RT Journal Article
T1 Impact of cardiosynchronous brain pulsations on Monte Carlo calculated doses for synchrotron micro- and minibeam radiation therapy.
A1 Manchado de Sola, Francisco
A1 Vilches, Manuel
A1 Prezado, Yolanda
A1 Lallena, Antonio M
K1 Monte Carlo simulation
K1 micro- and minibeam radiation therapy
K1 synchrotron radiation
AB The purpose of this study was to assess the effects of brain movements induced by heartbeat on dose distributions in synchrotron micro- and minibeam radiation therapy and to develop a model to help guide decisions and planning for future clinical trials. The Monte Carlo code PENELOPE was used to simulate the irradiation of a human head phantom with a variety of micro- and minibeam arrays, with beams narrower than 100 μm and above 500 μm, respectively, and with radiation fields of 1 × 2 cm and 2 × 2 cm. The dose in the phantom due to these beams was calculated by superposing the dose profiles obtained for a single beam of 1 μm × 2 cm. A parameter δ, accounting for the total displacement of the brain during the irradiation and due to the cardiosynchronous pulsation, was used to quantify the impact on peak-to-valley dose ratios and the full width at half maximum. The difference between the maximum (at the phantom entrance) and the minimum (at the phantom exit) values of the peak-to-valley dose ratio reduces when the parameter δ increases. The full width at half maximum remains almost constant with depth for any δ value. Sudden changes in the two quantities are observed at the interfaces between the various tissues (brain, skull, and skin) present in the head phantom. The peak-to-valley dose ratio at the center of the head phantom reduces when δ increases, remaining above 70% of the static value only for minibeams and δ smaller than ∼200 μm. Optimal setups for brain treatments with synchrotron radiation micro- and minibeam combs depend on the brain displacement due to cardiosynchronous pulsation. Peak-to-valley dose ratios larger than 90% of the maximum values obtained in the static case occur only for minibeams and relatively large dose rates.
YR 2018
FD 2018-06-08
LK http://hdl.handle.net/10668/12470
UL http://hdl.handle.net/10668/12470
LA en
DS RISalud
RD Apr 8, 2025