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Doses delivered to small and large breasts and adjacent organs in left breast cancer patients utilizing 3D and IM radiotherapy. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2023. [DOI: 10.1016/j.jrras.2022.100494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Jiménez-Ortega E, Agüera R, Ureba A, Balcerzyk M, Wals-Zurita A, García-Gómez FJ, Leal A. Implications of the Harmonization of [18F]FDG-PET/CT Imaging for Response Assessment of Treatment in Radiotherapy Planning. Tomography 2022; 8:1097-1112. [PMID: 35448724 PMCID: PMC9031488 DOI: 10.3390/tomography8020090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 11/16/2022] Open
Abstract
The purpose of this work is to present useful recommendations for the use of [18F]FDG-PET/CT imaging in radiotherapy planning and monitoring under different versions of EARL accreditation for harmonization of PET devices. A proof-of-concept experiment designed on an anthropomorphic phantom was carried out to establish the most suitable interpolation methods of the PET images in the different steps of the planning procedure. Based on PET/CT images obtained by using these optimal interpolations for the old EARL accreditation (EARL1) and for the new one (EARL2), the treatment plannings of representative actual clinical cases were calculated, and the clinical implications of the resulting differences were analyzed. As expected, EARL2 provided smaller volumes with higher resolution than EARL1. The increase in the size of the reconstructed volumes with EARL1 accreditation caused high doses in the organs at risk and in the regions adjacent to the target volumes. EARL2 accreditation allowed an improvement in the accuracy of the PET imaging precision, allowing more personalized radiotherapy. This work provides recommendations for those centers that intend to benefit from the new accreditation, EARL2, and can help build confidence of those that must continue working under the EARL1 accreditation.
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Affiliation(s)
- Elisa Jiménez-Ortega
- Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, 41009 Seville, Spain; (E.J.-O.); (R.A.); (M.B.)
- Instituto de Biomedicina de Sevilla, IBiS, 41013 Seville, Spain;
| | - Raquel Agüera
- Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, 41009 Seville, Spain; (E.J.-O.); (R.A.); (M.B.)
| | - Ana Ureba
- Instituto de Biomedicina de Sevilla, IBiS, 41013 Seville, Spain;
- Medical Radiation Physics, Department of Physics, Stockholm University, 114 21 Stockholm, Sweden
| | - Marcin Balcerzyk
- Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, 41009 Seville, Spain; (E.J.-O.); (R.A.); (M.B.)
- Centro Nacional de Aceleradores (CNA), Universidad de Sevilla, Junta de Andalucía, Consejo Superior de Investigaciones Científicas (CSIC), 41092 Seville, Spain
| | - Amadeo Wals-Zurita
- Hospital Universitario Virgen Macarena, Servicio de Radioterapia, 41009 Seville, Spain;
| | | | - Antonio Leal
- Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, 41009 Seville, Spain; (E.J.-O.); (R.A.); (M.B.)
- Instituto de Biomedicina de Sevilla, IBiS, 41013 Seville, Spain;
- Correspondence:
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Sinno N, Taylor E, Milosevic M, Jaffray DA, Coolens C. Incorporating cross-voxel exchange into the analysis of dynamic contrast-enhanced imaging data: theory, simulations and experimental results. Phys Med Biol 2021; 66. [PMID: 34650009 DOI: 10.1088/1361-6560/ac2205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 08/27/2021] [Indexed: 12/26/2022]
Abstract
Predictions of tumour perfusion are key determinants of drug delivery and responsiveness to therapy. Pharmacokinetic models allow for the estimation of perfusion properties of tumour tissues but many assume no dispersion associated with tracer transport away from the capillaries and through the tissue. At the level of a voxel, this translates to assuming no cross-voxel tracer exchange, often leading to the misinterpretation of derived perfusion parameters. Tofts model (TM), a compartmental model widely used in oncology, also makes this assumption. A more realistic description is required to quantify kinetic properties of tracers, such as convection and diffusion. We propose a Cross-Voxel Exchange Model (CVXM) for analysing cross-voxel tracer kinetics.In silicodatasets quantifying the roles of convection and diffusion in tracer transport (which TM ignores) were employed to investigate the interpretation of Tofts' perfusion parameters compared to CVXM. TM returned inaccurate values ofKtransandvewhere diffusive and convective mechanisms are pronounced (up to 20% and 300% error respectively). A mathematical equation, developed in this work, predicts and gives the correct physiological interpretation of Tofts've.Finally, transport parameters were derived from dynamic contrast enhanced-magnetic resonance imaging of a TS-415 human cervical carcinoma xenograft by using TM and CVXM. The latter deduced lower values ofKtransandvecompared to TM (lower by up to 63% and 76% respectively). It also allowed the detection of a diffusive flux (mean diffusivity 155μm2s-1) in the tumour tissue, as well as an increased convective flow at the periphery (mean velocity 2.3μm s-1detected). The results serve as a proof of concept establishing the feasibility of using CVXM for accurately determining transport metrics that characterize the exchange of tracer between voxels. CVXM needs to be investigated further as its parameters can be linked to the tumour microenvironment properties (permeability, pressure…), potentially leading to enhanced personalized treatment planning.
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Affiliation(s)
- Noha Sinno
- The Institute of Biomedical Engineering (BME), University of Toronto, Toronto, Canada.,Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Edward Taylor
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Canada.,TECHNA Institute, University Health Network, Toronto, Canada
| | - Michael Milosevic
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada
| | - David A Jaffray
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada.,TECHNA Institute, University Health Network, Toronto, Canada.,University of Texas, MD Anderson Cancer Centre, Texas, United States of America
| | - Catherine Coolens
- The Institute of Biomedical Engineering (BME), University of Toronto, Toronto, Canada.,Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada.,TECHNA Institute, University Health Network, Toronto, Canada
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