scholarly journals Analysis of local setup errors of sub-regions in cone-beam CT-guided post-mastectomy radiation therapy

2020 ◽  
Vol 61 (3) ◽  
pp. 457-463 ◽  
Author(s):  
Jidan Zhou ◽  
Shuai Li ◽  
Chengwei Ye ◽  
Konglong Shen ◽  
An Li ◽  
...  

ABSTRACT The purpose of the study was to quantify local setup errors and evaluate the planning target volume (PTV) margins for sub-regions in cone-beam computed tomography (CBCT)-guided post-mastectomy radiation therapy (PMRT). The local setup errors of 20 patients undergoing CBCT-guided PMRT were analysed retrospectively. Image registration between CBCT and planning CT was performed using four sub-regions of interest (ROIs): the supraclavicular area (SROI), ipsilateral chest wall region (CROI), ipsilateral chest wall plus supraclavicular region (SROI + CROI) and vertebral region (TROI). Bland–Altman analysis, correlation, local setup errors and PTV margins among these ROIs were evaluated. There was no significant consistency or correlation for registration results between the TROI and the CROI or SROI regions on any translational axis. When using the SROI + CROI as the ROI, the systematic error (Σ) and random error (σ) of the local setup errors for the CROI region were 1.81, 1.19 and 1.76 mm and 1.84, 2.64 and 3.00 mm along the medial–lateral (ML), superior–inferior (SI) and anterior–posterior (AP) directions, respectively. The PTV margins for the CROI region were 5.80, 4.82 and 6.50 mm. The Σ and σ of the local setup errors for the SROI region were 1.29, 1.15 and 0.77 mm and 1.96, 2.65 and 2.2 mm, respectively, and the PTV margins were 4.59, 4.73 and 3.47 mm. Large setup errors and local setup errors occur in PMRT. The vertebral body should not be a position surrogate for the supraclavicular region or chest wall. To compensate for the local setup errors, different PTV margins are required, even with CBCT guidance.

2020 ◽  
Vol 61 (6) ◽  
pp. 985-992
Author(s):  
Konglong Shen ◽  
Jie Xiong ◽  
Zhiguo Wang ◽  
Weifeng Wang ◽  
Wan Li ◽  
...  

Abstract To design a new breast vacuum bag to reduce global and local setup errors in post-mastectomy radiation therapy (PMRT). A total of 24 PMRT patients were immobilized with an old vacuum bag and 26 PMRT patients were immobilized with a new vacuum bag. The registration results were analysed using four regions of interest (ROI): the global ROI [including the whole region of the planning target volume (PTV), GROI], the supraclavicular area (SROI), the ipsilateral chest wall region (CROI) and the ipsilateral arm region (AROI). The global and local setup errors of the two groups were compared. The global setup errors of the new vacuum group were significantly smaller than those in the old vacuum group with the exception of yaw axes (P < 0.05). The systematic error (Σ) and random error (σ) ranged from 1.21 to 2.13 mm. In the new vacuum group, the local setup errors in the medial-lateral (ML) direction and roll axes for CROI (the Σ and σ ranged from 0.65 to 1.35 mm), and the local setup errors in ML and superior-inferior (SI) directions for SROI were significantly smaller than those in the old vacuum group. The total required PTV margins for the chest wall in ML, SI, and anterior-posterior (AP) were 4.40, 3.12 and 3.77 mm respectively. The new vacuum bag can significantly reduce the global setup errors and local setup errors in PMRT. The respiratory motion of the chest wall was negligible, and the 5 mm PTV margin could cover the local setup errors in PMRT using the new vacuum bag with cone beam CT (CBCT) correction.


2006 ◽  
Vol 33 (6Part7) ◽  
pp. 2063-2063 ◽  
Author(s):  
F Yin ◽  
L Marks ◽  
Z Wang ◽  
J Kirkpatrick ◽  
J Wu ◽  
...  

2017 ◽  
Vol 44 (5) ◽  
pp. 1796-1808 ◽  
Author(s):  
Linxi Shi ◽  
Tiffany Tsui ◽  
Jikun Wei ◽  
Lei Zhu

2005 ◽  
Vol 75 (3) ◽  
pp. 279-286 ◽  
Author(s):  
Daniel Létourneau ◽  
John W. Wong ◽  
Mark Oldham ◽  
Misbah Gulam ◽  
Lindsay Watt ◽  
...  

2005 ◽  
Vol 75 (3) ◽  
pp. 271.E1-271.E8 ◽  
Author(s):  
Mark Oldham ◽  
Daniel Létourneau ◽  
Lindsay Watt ◽  
Geoffrey Hugo ◽  
Di Yan ◽  
...  

2013 ◽  
Vol 40 (6Part29) ◽  
pp. 479-479 ◽  
Author(s):  
HY Zhang ◽  
L Liu ◽  
H Wu ◽  
HZ Yue ◽  
TY Niu ◽  
...  

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