2026-05-27T12:13:33Zhttps://riuma.uma.es/rest/oai/request

oai:riuma.uma.es:10630/366232026-02-03T11:13:45Zcom_10630_2254col_10630_37953

00925njm 22002777a 4500 dc Martínez Rovira, Immaculada author González-Infantes, Wilfredo author Brons, S. author Prezado, Yolanda author 2017-05-29 Abstract Purpose: To perform dosimetric characterization of a minibeam collimator in both carbon and oxygen ion beams to guide optimal set up geometry and irradiation for future radiobiological studies using these beams. Methods: Carbon and oxygen minibeams were generated using a prototype tungsten multislit collimator presenting line apertures 700 μm wide, which are spaced 3500 μm centre-to-centre distance apart. Several radiation beam spots generated the desired field size of 15×15 mm2 and production of a 50 mm long spread out Bragg peak (SOBP) centered at 80 mm-depth in water. Dose evaluations were performed with two different detectors: a PTW microDiamond R© single crystal diamond detector and radiochromic films (EBT3). Peak-to-valley dose ratio (PVDR) values, output factors (OF), penumbras and full width at half maximum (FWHM) were measured. Results: Measured lateral dose profiles exhibited spatial fractionation of dose at depth in a water phantom in the expected form of peaks and valleys for both carbon and oxygen radiation fields. The diamond detector and radiochromic film provided measurements of PVDR in good agreement. PVDR values at shallow depth were about 60 and decreased to about 10 at 80 mm-depth in water. OF in the center of the SOBP was about 0.4; this value is larger than the corresponding one in proton minibeam radiation therapy measured using comparable collimator due to a reduced lateral scattering for carbon and oxygen minibeams. Conclusions: Carbon and oxygen minibeams may be produced by a mechanical collimator. PVDR values and output factors measured in this first study of these minibeam radiation types indicate there is potential for their therapeutic use. Optimization of minibeam collimator design and the number and size of focal spots for irradiation are advocated to improve PDVR values and dose distributions for each specific applied use. Martínez‐Rovira, I., González, W., Brons, S., & Prezado, Y. (2017). Carbon and oxygen minibeam radiation therapy: An experimental dosimetric evaluation. Medical Physics (Lancaster), 44(8), 4223–4229. https://doi.org/10.1002/mp.12383 https://hdl.handle.net/10630/36623 10.1002/mp.12383 Radiobiología Hadrones Carbon and oxygen minibeam radiation therapy: An experimental dosimetric evaluation