Mirta Bárbara Torres Berdeguez1, Sylvia Thomas2, Patricia Rafful3, Tiago Arruda Sanchez3, Susie Medeiros Oliveira Ramos2, Marta Souza Albernaz2, Lidia Vasconcellos de Sá4, Sergio Augusto Lopes de Souza2, Felix Mas Milian5, Ademir Xavier da Silva1. 1. Department of Nuclear Engineering, Federal University of Rio de Janeiro, Horácio Macedo Ave., 2030 Block G-Room 206, Technology Center,, University City, Fundão Island, 21941-914,, Rio de Janeiro, RJ, Brazil. 2. Department of Nuclear Medicine, Clementino Fraga Filho University Hospital of Federal University of Rio de Janeiro, Street Rodolpho Paulo Rocco, 255, University City, Fundão Island, 21941-913,, Rio de Janeiro, RJ, Brazil. 3. Department of Radiology, Clementino Fraga Filho University Hospital of Federal University of Rio de Janeiro, Street Rodolpho Paulo Rocco, 255, University City, Fundão Island, 21941-913,, Rio de Janeiro, RJ, Brazil. 4. Institute of Radiation Protection and Dosimetry, Brazilian Nuclear Energy Commission, Salvador Allende Ave., s/n, Recreio dos Bandeirantes,, 22783-127,, Rio de Janeiro, RJ, Brazil. 5. CPqCTR - Research Center for Radiation Sciences and Technology, State University of Santa Cruz, Rodovia Ilhéus-Itabuna, Km 16, Salobrinho, 45662000, Ilhéus, BA, Brazil.
Abstract
PURPOSE: Recently, there has been a growing interest in a methodology for dose planning in radiosynoviorthesis to substitute fixed activity. Clinical practice based on fixed activity frequently does not embrace radiopharmaceutical dose optimization in patients. The aim of this paper is to propose and discuss a dose planning methodology considering the radiological findings of interest obtained by three-dimensional magnetic resonance imaging combined with Monte Carlo simulation in radiosynoviorthesis treatment applied to hemophilic arthropathy. METHOD: The parameters analyzed were: surface area of the synovial membrane (synovial size), synovial thickness and joint effusion obtained by 3D MRI of nine knees from nine patients on a SIEMENS AVANTO 1.5 T scanner using a knee coil. The 3D Slicer software performed both the semiautomatic segmentation and quantitation of these radiological findings. A Lucite phantom 3D MRI validated the quantitation methodology. The study used Monte Carlo N-Particle eXtended code version 2.6 for calculating the S-values required to set up the injected activity to deliver a 100 Gy absorbed dose at a determined synovial thickness. The radionuclides assessed were: 90Y, 32P, 188Re, 186Re, 153Sm, and 177Lu, and the present study shows their effective treatment ranges. RESULT: The quantitation methodology was successfully tested, with an error below 5% for different materials. S-values calculated could provide data on the activity to be injected into the joint, considering no extra-articular leakage from joint cavity. Calculation of effective treatment range could assist with the therapeutic decision, with an optimized protocol for dose prescription in RSO. CONCLUSION: Using 3D Slicer software, this study focused on segmentation and quantitation of radiological features such as joint effusion, synovial size, and thickness, all obtained by 3D MRI in patients' knees with hemophilic arthropathy. The combination of synovial size and thickness with the parameters obtained by Monte Carlo simulation such as effective treatment range and S-value, from which is calculated the injected activity, could be used for treatment planning in RSO. Data from this methodology could be a potential aid to clinical decision making by selecting the most suitable radionuclide; justifying the procedure, fractioning the dose, and the calculated injected activity for children and adolescents, considering both the synovial size and thickness.
PURPOSE: Recently, there has been a growing interest in a methodology for dose planning in radiosynoviorthesis to substitute fixed activity. Clinical practice based on fixed activity frequently does not embrace radiopharmaceutical dose optimization in patients. The aim of this paper is to propose and discuss a dose planning methodology considering the radiological findings of interest obtained by three-dimensional magnetic resonance imaging combined with Monte Carlo simulation in radiosynoviorthesis treatment applied to hemophilic arthropathy. METHOD: The parameters analyzed were: surface area of the synovial membrane (synovial size), synovial thickness and joint effusion obtained by 3D MRI of nine knees from nine patients on a SIEMENS AVANTO 1.5 T scanner using a knee coil. The 3D Slicer software performed both the semiautomatic segmentation and quantitation of these radiological findings. A Lucite phantom 3D MRI validated the quantitation methodology. The study used Monte Carlo N-Particle eXtended code version 2.6 for calculating the S-values required to set up the injected activity to deliver a 100 Gy absorbed dose at a determined synovial thickness. The radionuclides assessed were: 90Y, 32P, 188Re, 186Re, 153Sm, and 177Lu, and the present study shows their effective treatment ranges. RESULT: The quantitation methodology was successfully tested, with an error below 5% for different materials. S-values calculated could provide data on the activity to be injected into the joint, considering no extra-articular leakage from joint cavity. Calculation of effective treatment range could assist with the therapeutic decision, with an optimized protocol for dose prescription in RSO. CONCLUSION: Using 3D Slicer software, this study focused on segmentation and quantitation of radiological features such as joint effusion, synovial size, and thickness, all obtained by 3D MRI in patients' knees with hemophilic arthropathy. The combination of synovial size and thickness with the parameters obtained by Monte Carlo simulation such as effective treatment range and S-value, from which is calculated the injected activity, could be used for treatment planning in RSO. Data from this methodology could be a potential aid to clinical decision making by selecting the most suitable radionuclide; justifying the procedure, fractioning the dose, and the calculated injected activity for children and adolescents, considering both the synovial size and thickness.
Authors: Oana Viola Badulescu; Paul Dan Sirbu; Carmen Ungureanu; Alin Pȋnzariu; Elena Cojocaru; Nina Filip; Iris Bararu-Bojan; Maria Vladeanu; Manuela Ciocoiu Journal: Exp Ther Med Date: 2021-07-14 Impact factor: 2.447