RT Journal Article
T1 Small static radiosurgery field dosimetry with small volume ionization chambers
A1 López Sánchez, Miguel
A1 Pérez Fernández, María Reyes
A1 Pardo Pérez, Eduardo
A1 Fandiño Orgeira, José Manuel
A1 García Teijeiro, Antonio
A1 Gómez Fernández, Nicolás
A1 Gómez Rodríguez, Faustino
A1 González Castaño, Diego Miguel
K1 IBA razor nano
K1 Small field dosimetry
K1 SRS
K1 Monte Carlo simulation
AB Purpose: To evaluate the response of the four smallest active volume thimble type ionization chambers commercially available (IBA-dosimetry RAZOR Nano Chamber, Standard Imaging Exradin A16, IBA-dosimetry CC01 and PTW T31022) when measuring SRS cone collimated Flattening Filter Free (FFF) fields. Methods: We employed Monte Carlo simulation for calculating correction factors as defined in IAEA TRS-483. Monte Carlo simulation beam model and ion chamber geometry definitions were supported by an extensive set of measurements. Type A and B uncertainty components were evaluated.Results: Commissioning of Monte Carlo 6 MV and 10 MV FFF beam models yielded relative differences between measured and simulated dose distributions lower than 1.5%. Monte Carlo simulated output factors for 5 mm SRS field agree with experimental values within 1% local relative difference for all chambers. Smallest active volume ion chamber (IBA-dosimetry RAZOR Nano Chamber) exhibits smallest correction, being compatible with unity. Correction factor combined uncertainties range between 0.7% and 0.9%. Smallest uncertainties were recorded for smallest and largest active volume ion chambers, although the latter exhibited largest correction factor. Highest contribution to combined uncertainty was type B component associated with beam model initial electron spatial Full Width Half Maximum (FWHM) uncertainty. Conclusions: Among the investigated chambers, the IBA RAZOR Nano Chamber was found to be an excellent choice for narrow beam output factor measurement since it requires minimum correction (in line with IAEA TRS-483 recommendations). This is caused by its tiny size and tissue equivalence materials which produce minimum volume averaging and fluence perturbation
PB Elsevier
YR 2022
FD 2022
LK http://hdl.handle.net/10347/29899
UL http://hdl.handle.net/10347/29899
LA eng
NO Physica Medica 97 (2022). https://doi.org/10.1016/j.ejmp.2022.04.002
DS Minerva
RD 24 abr 2026