PROMPT-GAMMA RANGE VERIFICATION IN PROTONTHERAPY USING CONTRAST AGENTS

@misc{valladolid-onecha_prompt-gamma_2024,
	address = {Singapur},
	type = {Oral {Contribution}},
	title = {{PROMPT}-{GAMMA} {RANGE} {VERIFICATION} {IN} {PROTONTHERAPY} {USING} {CONTRAST} {AGENTS}},
	abstract = {Prompt gamma-ray (PG) emissions in proton therapy treatments have been proposed as a operational method for proton range
verification (Hueso-González et al., 2018). Current approaches employ PGs from natural tissues. This poses several challenges,
including the high energy of the emitted gamma-rays, which require the use of large and efficient devices for detection, and the
fact that the production cross sections vanish at the Bragg peak.
In this work we propose a novel approach to mitigate these issues but employing an external media, a contrast agent, able to
produce prompt-gamma radiation in a more suitable energy below 2 MeV. We select 18O as contrast agent, an innocuous element
already present in water, and already proposed as contrast agent for proton range verification using PET (España et al., 2022).
As a first step we present here experiments aimed at measuring the production yields, γ-ray angular distributions, and cross
sections of prompt-gamma emissions produced in the 18O(p,Xγ) reaction below 10 MeV, employing 18O-enriched water as
contrast. We employ a LaBr3(Ce)-based detection setup with a digital acquisition system that makes it possible to detect PGs at
high rates while maintaining good energy resolution.
We have identified and studied five PG emissions, three of them with energies close to 1 MeV. The measured γ-ray yields and the
derived cross-sections for prominent PGs from 18O(p,Xγ) reactions demonstrate the potential of 18O as a contrast agent. Compared
to natural PGs, 18O shows up to a tenfold increase in efficiency for PGs close to 1 MeV, compared to conventional oxygen-based PG
emissions. This work provides the basis for future research on the development of contrast-enhanced PG techniques.},
	author = {Valladolid-Onecha, V. and Espinosa Rodriguez, A. and Briz, J. A. and España, S. and García, G. and Ibañez, P. and Martínez Nouvilas, V. and Sánchez Parcerisa, D. and Viñals, S. and Udías, J. M. and Fraile, L. M.},
	month = jun,
	year = {2024},
}