Abstract 2534: A multimodal animal cradle inlay system to facilitate optical, PET, µCT, and MRI co-registrations of a metastatic, colorectal cancer syngeneic mouse model

Abstract INTRODUCTION: Multimodal imaging can dramatically enhance the diagnostic capabilities of pre-clinical animal research models. Investigators in the fields of oncology and immuno-oncology have sought to add optical imaging to their PET/µCT/MRI data sets because optical adds a sensitive, low-cost, high-throughput imaging capability that can predict the biodistributions of high-cost, low throughput PET/µCT/MRI data sets. In this poster, we demonstrate a proof-of-concept multimodal animal cradle system for optical/PET/µCT/MRI co-registrations. METHODS: Mouse Model: A CT26-luc mouse colorectal carcinoma cell line (derived from ATCC CRL-2638), expressing Red Firefly Luciferase, was injected into 12 adult Balb/C female mice, at dose levels of either 1x105 (n=6) or 5x105 (n=6) by tail vein IV injection. Optical/PET Reporters Used to Detect Cancer Cells: CT26-luc cells were detected in vivo either by Red Firefly Luciferase bioluminescent signal, and/or by the FDG PET/µCT/MRI at various points over the study time course. Mouse Multimodal Cradle Inlay System: A novel multimodal cradle inlay system was designed to be used in a range of preclinical imagers including the Lago X (optical), SkyScan (µCT), PET/CT Si78 (PET/µCT) and BioSpec (MRI) systems. All optical/PET/µCT/MRI multimodal co-registrations were performed in the PMOD software platform (Bruker BioSpin, Billerica, MA). RESULTS and DISCUSSION: Early, Predictive Detection of Metastatic Colorectal Cancer in the Mouse Lung by Optical Imaging. Metastatic colorectal cancer engraftment was achieved in the pulmonary cavity of 10 challenged female, Balb/C mice. The presence of CT26-luc cancer cells in mouse lungs was first detected as early as 24-hours post challenge, by Red Firefly Luciferase bioluminescent imaging (BLI). Soon thereafter, CT26-luc cancer cells were also detected by FDG PET. Optical BLI was found to be predictive of FDG PET biodistributions. Additionally, the quantitative tomographic, anatomical details of FDG PET biodistributions were confirmed by PET/µCT/MRI co-registrations. The ability of optical BLI to provide sensitive, high-throughput, early predictions of FDG PET biodistributions highlighted the value of the novel cradle inlay system tested here. Specifically, this cradle inlay system proved to be a vital hardware component that facilitated the process of acquiring multimodal optical/PET/µCT/MRI imaging data sets that could then be co-registered in PMOD. CONCLUSIONS: • In vivo Red FireFly BLI of metastatic colorectal cancer cells in a syngeneic mouse model successfully predicted observed in vivo FDG PET biodistributions. • A proof-of-concept cradle inlay system successfully facilitated the process of acquiring diagnostic, multimodal optical/PET/µCT/MRI data sets that were then readily co-registered in PMOD. Citation Format: Andrew D. G. Van Praagh, Todd Sasser, Ali Bahadur, Saaussan Madi, Kristin Granlund, Mark Mattingly, Paul Ballieu. A multimodal animal cradle inlay system to facilitate optical, PET, µCT, and MRI co-registrations of a metastatic, colorectal cancer syngeneic mouse model. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2534.