® is a novel liquid fiducial marker, developed and marketed by Nanovi, for use to enhance target visibility on imaging and enable high-precision radiation therapy across different cancer types.
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Study background and design
The publication introduces the study as follows: “Radiotherapy is a major modality in the radical treatment of cancer, being prescribed to >50% of patients during their treatment. In recent decades, significant advances in radiation therapy technology have enabled increasingly sophisticated, conformal delivery methods to be implemented into routine clinical practice”.
This study compared artifacts on CBCT imaging of BioXmark® and of two solid fiducial markers, using phantom image analysis. In vivo stability with regard to both volume and migration of BioXmark® markers were evaluated with CBCT imaging analyses over a 5-month period in a mouse model. The study also evaluated the impact of BioXmark® markers on in vivo tumor radiation response in 48 mice with Lewis lung carcinoma, using a randomized controlled design.
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Results and conclusions
In the phantom part of the study, BioXmark® markers were detectable on CBCT at volumes 10-60 µL. It was also shown that BioXmark® produced 89% and 84% lower imaging artifacts compared to solid gold- and polymer-based markers, respectively, which was significant. Reducing CBCT imaging artifacts may lead to improved segmentation and less uncertainty during radiation dose calculation.
In a mouse model, all injected volumes of BioXmark® were shown to be safe and well-tolerated. The markers were positionally stable with minimal migration from the injection site and no significant degradation for up to 5 months. The results support the use of this liquid fiducial marker in preclinical radiation therapy studies.
In a mouse tumor model, the effect of BioXmark® on tumor response in vivo from both single and fractionated radiation exposures was evaluated. BioXmark® had no significant impact on tumor growth in the control group. After a single fraction radiation, BioXmark® injected animals showed an equal tumor growth delay compared to the control group, indicating no adverse effect of BioXmark® on dose delivery. In the fractionated treatment setting, the delivered radiation dose was reduced due to artifacts by BioXmark® affecting the dose calculation. This could however, be mitigated by taking the impact into account in the treatment planning, leading to an even dose distribution to the tumors marked with BioXmark® compared to the control group. The publication concludes that BioXmark® is a useful tool for improving target delineation and align protocols in SAIGRT studies withing the NC3Rs framework.
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Link to the publication:
Nanovi contact:
Jesper Boysen, CEO
Phone: +45 24 65 60 33
E-mail: [email protected]
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Download the full press release here:
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Link to the NC3R’s homepage:
Link to Queens University Belfast homepage: https://www.qub.ac.uk/research-centres/cancer-research/