BEST IN PHYSICS (MULTI-DISCIPLINARY): Development of Quadruple On-Board Imaging to Guide Radiation Treatment in Small Animals
H Wang1,2*, X Li1,2, L Xu1,2, Y Ren1,2, W Deng1, H Feng3, Z Yang4, S Ma1,5, Q Ni6, Y Kuang7, (1) Medical Imaging and Translational Medicine Laboratory, Hangzhou Cancer Center, Hangzhou, CN, (2) Department of Radiotherapy, Affiliated Hangzhou Cancer Hospital, Zhejiang University School of Medicine, Hangzhou, CN, (3) Patient Follow-up Center, Hangzhou Cancer Hospital, Hangzhou, CN, (4) Department of Radiotherapy, Xiangya Hospital Central South University, Changsha, CN, (5) Medical Oncology, Xiaoshan Hospital Affiliated to Hangzhou Normal University, Hangzhou, CN, (6) Department of Radiology, Hunan Cancer Hospital, Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, CN, (7) Medical Physics Program, University of Nevada, Las Vegas, NV, USA
Presentations
MO-F-BRC-5 (Monday, 7/11/2022) 1:45 PM - 2:45 PM [Eastern Time (GMT-4)]
Ballroom C
Purpose: We investigated, for the first time to our best knowledge, the feasibility of integrating a novel quadruple on-board imaging design - including positron emission tomography (PET), single-photon emission computed tomography (SPECT), spectral CT, and cone-beam computed tomography (CBCT) - into a small animal radiation treatment (SART) platform for one-stop preclinical RT studies by using a Monte Carlo (MC) model.
Methods: As a proof-of-concept, the quad-modal image-guided SART system was designed using the GATE MC code. A PET subsystem with dual 90° arcs of symmetrically opposite PET detectors was integrated into our previously proposed SPECT/spectral-CT/CBCT on-board imaging system using a single photon-counting cadmium zinc tellurium imager. The PET scanner was designed based on novel pixelated thallium bromide detectors with a resolution of 1.25 mm × 1.25 mm. The spatial resolution, sensitivity, and scatter fraction of PET imaging was measured mainly by using the methods prescribed by the NEMA NU-4 standard. A simulated phantom with multiple imaging probes, incuding Iodine, ¹⁸F, and ⁹⁹ᵐTc, was imaged to demonstrate the imaging performance of the system. In spectral CT, virtual non-contrast (VNC) electron densities and iodine contrast agent fractions in the Kidney1 inserts within the phantom were decomposed and imaged quantitatively by using the Bayesian eigentissue decomposition and the maximum a posterior estimation methods.
Results: In PET imaging, the absolute peak sensitivity was measured as 18.5% with an energy window of 175–560 KeV; the measured scatter fraction was 3.5% for a mouse phantom with a default energy window of 480–540 KeV; the spatial resolution exceeded 1.2 mm. The system can successfully capture high-quality PET, SPECT, spectral-CT (including decomposed iodine contrast agent fraction and VNC electron density images), and CBCT images of the simulated phantom.
Conclusion: The results demonstrated the feasibility of the highly integrated quad-modal imaging configuration in a SART platform.
Keywords
Radiation Therapy, PET, Image Guidance
Taxonomy
TH- Small Animal RT: Development (new technology and techniques)
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