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Oh SJ, Lyoo CH, Ryu YH, Choi JY. Assessing the applicability of PMOD residence times model for PET image-based radiation dosimetry. Sci Rep 2023; 13:19387. [PMID: 37938605 PMCID: PMC10632489 DOI: 10.1038/s41598-023-46822-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 11/06/2023] [Indexed: 11/09/2023] Open
Abstract
The effective dose represents the overall internal radiation exposure to the whole body when exposed to radiation sources. This study aims to compare conventional and software-aided methods to derive the effective dose. In the present study, 8F-T807 and 18F-Mefway, specific radiotracers for the paired helical tau and serotonin 1A receptor, were administered to healthy subjects (n = 6, each radiotracer), following which whole-body positron emission tomography (PET) images were obtained for 2 h. Subsequently, time-activity curves for major organs were obtained, and the residence times were calculated using the "conventional" and "Residence Times model" tools in PMOD software. The residence times from each method was input into OLINDA/EXM software, and the effective dose was estimated. The differences in the average residence times of the brain, heart, lung, and liver were 18.4, 20.8, 10.4, and 13.3% for 18F-T807, and 17.5, 16.4, 18.1, and 17.5% for 18F-Mefway, respectively. For the mean effective dose, the error rates between the methods were 3.8 and 1.9% for 18F-T807 and 18F-Mefway, respectively. The organs that showed the greatest difference in the absorbed dose were the urinary bladder for 18F-T807 (40.4%) and the liver for 18F-Mefway (14.1%). This method of obtaining the residence time using PMOD can be easily used to derive the effective dose, and is applicable in evaluating the safety of radiotracers for clinical trials.
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Affiliation(s)
- Se Jong Oh
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, Korea
| | - Chul Hyoung Lyoo
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Young Hoon Ryu
- Department of Nuclear Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
| | - Jae Yong Choi
- Division of Applied RI, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, Korea.
- Radiological and Medico-Oncological Sciences, University of Science and Technology (UST), Seoul, Korea.
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2
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Hoseini-Ghahfarokhi M, Kamio Y, Mondor J, Jabbari K, Carrier JF. Development of a stand-alone precalculated Monte Carlo code to calculate the dose by alpha and beta emitters from the Ra-224 decay chain. Med Phys 2023; 50:5176-5188. [PMID: 37161766 DOI: 10.1002/mp.16446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 04/05/2023] [Accepted: 04/15/2023] [Indexed: 05/11/2023] Open
Abstract
BACKGROUND Recent developments in alpha and beta emitting radionuclide therapy highlight the importance of developing efficient methods for patient-specific dosimetry. Traditional tabulated methods such as Medical Internal Radiation Dose (MIRD) estimate the dose at the organ level while more recent numerical methods based on Monte Carlo (MC) simulations are able to calculate dose at the voxel level. A precalculated MC (PMC) approach was developed in this work as an alternative to time-consuming fully simulated MC. Once the spatial distribution of alpha and beta emitters is determined using imaging and/or numerical methods, the PMC code can be used to achieve an accurate voxelized 3D distribution of the deposited energy without relying on full MC calculations. PURPOSE To implement the PMC method to calculate energy deposited by alpha and beta particles emitted from the Ra-224 decay chain. METHODS The GEANT4 (version 10.7) MC toolkit was used to generate databases of precalculated tracks to be integrated in the PMC code as well as to benchmark its output. In this regard, energy spectra of alpha and beta particles emitted by the Ra-224 decay chain were generated using GAMOS (version 6.2.0) and imported into GEANT4 macro files. Either alpha or beta emitting sources were defined at the center of a homogeneous phantom filled with various materials such as soft tissue, bone, and lung where particles were emitted either mono-directionally (for database generation) or isotropically (for benchmarking). Two heterogeneous phantoms were used to demonstrate PMC code compatibility with boundary crossing events. Each precalculated database was generated step-by-step by storing particle track information from GEANT4 simulations followed by its integration in a PMC code developed in MATLAB. For a user-defined number of histories, one of the tracks in a given database was selected randomly and rotated randomly to reflect an isotropic emission. Afterward, deposited energy was divided between voxels based on step length in each voxel using a ray-tracing approach. The radial distribution of deposited energy was benchmarked against fully simulated MC calculations using GEANT4. The effect of the GEANT4 parameter StepMax on the accuracy and speed of the code was also investigated. RESULTS In the case of alpha decay, primary alpha particles show the highest contribution (>99%) in deposited energy compared to their secondary particles. In most cases, protons act as the main secondary particles in the deposition of energy. However, for a lung phantom, using a range cutoff parameter of 10 µm on primary alpha particles yields a higher contribution of secondary electrons than protons. Differences between deposited energy calculated by PMC and fully simulated MC are within 2% for all alpha and beta emitters in homogeneous and heterogeneous phantoms. Additionally, statistical uncertainties are less than 1% for voxels with doses higher than 5% of the maximum dose. Moreover, optimization of the parameter StepMax is necessary to achieve the best tradeoff between code accuracy and speed. CONCLUSIONS The PMC code shows good performance for dose calculations deposited by alpha and beta emitters. As a stand-alone algorithm, it is suitable to be integrated into clinical treatment planning systems.
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Affiliation(s)
- Mojtaba Hoseini-Ghahfarokhi
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
- Département de Physique, Université de Montréal, Montréal, Quebec, Canada
| | - Yuji Kamio
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Quebec, Canada
- Département de Radio-oncologie, Centre Hospitalier de l'Université de Montréal (CHUM), Montréal, Quebec, Canada
| | - Julien Mondor
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
- Département de Physique, Université de Montréal, Montréal, Quebec, Canada
| | - Keyvan Jabbari
- Department of Radiation Oncology, Champlain Valley Physicians Hospital, Plattsburgh, New York, USA
| | - Jean-François Carrier
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
- Département de Physique, Université de Montréal, Montréal, Quebec, Canada
- Département de Radio-oncologie, Centre Hospitalier de l'Université de Montréal (CHUM), Montréal, Quebec, Canada
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Cicone F, Santo G, Bodet-Milin C, Cascini GL, Kraeber-Bodéré F, Stokke C, Kolstad A. Radioimmunotherapy of Non-Hodgkin B-cell Lymphoma: An update. Semin Nucl Med 2023; 53:413-425. [PMID: 36635112 DOI: 10.1053/j.semnuclmed.2022.12.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 12/23/2022] [Indexed: 01/12/2023]
Abstract
Systemic radioimmunotherapy (RIT) is arguably the most effective and least toxic anticancer treatment for non-Hodgkin lymphoma (NHL). In treatment-naïve patients with indolent NHL, the efficacy of a single injection of RIT compares with that of multiple cycles of combination chemotherapy. However, 20 years following the approval of the first CD20-targeting radioimmunoconjugates 90Y-Ibritumomab-tiuxetan (Zevalin) and 131I-tositumomab (Bexxar), the number of patients referred for RIT in western countries has dramatically decreased. Notwithstanding this, the development of RIT has continued. Therapeutic targets other than CD20 have been identified, new vector molecules have been produced allowing for faster delivery of RIT to the target, and innovative radionuclides with favorable physical characteristics such as alpha emitters have been more widely available. In this article, we reviewed the current status of RIT in NHL, with particular focus on recent clinical and preclinical developments.
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Affiliation(s)
- Francesco Cicone
- Department of Experimental and Clinical Medicine, "Magna Graecia" University of Catanzaro, Catanzaro, Italy; Nuclear Medicine Unit, University Hospital "Mater Domini", Catanzaro, Italy.
| | - Giulia Santo
- Department of Experimental and Clinical Medicine, "Magna Graecia" University of Catanzaro, Catanzaro, Italy
| | - Caroline Bodet-Milin
- Nuclear Medicine Department, Nantes Université, Univ Angers, CHU Nantes, INSERM, CNRS, CRCI2NA, F-44000 Nantes, France
| | - Giuseppe Lucio Cascini
- Department of Experimental and Clinical Medicine, "Magna Graecia" University of Catanzaro, Catanzaro, Italy; Nuclear Medicine Unit, University Hospital "Mater Domini", Catanzaro, Italy
| | - Françoise Kraeber-Bodéré
- Nuclear Medicine Department, Nantes Université, Univ Angers, CHU Nantes, INSERM, CNRS, CRCI2NA, F-44000 Nantes, France
| | - Caroline Stokke
- Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway; Department of Physics, University of Oslo, Oslo, Norway
| | - Arne Kolstad
- Department of Oncology, Innlandet Hospital Trust Division Gjøvik, Lillehammer, Norway
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4
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Li WB, Bouvier-Capely C, Saldarriaga Vargas C, Andersson M, Madas B. Heterogeneity of dose distribution in normal tissues in case of radiopharmaceutical therapy with alpha-emitting radionuclides. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2022; 61:579-596. [PMID: 36239799 PMCID: PMC9630198 DOI: 10.1007/s00411-022-01000-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 10/06/2022] [Indexed: 05/10/2023]
Abstract
Heterogeneity of dose distribution has been shown at different spatial scales in diagnostic nuclear medicine. In cancer treatment using new radiopharmaceuticals with alpha-particle emitters, it has shown an extensive degree of dose heterogeneity affecting both tumour control and toxicity of organs at risk. This review aims to provide an overview of generalized internal dosimetry in nuclear medicine and highlight the need of consideration of the dose heterogeneity within organs at risk. The current methods used for patient dosimetry in radiopharmaceutical therapy are summarized. Bio-distribution and dose heterogeneities of alpha-particle emitting pharmaceutical 223Ra (Xofigo) within bone tissues are presented as an example. In line with the strategical research agendas of the Multidisciplinary European Low Dose Initiative (MELODI) and the European Radiation Dosimetry Group (EURADOS), future research direction of pharmacokinetic modelling and dosimetry in patient radiopharmaceutical therapy are recommended.
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Affiliation(s)
- Wei Bo Li
- Helmholtz Zentrum München-German Research Center for Environmental Health (GmbH), Institute of Radiation Medicine, Neuherberg, Germany.
| | - Céline Bouvier-Capely
- Institut de Radioprotection et Sûreté Nucléaire (IRSN), PSE-SANTE/SESANE/LRSI, Fontenay-aux-Roses, France
| | - Clarita Saldarriaga Vargas
- Radiation Protection Dosimetry and Calibrations, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
- In Vivo Cellular and Molecular Imaging Laboratory, Vrije Universiteit Brussel, Brussels, Belgium
| | - Michelle Andersson
- Radiation Protection Dosimetry and Calibrations, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
- Medical Physics Department, Jules Bordet Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - Balázs Madas
- Environmental Physics Department, Centre for Energy Research, Budapest, Hungary
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5
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Personalized Dosimetry in the Context of Radioiodine Therapy for Differentiated Thyroid Cancer. Diagnostics (Basel) 2022; 12:diagnostics12071763. [PMID: 35885666 PMCID: PMC9320760 DOI: 10.3390/diagnostics12071763] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/15/2022] [Accepted: 07/19/2022] [Indexed: 12/02/2022] Open
Abstract
The most frequent thyroid cancer is Differentiated Thyroid Cancer (DTC) representing more than 95% of cases. A suitable choice for the treatment of DTC is the systemic administration of 131-sodium or potassium iodide. It is an effective tool used for the irradiation of thyroid remnants, microscopic DTC, other nonresectable or incompletely resectable DTC, or all the cited purposes. Dosimetry represents a valid tool that permits a tailored therapy to be obtained, sparing healthy tissue and so minimizing potential damages to at-risk organs. Absorbed dose represents a reliable indicator of biological response due to its correlation to tissue irradiation effects. The present paper aims to focus attention on iodine therapy for DTC treatment and has developed due to the urgent need for standardization in procedures, since no unique approaches are available. This review aims to summarize new proposals for a dosimetry-based therapy and so explore new alternatives that could provide the possibility to achieve more tailored therapies, minimizing the possible side effects of radioiodine therapy for Differentiated Thyroid Cancer.
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Amato E, Gnesin S, Cicone F, Auditore L. Fundamentals of internal radiation dosimetry. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00142-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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7
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Principles and Applications of Auger-Electron Radionuclide Therapy. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00040-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Cicone F, Gnesin S, Cremonesi M. Dosimetry of nuclear medicine therapies: current controversies and impact on treatment optimization. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF... 2021; 65:327-332. [PMID: 34881850 DOI: 10.23736/s1824-4785.21.03418-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Nuclear medicine therapeutic procedures have considerably expanded over the last few years, and their number is expected to grow exponentially in the future. Internal dosimetry has significantly developed as well, but has not yet been uniformly accepted as a valuable tool for prediction of therapeutic efficacy and toxicity. In this paper, we briefly summarize some of the arguments about the implementation of internal dosimetry in clinical practice. In addition, we provide a few examples of radionuclide anticancer therapies for which internal dosimetry demonstrated a significant impact on treatment optimization and patient outcome.
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Affiliation(s)
- Francesco Cicone
- PET/RM Unit, Department of Experimental and Clinical Medicine, and Neuroscience Research Center, Magna Graecia University of Catanzaro, Catanzaro, Italy - .,Unit of Nuclear Medicine, Mater Domini University Hospital, Catanzaro, Italy - .,University of Lausanne, Lausanne, Switzerland -
| | - Silvano Gnesin
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Marta Cremonesi
- Unit of Radiation Research, Department of Medical Imaging and Radiation Sciences, IRCCS European Institute of Oncology, Milan, Italy
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Brosch-Lenz J, Yousefirizi F, Zukotynski K, Beauregard JM, Gaudet V, Saboury B, Rahmim A, Uribe C. Role of Artificial Intelligence in Theranostics:: Toward Routine Personalized Radiopharmaceutical Therapies. PET Clin 2021; 16:627-641. [PMID: 34537133 DOI: 10.1016/j.cpet.2021.06.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
We highlight emerging uses of artificial intelligence (AI) in the field of theranostics, focusing on its significant potential to enable routine and reliable personalization of radiopharmaceutical therapies (RPTs). Personalized RPTs require patient-specific dosimetry calculations accompanying therapy. Additionally we discuss the potential to exploit biological information from diagnostic and therapeutic molecular images to derive biomarkers for absorbed dose and outcome prediction; toward personalization of therapies. We try to motivate the nuclear medicine community to expand and align efforts into making routine and reliable personalization of RPTs a reality.
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Affiliation(s)
- Julia Brosch-Lenz
- Department of Integrative Oncology, BC Cancer Research Institute, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Fereshteh Yousefirizi
- Department of Integrative Oncology, BC Cancer Research Institute, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Katherine Zukotynski
- Department of Medicine and Radiology, McMaster University, 1200 Main Street West, Hamilton, Ontario L9G 4X5, Canada
| | - Jean-Mathieu Beauregard
- Department of Radiology and Nuclear Medicine, Cancer Research Centre, Université Laval, 2325 Rue de l'Université, Québec City, Quebec G1V 0A6, Canada; Department of Medical Imaging, Research Center (Oncology Axis), CHU de Québec - Université Laval, 2325 Rue de l'Université, Québec City, Quebec G1V 0A6, Canada
| | - Vincent Gaudet
- Department of Electrical and Computer Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Babak Saboury
- Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA; Department of Computer Science and Electrical Engineering, University of Maryland Baltimore County, Baltimore, MD, USA; Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Arman Rahmim
- Department of Integrative Oncology, BC Cancer Research Institute, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada; Department of Radiology, University of British Columbia, 11th Floor, 2775 Laurel St, Vancouver, British Columbia V5Z 1M9, Canada; Department of Physics, University of British Columbia, 325 - 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1, Canada
| | - Carlos Uribe
- Department of Radiology, University of British Columbia, 11th Floor, 2775 Laurel St, Vancouver, British Columbia V5Z 1M9, Canada; Department of Functional Imaging, BC Cancer, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada.
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10
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Bolcaen J, Kleynhans J, Nair S, Verhoeven J, Goethals I, Sathekge M, Vandevoorde C, Ebenhan T. A perspective on the radiopharmaceutical requirements for imaging and therapy of glioblastoma. Theranostics 2021; 11:7911-7947. [PMID: 34335972 PMCID: PMC8315062 DOI: 10.7150/thno.56639] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/29/2021] [Indexed: 11/26/2022] Open
Abstract
Despite numerous clinical trials and pre-clinical developments, the treatment of glioblastoma (GB) remains a challenge. The current survival rate of GB averages one year, even with an optimal standard of care. However, the future promises efficient patient-tailored treatments, including targeted radionuclide therapy (TRT). Advances in radiopharmaceutical development have unlocked the possibility to assess disease at the molecular level allowing individual diagnosis. This leads to the possibility of choosing a tailored, targeted approach for therapeutic modalities. Therapeutic modalities based on radiopharmaceuticals are an exciting development with great potential to promote a personalised approach to medicine. However, an effective targeted radionuclide therapy (TRT) for the treatment of GB entails caveats and requisites. This review provides an overview of existing nuclear imaging and TRT strategies for GB. A critical discussion of the optimal characteristics for new GB targeting therapeutic radiopharmaceuticals and clinical indications are provided. Considerations for target selection are discussed, i.e. specific presence of the target, expression level and pharmacological access to the target, with particular attention to blood-brain barrier crossing. An overview of the most promising radionuclides is given along with a validation of the relevant radiopharmaceuticals and theranostic agents (based on small molecules, peptides and monoclonal antibodies). Moreover, toxicity issues and safety pharmacology aspects will be presented, both in general and for the brain in particular.
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Affiliation(s)
- Julie Bolcaen
- Radiobiology, Radiation Biophysics Division, Nuclear Medicine Department, iThemba LABS, Cape Town, South Africa
| | - Janke Kleynhans
- Nuclear Medicine Research Infrastructure NPC, Pretoria, South Africa
- Nuclear Medicine Department, University of Pretoria and Steve Biko Academic Hospital, Pretoria, South Africa
| | - Shankari Nair
- Radiobiology, Radiation Biophysics Division, Nuclear Medicine Department, iThemba LABS, Cape Town, South Africa
| | | | - Ingeborg Goethals
- Ghent University Hospital, Department of Nuclear Medicine, Ghent, Belgium
| | - Mike Sathekge
- Nuclear Medicine Research Infrastructure NPC, Pretoria, South Africa
- Nuclear Medicine Department, University of Pretoria and Steve Biko Academic Hospital, Pretoria, South Africa
| | - Charlot Vandevoorde
- Radiobiology, Radiation Biophysics Division, Nuclear Medicine Department, iThemba LABS, Cape Town, South Africa
| | - Thomas Ebenhan
- Nuclear Medicine Research Infrastructure NPC, Pretoria, South Africa
- Nuclear Medicine Department, University of Pretoria, Pretoria, South Africa
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Toward Individualized Voxel-Level Dosimetry for Radiopharmaceutical Therapy. Int J Radiat Oncol Biol Phys 2021; 109:902-904. [PMID: 33610302 PMCID: PMC10081021 DOI: 10.1016/j.ijrobp.2020.08.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/03/2020] [Accepted: 08/06/2020] [Indexed: 11/21/2022]
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Abstract
Radiopharmaceutical therapy (RPT) is emerging as a safe and effective targeted approach to treating many types of cancer. In RPT, radiation is systemically or locally delivered using pharmaceuticals that either bind preferentially to cancer cells or accumulate by physiological mechanisms. Almost all radionuclides used in RPT emit photons that can be imaged, enabling non-invasive visualization of the biodistribution of the therapeutic agent. Compared with almost all other systemic cancer treatment options, RPT has shown efficacy with minimal toxicity. With the recent FDA approval of several RPT agents, the remarkable potential of this treatment is now being recognized. This Review covers the fundamental properties, clinical development and associated challenges of RPT. Radiopharmaceutical therapy is emerging as a safe and effective approach for the treatment of cancer, offering several advantages over existing therapeutic strategies. Here, Sgouros and colleagues provide an overview of the fundamental properties of radiopharmaceutical therapy, discuss agents in use and in clinical development and highlight the associated translational challenges.
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Jackson P, McIntosh L, Hofman MS, Kong G, Hicks RJ. Technical Note: Rapid multiexponential curve fitting algorithm for voxel-based targeted radionuclide dosimetry. Med Phys 2020; 47:4332-4339. [PMID: 32426853 DOI: 10.1002/mp.14243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 04/24/2020] [Accepted: 05/11/2020] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Dosimetry in nuclear medicine often relies on estimating pharmacokinetics based on sparse temporal data. As analysis methods move toward image-based three-dimensional computation, it becomes important to interpolate and extrapolate these data without requiring manual intervention; that is, in a manner that is highly efficient and reproducible. Iterative least-squares solvers are poorly suited to this task because of the computational overhead and potential to optimize to local minima without applying tight constraints at the outset. METHODOLOGY This work describes a fully analytical method for solving three-phase exponential time-activity curves based on three measured time points in a manner that may be readily employed by image-based dosimetry tools. The methodology uses a series of conditional statements and a piecewise approach for solving exponential slope directly through measured values in most instances. The proposed algorithm is tested against a purpose-designed iterative fitting technique and linear piecewise method followed by single exponential in a cohort of ten patients receiving 177 Lu-DOTA-Octreotate therapy. RESULTS Tri-exponential time-integrated values are shown to be comparable to previously published methods with an average difference between organs when computed at the voxel level of 9.8 ± 14.2% and -3.6 ± 10.4% compared to iterative and interpolated methods, respectively. Of the three methods, the proposed tri-exponential algorithm was most consistent when regional time-integrated activity was evaluated at both voxel- and whole-organ levels. For whole-body SPECT imaging, it is possible to compute 3D time-integrated activity maps in <5 min processing time. Furthermore, the technique is able to predictably and reproducibly handle artefactual measurements due to noise or spatial misalignment over multiple image times. CONCLUSIONS An efficient, analytical algorithm for solving multiphase exponential pharmacokinetics is reported. The method may be readily incorporated into voxel-dose routines by combining with widely available image registration and radiation transport tools.
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Affiliation(s)
- Price Jackson
- Department of Molecular Imaging & Therapeutic Nuclear Medicine, Peter MacCallum Cancer Centre, Melbourne, 3000, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, 3010, Australia
| | - Lachlan McIntosh
- Department of Molecular Imaging & Therapeutic Nuclear Medicine, Peter MacCallum Cancer Centre, Melbourne, 3000, Australia
| | - Michael S Hofman
- Department of Molecular Imaging & Therapeutic Nuclear Medicine, Peter MacCallum Cancer Centre, Melbourne, 3000, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, 3010, Australia
| | - Grace Kong
- Department of Molecular Imaging & Therapeutic Nuclear Medicine, Peter MacCallum Cancer Centre, Melbourne, 3000, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, 3010, Australia
| | - Rodney J Hicks
- Department of Molecular Imaging & Therapeutic Nuclear Medicine, Peter MacCallum Cancer Centre, Melbourne, 3000, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, 3010, Australia
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14
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Gupta A, Lee MS, Kim JH, Lee DS, Lee JS. Preclinical Voxel-Based Dosimetry in Theranostics: a Review. Nucl Med Mol Imaging 2020; 54:86-97. [PMID: 32377260 DOI: 10.1007/s13139-020-00640-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/27/2020] [Accepted: 03/31/2020] [Indexed: 12/22/2022] Open
Abstract
Due to the increasing use of preclinical targeted radionuclide therapy (TRT) studies for the development of novel theranostic agents, several studies have been performed to accurately estimate absorbed doses to mice at the voxel level using reference mouse phantoms and Monte Carlo (MC) simulations. Accurate dosimetry is important in preclinical theranostics to interpret radiobiological dose-response relationships and to translate results for clinical use. Direct MC (DMC) simulation is believed to produce more realistic voxel-level dose distribution with high precision because tissue heterogeneities and nonuniform source distributions in patients or animals are considered. Although MC simulation is considered to be an accurate method for voxel-based absorbed dose calculations, it is time-consuming, computationally demanding, and often impractical in daily practice. In this review, we focus on the current status of voxel-based dosimetry methods applied in preclinical theranostics and discuss the need for accurate and fast voxel-based dosimetry methods for pretherapy absorbed dose calculations to optimize the dose computation time in preclinical TRT.
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Affiliation(s)
- Arun Gupta
- 1Department of Radiology & Imaging, B.P. Koirala Institute of Health Sciences, Dharan, Nepal
| | - Min Sun Lee
- 2Department of Radiology, School of Medicine, Stanford University, Stanford, CA USA
| | - Joong Hyun Kim
- 3Center for Ionizing Radiation, Korea Research Institute of Standards and Science, Daejeon, South Korea
| | - Dong Soo Lee
- 4Department of Nuclear Medicine, College of Medicine, Seoul National University, 103 Daehak-ro, Jongno-gu, Seoul, 03080 South Korea
| | - Jae Sung Lee
- 4Department of Nuclear Medicine, College of Medicine, Seoul National University, 103 Daehak-ro, Jongno-gu, Seoul, 03080 South Korea.,5Interdisciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, South Korea.,6Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, South Korea
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Tran-Gia J, Salas-Ramirez M, Lassmann M. What You See Is Not What You Get: On the Accuracy of Voxel-Based Dosimetry in Molecular Radiotherapy. J Nucl Med 2019; 61:1178-1186. [PMID: 31862802 DOI: 10.2967/jnumed.119.231480] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 12/11/2019] [Indexed: 11/16/2022] Open
Abstract
Improvements in quantitative SPECT/CT have aroused growing interest in voxel-based dosimetry for radionuclide therapies, because it promises visualization of absorbed doses at a voxel level. In this work, SPECT/CT-based voxel-level dosimetry of a 3-dimensional (3D) printed 2-compartment kidney phantom was performed, and the resulting absorbed dose distributions were examined. Additionally, the potential of the PETPVC partial-volume correction tool was investigated. Methods: Both kidney compartments (70% cortex, 30% medulla) were filled with different activity concentrations, and SPECT/CT imaging was performed. The images were reconstructed using varying settings (iterations, subsets, and postfiltering). On the basis of these activity concentration maps, absorbed dose distributions were calculated with precalculated 177Lu voxel S values and an empiric kidney half-life. An additional set of absorbed doses was calculated after applying PETPVC for partial-volume correction of the SPECT reconstructions. Results: SPECT/CT imaging blurs the 2 discrete suborgan absorbed dose values into a continuous distribution. Although this effect is slightly improved by applying more iterations, it is enhanced by additional postfiltering. By applying PETPVC, the absorbed dose values are separated into 2 peaks. Although this leads to a better agreement between SPECT/CT-based and nominal values, considerable discrepancies remain. In contrast to the calculated nominal absorbed doses of 7.8 and 1.6 Gy (in the cortex and medulla, respectively), SPECT/CT-based voxel-level dosimetry resulted in mean absorbed doses of 3.0-6.6 Gy (cortex) and 2.7-5.1 Gy (medulla). PETPVC led to improved ranges of 6.1-8.9 Gy (cortex) and 2.1-5.4 Gy (medulla). Conclusion: Our study showed that 177Lu quantitative SPECT/CT imaging leads to voxel-based dose distributions largely differing from the real organ distribution. SPECT/CT imaging and reconstruction deficiencies might directly translate into unrealistic absorbed dose distributions, thus questioning the reliability of SPECT-based voxel-level dosimetry. Therefore, SPECT/CT reconstructions should be adapted to ensure an accurate quantification of the underlying activity and, therefore, absorbed dose in a volume of interest of the expected object size (e.g., organs, organ substructures, lesions, or voxels). As an example, PETPVC largely improves the match between SPECT/CT-based and nominal dose distributions. In conclusion, the concept of voxel-based dosimetry should be treated with caution. Specifically, one should remember that the absorbed dose distribution is mainly a convolved version of the underlying SPECT reconstruction.
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Affiliation(s)
- Johannes Tran-Gia
- Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany
| | | | - Michael Lassmann
- Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany
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16
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Götz T, Schmidkonz C, Lang EW, Maier A, Kuwert T, Ritt P. A comparison of methods for adapting $^{177}{\rm Lu}$ dose-voxel-kernels to tissue inhomogeneities. ACTA ACUST UNITED AC 2019; 64:245011. [DOI: 10.1088/1361-6560/ab5b81] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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17
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Tafreshi NK, Doligalski ML, Tichacek CJ, Pandya DN, Budzevich MM, El-Haddad G, Khushalani NI, Moros EG, McLaughlin ML, Wadas TJ, Morse DL. Development of Targeted Alpha Particle Therapy for Solid Tumors. Molecules 2019; 24:molecules24234314. [PMID: 31779154 PMCID: PMC6930656 DOI: 10.3390/molecules24234314] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 12/11/2022] Open
Abstract
Targeted alpha-particle therapy (TAT) aims to selectively deliver radionuclides emitting α-particles (cytotoxic payload) to tumors by chelation to monoclonal antibodies, peptides or small molecules that recognize tumor-associated antigens or cell-surface receptors. Because of the high linear energy transfer (LET) and short range of alpha (α) particles in tissue, cancer cells can be significantly damaged while causing minimal toxicity to surrounding healthy cells. Recent clinical studies have demonstrated the remarkable efficacy of TAT in the treatment of metastatic, castration-resistant prostate cancer. In this comprehensive review, we discuss the current consensus regarding the properties of the α-particle-emitting radionuclides that are potentially relevant for use in the clinic; the TAT-mediated mechanisms responsible for cell death; the different classes of targeting moieties and radiometal chelators available for TAT development; current approaches to calculating radiation dosimetry for TATs; and lead optimization via medicinal chemistry to improve the TAT radiopharmaceutical properties. We have also summarized the use of TATs in pre-clinical and clinical studies to date.
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Affiliation(s)
- Narges K. Tafreshi
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (N.K.T.); (M.L.D.); (C.J.T.); (E.G.M.)
| | - Michael L. Doligalski
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (N.K.T.); (M.L.D.); (C.J.T.); (E.G.M.)
| | - Christopher J. Tichacek
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (N.K.T.); (M.L.D.); (C.J.T.); (E.G.M.)
| | - Darpan N. Pandya
- Department of Cancer Biology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA; (D.N.P.); (T.J.W.)
| | - Mikalai M. Budzevich
- Small Animal Imaging Laboratory, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA;
| | - Ghassan El-Haddad
- Depts. of Diagnostic Imaging and Interventional Radiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA;
| | - Nikhil I. Khushalani
- Department of Cutaneous Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA;
| | - Eduardo G. Moros
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (N.K.T.); (M.L.D.); (C.J.T.); (E.G.M.)
- Department of Radiation Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
- Department of Physics, University of South Florida, Tampa, FL 33612, USA
- Department of Oncologic Sciences, University of South Florida, Tampa, FL 33612, USA
| | - Mark L. McLaughlin
- Department of Pharmaceutical Sciences, West Virginia University, Health Sciences Center, Morgantown, WV & Modulation Therapeutics Inc., 64 Medical Center Drive, Morgantown, WV 26506, USA;
| | - Thaddeus J. Wadas
- Department of Cancer Biology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA; (D.N.P.); (T.J.W.)
| | - David L. Morse
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (N.K.T.); (M.L.D.); (C.J.T.); (E.G.M.)
- Department of Physics, University of South Florida, Tampa, FL 33612, USA
- Small Animal Imaging Laboratory, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA;
- Department of Oncologic Sciences, University of South Florida, Tampa, FL 33612, USA
- Correspondence: ; Tel.: +1-813-745-8948; Fax: +1-813-745-8375
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18
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K EG, R AF, F K, N AG, A B, Gh A. Estimating the Absorbed Dose of Organs in Pediatric Imaging of 99mTc-DTPATc-DTPA Radiopharmaceutical using MIRDOSE Software. J Biomed Phys Eng 2019; 9:285-294. [PMID: 31341874 PMCID: PMC6613160 DOI: 10.31661/jbpe.v0i0.984] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 10/30/2018] [Indexed: 11/26/2022]
Abstract
Introduction: In this study, organ radiation doses were calculated for the renal agent 99mTc-DTPATc-DTPA in children. Bio-kinetic energy of 99mTc-DTPATc-DTPA was evaluated
by scintigraphy and estimates for absorbed radiation dose were provided using standard medical internal radiation dosimetry (MIRD) techniques.
Material and Methods: In this applied research, fourteen children patients (6 males and 8 females) were imaged using a series of planar and SPECT images after injecting with technetium-99mTc-DTPA
diethylenetriaminepentaacetic acid (99mTc-DTPATc-DTPA). A hybrid planar/SPECT method was used to plot time-activity curves to obtain the residence time of the
source organs and also MIRDOSE software was used to calculate the absorbed dose of every organ. P-values were calculated using t-tests in order to make a comparison between the adsorbed doses of male and female groups.
Results: Mean absorbed doses (µGy/MBq) for urinary bladder wall, kidneys, gonads, liver and adrenals were 213.5±47.8, 12.97±6.23, 12.0±2.5, 4.29±1.47, and 3.31±0.96, respectively. Furthermore,
the mean effective dose was 17.5±3.7 µSv/MBq. There was not any significant difference in the mean absorbed dose of the two groups.
Conclusion: Bladder cumulated activity was the most contribution in the effective dose of patients scanned with 99mTc-DTPATc-DTPA. Using a hybrid planar/SPECT method
can cause an increase in accumulated activity accuracy for the region of interest. Moreover, patient-specified internal dosimetry is recommended.
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Affiliation(s)
- Ebrahimnejad Gorji K
- Department of Medical Physics Radiobiology and Radiation Protection, Babol University of Medical Sciences, Babol, Iran
| | - Abedi Firouzjah R
- Department of Medical Physics Radiobiology and Radiation Protection, Babol University of Medical Sciences, Babol, Iran
| | - Khanzadeh F
- Department of Medical Radiation, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Abdi-Goushbolagh N
- Department of Medical Physics, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Banaei A
- Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Ataei Gh
- Department of Radiology Technology, Faculty of Paramedical Sciences, Babol University of Medical Science, Babol, Iran
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19
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Carter LM, Crawford TM, Sato T, Furuta T, Choi C, Kim CH, Brown JL, Bolch WE, Zanzonico PB, Lewis JS. PARaDIM: A PHITS-Based Monte Carlo Tool for Internal Dosimetry with Tetrahedral Mesh Computational Phantoms. J Nucl Med 2019; 60:1802-1811. [PMID: 31201251 DOI: 10.2967/jnumed.119.229013] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 05/29/2019] [Indexed: 11/16/2022] Open
Abstract
Mesh-type and voxel-based computational phantoms comprise the current state of the art for internal dose assessment via Monte Carlo simulations but excel in different aspects, with mesh-type phantoms offering advantages over their voxel counterparts in terms of their flexibility and realistic representation of detailed patient- or subject-specific anatomy. We have developed PARaDIM (pronounced "paradigm": Particle and Heavy Ion Transport Code System-Based Application for Radionuclide Dosimetry in Meshes), a freeware application for implementing tetrahedral mesh-type phantoms in absorbed dose calculations. It considers all medically relevant radionuclides, including α, β, γ, positron, and Auger/conversion electron emitters, and handles calculation of mean dose to individual regions, as well as 3-dimensional dose distributions for visualization and analysis in a variety of medical imaging software. This work describes the development of PARaDIM, documents the measures taken to test and validate its performance, and presents examples of its uses. Methods: Human, small-animal, and cell-level dose calculations were performed with PARaDIM and the results compared with those of widely accepted dosimetry programs and literature data. Several tetrahedral phantoms were developed or adapted using computer-aided modeling techniques for these comparisons. Results: For human dose calculations, agreement of PARaDIM with OLINDA 2.0 was good-within 10%-20% for most organs-despite geometric differences among the phantoms tested. Agreement with MIRDcell for cell-level S value calculations was within 5% in most cases. Conclusion: PARaDIM extends the use of Monte Carlo dose calculations to the broader community in nuclear medicine by providing a user-friendly graphical user interface for calculation setup and execution. PARaDIM leverages the enhanced anatomic realism provided by advanced computational reference phantoms or bespoke image-derived phantoms to enable improved assessments of radiation doses in a variety of radiopharmaceutical use cases, research, and preclinical development. PARaDIM can be downloaded freely at www.paradim-dose.org.
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Affiliation(s)
- Lukas M Carter
- Program in Pharmacology, the Radiochemistry and Molecular Imaging Probes Core, and the Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Troy M Crawford
- Department of Physics, University of Rhode Island, Kingston, Rhode Island
| | - Tatsuhiko Sato
- Japan Atomic Energy Agency, Ibaraki, Japan.,Research Center for Nuclear Physics, Osaka University, Osaka, Japan
| | | | - Chansoo Choi
- Department of Nuclear Engineering, Hanyang University, Seoul, Korea
| | - Chan Hyeong Kim
- Department of Nuclear Engineering, Hanyang University, Seoul, Korea
| | - Justin L Brown
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Wesley E Bolch
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Pat B Zanzonico
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York; and
| | - Jason S Lewis
- Program in Pharmacology, the Radiochemistry and Molecular Imaging Probes Core, and the Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York .,Department of Radiology and Department of Pharmacology, Weill Cornell Medical College, New York, New York
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20
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Factors affecting accuracy of S values and determination of time-integrated activity in clinical Lu-177 dosimetry. Ann Nucl Med 2019; 33:521-531. [DOI: 10.1007/s12149-019-01365-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 04/16/2019] [Indexed: 12/20/2022]
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21
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Gupta A, Lee MS, Kim JH, Park S, Park HS, Kim SE, Lee DS, Lee JS. Preclinical voxel-based dosimetry through GATE Monte Carlo simulation using PET/CT imaging of mice. Phys Med Biol 2019; 64:095007. [PMID: 30913544 DOI: 10.1088/1361-6560/ab134b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Internal dosimetry is of critical importance to obtain an accurate absorbed dose-response relationship during preclinical molecular imaging and targeted radionuclide therapy (TRT). Conventionally, absorbed dose calculations have been performed using organ-level dosimetry based on the Medical Internal Radiation Dose (MIRD) schema. However, recent research has focused on developing more accurate voxel-level calculation methods. Geant4 application for emission tomography (GATE) Monte Carlo (MC) is a simulation toolkit gaining attention in voxel-based dosimetry. In this study, we used PET/CT images of real mice to estimate the absorbed doses in sensitive organs at voxel-level to evaluate the suitability of GATE MC simulation for preclinical dosimetry. Thirteen normal C57BL/6 mice (male, body weight: 27.71 ± 4.25 g) were used to acquire dynamic positron emission tomography/computed tomography (PET/CT) images after IV injection of 18F-FDG. GATE MC toolkit was applied to estimate the absorbed doses in various organs of mice at voxel-level using CT and PET images as voxelized phantom and voxelized source, respectively. In addition, mean absorbed dose at organ-level was calculated using MIRD schema for comparison purposes. The differences in the respective absorbed doses (mGy MBq-1) between GATE MC and MIRD schema for brain, heart wall, liver, lungs, stomach wall, spleen, kidneys, and bladder wall were 1.36, 12.3, -22.4, -11.2, -16.9, -2.87, -4.29, and 3.71%, respectively. Considering that the PET/CT data of real mice were used for GATE simulation, the absorbed doses estimated in this study are mouse-specific. Therefore, the GATE-based Monte Carlo is likely to allow for more accurate internal dosimetry calculations. This method can be used in TRT for personalized dosimetry because it considers patient-specific heterogeneous tissue compositions and activity distributions.
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Affiliation(s)
- Arun Gupta
- Department of Nuclear Medicine, College of Medicine, Seoul National University, Seoul, Republic of Korea
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22
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Gupta A, Shin JH, Lee MS, Park JY, Kim K, Kim JH, Suh M, Park CR, Kim YJ, Song MG, Jeong JM, Lee DS, Lee YS, Lee JS. Voxel-Based Dosimetry of Iron Oxide Nanoparticle-Conjugated 177Lu-Labeled Folic Acid Using SPECT/CT Imaging of Mice. Mol Pharm 2019; 16:1498-1506. [PMID: 30821463 DOI: 10.1021/acs.molpharmaceut.8b01125] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Several radiolabeled folic acid conjugates have been developed for targeted imaging and therapy. However, the therapeutic concept with radiolabeled folate conjugates has not yet been applied to clinical applications owing to the high renal absorbed dose. The effectiveness of targeted radionuclide therapy (TRT) depends primarily on the absorbed dose rate and on the total absorbed dose delivered to the tumor and to normal tissue. Owing to various limitations associated with organ level dosimetry, voxel-based dosimetry has become essential for the assessment of a more accurate absorbed dose during TRT. In this study, we synthesized iron oxide nanoparticle (IONP)-conjugated radiolabeled folate (177Lu-IONP-Folate) and performed voxel-based dosimetry using SPECT/CT images of normal mice through direct Geant4 application for emission tomography (GATE) Monte Carlo (MC) simulation. We also prepared 177Lu-Folate and 177Lu-IONPs for the comparison of absorbed doses with that of 177Lu-IONP-Folate. In addition, we calculated the mean absorbed dose at the organ-level using the medical internal radiation dose (MIRD) schema. The radioactivities of all three radiotracers were mainly accumulated in the liver and kidneys immediately after injection. For the kidneys, the voxel-based absorbed doses obtained with 177Lu-IONP-Folate, 177Lu-Folate, and 177Lu-IONPs were 1.01 ± 0.17, 2.46 ± 0.50, and 0.52 ± 0.08 Gy/MBq, respectively. The renal absorbed dose decreased significantly (∼half) when 177Lu-IONP-Folate was used compared with when the 177Lu-Folate only was used. The mean absorbed dose values obtained at organ-level using the MIRD schema were comparable to voxel-based absorbed doses estimated with GATE MC. The voxel-based absorbed dose values obtained in this study of individualized activity show that the renal absorbed dose could be reduced to almost half with 177Lu-IONP-Folate. Therefore, 177Lu-IONP-Folate could be clinically applicable in the TRT of folate receptor-positive cancers in a personalized manner when using the voxel-based dosimetry method.
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Affiliation(s)
- Arun Gupta
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea
| | - Jae H Shin
- Department of Chemistry, Graduate School , Kyung Hee University , Seoul 02447 , Korea
| | - Min S Lee
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea.,Interdisciplinary Program in Radiation Applied Life Science , Seoul National University , Seoul 08826 , Korea
| | - Ji Y Park
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea
| | - Kyuwan Kim
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea
| | - Joong H Kim
- Center for Ionizing Radiation , Korea Research Institute of Standards and Science , Daejeon 34113 , Korea
| | - Minseok Suh
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea
| | - Cho R Park
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea
| | - Young J Kim
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea
| | - Myung G Song
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea
| | - Jae M Jeong
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea
| | - Dong S Lee
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea.,Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology , Seoul National University , Suwon 08826 , Korea
| | - Yun-Sang Lee
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea
| | - Jae S Lee
- Department of Nuclear Medicine , Seoul National University College of Medicine , Seoul 03080 , Korea.,Interdisciplinary Program in Radiation Applied Life Science , Seoul National University , Seoul 08826 , Korea.,Department of Biomedical Sciences , Seoul National University College of Medicine , Seoul 03080 , Korea
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23
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Abstract
Radiopharmaceutical therapy involves the use of radionuclides that are either conjugated to tumor-targeting agents (e.g., nanoscale constructs, antibodies, peptides, and small molecules) or that concentrate in tumors through natural physiological mechanisms that occur predominantly in neoplastic cells. In the latter category, radioiodine therapy of thyroid cancer is the prototypical and most widely implemented radiopharmaceutical therapy. In the category of radionuclide-ligand conjugates, antibody and peptide conjugates have been studied extensively. The efficacy of radiopharmaceutical therapy relies on the ability to deliver cytotoxic radiation to tumor cells without causing prohibitive normal tissue toxicity. After some 30 y of preclinical and clinical research, a number of recent developments suggest that radiopharmaceutical therapy is poised to emerge as an important and widely recognized therapeutic modality. These developments include the substantial investment in antibodies by the pharmaceutical industry and the compelling rationale to build upon this already existing and widely tested platform. In addition, the growing recognition that the signaling pathways responsible for tumor cell survival and proliferation are less easily and durably inhibited than originally envisioned has also provided a rationale for identifying agents that are cytotoxic rather than inhibitory. A number of radiopharmaceutical agents are currently undergoing clinical trial investigation; these include beta-particle emitters, such as Lu, that are being used to label antisomatostatin receptor peptides for neuroendocrine cancers and also prostate-specific membrane antigen targeting small molecules for prostate cancer. Alpha-particle-emitting radionuclides have also been studied for radiopharmaceutical therapy; these include At for glioblastoma, Ac for leukemias and prostate cancer, Pb for breast cancer, and Ra for prostate cancer. The alpha emitters have tended to show particular promise, and there is substantial interest in further developing these agents for therapy of cancers that are particularly difficult to treat.
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Affiliation(s)
- George Sgouros
- Johns Hopkins University, School of Medicine, The Russell H. Morgan Department of Radiology and Radiological Sciences, 1550 Orleans Street, Baltimore, MD 21287-0014
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24
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Wevrett J, Fenwick A, Scuffham J, Johansson L, Gear J, Schlögl S, Segbers M, Sjögreen-Gleisner K, Solný P, Lassmann M, Tipping J, Nisbet A. Inter-comparison of quantitative imaging of lutetium-177 ( 177Lu) in European hospitals. EJNMMI Phys 2018; 5:17. [PMID: 30069805 PMCID: PMC6070453 DOI: 10.1186/s40658-018-0213-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 04/13/2018] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND This inter-comparison exercise was performed to demonstrate the variability of quantitative SPECT/CT imaging for lutetium-177 (177Lu) in current clinical practice. Our aim was to assess the feasibility of using international inter-comparison exercises as a means to ensure consistency between clinical sites whilst enabling the sites to use their own choice of quantitative imaging protocols, specific to their systems. Dual-compartment concentric spherical sources of accurately known activity concentrations were prepared and sent to seven European clinical sites. The site staff were not aware of the true volumes or activity within the sources-they performed SPECT/CT imaging of the source, positioned within a water-filled phantom, using their own choice of parameters and reported their estimate of the activities within the source. RESULTS The volumes reported by the participants for the inner section of the source were all within 29% of the true value and within 60% of the true value for the outer section. The activities reported by the participants for the inner section of the source were all within 20% of the true value, whilst those reported for the outer section were up to 83% different to the true value. CONCLUSIONS A variety of calibration and segmentation methods were used by the participants for this exercise which demonstrated the variability of quantitative imaging across clinical sites. This paper presents a method to assess consistency between sites using different calibration and segmentation methods.
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Affiliation(s)
- Jill Wevrett
- University of Surrey, Guildford, UK.
- National Physical Laboratory, Teddington, UK.
- Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK.
| | | | - James Scuffham
- University of Surrey, Guildford, UK
- Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK
| | | | | | | | - Marcel Segbers
- Erasmus University Medical Centre, Rotterdam, Netherlands
| | | | - Pavel Solný
- Motol University Hospital, Prague, Czech Republic
| | | | - Jill Tipping
- The Christie NHS Foundation Trust, Manchester, UK
| | - Andrew Nisbet
- University of Surrey, Guildford, UK
- Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK
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25
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Plyku D, Mena E, Rowe SP, Lodge MA, Szabo Z, Cho SY, Pomper MG, Sgouros G, Hobbs RF. Combined model-based and patient-specific dosimetry for 18F-DCFPyL, a PSMA-targeted PET agent. Eur J Nucl Med Mol Imaging 2018; 45:989-998. [PMID: 29460025 DOI: 10.1007/s00259-018-3939-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 01/04/2018] [Indexed: 12/11/2022]
Abstract
PURPOSE Prostate-specific membrane antigen (PSMA), a type-II integral membrane protein highly expressed in prostate cancer, has been extensively used as a target for imaging and therapy. Among the available PET radiotracers, the low molecular weight agents that bind to PSMA are proving particularly effective. We present the dosimetry results for 18F-DCFPyL in nine patients with metastatic prostate cancer. METHODS Nine patients were imaged using sequential PET/CT scans at approximately 1, 12, 35 and 70 min, and a final PET/CT scan at approximately 120 min after intravenous administration of 321 ± 8 MBq (8.7 ± 0.2 mCi) of18F-DCFPyL. Time-integrated-activity coefficients were calculated and used as input in OLINDA/EXM software to obtain dose estimates for the majority of the major organs. The absorbed doses (AD) to the eye lens and lacrimal glands were calculated using Monte-Carlo models based on idealized anatomy combined with patient-specific volumes and activity from the PET/CT scans. Monte-Carlo based models were also developed for calculation of the dose to two major salivary glands (parotid and submandibular) using CT-based patient-specific gland volumes. RESULTS The highest calculated mean AD per unit administered activity of 18F was found in the lacrimal glands, followed by the submandibular glands, kidneys, urinary bladder wall, and parotid glands. The S-values for the lacrimal glands to the eye lens (0.42 mGy/MBq h), the tear film to the eye lens (1.78 mGy/MBq h) and the lacrimal gland self-dose (574.10 mGy/MBq h) were calculated. Average S-values for the salivary glands were 3.58 mGy/MBq h for the parotid self-dose and 6.78 mGy/MBq h for the submandibular self-dose. The resultant mean effective dose of 18F-DCFPyL was 0.017 ± 0.002 mSv/MBq. CONCLUSIONS 18F-DCFPyL dosimetry in nine patients was obtained using novel models for the lacrimal and salivary glands, two organs with potentially dose-limiting uptake for therapy and diagnosis which lacked pre-existing models.
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Affiliation(s)
- Donika Plyku
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Esther Mena
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Steven P Rowe
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Martin A Lodge
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Zsolt Szabo
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Steve Y Cho
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.,Department of Radiology, School of Medicine and Public Health, University of Wisconsin, CRB II 4M.60, 1550 Orleans St., Baltimore, MD, 21287, USA
| | - Martin G Pomper
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.,Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - George Sgouros
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.,Department of Radiation Oncology, School of Medicine, Johns Hopkins University, CRB II 4M.60, 1550 Orleans St., Baltimore, MD, USA
| | - Robert F Hobbs
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA. .,Department of Radiation Oncology, School of Medicine, Johns Hopkins University, CRB II 4M.60, 1550 Orleans St., Baltimore, MD, USA.
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Torres Berdeguez MB, Thomas S, Medeiros S, de Sá LV, Mas Milian F, da Silva AX. Dosimetry in Radiosynoviorthesis: 90Y VS. 153Sm. HEALTH PHYSICS 2018; 114:1-6. [PMID: 28990969 DOI: 10.1097/hp.0000000000000730] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Although there are several radionuclides suitable for radiosynoviorthesis (RSO), not all of them can irradiate deeper synovium. Yttrium-90 (Y) is the beta radionuclide with more penetration range; therefore, it is predominantly used to treat knees. The aim of this paper is to highlight several dosimetry concepts to compare Y and Sm, also discussing the feasibility of implementing a dose planning methodology for both in RSO. The MCNPX Monte Carlo nuclear code version 2.6 was used for calculating S-values from which the activity to be injected into the joint was obtained. This activity is considered sufficient to deliver a 100-Gy absorbed dose in 1 mm of synovial tissue. The simulated mathematical model consisted of a system formed by several cylindrical slabs of 1-mm thickness, aligned consecutively. The different areas of the cylinder base simulate several synovial membrane sizes. The effective treatment range for each radionuclide was also calculated. Quantification of the synovial joint features (synovial thickness and synovial surface) by diagnostic imaging, such as magnetic resonance (MRI) combined with a Monte Carlo simulation, can be used to achieve a treatment planning strategy in RSO with the available radionuclides.
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Hesterman JY, Kost SD, Holt RW, Dobson H, Verma A, Mozley PD. Three-Dimensional Dosimetry for Radiation Safety Estimates from Intrathecal Administration. J Nucl Med 2017; 58:1672-1678. [PMID: 28336783 DOI: 10.2967/jnumed.117.190611] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/13/2017] [Indexed: 11/16/2022] Open
Abstract
Intrathecal administration is of growing interest for drug delivery, and its utility is being increasingly investigated through imaging. In this work, the 3-dimensional Voxel-Based Internal Dosimetry Application (VIDA) and 4D Extended Cardiac Torso Phantom (XCAT) were extended to provide radiation safety estimates specific to intrathecal administration. Methods: The 3-dimensional VIDA dosimetry application Monte Carlo simulation was run using a modified XCAT phantom with additional and edited cerebrospinal fluid (CSF) regions to produce voxel-level absorbed dose per unit cumulated activity maps for 9 selected source regions. Simulation validation was performed to compare absorbed dose estimates for common organs in a preexisting dosimetry tool (OLINDA/EXM). Dynamic planar imaging data were acquired in 6 healthy subjects using administered volumes of 5 or 15 mL (n = 3 each) of 185 MBq of 99mTc-diethylenetriaminepentaacetic acid. Absorbed dose was estimated for each subject using the intrathecal-specific dosimetry application. Results: Simulation results were within 6% of OLINDA estimates for common organs. Absorbed dose estimates were highest (0.3-0.8 mGy/MBq) in the lumbar CSF space. A whole-body effective dose estimate of 0.003 mSv/MBq was observed. An administered volume dependency was observed with a 15-mL volume, resulting in lower absorbed dose estimates for several intrathecal and nonintrathecal regions. Conclusion: The intrathecal-specific VIDA implementation enables tailored dosimetry estimation for regions most relevant in intrathecal administration. Absorbed doses are highly localized to CSF and spinal regions and should be taken into consideration when designing intrathecal imaging studies. A potentially interesting relationship was observed between absorbed dose and administered volume, which merits further investigation.
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Affiliation(s)
| | | | | | | | | | - P David Mozley
- Weill Cornell Graduate College of Medical Sciences, New York, New York
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28
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Plyku D, Hobbs RF, Huang K, Atkins F, Garcia C, Sgouros G, Van Nostrand D. Recombinant Human Thyroid-Stimulating Hormone Versus Thyroid Hormone Withdrawal in 124I PET/CT-Based Dosimetry for 131I Therapy of Metastatic Differentiated Thyroid Cancer. J Nucl Med 2017; 58:1146-1154. [PMID: 28104741 DOI: 10.2967/jnumed.116.179366] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 12/08/2016] [Indexed: 11/16/2022] Open
Abstract
Patients with metastatic differentiated thyroid cancer (DTC) may be prepared using either thyroid-stimulating hormone withdrawal (THW) or recombinant human thyroid-stimulating hormone (rhTSH) injections before 131I administration for treatment. The objective of this study was to compare the absorbed dose to the critical organs and tumors determined by 124I PET/CT-based dosimetry for 131I therapy of metastatic DTC when the same patient was prepared with and imaged after both THW and rhTSH injections. Methods: Four DTC patients at MedStar Washington Hospital Center were first prepared using the rhTSH method and imaged by 124I PET/CT at 2, 24, 48, 72, and 96 h after administration of approximately 30-63 MBq of 124I. After 5-8 wk, the same patients were prepared using the THW method and imaged as before. The 124I PET/CT images acquired as part of a prospective study were used to perform retrospective dosimetric calculations for 131I therapy for the normal organs with the dosimetry package 3D-RD. The absorbed doses from 131I for the lungs, liver, heart, kidneys, and bone marrow were obtained for each study (rhTSH and THW). Twenty-two lesions in 3 patients were identified. The contours were drawn on each PET image of each study. Time-integrated activity coefficients were calculated and used as input in OLINDA/EXM sphere dose calculator to obtain the absorbed dose to tumors. Results: The THW-to-rhTSH organ absorbed dose ratio averaged over 5 organs for the first 3 patients was 1.5, 2.5, and 0.64, respectively, and averaged over 3 organs for the fourth patient was 1.1. The absorbed dose per unit administered activity to the bone marrow was 0.13, 0.086, 0.33, and 0.068 mGy/MBq after rhTSH and 0.11, 0.14, 0.22, and 0.080 mGy/MBq after THW for each patient, respectively. With the exception of 3 lesions of 1 patient, the absorbed dose per unit administered activity of 131I was higher in the THW study than in the rhTSH study. The ratio of the average tumor absorbed dose after stimulation by THW compared with stimulation by rhTSH injections was 3.9, 27, and 1.4 for patient 1, patient 2, and patient 3, respectively. The ratio of mean tumor to bone marrow absorbed dose per unit administered activity of 131I, after THW and rhTSH, was 232 and 62 (patient 1), 12 and 0.78 (patient 2), and 22 and 11 (patient 3), respectively. Conclusion: The results suggest a high patient variability in the overall absorbed dose to the normal organs per MBq of 131I administered, between the 2 TSH stimulation methods. The tumor-to-dose-limiting-organ (bone marrow) absorbed dose ratio, that is, the therapeutic index, was higher in the THW-aided than rhTSH-aided administrations. Additional comparison for tumor and normal organ absorbed dose in patients prepared using both methods is needed before definitive conclusions may be drawn regarding rhTSH versus THW patient preparation methods for 131I therapy of metastatic DTC.
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Affiliation(s)
- Donika Plyku
- Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Robert F Hobbs
- Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland.,Department of Radiation Oncology, Johns Hopkins University, School of Medicine, Baltimore Maryland; and
| | - Kevin Huang
- Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Frank Atkins
- Medstar Health Research Institute and Division of Nuclear Medicine, MedStar Washington Hospital Center, Washington, District of Columbia
| | - Carlos Garcia
- Medstar Health Research Institute and Division of Nuclear Medicine, MedStar Washington Hospital Center, Washington, District of Columbia
| | - George Sgouros
- Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland.,Department of Radiation Oncology, Johns Hopkins University, School of Medicine, Baltimore Maryland; and
| | - Douglas Van Nostrand
- Medstar Health Research Institute and Division of Nuclear Medicine, MedStar Washington Hospital Center, Washington, District of Columbia
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Lysak Y, Dyomin V, Klimanov V, Narkevich B, Romodanov V. Approach to radionuclide therapy dosimetry planning. NUCLEAR ENERGY AND TECHNOLOGY 2016. [DOI: 10.1016/j.nucet.2016.11.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Braad PEN, Andersen T, Hansen SB, Høilund-Carlsen PF. Strategies for CT tissue segmentation for Monte Carlo calculations in nuclear medicine dosimetry. Med Phys 2016; 43:6507. [DOI: 10.1118/1.4967267] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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31
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Plyku D, Loeb DM, Prideaux AR, Baechler S, Wahl RL, Sgouros G, Hobbs RF. Strengths and Weaknesses of a Planar Whole-Body Method of (153)Sm Dosimetry for Patients with Metastatic Osteosarcoma and Comparison with Three-Dimensional Dosimetry. Cancer Biother Radiopharm 2016; 30:369-79. [PMID: 26560193 DOI: 10.1089/cbr.2014.1803] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Dosimetric accuracy depends directly upon the accuracy of the activity measurements in tumors and organs. The authors present the methods and results of a retrospective tumor dosimetry analysis in 14 patients with a total of 28 tumors treated with high activities of (153)Sm-ethylenediaminetetramethylenephosphonate ((153)Sm-EDTMP) for therapy of metastatic osteosarcoma using planar images and compare the results with three-dimensional dosimetry. MATERIALS AND METHODS Analysis of phantom data provided a complete set of parameters for dosimetric calculations, including buildup factor, attenuation coefficient, and camera dead-time compensation. The latter was obtained using a previously developed methodology that accounts for the relative motion of the camera and patient during whole-body (WB) imaging. Tumor activity values calculated from the anterior and posterior views of WB planar images of patients treated with (153)Sm-EDTMP for pediatric osteosarcoma were compared with the geometric mean value. The mean activities were integrated over time and tumor-absorbed doses were calculated using the software package OLINDA/EXM. RESULTS The authors found that it was necessary to employ the dead-time correction algorithm to prevent measured tumor activity half-lives from often exceeding the physical decay half-life of (153)Sm. Measured half-lives so long are unquestionably in error. Tumor-absorbed doses varied between 0.0022 and 0.27 cGy/MBq with an average of 0.065 cGy/MBq; however, a comparison with absorbed dose values derived from a three-dimensional analysis for the same tumors showed no correlation; moreover, the ratio of three-dimensional absorbed dose value to planar absorbed dose value was 2.19. From the anterior and posterior activity comparisons, the order of clinical uncertainty for activity and dose calculations from WB planar images, with the present methodology, is hypothesized to be about 70%. CONCLUSION The dosimetric results from clinical patient data indicate that absolute planar dosimetry is unreliable and dosimetry using three-dimensional imaging is preferable, particularly for tumors, except perhaps for the most sophisticated planar methods. The relative activity and patient kinetics derived from planar imaging show a greater level of reliability than the dosimetry.
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Affiliation(s)
- Donika Plyku
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - David M Loeb
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Andrew R Prideaux
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Sébastien Baechler
- 2 University Institute of Radiation Physics, University of Lausanne , Lausanne, Switzerland
| | - Richard L Wahl
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - George Sgouros
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Robert F Hobbs
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
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Blakkisrud J, Løndalen A, Martinsen ACT, Dahle J, Holtedahl JE, Bach-Gansmo T, Holte H, Kolstad A, Stokke C. Tumor-Absorbed Dose for Non-Hodgkin Lymphoma Patients Treated with the Anti-CD37 Antibody Radionuclide Conjugate 177Lu-Lilotomab Satetraxetan. J Nucl Med 2016; 58:48-54. [PMID: 27493270 DOI: 10.2967/jnumed.116.173922] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 07/05/2016] [Indexed: 12/22/2022] Open
Abstract
177Lu-lilotomab satetraxetan is a novel antibody radionuclide conjugate currently tested in a phase 1/2a first-in-human dosage escalation trial for patients with relapsed CD37+ indolent non-Hodgkin lymphoma. The aim of this work was to develop dosimetric methods and calculate tumor-absorbed radiation doses for patients treated with 177Lu-lilotomab satetraxetan. METHODS Patients were treated at escalating injected activities (10, 15 and 20 MBq/kg) of 177Lu-lilotomab satetraxetan and with different predosing, with or without 40 mg of unlabeled lilotomab. Eight patients were included for the tumor dosimetry study. Tumor radioactivity concentrations were calculated from SPECT acquisitions at multiple time points, and tumor masses were delineated from corresponding CT scans. Tumor-absorbed doses were then calculated using the OLINDA sphere model. To perform voxel dosimetry, the SPECT/CT data and an in-house-developed MATLAB program were combined to investigate the dose rate homogeneity. RESULTS Twenty-six tumors in 8 patients were ascribed a mean tumor-absorbed dose. Absorbed doses ranged from 75 to 794 cGy, with a median of 264 cGy across different dosage levels and different predosing. A significant correlation between the dosage level and tumor-absorbed dose was found. Twenty-one tumors were included for voxel dosimetry and parameters describing dose-volume coverage calculated. The investigation of intratumor voxel doses indicates that mean tumor dose is correlated to these parameters. CONCLUSION Tumor-absorbed doses for patients treated with 177Lu-lilotomab satetraxetan are comparable to doses reported for other radioimmunotherapy compounds. Although the intertumor variability was considerable, a correlation between tumor dose and patient dosage level was found. Our results indicate that mean dose may be used as the sole dosimetric parameter on the lesion level.
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Affiliation(s)
- Johan Blakkisrud
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
| | - Ayca Løndalen
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Anne C T Martinsen
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway.,The Department of Physics, University of Oslo, Oslo, Norway
| | | | - Jon E Holtedahl
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
| | - Tore Bach-Gansmo
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Harald Holte
- Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway; and
| | - Arne Kolstad
- Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway; and
| | - Caroline Stokke
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway .,Department of Life Science and Health, Oslo and Akershus University College of Applied Sciences, Oslo, Norway
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Šefl M, Kyriakou I, Emfietzoglou D. Technical Note: Impact of cell repopulation and radionuclide uptake phase on cell survival. Med Phys 2016; 43:2715-2720. [DOI: 10.1118/1.4948504] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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34
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Cheng L, Hobbs RF, Sgouros G, Frey EC. Development and evaluation of convergent and accelerated penalized SPECT image reconstruction methods for improved dose-volume histogram estimation in radiopharmaceutical therapy. Med Phys 2015; 41:112507. [PMID: 25370666 DOI: 10.1118/1.4897613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Three-dimensional (3D) dosimetry has the potential to provide better prediction of response of normal tissues and tumors and is based on 3D estimates of the activity distribution in the patient obtained from emission tomography. Dose-volume histograms (DVHs) are an important summary measure of 3D dosimetry and a widely used tool for treatment planning in radiation therapy. Accurate estimates of the radioactivity distribution in space and time are desirable for accurate 3D dosimetry. The purpose of this work was to develop and demonstrate the potential of penalized SPECT image reconstruction methods to improve DVHs estimates obtained from 3D dosimetry methods. METHODS The authors developed penalized image reconstruction methods, using maximum a posteriori (MAP) formalism, which intrinsically incorporate regularization in order to control noise and, unlike linear filters, are designed to retain sharp edges. Two priors were studied: one is a 3D hyperbolic prior, termed single-time MAP (STMAP), and the second is a 4D hyperbolic prior, termed cross-time MAP (CTMAP), using both the spatial and temporal information to control noise. The CTMAP method assumed perfect registration between the estimated activity distributions and projection datasets from the different time points. Accelerated and convergent algorithms were derived and implemented. A modified NURBS-based cardiac-torso phantom with a multicompartment kidney model and organ activities and parameters derived from clinical studies were used in a Monte Carlo simulation study to evaluate the methods. Cumulative dose-rate volume histograms (CDRVHs) and cumulative DVHs (CDVHs) obtained from the phantom and from SPECT images reconstructed with both the penalized algorithms and OS-EM were calculated and compared both qualitatively and quantitatively. The STMAP method was applied to patient data and CDRVHs obtained with STMAP and OS-EM were compared qualitatively. RESULTS The results showed that the penalized algorithms substantially improved the CDRVH and CDVH estimates for large organs such as the liver compared to optimally postfiltered OS-EM. For example, the mean squared errors (MSEs) of the CDRVHs for the liver at 5 h postinjection obtained with CTMAP and STMAP were about 15% and 17%, respectively, of the MSEs obtained with optimally filtered OS-EM. For the CDVH estimates, the MSEs obtained with CTMAP and STMAP were about 16% and 19%, respectively, of the MSEs from OS-EM. For the kidneys and renal cortices, larger residual errors were observed for all algorithms, likely due to partial volume effects. The STMAP method showed promising qualitative results when applied to patient data. CONCLUSIONS Penalized image reconstruction methods were developed and evaluated through a simulation study. The study showed that the MAP algorithms substantially improved CDVH estimates for large organs such as the liver compared to optimally postfiltered OS-EM reconstructions. For small organs with fine structural detail such as the kidneys, a large residual error was observed for both MAP algorithms and OS-EM. While CTMAP provided marginally better MSEs than STMAP, given the extra effort needed to handle misregistration of images at different time points in the algorithm and the potential impact of residual misregistration, 3D regularization methods, such as that used in STMAP, appear to be a more practical choice.
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Affiliation(s)
- Lishui Cheng
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287 and Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - Robert F Hobbs
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - George Sgouros
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - Eric C Frey
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
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Roshan HR, Azarm A, Mahmoudian B, Islamian JP. Advances in SPECT for Optimizing the Liver Tumors Radioembolization Using Yttrium-90 Microspheres. World J Nucl Med 2015; 14:75-80. [PMID: 26097416 PMCID: PMC4455176 DOI: 10.4103/1450-1147.157120] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Radioembolization (RE) with Yttrium-90 ((90)Y) microspheres is an effective treatment for unresectable liver tumors. The activity of the microspheres to be administered should be calculated based on the type of microspheres. Technetium-99m macroaggregated albumin ((99m)Tc-MAA) single photon emission computed tomography/computed tomography (SPECT/CT) is a reliable assessment before RE to ensure the safe delivery of microspheres into the target. (90)Y bremsstrahlung SPECT imaging as a posttherapeutic assessment approach enables the reliable determination of absorbed dose, which is indispensable for the verification of treatment efficacy. This article intends to provide a review of the methods of optimizing (90)Y bremsstrahlung SPECT imaging to improve the treatment efficacy of liver tumor RE using (90)Y microspheres.
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Affiliation(s)
- Hoda Rezaei Roshan
- Department of Medical Physics, Nuclear Medicine Unit, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ahmadreza Azarm
- Department of Medical Physics, Nuclear Medicine Unit, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Babak Mahmoudian
- Department of Radiology, Nuclear Medicine Unit, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Jalil Pirayesh Islamian
- Department of Medical Physics, Nuclear Medicine Unit, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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Kletting P, Schimmel S, Hänscheid H, Luster M, Fernández M, Nosske D, Lassmann M, Glatting G. The NUKDOS software for treatment planning in molecular radiotherapy. Z Med Phys 2015; 25:264-74. [PMID: 25791740 DOI: 10.1016/j.zemedi.2015.01.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/22/2014] [Accepted: 01/12/2015] [Indexed: 02/04/2023]
Abstract
The aim of this work was the development of a software tool for treatment planning prior to molecular radiotherapy, which comprises all functionality to objectively determine the activity to administer and the pertaining absorbed doses (including the corresponding error) based on a series of gamma camera images and one SPECT/CT or probe data. NUKDOS was developed in MATLAB. The workflow is based on the MIRD formalism For determination of the tissue or organ pharmacokinetics, gamma camera images as well as probe, urine, serum and blood activity data can be processed. To estimate the time-integrated activity coefficients (TIAC), sums of exponentials are fitted to the time activity data and integrated analytically. To obtain the TIAC on the voxel level, the voxel activity distribution from the quantitative 3D SPECT/CT (or PET/CT) is used for scaling and weighting the TIAC derived from the 2D organ data. The voxel S-values are automatically calculated based on the voxel-size of the image and the therapeutic nuclide ((90)Y, (131)I or (177)Lu). The absorbed dose coefficients are computed by convolution of the voxel TIAC and the voxel S-values. The activity to administer and the pertaining absorbed doses are determined by entering the absorbed dose for the organ at risk. The overall error of the calculated absorbed doses is determined by Gaussian error propagation. NUKDOS was tested for the operation systems Windows(®) 7 (64 Bit) and 8 (64 Bit). The results of each working step were compared to commercially available (SAAMII, OLINDA/EXM) and in-house (UlmDOS) software. The application of the software is demonstrated using examples form peptide receptor radionuclide therapy (PRRT) and from radioiodine therapy of benign thyroid diseases. For the example from PRRT, the calculated activity to administer differed by 4% comparing NUKDOS and the final result using UlmDos, SAAMII and OLINDA/EXM sequentially. The absorbed dose for the spleen and tumour differed by 7% and 8%, respectively. The results from the example from radioiodine therapy of benign thyroid diseases and the example given in the latest corresponding SOP were identical. The implemented, objective methods facilitate accurate and reproducible results. The software is freely available.
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Affiliation(s)
- Peter Kletting
- Klinik für Nuklearmedizin, Universität Ulm, Ulm, Germany.
| | | | | | - Markus Luster
- Klinik für Nuklearmedizin, Universität Marburg, Marburg, Germany
| | - Maria Fernández
- Klinik für Nuklearmedizin, Universität Würzburg, Würzburg, Germany
| | - Dietmar Nosske
- Bundesamt für Strahlenschutz, Fachbereich Strahlenschutz und Gesundheit, Oberschleißheim, Germany
| | - Michael Lassmann
- Klinik für Nuklearmedizin, Universität Würzburg, Würzburg, Germany
| | - Gerhard Glatting
- Medical Radiation Physics/Radiation Protection, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Woliner-van der Weg W, Schoffelen R, Hobbs RF, Gotthardt M, Goldenberg DM, Sharkey RM, Slump CH, van der Graaf WT, Oyen WJ, Boerman OC, Sgouros G, Visser EP. Tumor and red bone marrow dosimetry: comparison of methods for prospective treatment planning in pretargeted radioimmunotherapy. EJNMMI Phys 2015; 2:5. [PMID: 26501807 PMCID: PMC4545615 DOI: 10.1186/s40658-014-0104-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 11/25/2014] [Indexed: 11/20/2022] Open
Abstract
Background Red bone marrow (RBM) toxicity is dose-limiting in (pretargeted) radioimmunotherapy (RIT). Previous blood-based and two-dimensional (2D) image-based methods have failed to show a clear dose-response relationship. We developed a three-dimensional (3D) image-based RBM dosimetry approach using the Monte Carlo-based 3D radiobiological dosimetry (3D-RD) software and determined its additional value for predicting RBM toxicity. Methods RBM doses were calculated for 13 colorectal cancer patients after pretargeted RIT with the two-step administration of an anti-CEA × anti-HSG bispecific monoclonal antibody and a 177Lu-labeled di-HSG-peptide. 3D-RD RBM dosimetry was based on the lumbar vertebrae, delineated on single photon emission computed tomography (SPECT) scans acquired directly, 3, 24, and 72 h after 177Lu administration. RBM doses were correlated to hematologic effects, according to NCI-CTC v3 and compared with conventional 2D cranium-based and blood-based dosimetry results. Tumor doses were calculated with 3D-RD, which has not been possible with 2D dosimetry. Tumor-to-RBM dose ratios were calculated and compared for 177Lu-based pretargeted RIT and simulated pretargeted RIT with 90Y. Results 3D-RD RBM doses of all seven patients who developed thrombocytopenia were higher (range 0.43 to 0.97 Gy) than that of the six patients without thrombocytopenia (range 0.12 to 0.39 Gy), except in one patient (0.47 Gy) without thrombocytopenia but with grade 2 leucopenia. Blood and 2D image-based RBM doses for patients with grade 1 to 2 thrombocytopenia were in the same range as in patients without thrombocytopenia (0.14 to 0.29 and 0.11 to 0.26 Gy, respectively). Blood-based RBM doses for two grade 3 to 4 patients were higher (0.66 and 0.51 Gy, respectively) than the others, and the cranium-based dose of only the grade 4 patient was higher (0.34 Gy). Tumor-to-RBM dose ratios would increase by 25% on average when treating with 90Y instead of 177Lu. Conclusions 3D dosimetry identifies patients at risk of developing any grade of RBM toxicity more accurately than blood- or 2D image-based methods. It has the added value to enable calculation of tumor-to-RBM dose ratios.
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Affiliation(s)
- Wietske Woliner-van der Weg
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box 9101, 6500, HB, Nijmegen, The Netherlands.
| | - Rafke Schoffelen
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box 9101, 6500, HB, Nijmegen, The Netherlands.
| | - Robert F Hobbs
- Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.
| | - Martin Gotthardt
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box 9101, 6500, HB, Nijmegen, The Netherlands.
| | | | | | | | | | - Wim Jg Oyen
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box 9101, 6500, HB, Nijmegen, The Netherlands.
| | - Otto C Boerman
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box 9101, 6500, HB, Nijmegen, The Netherlands.
| | - George Sgouros
- Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.
| | - Eric P Visser
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box 9101, 6500, HB, Nijmegen, The Netherlands.
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Kost SD, Dewaraja YK, Abramson RG, Stabin MG. VIDA: a voxel-based dosimetry method for targeted radionuclide therapy using Geant4. Cancer Biother Radiopharm 2015; 30:16-26. [PMID: 25594357 PMCID: PMC4322792 DOI: 10.1089/cbr.2014.1713] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We have developed the Voxel-Based Internal Dosimetry Application (VIDA) to provide patient-specific dosimetry in targeted radionuclide therapy performing Monte Carlo simulations of radiation transport with the Geant4 toolkit. The code generates voxel-level dose rate maps using anatomical and physiological data taken from individual patients. Voxel level dose rate curves are then fit and integrated to yield a spatial map of radiation absorbed dose. In this article, we present validation studies using established dosimetry results, including self-dose factors (DFs) from the OLINDA/EXM program for uniform activity in unit density spheres and organ self- and cross-organ DFs in the Radiation Dose Assessment Resource (RADAR) reference adult phantom. The comparison with reference data demonstrated agreement within 5% for self-DFs to spheres and reference phantom source organs for four common radionuclides used in targeted therapy ((131)I, (90)Y, (111)In, (177)Lu). Agreement within 9% was achieved for cross-organ DFs. We also present dose estimates to normal tissues and tumors from studies of two non-Hodgkin Lymphoma patients treated by (131)I radioimmunotherapy, with comparison to results generated independently with another dosimetry code. A relative difference of 12% or less was found between methods for mean absorbed tumor doses accounting for tumor regression.
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Affiliation(s)
- Susan D. Kost
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee
| | - Yuni K. Dewaraja
- Department of Radiology, University of Michigan, Ann Arbor, Michigan
| | - Richard G. Abramson
- Department of Radiology/Radiological Science, Vanderbilt University, Nashville, Tennessee
| | - Michael G. Stabin
- Department of Radiology/Radiological Science, Vanderbilt University, Nashville, Tennessee
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Cremonesi M, Ferrari M, Botta F, Guerriero F, Garibaldi C, Bodei L, De Cicco C, Grana CM, Pedroli G, Orecchia R. Planning combined treatments of external beam radiation therapy and molecular radiotherapy. Cancer Biother Radiopharm 2014; 29:227-37. [PMID: 25006794 DOI: 10.1089/cbr.2014.1607] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Molecular radiotherapy (MRT) with radiolabeled molecules has being constantly evolving, leading to notable results in cancer treatment. In some cases, the absorbed doses delivered to tumors by MRT are sufficient to obtain complete responses; in other cases, instead, to be effective, MRT needs to be combined with other therapeutic approaches. Recently, several studies proposed the combination of MRT with external beam radiation therapy (EBRT). Some describe the theoretical basis within radiobiological models, others report the results of clinical phase I-II studies aimed to assess the feasibility and tolerability. The latter includes the treatment of various tumors, such as meningiomas, paragangliomas, non-Hodgkin's lymphomas, bone, brain, hepatic, and breast lesions. The underlying principle of combined MRT and EBRT is the possibility of exploiting the full potential of each modality, given the different organs at risk. Target tissues can indeed receive a higher irradiation, while respecting the threshold limits of more than one critical tissue. Nevertheless, clinical trials are empirical and optimization is still a theoretical issue. This article describes the state of the art of combined MRT and EBRT regarding the rationale and the results of clinical studies, with special focus on the possibility of treatment improvement.
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Affiliation(s)
- Marta Cremonesi
- Department of Medical Imaging and Radiation Sciences, Istituto Europeo di Oncologia , Milan, Italy
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40
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Sgouros G, Goldenberg DM. Radiopharmaceutical therapy in the era of precision medicine. Eur J Cancer 2014; 50:2360-3. [PMID: 24953565 DOI: 10.1016/j.ejca.2014.04.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 04/26/2014] [Accepted: 04/26/2014] [Indexed: 10/25/2022]
Abstract
Precision medicine is the selection of a treatment modality that is specifically tailored to the genetic and phenotypic characteristics of a particular patient's disease. In cancer, the objective is to treat with agents that inhibit cell signalling pathways that drive uncontrolled proliferation and dissemination of the disease. To overcome the eventual resistance to pathway inhibition therapy, this treatment modality has been combined with chemotherapy. We propose that pathway inhibition therapy is more rationally combined with radiopharmaceutical therapy (RPT), a cytotoxic treatment that is also targeted. RPT exploits pharmaceuticals that either bind specifically to tumours or accumulate by a broad array of physiological mechanisms indigenous to the neoplastic cells to deliver radiation specifically to these cells. Consistent with pathway inhibition therapy and in contrast to chemotherapy, RPT is well tolerated. However, the potential of RPT has not been fully exploited; for the most part, treatment has been implemented without using the ability to customise RPT by imaging and deriving individual patient tumour and normal organ radiation absorbed doses. These are more closely related to biological response and their determination should enable RPT treatment administration to maximum therapeutic benefit by treating to normal organ tolerance or demonstrating futility via tumour dosimetry. This is the essence of precision medicine.
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Affiliation(s)
- George Sgouros
- Division of Nuclear Medicine, Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
| | - David M Goldenberg
- Garden State Cancer Center, Center for Molecular Medicine and Immunology, Morris Plains, NJ, United States
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Sgouros G, Hobbs RF, Abou DS. The role of preclinical models in radiopharmaceutical therapy. Am Soc Clin Oncol Educ Book 2014:e121-5. [PMID: 24857091 DOI: 10.14694/edbook_am.2014.34.e121] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Radiopharmaceutical therapy (RPT) is a treatment modality that involves the use of radioactively labeled targeting agents to deliver a cytotoxic dose of radiation to tumor while sparing normal tissue. The biologic function of the target and the biologic action of the targeting agent is largely irrelevant as long as the targeting agent delivers cytotoxic radiation to the tumor. Preclinical RPT studies use imaging and ex vivo evaluation of radioactivity concentration in target and normal tissues to obtain biodistribution and pharmacokinetic data that can be used to evaluate radiation absorbed doses. Since the efficacy and toxicity of RPT depend on radiation absorbed dose, this quantity can be used to translate results from preclinical studies to human studies. The absorbed dose can also be used to customize therapy to account for pharmacokinetic and other differences among patients so as to deliver a prespecified absorbed dose to the tumor or to dose-limiting tissue. The combination of RPT with other agents can be investigated and optimized by identifying the effect of other agents on tumor or normal tissue radiosensitivity and also on how other agents change the absorbed dose to these tissues. RPT is a distinct therapeutic modality whose mechanism of action is well understood. Measurements can be made in preclinical models to help guide clinical implementation of RPT and optimize combination therapy using RPT.
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Affiliation(s)
- George Sgouros
- From the Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, School of Medicine, Baltimore, MD
| | - Robert F Hobbs
- From the Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, School of Medicine, Baltimore, MD
| | - Diane S Abou
- From the Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, School of Medicine, Baltimore, MD
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Grimes J, Uribe C, Celler A. JADA: a graphical user interface for comprehensive internal dose assessment in nuclear medicine. Med Phys 2014; 40:072501. [PMID: 23822450 DOI: 10.1118/1.4810963] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The main objective of this work was to design a comprehensive dosimetry package that would keep all aspects of internal dose calculation within the framework of a single software environment and that would be applicable for a variety of dose calculation approaches. METHODS Our MATLAB-based graphical user interface (GUI) can be used for processing data obtained using pure planar, pure SPECT, or hybrid planar/SPECT imaging. Time-activity data for source regions are obtained using a set of tools that allow the user to reconstruct SPECT images, load images, coregister a series of planar images, and to perform two-dimensional and three-dimensional image segmentation. Curve fits are applied to the acquired time-activity data to construct time-activity curves, which are then integrated to obtain time-integrated activity coefficients. Subsequently, dose estimates are made using one of three methods. RESULTS The organ level dose calculation subGUI calculates mean organ doses that are equivalent to dose assessment performed by OLINDA/EXM. Voxelized dose calculation options, which include the voxel S value approach and Monte Carlo simulation using the EGSnrc user code DOSXYZnrc, are available within the process 3D image data subGUI. CONCLUSIONS The developed internal dosimetry software package provides an assortment of tools for every step in the dose calculation process, eliminating the need for manual data transfer between programs. This saves times and minimizes user errors, while offering a versatility that can be used to efficiently perform patient-specific internal dose calculations in a variety of clinical situations.
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Affiliation(s)
- Joshua Grimes
- Department of Physics and Astronomy, University of British Columbia, Vancouver V5Z 1M9, Canada.
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Kletting P, Schimmel S, Kestler HA, Hänscheid H, Luster M, Fernández M, Bröer JH, Nosske D, Lassmann M, Glatting G. Molecular radiotherapy: The NUKFIT software for calculating the time-integrated activity coefficient. Med Phys 2013; 40:102504. [DOI: 10.1118/1.4820367] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Rong X, Frey EC. A collimator optimization method for quantitative imaging: application to Y-90 bremsstrahlung SPECT. Med Phys 2013; 40:082504. [PMID: 23927349 PMCID: PMC3732303 DOI: 10.1118/1.4813297] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 06/01/2013] [Accepted: 06/23/2013] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Post-therapy quantitative 90Y bremsstrahlung single photon emission computed tomography (SPECT) has shown great potential to provide reliable activity estimates, which are essential for dose verification. Typically 90Y imaging is performed with high- or medium-energy collimators. However, the energy spectrum of 90Y bremsstrahlung photons is substantially different than typical for these collimators. In addition, dosimetry requires quantitative images, and collimators are not typically optimized for such tasks. Optimizing a collimator for 90Y imaging is both novel and potentially important. Conventional optimization methods are not appropriate for 90Y bremsstrahlung photons, which have a continuous and broad energy distribution. In this work, the authors developed a parallel-hole collimator optimization method for quantitative tasks that is particularly applicable to radionuclides with complex emission energy spectra. The authors applied the proposed method to develop an optimal collimator for quantitative 90Y bremsstrahlung SPECT in the context of microsphere radioembolization. METHODS To account for the effects of the collimator on both the bias and the variance of the activity estimates, the authors used the root mean squared error (RMSE) of the volume of interest activity estimates as the figure of merit (FOM). In the FOM, the bias due to the null space of the image formation process was taken in account. The RMSE was weighted by the inverse mass to reflect the application to dosimetry; for a different application, more relevant weighting could easily be adopted. The authors proposed a parameterization for the collimator that facilitates the incorporation of the important factors (geometric sensitivity, geometric resolution, and septal penetration fraction) determining collimator performance, while keeping the number of free parameters describing the collimator small (i.e., two parameters). To make the optimization results for quantitative 90Y bremsstrahlung SPECT more general, the authors simulated multiple tumors of various sizes in the liver. The authors realistically simulated human anatomy using a digital phantom and the image formation process using a previously validated and computationally efficient method for modeling the image-degrading effects including object scatter, attenuation, and the full collimator-detector response (CDR). The scatter kernels and CDR function tables used in the modeling method were generated using a previously validated Monte Carlo simulation code. RESULTS The hole length, hole diameter, and septal thickness of the obtained optimal collimator were 84, 3.5, and 1.4 mm, respectively. Compared to a commercial high-energy general-purpose collimator, the optimal collimator improved the resolution and FOM by 27% and 18%, respectively. CONCLUSIONS The proposed collimator optimization method may be useful for improving quantitative SPECT imaging for radionuclides with complex energy spectra. The obtained optimal collimator provided a substantial improvement in quantitative performance for the microsphere radioembolization task considered.
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Affiliation(s)
- Xing Rong
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21287-0859, USA.
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45
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Cheng L, Hobbs RF, Segars PW, Sgouros G, Frey EC. Improved dose-volume histogram estimates for radiopharmaceutical therapy by optimizing quantitative SPECT reconstruction parameters. Phys Med Biol 2013; 58:3631-47. [PMID: 23648371 DOI: 10.1088/0031-9155/58/11/3631] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In radiopharmaceutical therapy, an understanding of the dose distribution in normal and target tissues is important for optimizing treatment. Three-dimensional (3D) dosimetry takes into account patient anatomy and the nonuniform uptake of radiopharmaceuticals in tissues. Dose-volume histograms (DVHs) provide a useful summary representation of the 3D dose distribution and have been widely used for external beam treatment planning. Reliable 3D dosimetry requires an accurate 3D radioactivity distribution as the input. However, activity distribution estimates from SPECT are corrupted by noise and partial volume effects (PVEs). In this work, we systematically investigated OS-EM based quantitative SPECT (QSPECT) image reconstruction in terms of its effect on DVHs estimates. A modified 3D NURBS-based Cardiac-Torso (NCAT) phantom that incorporated a non-uniform kidney model and clinically realistic organ activities and biokinetics was used. Projections were generated using a Monte Carlo (MC) simulation; noise effects were studied using 50 noise realizations with clinical count levels. Activity images were reconstructed using QSPECT with compensation for attenuation, scatter and collimator-detector response (CDR). Dose rate distributions were estimated by convolution of the activity image with a voxel S kernel. Cumulative DVHs were calculated from the phantom and QSPECT images and compared both qualitatively and quantitatively. We found that noise, PVEs, and ringing artifacts due to CDR compensation all degraded histogram estimates. Low-pass filtering and early termination of the iterative process were needed to reduce the effects of noise and ringing artifacts on DVHs, but resulted in increased degradations due to PVEs. Large objects with few features, such as the liver, had more accurate histogram estimates and required fewer iterations and more smoothing for optimal results. Smaller objects with fine details, such as the kidneys, required more iterations and less smoothing at early time points post-radiopharmaceutical administration but more smoothing and fewer iterations at later time points when the total organ activity was lower. The results of this study demonstrate the importance of using optimal reconstruction and regularization parameters. Optimal results were obtained with different parameters at each time point, but using a single set of parameters for all time points produced near-optimal dose-volume histograms.
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Affiliation(s)
- Lishui Cheng
- The Russell H Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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Abstract
Primary and metastatic malignant bone lesions result in significant pain and disability in oncology patients. Targeted bone-seeking radioisotopes including 153Samarium ethylene-diamine-tetramethylene-phosphonic acid (153Sm-EDTMP) have been shown to effectively palliate bone pain, often when external beam radiotherapy (EBRT) is not feasible. However, recent evidence also suggests 153Sm-EDTMP has cytotoxic activity either alone or in combination with chemotherapy or EBRT. 153Sm-EDTMP may be useful as anti-neoplastic therapy apart from pain palliation in a variety of malignancies. For prostate cancer patients, several phase I and II clinical trials have shown that combined 153Sm-EDTMP and docetaxel-based chemotherapy can result in >50% decrease in prostate-specific antigen with manageable myelosuppression. In hematologic malignancies, 153Sm-EDTMP produced clinical responses when combined with bortezomib in multiple myeloma. 153Sm-EDTMP also can be used with myeloablative chemotherapy for marrow conditioning prior to stem cell transplant. In osteosarcoma, 153Sm-EDTMP infusion delivers radiation to multiple unresectable lesions simultaneously and provides local cytotoxicity without soft tissue damage that can be combined with chemotherapy or radiation. Prior to routine incorporation of 153Sm-EDTMP into therapeutic regimens, we must learn how to ensure optimal delivery to tumors, determine which patients are likely to benefit, improve our ability to assess clinical response in bone lesions and further evaluate the efficacy 153Sm-EDTMP in combination with chemotherapy, radiation and novel targeted agents.
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Affiliation(s)
- Breelyn A Wilky
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - David M Loeb
- Department of Pediatric Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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Cutler CS, Hennkens HM, Sisay N, Huclier-Markai S, Jurisson SS. Radiometals for Combined Imaging and Therapy. Chem Rev 2012. [DOI: 10.1021/cr3003104] [Citation(s) in RCA: 281] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Cathy S. Cutler
- University of Missouri Research Reactor Center, Columbia, Missouri 65211, United
States
| | - Heather M. Hennkens
- University of Missouri Research Reactor Center, Columbia, Missouri 65211, United
States
| | - Nebiat Sisay
- University of Missouri Research Reactor Center, Columbia, Missouri 65211, United
States
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United
States
| | - Sandrine Huclier-Markai
- Laboratoire Subatech,
UMR 6457, Ecole des Mines de Nantes/Université de Nantes/CNRS-IN2P3, 4 Rue A. Kastler, BP 20722, F-44307
Nantes Cedex 3, France
| | - Silvia S. Jurisson
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United
States
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Sgouros G, Hobbs RF. Patient-Specific Dosimetry, Radiobiology, and the Previously-Treated Patient. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/174_2012_684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Rong X, Du Y, Ljungberg M, Rault E, Vandenberghe S, Frey EC. Development and evaluation of an improved quantitative (90)Y bremsstrahlung SPECT method. Med Phys 2012; 39:2346-58. [PMID: 22559605 DOI: 10.1118/1.3700174] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
PURPOSE Yttrium-90 ((90)Y) is one of the most commonly used radionuclides in targeted radionuclide therapy (TRT). Since it decays with essentially no gamma photon emissions, surrogate radionuclides (e.g., (111)In) or imaging agents (e.g., (99m)Tc MAA) are typically used for treatment planning. It would, however, be useful to image (90)Y directly in order to confirm that the distributions measured with these other radionuclides or agents are the same as for the (90)Y labeled agents. As a result, there has been a great deal of interest in quantitative imaging of (90)Y bremsstrahlung photons using single photon emission computed tomography (SPECT) imaging. The continuous and broad energy distribution of bremsstrahlung photons, however, imposes substantial challenges on accurate quantification of the activity distribution. The aim of this work was to develop and evaluate an improved quantitative (90)Y bremsstrahlung SPECT reconstruction method appropriate for these imaging applications. METHODS Accurate modeling of image degrading factors such as object attenuation and scatter and the collimator-detector response is essential to obtain quantitatively accurate images. All of the image degrading factors are energy dependent. Thus, the authors separated the modeling of the bremsstrahlung photons into multiple categories and energy ranges. To improve the accuracy, the authors used a bremsstrahlung energy spectrum previously estimated from experimental measurements and incorporated a model of the distance between (90)Y decay location and bremsstrahlung emission location into the SIMIND code used to generate the response functions and kernels used in the model. This improved Monte Carlo bremsstrahlung simulation was validated by comparison to experimentally measured projection data of a (90)Y line source. The authors validated the accuracy of the forward projection model for photons in the various categories and energy ranges using the validated Monte Carlo (MC) simulation method. The forward projection model was incorporated into an iterative ordered subsets-expectation maximization (OS-EM) reconstruction code to allow for quantitative SPECT reconstruction. The resulting code was validated using both a physical phantom experiment with spherical objects in a warm background and a realistic anatomical phantom simulation. In the physical phantom study, the authors evaluated the method in terms of quantitative accuracy of activity estimates in the spheres; in the simulation study, the authors evaluated the accuracy and precision of activity estimates from various organs and compared them to results from a previously proposed method. RESULTS The authors demonstrated excellent agreement between the experimental measurement and Monte Carlo simulation. In the XCAT phantom simulation, the proposed method achieved much better accuracy in the modeling (error in photon counts was -1.1 %) compared to a previously proposed method (errors were more than 20 %); the quantitative accuracy of activity estimates was excellent for all organs (errors were from -1.6 % to 11.9 %) and comparable to previously published results for (131)I using the same collimator. CONCLUSIONS The proposed (90)Y bremsstrahlung SPECT reconstruction method provided very accurate estimates of organ activities, with accuracies approaching those previously observed for (131)I. The method may be useful in verifying organ doses for targeted radionuclide therapy using (90)Y.
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Affiliation(s)
- Xing Rong
- Department of Radiology, Johns Hopkins University, Baltimore, MD 21287-0859, USA.
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Rong X, Du Y, Frey EC. A method for energy window optimization for quantitative tasks that includes the effects of model-mismatch on bias: application to Y-90 bremsstrahlung SPECT imaging. Phys Med Biol 2012; 57:3711-25. [PMID: 22617760 DOI: 10.1088/0031-9155/57/12/3711] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Quantitative Yttrium-90 ((90)Y) bremsstrahlung single photon emission computed tomography (SPECT) imaging has shown great potential to provide reliable estimates of (90)Y activity distribution for targeted radionuclide therapy dosimetry applications. One factor that potentially affects the reliability of the activity estimates is the choice of the acquisition energy window. In contrast to imaging conventional gamma photon emitters where the acquisition energy windows are usually placed around photopeaks, there has been great variation in the choice of the acquisition energy window for (90)Y imaging due to the continuous and broad energy distribution of the bremsstrahlung photons. In quantitative imaging of conventional gamma photon emitters, previous methods for optimizing the acquisition energy window assumed unbiased estimators and used the variance in the estimates as a figure of merit (FOM). However, for situations, such as (90)Y imaging, where there are errors in the modeling of the image formation process used in the reconstruction there will be bias in the activity estimates. In (90)Y bremsstrahlung imaging this will be especially important due to the high levels of scatter, multiple scatter, and collimator septal penetration and scatter. Thus variance will not be a complete measure of reliability of the estimates and thus is not a complete FOM. To address this, we first aimed to develop a new method to optimize the energy window that accounts for both the bias due to model-mismatch and the variance of the activity estimates. We applied this method to optimize the acquisition energy window for quantitative (90)Y bremsstrahlung SPECT imaging in microsphere brachytherapy. Since absorbed dose is defined as the absorbed energy from the radiation per unit mass of tissues in this new method we proposed a mass-weighted root mean squared error of the volume of interest (VOI) activity estimates as the FOM. To calculate this FOM, two analytical expressions were derived for calculating the bias due to model-mismatch and the variance of the VOI activity estimates, respectively. To obtain the optimal acquisition energy window for general situations of interest in clinical (90)Y microsphere imaging, we generated phantoms with multiple tumors of various sizes and various tumor-to-normal activity concentration ratios using a digital phantom that realistically simulates human anatomy, simulated (90)Y microsphere imaging with a clinical SPECT system and typical imaging parameters using a previously validated Monte Carlo simulation code, and used a previously proposed method for modeling the image degrading effects in quantitative SPECT reconstruction. The obtained optimal acquisition energy window was 100-160 keV. The values of the proposed FOM were much larger than the FOM taking into account only the variance of the activity estimates, thus demonstrating in our experiment that the bias of the activity estimates due to model-mismatch was a more important factor than the variance in terms of limiting the reliability of activity estimates.
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Affiliation(s)
- Xing Rong
- Division of Medical Imaging Physics, Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.
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