Changes in Rectal Dose Due to Alterations in Beam Angles for Setup Uncertainty and Range Uncertainty in Carbon-Ion Radiotherapy for Prostate Cancer - Fig 3

<p>Data on one patient without a metal implant, for four field angles: (a) 0° field, (b) 30° field, (c) 60° field, and (d) 90° field. Green line shows prostate, light yellow line shows PTV, and magenta line shows rectum. (i) Dose distribution in the normal case. (ii) Yellow line shows the 95% isodose line for the prescription dose in the normal case, blue line shows the 95% isodose line of the prescription dose in the worst case, and red line shows the 95% isodose line of the prescription dose in the best case.</p

Averaging dose volume histogram (DVH) graphs of rectal dose and CTV dose.

<p>Red lines are the DVHs of the CTV dose shown as relative volume (%) and blue lines are DVHs of the rectal dose shown as absolute volume (cm³). (i) Ten patients in each beam angle. The light blue error bars represent the standard deviations for 10 patients. (ii) (e) is patient 1 with a 60° field. (f) is patient 2 with a 68° field. (g) is patient 3 with a −35° field. Patients in (e), (f) and (g) have hip implants and all fields avoid the implants. The solid lines show normal cases, and the dashed lines show the best or worst cases for setup and range uncertainties.</p

Clinical case data of a patient with a metal implant.

<p>The upper row shows CT images and the bottom row shows CT images together with the dose distribution. Left column shows axial images, middle column shows sagittal images, and right column shows coronal images. Red lines show the metal implant after hip replacement. Green line shows prostate, light yellow line shows PTV, magenta line shows rectum, and purple line shows the bladder.</p

The two patterns of CT image sets used for the calculation.

<p>Arrows show the beam directions, blue regions show the CTV, and red regions show the metal implant. (a) Diagram of a patient with no implant and a beam that can enter from the left (negative angle, gray arrows) or the right (positive angle, white arrows). (b) Diagram of a patient with a hip implant, showing the field directions of 0°, 30°, 60°, and 90°. (c) Diagram of a patient with a hip implant, showing the oblique field avoiding the implant. (d) Field directions from −90° to 90°; 90° represents left horizontal, and −90° represents right horizontal.</p

Patient information, CTVs, and rectal volumes.

<p>CTV shows the clinical target volume, metal implant shows which side the patient has in or not.</p

Increasing ratio graph of rectal mean dose from each uncertainty for the 10 patients enrolled in the study.

<p>(a) is the increasing ratio from setup uncertainty in anterior-posterior (AP), left-right (LR), and cranial-caudal (CC) directions, (b) is the ratio from range uncertainty, and (c) is the ratio from the setup and range uncertainties. The error bars represent the standard deviations for 10 patients. * in (a), and (b) show <i>p</i> < 0.05 using the Wilcoxon test, and * in (c) shows <i>p</i> < 0.05 using Dunnett’s multiple test.</p

Beam parameters used in calculations for treatment planning for each field angle (n = 10).

<p>Beam parameters used in calculations for treatment planning for each field angle (n = 10).</p