Xochitl Lopez-Rendon1, Guozhi Zhang2, Walter Coudyzer2, Wim Develter3, Hilde Bosmans3,2, Federica Zanca2. 1. Department of Imaging and Pathology, Division of Medical Physics & Quality Assessment, KU Leuven, Herestraat 49, Leuven, 3000, Belgium. xochitl.lopezrendon@uzleuven.be. 2. Department of Radiology, University Hospitals of the KU Leuven, Herestraat 49, 3000, Leuven, Belgium. 3. Department of Imaging and Pathology, Division of Medical Physics & Quality Assessment, KU Leuven, Herestraat 49, Leuven, 3000, Belgium.
Abstract
OBJECTIVES: To compare the lung and breast dose associated with three chest protocols: standard, organ-based tube current modulation (OBTCM) and fast-speed scanning; and to estimate the error associated with organ dose when modelling the longitudinal (z-) TCM versus the 3D-TCM in Monte Carlo simulations (MC) for these three protocols. METHOD: Five adult and three paediatric cadavers with different BMI were scanned. The CTDIvol of the OBTCM and the fast-speed protocols were matched to the patient-specific CTDIvol of the standard protocol. Lung and breast doses were estimated using MC with both z- and 3D-TCM simulated and compared between protocols. RESULTS: The fast-speed scanning protocol delivered the highest doses. A slight reduction for breast dose (up to 5.1%) was observed for two of the three female cadavers with the OBTCM in comparison to the standard. For both adult and paediatric, the implementation of the z-TCM data only for organ dose estimation resulted in 10.0% accuracy for the standard and fast-speed protocols, while relative dose differences were up to 15.3% for the OBTCM protocol. CONCLUSION: At identical CTDIvol values, the standard protocol delivered the lowest overall doses. Only for the OBTCM protocol is the 3D-TCM needed if an accurate (<10.0%) organ dosimetry is desired. KEY POINTS: • The z-TCM information is sufficient for accurate dosimetry for standard protocols. • The z-TCM information is sufficient for accurate dosimetry for fast-speed scanning protocols. • For organ-based TCM schemes, the 3D-TCM information is necessary for accurate dosimetry. • At identical CTDI vol , the fast-speed scanning protocol delivered the highest doses. • Lung dose was higher in XCare than standard protocol at identical CTDI vol .
OBJECTIVES: To compare the lung and breast dose associated with three chest protocols: standard, organ-based tube current modulation (OBTCM) and fast-speed scanning; and to estimate the error associated with organ dose when modelling the longitudinal (z-) TCM versus the 3D-TCM in Monte Carlo simulations (MC) for these three protocols. METHOD: Five adult and three paediatric cadavers with different BMI were scanned. The CTDIvol of the OBTCM and the fast-speed protocols were matched to the patient-specific CTDIvol of the standard protocol. Lung and breast doses were estimated using MC with both z- and 3D-TCM simulated and compared between protocols. RESULTS: The fast-speed scanning protocol delivered the highest doses. A slight reduction for breast dose (up to 5.1%) was observed for two of the three female cadavers with the OBTCM in comparison to the standard. For both adult and paediatric, the implementation of the z-TCM data only for organ dose estimation resulted in 10.0% accuracy for the standard and fast-speed protocols, while relative dose differences were up to 15.3% for the OBTCM protocol. CONCLUSION: At identical CTDIvol values, the standard protocol delivered the lowest overall doses. Only for the OBTCM protocol is the 3D-TCM needed if an accurate (<10.0%) organ dosimetry is desired. KEY POINTS: • The z-TCM information is sufficient for accurate dosimetry for standard protocols. • The z-TCM information is sufficient for accurate dosimetry for fast-speed scanning protocols. • For organ-based TCM schemes, the 3D-TCM information is necessary for accurate dosimetry. • At identical CTDI vol , the fast-speed scanning protocol delivered the highest doses. • Lung dose was higher in XCare than standard protocol at identical CTDI vol .
Entities:
Keywords:
3D tube current modulation; Cadavers; Longitudinal tube current modulation; Monte Carlo simulations; Organ doses
Authors: Matthew P Lungren; Terry T Yoshizumi; Samuel M Brady; Greta Toncheva; Colin Anderson-Evans; Carolyn Lowry; Xiaodong R Zhou; Donald Frush; Lynne M Hurwitz Journal: AJR Am J Roentgenol Date: 2012-07 Impact factor: 3.959
Authors: Andrew N Primak; Cynthia H McCollough; Michael R Bruesewitz; Jie Zhang; Joel G Fletcher Journal: Radiographics Date: 2006 Nov-Dec Impact factor: 5.333
Authors: Maryam Khatonabadi; Di Zhang; Kelsey Mathieu; Hyun J Kim; Peiyun Lu; Dianna Cody; John J Demarco; Chris H Cagnon; Michael F McNitt-Gray Journal: Med Phys Date: 2012-08 Impact factor: 4.071
Authors: Rick R Layman; Anthony J Hardy; Hyun J Kim; Ei Ne Chou; Maryam Bostani; Chris Cagnon; Dianna Cody; Michael McNitt-Gray Journal: J Appl Clin Med Phys Date: 2021-05-03 Impact factor: 2.102