RT Journal Article
T1 Real-time dose reconstruction in proton therapy from in-beam PET measurements
A1 Valladolid Onecha, Víctor
A1 Espinosa Rodríguez, Andrea
A1 Soneira-Landín, C.
A1 Arias Valcayo, Fernando
A1 Gaitán-Dominguez, S.
A1 Martínez Nouvilas, Víctor
A1 García Díez, Marcos
A1 Ibáñez García, Paula Beatriz
A1 España, S.
A1 Sánchez Parcerisa, Daniel
A1 Cerrón-Campoo, F.
A1 Vera-Sánchez, J. A.
A1 Mazal, A.
A1 Udías Moinelo, José Manuel
A1 Fraile Prieto, Luis Mario
AB Objective. Clinical implementation of in-beam positron emission tomography (PET) monitoring in proton therapy (PT) requires the integration of an online fast and reliable dose calculation engine. This manuscript reports on the achievement of real-time reconstruction of 3D dose and activity maps with proton range verification from experimental in-beam PET measurements. Approach. Several cylindrical homogeneous PMMA phantoms were irradiated with a monoenergetic 70 MeV proton beam in a clinical facility. Additionally, PMMA range-shifting foils of varying thicknesses were placed at the proximal surface of the phantom to investigate range shift prediction capabilities. PET activity was measured using a state-of-the-art in-house developed six-module PET scanner equipped with online PET reconstruction capabilities. For real-time dose estimation, we integrated this system with an in-beam dose estimation algorithm, which combines a graphical processing unit-based 3D reconstruction algorithm with a dictionary-based software, capable of estimating deposited doses from the 3D PET activity images. The range shift prediction performance has been quantitatively studied in terms of the minimum dose to be delivered and the maximum acquisition time. Main results. With this framework, 3D dose maps were accurately reconstructed and displayed with a delay as short as one second. For a dose fraction of 8.4 Gy at the Bragg peak maximum, range shifts as small as 1 mm could be detected. The quantitative analysis shows that accumulating 20 s of statistics from the start of the irradiation, doses down to 1 Gy could be estimated online with total uncertainties smaller than 2 mm. Significance. The hardware and software combination employed in this work can deliver dose maps and accurately predict range shifts after short acquisition times and small doses, suggesting that real-time monitoring and dose reconstruction during PT are within reach. Future work will focus on testing the methodology in more complex clinical scenarios and on upgrading the PET prototype for increased sensitivity.
PB Elsevier
SN 0031-9155
YR 2025
FD 2025-03-21
LK https://hdl.handle.net/20.500.14352/122635
UL https://hdl.handle.net/20.500.14352/122635
LA eng
NO V V Onecha et al 2025 Phys. Med. Biol. 70 075008
NO "This work was funded by Comunidad de Madrid, Spain under Projects PRONTO-CM (B2017/BMD-3888) and ASAP-CM (S2022/BMD7434). We acknowledge support by UCM under project pFLASH(PR27/21-014); Spanish MCIN/AEI/10.13039/501100011033 under Grants RADFLAP (PID2021-124094OA-I00), FLASHonCHIP (PLEC2022-009256), PROTOTWIN (TED2021-130592B-I00),mPET (PID2021-126998OB-I00) and INVENTOR (PID2022-137114OA-I00); European Union as part of the European Innovation Council’s Pathfinder Open Programme: RETIMAGER, 101099096. The authors acknowledge the support from The Centro de protonterapia Quirónsalud, for the beam time, and its technical staff for their contribution to the operation of the accelerator. This contribution is for the Moncloa Campus of International Excellence, ”Nuclear Physics Group-UCM,” Ref. 910059. Part of the calculations for this work were performed on the ”Computing Cluster for Physical Techniques,” funded partially by UCM and partially by EU Regional Funds."
NO Ministerio de Ciencia, Innovación y Universidades (España)
NO Comunidad de Madrid
NO European Commission
NO Universidad Complutense de Madrid
DS Docta Complutense
RD 25 dic 2025