E. Sadiki et al.: Radioprotection 2026, 61( 2), 140 – 145 143
Fig. 4. Relative dose variation histogram for the bladder, rectum and CTV high-risk during simulated rotational displacements along the lateral( Y-axis).
Fig. 5. Relative dose variation histogram for the bladder, rectum and CTV high-risk during simulated rotational displacements along the axial rotation( Z-axis).
presents a histogram illustrating the Vertical dose variation as a function of rotation angles.
3.3 Dose variations along the Z-axis( axial rotation)
Rotations around the Z-axis( applicator axis) caused minor dose variations. The bladder dose varied by a maximum of þ1.02 %, the rectum by þ0.24 %, and the CTV by �0.94 % to þ0.55 %. While these variations are relatively small, they can affect dose distribution, particularly when structures like the bladder or rectum are close to the applicator. The impact of axial rotations is generally less critical than that of vertical displacements but is still important. Figure 5 presents a histogram illustrating the Axial Rotation dose variation as a function of rotation angles.
3.4 Clinical implications
Applicator displacements, especially along the vertical axis, frequently occur during patient transportation between imaging and treatment rooms or during applicator insertion. These shifts may not be immediately visible but can lead to