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Portugal M, Baptista M, Vaz P, Belchior A. Patients’ organ dose and risk assessment in interventional cardiology procedures. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Baptista M, Di Maria S, Vieira S, Santos J, Pereira J, Pereira M, Vaz P. Dosimetric assessment of the exposure of radiotherapy patients due to cone-beam CT procedures. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2019; 58:21-37. [PMID: 30392077 DOI: 10.1007/s00411-018-0760-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 10/30/2018] [Indexed: 06/08/2023]
Abstract
Cone-beam computed tomography (CBCT) is widely used for pre-treatment verification and patient setup in image-guided radiation therapy (IGRT). CBCT imaging is employed daily and several times per patient, resulting in potentially high cumulative imaging doses to healthy tissues that surround exposed target organs. Computed tomography dose index (CTDI) is the parameter used by CBCT equipment as indication of the radiation output to patients. This study aimed to increase the knowledge on the relation between CBCT organ doses and weighted CTDI (CTDIW) for a thorax scanning protocol. A CBCT system was modelled using the Monte Carlo (MC) radiation transport program MCNPX2.7.0. Simulation results were validated against half-value layer (HVL), axial beam profile, patient skin dose (PSD) and CTDI measurements. For organ dose calculations, a male voxel phantom ("Golem") was implemented with the CBCT scanner computational model. After a successful MC model validation with measurements, a systematic comparison was performed between organ doses (and their distribution) and CTDI dosimetry concepts [CTDIW and cumulative dose quantities f100(150) and [Formula: see text]]. The results obtained show that CBCT organ doses vary between 1.2 ± 0.1 mGy and 3.3 ± 0.2 mGy for organs located within the primary beam. It was also verified that CTDIW allows prediction of absorbed doses to tissues at distances of about 5 cm from the isocentre of the CBCT system, whereas f100(150) allows prediction of organ doses at distances of about 10 cm from the isocentre, independently from its location. This study demonstrates that these dosimetric concepts are suitable methods that easily allow a good approximation of the additional CBCT imaging doses during a typical lung cancer IGRT treatment.
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Affiliation(s)
- Mariana Baptista
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal.
| | - Salvatore Di Maria
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
| | - Sandra Vieira
- Fundação Champalimaud, Centro Clínico Champalimaud, Avenida de Brasília, 1400-038, Lisbon, Portugal
| | - Joana Santos
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
- Instituto Politécnico de Coimbra, ESTESC, DIMR, Rua 5 de Outubro, 3046-854, Coimbra, Portugal
| | - Joana Pereira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
- Laboratório de Protecção e Segurança Radiológica, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
| | - Miguel Pereira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
- Laboratório de Protecção e Segurança Radiológica, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
| | - Pedro Vaz
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
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Baptista M, Di Maria S, Vieira S, Vaz P. Entrance surface dose distribution and organ dose assessment for cone-beam computed tomography using measurements and Monte Carlo simulations with voxel phantoms. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2017.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Baptista M, Figueira C, Teles P, Cardoso G, Zankl M, Vaz P. Assessment of the occupational exposure in real time during interventional cardiology procedures. RADIATION PROTECTION DOSIMETRY 2015; 165:304-309. [PMID: 25848113 DOI: 10.1093/rpd/ncv052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Interventional cardiology (IC) procedures can be complex, requiring the operators to work near the patient, during long exposure times. Owing to scattered radiation in the patient and the fluoroscopic equipment, the medical staff are exposed to a non-uniform radiation field and can receive high radiation doses. In this study, it is proposed to analyse staff doses obtained in real time, during IC procedures. A system for occupational dosimetry in real time was used. In order to identify some parameters that may affect the staff doses, Monte Carlo (MC) calculations, using MCNPX v.2.7.0 code and voxel phantoms, were performed. The data obtained from measurements, together with MC simulations, allowed the identification of actions and behaviours of the medical staff that could be considered a risk under routine working conditions. The implementation of this monitoring system for exposure of personnel may have a positive effect on optimisation of radiological protection in fluoroscopically guided cardiac procedures.
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Affiliation(s)
- M Baptista
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139,7, 2695-066 Bobadela LRS, Portugal
| | - C Figueira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139,7, 2695-066 Bobadela LRS, Portugal
| | - P Teles
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139,7, 2695-066 Bobadela LRS, Portugal
| | - G Cardoso
- Hospital Garcia de Orta, EPE, Av. Torrado da Silva, 2801-951 Almada, Portugal
| | - M Zankl
- Helmholtz Zentrum München-German Research Center for Environmental Health, Medical Radiation Physics and Diagnostics, 85758 Neuherberg, Germany
| | - P Vaz
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139,7, 2695-066 Bobadela LRS, Portugal
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