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
| Autor: | Steven Bartolac, Sara R. Alcorn, Matthew M. Ladra, Stephanie A. Terezakis, Junghoon Lee, Joseph Moore, Mahadevappa Mahesh, Wei Fu, Avani D. Rao, Sarah Nicholas |
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| Rok vydání: | 2019 |
| Předmět: |
Cone beam computed tomography
medicine.medical_treatment Bone and Bones Pelvis 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Neoplasms Abdomen medicine Humans Radiology Nuclear Medicine and imaging Child Image-guided radiation therapy business.industry Radiotherapy Planning Computer-Assisted Low dose Abdomen+Pelvis Infant Soft tissue Radiotherapy Dosage Cone-Beam Computed Tomography Radiation therapy medicine.anatomical_structure Oncology Child Preschool 030220 oncology & carcinogenesis Nuclear medicine business Radiotherapy Image-Guided |
| Zdroj: | Practical Radiation Oncology. 9:e307-e313 |
| ISSN: | 1879-8500 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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