Abstract
We investigate the feasibility for intra-fraction online multiple scanning proton beam range verifications (BRVs) with in-situ PET imaging, which is beyond the single-beam BRV we had previously studies. We simulated various 132-MeV proton beams with 4-mm diameter and different beamseparations irradiating PMMA phantoms by GATE simulations. The generated nuclear interaction-induced positrons, which were distributed in either a planar or a curved positron activity range profile, were imaged by a PET (∼2-mm resolution, 17% sensitivity in the energy range from 350 keV to 650 keV, 250×250×128 mm3 field-of-view). We calculated the activity ranges (ARs) from reconstructed PET images and compared them with the corresponding ARs of the original positron distributions. Preliminary studies show that: 1) for two separated beams with overlapped positrons, errors of AR measurement for each beam varied from 0.2 mm to 2.3 mm as center-to-center beam separation and AR difference were in the range of 8-12 mm and 2-8 mm respectively. It is feasible to achieve < 1.0-mm accuracy for two beams with a 100-second PET acquisition and 12-mm beam-separation; 2) for densely distributed beams with a continuous profile of AR distributions, PET image was blurred further at non-planar AR region than planar region which led to worsened AR measurement accuracy at non-planar region. Further studies will focus on identifying key factors that impact the AR measurement with multi-beam irradiations, such as the PET resolution model and the ways to reduce the error in nonplanar regions, sensitivity, configuration, image process and enhancement, to improve beam range verifications.
Original language | English (US) |
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Title of host publication | 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop, NSS/MIC/RTSD 2016 |
Publisher | Institute of Electrical and Electronics Engineers Inc. |
Volume | 2017-January |
ISBN (Electronic) | 9781509016426 |
DOIs | |
State | Published - Oct 16 2017 |
Event | 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop, NSS/MIC/RTSD 2016 - Strasbourg, France Duration: Oct 29 2016 → Nov 6 2016 |
Other
Other | 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop, NSS/MIC/RTSD 2016 |
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Country | France |
City | Strasbourg |
Period | 10/29/16 → 11/6/16 |
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Instrumentation
- Nuclear and High Energy Physics
- Electronic, Optical and Magnetic Materials