2019

# Erratum to: Monte Carlo study of ionization chamber magnetic field correction factors as a function of angle and beam quality (Medical Physics, (2018), 45, 2, (908-925), 10.1002/mp.12716)

## Publication

### Publication

Figures 6 and 8 in our 2018 paper were found to be incorrectly plotted and should have the data flipped about the 180 (Formula presented.) mark of the angle axis. The updated figures are provided below. This error impacts Table III of the paper and the values in the 90 (Formula presented.) and 270 (Formula presented.) columns must be exchanged to provide the corrected Table III below. 6 (Figure presented.) Values of k (Formula presented.) as a function of angle for (Formula presented.) Co at 0.35 T and 7 MV at 1.5 T. The horizontal dashed lines are the 0 T k (Formula presented.) values for the chambers and associated beam quality (k (Formula presented.) for (Formula presented.) Co). Simulation uncertainty is k = 1. The 0 T results are for the 0 (Formula presented.) simulation only (sample simulations demonstrate that there is no variation in k (Formula presented.) as a function of angle in the absence of a magnetic field). The entire geometric sensitive volume is used. The circles at 0 and 180 (Formula presented.) for guiding the eye. 8 (Figure presented.) Values of k (Formula presented.) as a function of angle for (Formula presented.) Co at 0.35 T and 7 MV at 1.5 T with either the full geometric sensitive volume (0 mm labels) or with the geometric sensitive volume reduced by the volume corresponding to 1 mm away from the stem (1 mm labels) used for the ion chamber simulations. The circles at 0 and 180 (Formula presented.) are for guiding the eye. III Values of (Formula presented.), maximum absolute percent difference in k (Formula presented.) due to a (Formula presented.) kqmag calculated using the full geometric sensitive volume and excluding the air corresponding to the first 1 mm away from the stem, for the 7 MV and (Formula presented.) Co simulations for the four cardinal angular orientations. The statistical uncertainty on each value is ns were interchanged from the original 2018 version (Table presented.) It should be noted that all other calculations, including all k (Formula presented.), k (Formula presented.), and k (Formula presented.) values, are unaffected by this change. The physics pertaining to the sensitive volume impact on the chamber response as a function of angle in the magnetic field was originally correctly explained and now properly corresponds to what is observed in the updated figures. The sole impact on the discussion is in the first paragraph of section 3.A in which the statement:”This is observed for all chambers, and is particularly highlighted for the (Formula presented.) Co simulations of the Exradin A1SL, Exradin A12S, and the PTW 31006 in which the chamber dose, in comparison to the 0 T results, decreases near the C-II orientation and increases near the C-IV orientation." should be corrected to:“This is observed for all chambers, and is particularly highlighted for the (Formula presented.) Co simulations of the Exradin A1SL, Exradin A12S, and the PTW 31006 in which the chamber dose, in comparison to the 0 T results, increases near the C-II orientation and decreases near the C-IV orientation."

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dx.doi.org/10.1002/mp.13782 | |

Medical Physics | |

Organisation | Department of Physics |

Malkov, V.N. (Victor N.), & Rogers, D.W.O. (2019). Erratum to: Monte Carlo study of ionization chamber magnetic field correction factors as a function of angle and beam quality (Medical Physics, (2018), 45, 2, (908-925), 10.1002/mp.12716).
Medical Physics. doi:10.1002/mp.13782 |