Program Information
Pre-Clinical Radionuclide Therapy Dosimetry in Several Pediatric Cancer Xenografts
I Marsh*, M Otto , J Weichert , D Baiu , B Bednarz , University of Wisconsin, Madison, WI
Presentations
SU-G-TeP3-8 (Sunday, July 31, 2016) 5:00 PM - 5:30 PM Room: ePoster Theater
Purpose: The focus of this work is to perform Monte Carlo-based dosimetry for several pediatric cancer xenografts in mice treated with a novel radiopharmaceutical ¹³¹I-CLR1404.
Methods: Four mice for each tumor cell line were injected with 8-13 μCi/g of the ¹²⁴124I-CLR1404. PET/CT images of each individual mouse were acquired at 5-6 time points over the span of 96-170 hours post-injection. Following acquisition, the images were co-registered, resampled, rescaled, corrected for partial volume effects (PVE), and masked. For this work the pre-treatment PET images of ¹²⁴I-CLR1404 were used to predict therapeutic doses from ¹³¹I-CLR1404 at each time point by assuming the same injection activity and accounting for the difference in physical decay rates. Tumors and normal tissues were manually contoured using anatomical and functional images. The CT and the PET images were used in the Geant4 (v9.6) Monte Carlo simulation to define the geometry and source distribution, respectively. The total cumulated absorbed dose was calculated by numerically integrating the dose-rate at each time point over all time on a voxel-by-voxel basis.
Results: Spatial distributions of the absorbed dose rates and dose volume histograms as well as mean, minimum, maximum, and total dose values for each ROI were generated for each time point.
Conclusion: This work demonstrates how mouse-specific MC-based dosimetry could potentially provide more accurate characterization of efficacy of novel radiopharmaceuticals in radionuclide therapy.
Funding Support, Disclosures, and Conflict of Interest: This work is partially funded by NIH grant CA198392.
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