TY - JOUR
T1 - Precision of 2 Low-dose Abdomen/Pelvis Cone Beam Computed Tomography Protocols for Alignment to Bone and Soft Tissue in Pediatric Patients Receiving Image Guided Radiation Therapy
AU - Rao, Avani D.
AU - Lee, Junghoon
AU - Fu, Wei
AU - Nicholas, Sarah
AU - Alcorn, Sara R.
AU - Moore, Joseph
AU - Ladra, Matthew
AU - Mahesh, Mahadevappa
AU - Bartolac, Steven
AU - Terezakis, Stephanie A.
N1 - Funding Information:
Sources of support: This research was supported by a scientific grant from Elekta Industries.Conflicts of interest: Dr Terezakis received an educational grant from Elekta Industries.
Publisher Copyright:
© 2019
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019/5
Y1 - 2019/5
N2 - Purpose: To evaluate the precision of 2 low-dose cone (LD) beam computed tomography (CBCT) protocols to align to bone and soft tissue for pediatric patients receiving image guided radiation therapy (IGRT) to the abdomen and pelvis. Methods and Materials: Image-quality evaluation was done for 858 CBCT scans from 46 pediatric patients treated with IGRT from January 2015 to December 2017. The evaluations guided the development of 2 significantly dose-reduced protocols, LD-CBCT1 and a further dose-reduced LD-CBCT2. Representative scans from LD-CBCT1 and LD-CBCT2 from 8 patients with at least 1 CBCT scan from both protocols were registered separately to a bone and soft-tissue landmark on the simulation computed tomography scan. Eighteen identical blinded random offsets were applied to each patient's LD-CBCT1 and LD-CBCT2 from a starting registration that was then realigned using rigid registration. The residual offset between the baseline registration and the final registration attempt was calculated and analyzed using a 1-sided, 1 sample t test to evaluate whether LD-CBCT1, delivering a higher dose, was superior to the lower-dose LD-CBCT2 for bone and soft-tissue alignment. Results: In comparing 288 registrations with a bone landmark across 8 patients, no difference was found in the vector magnitude offsets using LD-CBCT 1 (mean [x¯], 0.73 mm; standard deviation [σ], 0.39 mm) and LD-CBCT2 (x¯, 0.74 mm; σ, 0.40 mm; P =.425). Comparing 216 registrations with a soft-tissue landmark across 6 patients, alignment using LD-CBCT2 (x¯, 1.55 mm; σ, 1.08 mm) resulted in larger differences in the vector magnitude of the offsets compared with LD-CBCT1 (x¯, 1.37 mm; σ, 0.74 mm; P =.049). Conclusions: Clinics treating pediatric patients should consider implementing a protocol mirroring LD-CBCT2 for abdomen and pelvis IGRT bone alignment. Further evaluation of the precision of LD-CBCTs for soft-tissue alignment is necessary.
AB - Purpose: To evaluate the precision of 2 low-dose cone (LD) beam computed tomography (CBCT) protocols to align to bone and soft tissue for pediatric patients receiving image guided radiation therapy (IGRT) to the abdomen and pelvis. Methods and Materials: Image-quality evaluation was done for 858 CBCT scans from 46 pediatric patients treated with IGRT from January 2015 to December 2017. The evaluations guided the development of 2 significantly dose-reduced protocols, LD-CBCT1 and a further dose-reduced LD-CBCT2. Representative scans from LD-CBCT1 and LD-CBCT2 from 8 patients with at least 1 CBCT scan from both protocols were registered separately to a bone and soft-tissue landmark on the simulation computed tomography scan. Eighteen identical blinded random offsets were applied to each patient's LD-CBCT1 and LD-CBCT2 from a starting registration that was then realigned using rigid registration. The residual offset between the baseline registration and the final registration attempt was calculated and analyzed using a 1-sided, 1 sample t test to evaluate whether LD-CBCT1, delivering a higher dose, was superior to the lower-dose LD-CBCT2 for bone and soft-tissue alignment. Results: In comparing 288 registrations with a bone landmark across 8 patients, no difference was found in the vector magnitude offsets using LD-CBCT 1 (mean [x¯], 0.73 mm; standard deviation [σ], 0.39 mm) and LD-CBCT2 (x¯, 0.74 mm; σ, 0.40 mm; P =.425). Comparing 216 registrations with a soft-tissue landmark across 6 patients, alignment using LD-CBCT2 (x¯, 1.55 mm; σ, 1.08 mm) resulted in larger differences in the vector magnitude of the offsets compared with LD-CBCT1 (x¯, 1.37 mm; σ, 0.74 mm; P =.049). Conclusions: Clinics treating pediatric patients should consider implementing a protocol mirroring LD-CBCT2 for abdomen and pelvis IGRT bone alignment. Further evaluation of the precision of LD-CBCTs for soft-tissue alignment is necessary.
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U2 - 10.1016/j.prro.2019.01.005
DO - 10.1016/j.prro.2019.01.005
M3 - Article
C2 - 30684586
AN - SCOPUS:85062360253
SN - 1879-8500
VL - 9
SP - e307-e313
JO - Practical Radiation Oncology
JF - Practical Radiation Oncology
IS - 3
ER -