Program Information
Prompt Gamma Ray Spectroscopy of Contrast Agents in Proton Radiotherapy
E Kasanda*, D Muecher , V Bildstein , J Turko , University of Guelph, Guelph, ON
Presentations
SU-F-601-7 (Sunday, July 30, 2017) 2:05 PM - 3:00 PM Room: 601
Purpose: In recent years, the number proton treatment facilities and the number of patients treated for cancer with proton radiotherapy have increased steadily. Despite this, the technique still requires some fine-tuning and could be greatly improved. Dose and range verification in proton radiotherapy are of particular importance, due to the mechanism of interaction of protons with tissue.
Methods: In this project, we explore the possibility of detecting characteristic gamma rays from the fusion-evaporation reaction between the proton beam and a contrast agent that has been administered to a tumor. Successful detection of these gamma rays would offer a unique way to measure the dose received by the tumor in real time. In addition, our method allows precise range verification and gives feedback on the actual location of the tumor in the patient.In order to determine the viability of this technique and optimize the setup, we used Geant4 in combination with ROOT to simulate the treatment and analyze the resulting spectra. The performance of different geometries, detectors, and optimization techniques were explored. The resolutions of a Lanthanum Bromide (LaBr₃) scintillation detector were compared with the resolutions of a High Purity Germanium (HPGe) detector array in order to determine which detector best suited our needs. Optimization techniques of interest include time-gating, collimation, and gamma-gamma coincidence.
Results: The results of the simulation show that this method allows for the detection of a contrast agent in tissue under realistic conditions.
Conclusion: The simulation shows a promising signal-to-noise ratio, suggesting that this method is feasible. We are in the process of planning a precursor experiment at TRIUMF.
Funding Support, Disclosures, and Conflict of Interest: Supported by NSERC under grant Nr. SAPIN-2016-00030
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