Table 1.
Characteristics of the patients and treatment included in this study.
Fig 1.
Patient setup position for radiotherapy.
(A) supine position, (B) head-tilted supine position.
Fig 2.
Image registration using the planning computed tomography (CT) and cone beam CT (CBCT) in the c-SP.
(A) Planning CT, (B) CBCT, and (C) registration image.
Fig 3.
Image registration using the planning computed tomography (CT) and cone beam CT (CBCT) in the ht-SP.
(A) Planning CT, (B) CBCT, and (C) registration image.
Fig 4.
Histograms and normal distribution curves of the setup errors in the translation and rotation for the supine position (c-SP).
Setup errors in the (A) lateral, (B) longitudinal, (C) vertical, and (D) yaw directions.
Fig 5.
Histograms and normal distribution curves of the setup errors in the translation and rotation for the head-tilted supine position (ht-SP).
Setup errors in the (A) lateral, (B) longitudinal, (C) vertical, and (D) yaw directions.
Table 2.
Systematic errors (Σ) and random errors (σ) in the translational (lateral [x-axis], longitudinal [z-axis], and vertical [y-axis]) and rotational (yaw [y-axis]) directions.
Fig 6.
Boxplot and p-value of the Mann–Whitney U-test in the translation and rotation be-tween the c-SP and ht-SP.
Setup errors in the (A) lateral, (B) longitudinal, (C) vertical, and (D) yaw directions.
Fig 7.
Boxplot and p-value of the Mann–Whitney U-test in the three-dimensional radiotherapy (3D) vector between the c-SP and ht-SPs.
Table 3.
Clinical target volume (CTV) to planning target volume (PTV) margin calculations calculated by Stroom et al.’s [14] and van Herk et al.’s [15] margin recipe for systematic (Σ) and random errors (σ).