TY - JOUR
T1 - Dose specification for Ir-192 high dose rate brachytherapy in terms of dose-to-water-in-medium and dose-to-medium-in-medium
AU - Fonseca, Gabriel Paiva
AU - Tedgren, Asa Carlsson
AU - Reniers, Brigitte
AU - Nilsson, Josef
AU - Persson, Maria
AU - Yoriyaz, Helio
AU - Verhaegen, Frank
PY - 2015/6/7
Y1 - 2015/6/7
N2 - Dose calculation in high dose rate brachytherapy with Ir-192 is usually based on the TG-43U1 protocol where all media are considered to be water. Several dose calculation algorithms have been developed that are capable of handling heterogeneities with two possibilities to report dose: dose-to-medium-inmedium (D-m,D-m) and dose-to-water-in-medium (D-w,D-m). The relation between D-m,D-m and D-w,D-m for Ir-192 is the main goal of this study, in particular the dependence of D-w,D-m on the dose calculation approach using either large cavity theory (LCT) or small cavity theory (SCT). A head and neck case was selected due to the presence of media with a large range of atomic numbers relevant to tissues and mass densities such as air, soft tissues and bone interfaces. This case was simulated using a Monte Carlo (MC) code to score: D-m,D-m, D-w,D-m (LCT), mean photon energy and photon fluence. D-w,D-m (SCT) was derived from MC simulations using the ratio between the unrestricted collisional stopping power of the actual medium and water. Differences between D-m,D-m and D-w,D-m (SCT or LCT) can be negligible (
AB - Dose calculation in high dose rate brachytherapy with Ir-192 is usually based on the TG-43U1 protocol where all media are considered to be water. Several dose calculation algorithms have been developed that are capable of handling heterogeneities with two possibilities to report dose: dose-to-medium-inmedium (D-m,D-m) and dose-to-water-in-medium (D-w,D-m). The relation between D-m,D-m and D-w,D-m for Ir-192 is the main goal of this study, in particular the dependence of D-w,D-m on the dose calculation approach using either large cavity theory (LCT) or small cavity theory (SCT). A head and neck case was selected due to the presence of media with a large range of atomic numbers relevant to tissues and mass densities such as air, soft tissues and bone interfaces. This case was simulated using a Monte Carlo (MC) code to score: D-m,D-m, D-w,D-m (LCT), mean photon energy and photon fluence. D-w,D-m (SCT) was derived from MC simulations using the ratio between the unrestricted collisional stopping power of the actual medium and water. Differences between D-m,D-m and D-w,D-m (SCT or LCT) can be negligible (
KW - brachytherapy
KW - Ir-192
KW - dose-to-water-in-medium
KW - dose-to-medium-in-medium
U2 - 10.1088/0031-9155/60/11/4565
DO - 10.1088/0031-9155/60/11/4565
M3 - Article
C2 - 26009538
SN - 0031-9155
VL - 60
SP - 4565
EP - 4579
JO - Physics in Medicine and Biology
JF - Physics in Medicine and Biology
IS - 11
ER -