Abstract B142: Evaluating the feasibility and throughput of quintuple modality imaging in disseminated models of cancer with PET, CT, MRI, bioluminescence, and fluorescence molecular tomography.

Background: Multimodality imaging presents a unique opportunity to image the efficacy of candidate compounds against various models of cancer. The challenge is in integrating the complimentary data that these modalities can provide. The purpose of this study was to evaluate the feasibility of quintuple modality imaging in order to optimize workflows for maximal efficacy testing of candidate compounds using PET, CT, MRI, Bioluminescence imaging (BLI), and Fluorescence Molecular Tomography (FMT). Materials and Methods: Female SCID-Beige mice were implanted IV with 5×10∧6 MM1s-luc cells and female NIH III mice were implanted with 5×10∧6 5TGM-1-luc cells. The presence and extent of disease was confirmed with BLI concurrently or before multimodality imaging was initiated 28-35 days post-implant. The day prior to imaging, mice were injected IV with 2nmol of Integrisense 750 (PerkinElmer) to allow for 24 hours of uptake prior to FMT imaging. The next day, animals were anesthetized with 2.0% isoflurane, were injected with 200µCi 18F-FDG, and were immediately positioned in an FMT cassette for imaging. Whole body FMT data was acquired with excitation/emission at 755nm/775nm. MicroCT data was then acquired by placing the FMT cassette into a custom Animal Handling System (AHS) dock that coupled the FMT cassette to an integrated bed holder (ASI Instruments) for the remaining modalities. Whole body CT images were acquired at 512 projections, 75kVp, and 220µA. A ten minute static PET data set was then acquired with a Seimen's Inveon system after a 1 hour tracer uptake period, and reconstructed with a 3D-OSEM algorithm. MicroPET imaging was followed by a series of T1-weighted, gadolinium-enhanced, and T2-weighted anatomical MR images using an Agilent 7 Tesla MRI. Results: Animals were maintained under anesthesia for a total of approximately 2 hours in order to acquire data from all the modalities. Data was able to be co-registered in various forms in order to verify the location and extent of disease, as well as the usefulness of 18F-FDG PET and Integrisense to serve as biomarker probes. Conclusions: Animals tolerated the length of anesthesia well. Initial difficulties were found in performing the BLI on the same day as the remaining modalities, as anesthesia administration to animals inside the FMT cassette while acquiring BLI perturbed animal positioning. When BLI was acquired the day prior to multimodality imaging, the reliability of positioning was increased, permitting more facile fusion of the various modalities. The feasibility of this imaging was only made possible through the use of the AHS bed and dock that permitted reproducible imaging across the different platforms. In order to further optimize workflows, multiple AHS bed systems should be employed so that data can be acquired on the various modalities in parallel, instead of sequentially, thereby greatly increasing animal throughputs. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B142. Citation Format: John L. Chunta, Deanne Lister, Chris Bull, Deepa Balagurunathan, Erin Trachet, Chris Chiodo, Scott Wise, Wilbur R. Leopold, Patrick McConville. Evaluating the feasibility and throughput of quintuple modality imaging in disseminated models of cancer with PET, CT, MRI, bioluminescence, and fluorescence molecular tomography. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B142.