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Jundi AF, Naqiyyun MD, Patrianesha BB, Mu’minah IAS, Riana A, Hardiansyah D. Uncertainty Analysis of Time-Integrated Activity Coefficient in Single-Time-Point Dosimetry Using Bayesian Fitting Method. Nucl Med Mol Imaging 2024; 58:120-128. [PMID: 38633290 PMCID: PMC11018592 DOI: 10.1007/s13139-024-00851-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 12/12/2023] [Accepted: 02/06/2024] [Indexed: 04/19/2024] Open
Abstract
Purpose Calculation of the uncertainty of the individual time-integrated activity coefficient (TIACs) is desirable in molecular radiotherapy. However, the calculation of TIAC's uncertainty in single-time-point (STP) method has never been reported in the literature. This study presents a method based on the Bayesian fitting (BF) to calculate the standard deviation (SD) of individual TIACs in the STP dosimetry. Methods Biokinetic data of 177Lu-DOTATATE in kidneys were obtained from PMID33443063. BF methods with extended objective function, which optimize the fitting using prior knowledge of the function's parameters, were used. Reference TIACs (rTIACs) were calculated by fitting a mono-exponential function to the all-time-point data. The goodness of fit was checked based on the visual inspection and the coefficient of variations (CV) of the fitted parameters < 0.5. BF with relative (BFr) and absolute-based (BFa) variance methods were used to obtain the calculated TIACs (cTIACs) from the STP dosimetry. Performance of the STP method was obtained by calculating the relative deviation (RD) between cTIACs and rTIACs. Results Visual inspection showed a good fit for all patients with CV of fitted parameters less than 50%. The mean ± SD of cTIAC's %RD were 7.0 ± 25.2 for BFr and 2.6 ± 8.9 for BFa. The range of %CV of the individual cTIAC's SD for BFr and BFa methods was 36-78% and 22-33%, respectively, while the %CV of the rTIAC SD was 0.8-49%. Conclusion We introduce the BF method to calculate the SD of individual TIACs in STP dosimetry. The presented method might be used as an alternative method for uncertainty analysis in STP dosimetry. Supplementary Information The online version contains supplementary material available at 10.1007/s13139-024-00851-8.
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Affiliation(s)
- Achmad Faturrahman Jundi
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424 Indonesia
- Research Center for Safety, Metrology, and Nuclear Quality Technology, National Research and Innovation Agency, KST B. J. Habibie, South Tangerang, 15314 Indonesia
| | - M. Dlorifun Naqiyyun
- Nuclear Medicine Department, MRCCC Siloam Hospital, South Jakarta, 12930 Indonesia
| | - Bisma Barron Patrianesha
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424 Indonesia
- Directorate of Nuclear Facility Management, National Research and Innovation Agency, KST B. J. Habibie, South Tangerang, 15314 Indonesia
| | - Intan A. S. Mu’minah
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424 Indonesia
| | - Ade Riana
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424 Indonesia
| | - Deni Hardiansyah
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424 Indonesia
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Rinscheid A, Gäble A, Wienand G, Dierks A, Kircher M, Günther T, Patt M, Bundschuh RA, Lapa C, Pfob CH. Biodistribution and radiation dosimetry of [ 99mTc]Tc-N4-BTG in patients with biochemical recurrence of prostate cancer. EJNMMI Res 2024; 14:42. [PMID: 38668903 PMCID: PMC11052738 DOI: 10.1186/s13550-024-01105-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 04/15/2024] [Indexed: 04/29/2024] Open
Abstract
BACKGROUND In patients with prostate cancer (PCa), imaging with gastrin-releasing peptide receptor (GRPR) ligands is an alternative to PSMA-targeted tracers, particularly if PSMA expression is low or absent. [99mTc]Tc-N4-BTG is a newly developed GRPR-directed probe for conventional scintigraphy and single photon emission computed tomography (SPECT) imaging. The current study aims to investigate the safety, biodistribution and dosimetry of [99mTc]Tc-N4-BTG in patients with biochemical recurrence (BCR) of PCa. RESULTS No adverse pharmacologic effects were observed. Injection of [99mTc]Tc-N4-BTG resulted in an effective dose of 0.0027 ± 0.0002 mSv/MBq. The urinary bladder was the critical organ with the highest mean absorbed dose of 0.028 ± 0.001 mGy/MBq, followed by the pancreas with 0.0043 ± 0.0015 mGy/MBq, osteogenic cells with 0.0039 ± 0.0005 mGy/MBq, the kidneys with 0.0034 ± 0.0003 mGy/MBq, and the liver with 0.0019 ± 0.0004 mGy/MBq, respectively. No focal tracer uptake suggestive of PCa recurrence could be revealed for any of the patients. CONCLUSION [99mTc]Tc-N4-BTG appears to be a safe diagnostic agent. Compared to GRPR-targeted PET tracers, this 99mTc-labelled SPECT agent could contribute to a broader application and better availability of this novel approach. Further research to assess its clinical value is warranted.
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Affiliation(s)
- Andreas Rinscheid
- Medical Physics and Radiation Protection, University Hospital Augsburg, Augsburg, Germany
| | - Alexander Gäble
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Georgine Wienand
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Alexander Dierks
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Malte Kircher
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Thomas Günther
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - Marianne Patt
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
- Bavarian Cancer Research Center (BZKF), Erlangen, Bavaria, Germany
| | - Ralph A Bundschuh
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
- Bavarian Cancer Research Center (BZKF), Erlangen, Bavaria, Germany
| | - Constantin Lapa
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany.
- Bavarian Cancer Research Center (BZKF), Erlangen, Bavaria, Germany.
| | - Christian H Pfob
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
- Bavarian Cancer Research Center (BZKF), Erlangen, Bavaria, Germany
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Stokke C, Gnesin S, Tran-Gia J, Cicone F, Holm S, Cremonesi M, Blakkisrud J, Wendler T, Gillings N, Herrmann K, Mottaghy FM, Gear J. EANM guidance document: dosimetry for first-in-human studies and early phase clinical trials. Eur J Nucl Med Mol Imaging 2024; 51:1268-1286. [PMID: 38366197 PMCID: PMC10957710 DOI: 10.1007/s00259-024-06640-x] [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: 11/29/2023] [Accepted: 02/04/2024] [Indexed: 02/18/2024]
Abstract
The numbers of diagnostic and therapeutic nuclear medicine agents under investigation are rapidly increasing. Both novel emitters and novel carrier molecules require careful selection of measurement procedures. This document provides guidance relevant to dosimetry for first-in human and early phase clinical trials of such novel agents. The guideline includes a short introduction to different emitters and carrier molecules, followed by recommendations on the methods for activity measurement, pharmacokinetic analyses, as well as absorbed dose calculations and uncertainty analyses. The optimal use of preclinical information and studies involving diagnostic analogues is discussed. Good practice reporting is emphasised, and relevant dosimetry parameters and method descriptions to be included are listed. Three examples of first-in-human dosimetry studies, both for diagnostic tracers and radionuclide therapies, are given.
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Affiliation(s)
- Caroline Stokke
- Department of Diagnostic Physics and Computational Radiology, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
- Department of Physics, University of Oslo, Oslo, Norway.
| | - Silvano Gnesin
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Johannes Tran-Gia
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Francesco Cicone
- Nuclear Medicine Unit, Department of Experimental and Clinical Medicine, "Magna Graecia" University of Catanzaro, Catanzaro, Italy
| | - Søren Holm
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Marta Cremonesi
- Department of Medical Imaging and Radiation Sciences, European Institute of Oncology, IRCCS, Milan, Italy
| | - Johan Blakkisrud
- Department of Diagnostic Physics and Computational Radiology, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Thomas Wendler
- Computer-Aided Medical Procedures and Augmented Reality, Technische Universität München, Munich, Germany
- Clinical Computational Medical Imaging Research, Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany
| | - Nic Gillings
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Ken Herrmann
- Department of Nuclear Medicine, University of Duisburg-Essen, and German Cancer Consortium (DKTK)-University Hospital Essen, Essen, Germany
- National Center for Tumor Diseases (NCT), NCT West, Heidelberg, Germany
| | - Felix M Mottaghy
- Department of Radiology and Nuclear Medicine, GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands
- Department of Nuclear Medicine, University Hospital RWTH Aachen, Aachen, Germany
| | - Jonathan Gear
- Joint Department of Physics, Royal Marsden NHSFT & Institute of Cancer Research, Sutton, UK
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Hardiansyah D, Yousefzadeh-Nowshahr E, Kind F, Beer AJ, Ruf J, Glatting G, Mix M. Single-Time-Point Renal Dosimetry Using Nonlinear Mixed-Effects Modeling and Population-Based Model Selection in [ 177Lu]Lu-PSMA-617 Therapy. J Nucl Med 2024; 65:566-572. [PMID: 38423787 DOI: 10.2967/jnumed.123.266268] [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: 07/05/2023] [Revised: 01/23/2024] [Indexed: 03/02/2024] Open
Abstract
The aim of this study was to investigate the accuracy of single-time-point (STP) renal dosimetry imaging using SPECT/CT data, a nonlinear mixed-effects (NLME) model, and a population-based model selection (PBMS) in a large population for 177Lu-labeled prostate-specific membrane antigen therapy. Methods: Biokinetic data (mean ± SD) of [177Lu]Lu-PSMA-617 in kidneys at time points 1 (1.8 ± 0.8 h), 2 (18.7 ± 0.9 h), 3 (42.6 ± 1.0 h), 4 (66.3 ± 0.9 h), and 5 (160.3 ± 24.2 h) after injection were obtained from 63 patients with metastatic castration-resistant prostate cancer using SPECT/CT. Thirteen functions were derived from various parameterizations of 1- to 5-exponential functions. The function's parameters were fitted in the NLME framework to the all-time-point (ATP) data. The PBMS NLME method was performed using the goodness-of-fit test and Akaike weight to select the best function fitting the data. The best function from ATP fitting was used to calculate the reference time-integrated activity and absorbed doses. In STP dosimetry, the parameters of a particular patient with STP data were fitted simultaneously to the STP data at different time points of that patient with ATP data of all other patients. The parameters from STP fitting were used to calculate the STP time-integrated activity and absorbed doses. Relative deviations (RDs) and root-mean-square errors (RMSEs) were used to analyze the accuracy of the calculated STP absorbed dose compared with the reference absorbed dose obtained from the best-fit ATP function. The performance of STP dosimetry using PBMS NLME modeling was compared with the Hänscheid and Madsen methods. Results: The function [Formula: see text] was selected as the best-fit ATP function, with an Akaike weight of 100%. For STP dosimetry, the STP measurement by SPECT/CT at time point 3 (42.6 ± 1.0 h) showed a relatively low mean RD of -4.4% ± 9.4% and median RD of -0.7%. Time point 3 had the lowest RMSE value compared with those at the other 4 time points. The RMSEs of the absorbed dose RDs for time points 1-5 were 23%, 16%, 10%, 20%, and 53%, respectively. The STP dosimetry using the PBMS NLME method outperformed the Hänscheid and Madsen methods for all investigated time points. Conclusion: Our results show that a single measurement of SPECT/CT at 2 d after injection might be used to calculate accurate kidney-absorbed doses using the NLME method and PBMS.
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Affiliation(s)
- Deni Hardiansyah
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia;
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Elham Yousefzadeh-Nowshahr
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Felix Kind
- Department of Nuclear Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; and
| | - Ambros J Beer
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Juri Ruf
- Department of Nuclear Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; and
| | - Gerhard Glatting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Michael Mix
- Department of Nuclear Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; and
- Nuclear Medicine Division, Department of Medical Imaging and Clinical Oncology, Faculty of Medicine and Health Science, Stellenbosch University, Cape Town, South Africa
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Vasić V, Gustafsson J, Nowshahr EY, Stenvall A, Beer AJ, Gleisner KS, Glatting G. A PBPK model for PRRT with [ 177Lu]Lu-DOTA-TATE: Comparison of model implementations in SAAM II and MATLAB/SimBiology. Phys Med 2024; 119:103299. [PMID: 38367588 DOI: 10.1016/j.ejmp.2024.103299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/06/2023] [Accepted: 01/23/2024] [Indexed: 02/19/2024] Open
Abstract
Physiologically based pharmacokinetic (PBPK) models offer the ability to simulate and predict the biodistribution of radiopharmaceuticals and have the potential to enable individualised treatment planning in molecular radiotherapy. The objective of this study was to develop and implement a whole-body compartmental PBPK model for peptide receptor radionuclide therapy (PRRT) with [177Lu]Lu-DOTA-TATE in SimBiology to allow for more complex analyses. The correctness of the model implementation was ensured by comparing its outputs, such as the time-integrated activity (TIA), with those of a PBPK model implemented in SAAM II software. METHODS A combined PBPK model for [68Ga]Ga-DOTA-TATE and [177Lu]Lu-DOTA-TATE was developed and implemented in both SAAM II and SimBiology. A retrospective analysis of 12 patients with metastatic neuroendocrine tumours (NETs) was conducted. First, time-activity curves (TACs) and TIAs from the two software were calculated and compared for identical parameter values. Second, pharmacokinetic parameters were fitted to activity concentrations, analysed and compared. RESULTS The PBPK model implemented in SimBiology produced TIA results comparable to those generated by the model implemented in SAAM II, with a relative deviation of less than 0.5% when using the same input parameters. The relative deviation of the fitted TIAs was less than 5% when model parameter values were fitted to the measured activity concentrations. CONCLUSION The proposed PBPK model implemented in SimBiology can be used for dosimetry in radioligand therapy and TIA prediction. Its outputs are similar to those generated by the PBPK model implemented in SAAM II, confirming the correctness of the model implementation in SimBiology.
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Affiliation(s)
- Valentina Vasić
- Department of Nuclear Medicine, Ulm University, Ulm, Germany; Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany.
| | | | - Elham Yousefzadeh Nowshahr
- Department of Nuclear Medicine, Ulm University, Ulm, Germany; Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Anna Stenvall
- Medical Radiation Physics, Lund University, Lund, Sweden
| | - Ambros J Beer
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | | | - Gerhard Glatting
- Department of Nuclear Medicine, Ulm University, Ulm, Germany; Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
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Ciucci D, Cassano B, Donatiello S, Martire F, Napolitano A, Polito C, Solfaroli Camillocci E, Cervino G, Pungitore L, Altini C, Villani MF, Pizzoferro M, Garganese MC, Cannatà V. Fit of biokinetic data in molecular radiotherapy: a machine learning approach. EJNMMI Phys 2024; 11:19. [PMID: 38383799 PMCID: PMC10881934 DOI: 10.1186/s40658-024-00623-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 02/15/2024] [Indexed: 02/23/2024] Open
Abstract
BACKGROUND In literature are reported different analytical methods (AM) to choose the proper fit model and to fit data of the time-activity curve (TAC). On the other hand, Machine Learning algorithms (ML) are increasingly used for both classification and regression tasks. The aim of this work was to investigate the possibility of employing ML both to classify the most appropriate fit model and to predict the area under the curve (τ). METHODS Two different ML systems have been developed for classifying the fit model and to predict the biokinetic parameters. The two systems were trained and tested with synthetic TACs simulating a whole-body Fraction Injected Activity for patients affected by metastatic Differentiated Thyroid Carcinoma, administered with [131I]I-NaI. Test performances, defined as classification accuracy (CA) and percentage difference between the actual and the estimated area under the curve (Δτ), were compared with those obtained using AM varying the number of points (N) of the TACs. A comparison between AM and ML were performed using data of 20 real patients. RESULTS As N varies, CA remains constant for ML (about 98%), while it improves for F-test (from 62 to 92%) and AICc (from 50 to 92%), as N increases. With AM, [Formula: see text] can reach down to - 67%, while using ML [Formula: see text] ranges within ± 25%. Using real TACs, there is a good agreement between τ obtained with ML system and AM. CONCLUSIONS The employing of ML systems may be feasible, having both a better classification and a better estimation of biokinetic parameters.
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Affiliation(s)
- Davide Ciucci
- Medical Physics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Bartolomeo Cassano
- Medical Physics Department, IRCCS Regina Elena National Cancer Institute, Rome, Italy.
| | | | - Federica Martire
- Tor Vergata Postgraduate School of Medical Physics, University of Rome, Rome, Italy
| | - Antonio Napolitano
- Medical Physics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Claudia Polito
- Medical Physics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | | | | | - Claudio Altini
- Nuclear Medicine Unit/Imaging Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Maria Felicia Villani
- Nuclear Medicine Unit/Imaging Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Milena Pizzoferro
- Nuclear Medicine Unit/Imaging Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Maria Carmen Garganese
- Nuclear Medicine Unit/Imaging Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Vittorio Cannatà
- Medical Physics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
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Carter LM, Zanzonico PB. MIB Guides: Preclinical Radiopharmaceutical Dosimetry. Mol Imaging Biol 2024; 26:17-28. [PMID: 37964036 DOI: 10.1007/s11307-023-01868-9] [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: 08/03/2023] [Revised: 09/26/2023] [Accepted: 10/20/2023] [Indexed: 11/16/2023]
Abstract
Preclinical dosimetry is essential for guiding the design of animal radiopharmaceutical biodistribution, imaging, and therapy experiments, evaluating efficacy and/or toxicities in such experiments, ensuring compliance with ethical standards for animal research, and, perhaps most importantly, providing reasonable initial estimates of normal-organ doses in humans, required for clinical translation of new radiopharmaceuticals. This MIB Guide provides a basic protocol for obtaining preclinical dosimetry estimates with organ-level dosimetry software.
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Affiliation(s)
- Lukas M Carter
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
| | - Pat B Zanzonico
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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Brosch-Lenz JF, Delker A, Schmidt F, Tran-Gia J. On the Use of Artificial Intelligence for Dosimetry of Radiopharmaceutical Therapies. Nuklearmedizin 2023; 62:379-388. [PMID: 37827503 DOI: 10.1055/a-2179-6872] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
Routine clinical dosimetry along with radiopharmaceutical therapies is key for future treatment personalization. However, dosimetry is considered complex and time-consuming with various challenges amongst the required steps within the dosimetry workflow. The general workflow for image-based dosimetry consists of quantitative imaging, the segmentation of organs and tumors, fitting of the time-activity-curves, and the conversion to absorbed dose. This work reviews the potential and advantages of the use of artificial intelligence to improve speed and accuracy of every single step of the dosimetry workflow.
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Affiliation(s)
| | - Astrid Delker
- Department of Nuclear Medicine, LMU University Hospital, Munich, Germany
| | - Fabian Schmidt
- Department of Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, Tuebingen, Germany
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Tuebingen, Germany
| | - Johannes Tran-Gia
- Department of Nuclear Medicine, University Hospital Wuerzburg, Wuerzburg, Germany
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Konrad M, Rinscheid A, Wienand G, Nittbaur B, Wester HJ, Janzen T, Lapa C, Pfob CH, Schottelius M. [ 99mTc]Tc-PentixaTec: development, extensive pre-clinical evaluation, and first human experience. Eur J Nucl Med Mol Imaging 2023; 50:3937-3948. [PMID: 37597009 PMCID: PMC10611619 DOI: 10.1007/s00259-023-06395-x] [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: 06/02/2023] [Accepted: 08/05/2023] [Indexed: 08/21/2023]
Abstract
PURPOSE The clinical success non-invasive imaging of CXCR4 expression using [68 Ga]Ga-PentixaFor-PET warrants an expansion of the targeting concept towards conventional scintigraphy/SPECT with their lower cost and general availability. To this aim, we developed and comparatively evaluated a series of 99mTc-labeled cyclic pentapeptides based on the PentixaFor scaffold. METHODS Six mas3-conjugated CPCR4 analogs with different 4-aminobenzoic acid (Abz)-D-Ala-D-Arg-aa3 linkers (L1-L6) as well as the corresponding HYNIC- and N4-analogs of L6-CPCR4 were synthesized via standard SPPS. Competitive binding studies (IC50 and IC50inv) were carried out using Jurkat T cell lymphoma cells and [125I]FC-131 as radioligand. Internalization kinetics were investigated using hCXCR4-overexpressing Chem-1 cells. Biodistribution studies and small animal SPECT/CT imaging (1 h p.i.) were carried out using Jurkat xenograft bearing CB17/SCID mice. Based on the preclinical results, [99mTc]Tc-N4-L6-CPCR4 ([99mTc]Tc-PentixaTec) was selected for an early translation to the human setting. Five patients with hematologic malignancies underwent [99mTc]Tc-N4-L6-CPCR4 SPECT/planar imaging with individual dosimetry. RESULTS Of the six mas3-conjugated peptides, mas3-L6-CPCR4 (mas3-dap-r-a-Abz-CPCR4) showed the highest CXCR4 affinity (IC50 = 5.0 ± 1.3 nM). Conjugation with N4 (N4-L6-CPCR4) further improved hCXCR4 affinity to 0.6 ± 0.1 nM. [99mTc]Tc-N4-L6-CPCR4 also showed the most efficient internalization (97% of total cellular activity at 2 h) and the highest tumor accumulation (8.6 ± 1.3% iD/g, 1 h p.i.) of the compounds investigated. Therefore, [99mTc]Tc-N4-L6-CPCR4 (termed [99mTc]Tc-PentixaTec) was selected for first-in-human application. [99mTc]Tc-PentixaTec was well tolerated, exhibits a favorable biodistribution and dosimetry profile (2.1-3.4 mSv per 500 MBq) and excellent tumor/background ratios in SPECT and planar imaging. CONCLUSION The successive optimization of the amino acid composition of the linker structure and the N-terminal 99mTc-labeling strategies (mas3 vs HYNIC vs N4) has provided [99mTc]Tc-PentixaTec as a novel, highly promising CXCR4-targeted SPECT agent for clinical application. With its excellent CXCR4 affinity, efficient internalization, high uptake in CXCR4-expressing tissues, suitable clearance/biodistribution characteristics, and favorable human dosimetry, it holds great potential for further clinical use.
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Affiliation(s)
- Matthias Konrad
- Chair for Pharmaceutical Radiochemistry, Faculties of Chemistry and Medicine, Technische Universität München, 85748, Garching, Germany
| | - Andreas Rinscheid
- Medical Physics and Radiation Protection, University Hospital Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany
| | - Georgine Wienand
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany
| | - Bernd Nittbaur
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany
| | - Hans-Jürgen Wester
- Chair for Pharmaceutical Radiochemistry, Faculties of Chemistry and Medicine, Technische Universität München, 85748, Garching, Germany
| | - Tilman Janzen
- Medical Physics and Radiation Protection, University Hospital Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany
| | - Constantin Lapa
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany
| | - Christian Helmut Pfob
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany.
| | - Margret Schottelius
- Translational Radiopharmaceutical Sciences, Department of Nuclear Medicine and Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Rue du Bugnon 25A, Agora, CH-1011, Lausanne, Switzerland.
- AGORA, Pôle de Recherche Sur Le Cancer, 1011, Lausanne, Switzerland.
- SCCL Swiss Cancer Center Leman, 1011, Lausanne, Switzerland.
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Meyer C, Stuparu A, Lueckerath K, Calais J, Czernin J, Slavik R, Dahlbom M. Tandem Isotope Therapy with 225Ac- and 177Lu-PSMA-617 in a Murine Model of Prostate Cancer. J Nucl Med 2023; 64:1772-1778. [PMID: 37797974 PMCID: PMC10626377 DOI: 10.2967/jnumed.123.265433] [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: 01/13/2023] [Revised: 06/17/2023] [Indexed: 10/07/2023] Open
Abstract
Radionuclide therapy targeting prostate-specific membrane antigen (PSMA) is a promising option for metastatic castration-resistant prostate cancer. Clinical experience using 177Lu or 225Ac has demonstrated encouraging treatment responses; however, responses are not durable. Dual-isotope combinations, or "tandem" approaches, may improve tolerability while retaining a high tumor dose. In this study, we directly compared α- versus β-particle treatment, as well as a combination thereof, at different stages of disease in a murine model of disseminated prostate cancer. Methods: First, to determine comparable injected activities from 177Lu- and 225Ac-PSMA-617, ex vivo biodistribution studies were performed at 5 time points after treatment of C4-2 subcutaneous tumor-bearing NSG mice. To establish a more representative model of metastatic prostate cancer, NSG mice were inoculated with luciferase-expressing C4-2 cells in the left ventricle, leading to disseminated visceral and bone lesions. At either 3 or 5 wk after inoculation, the mice were treated with equivalent tumor dose-depositing activities of 177Lu- or 225Ac-PSMA-617 alone or in combination (35 MBq of 177Lu, 40 kBq of 225Ac, or 17 MBq of 177Lu + 20 kBq 225Ac; 10/group). Disease burden was assessed by weekly bioluminescence imaging. Treatment efficacy was evaluated using whole-body tumor burden and overall survival. Results: The ex vivo biodistribution studies revealed that 35 MBq of 177Lu and 40 kBq of 225Ac yield equivalent absorbed tumor doses in a subcutaneous C4-2 model. The disease burden of mice treated at 3 wk after inoculation (microscopic disease) with 177Lu was not significantly different from that of untreated mice. However, 225Ac-PSMA-617 both as a single agent and in combination with 177Lu (17 MBq of 177Lu + 20 kBq of 225Ac) were associated with significant whole-body tumor growth retardation and survival benefit (overall survival, 8.3 wk for nontreatment, 9.4 wk for 177Lu, 15.3 wk for 225Ac alone, and 14.1 wk for tandem therapy). When treated at 5 wk after inoculation (macroscopic disease), all treatment groups showed retarded tumor growth and improved survival, with no significant differences between 225Ac alone and administration of half the 225Ac activity in tandem with 177Lu (overall survival, 7.9 wk for nontreatment, 10.3 wk for 177Lu, 14.6 wk for 225Ac alone, and 13.2 wk for tandem therapy). Conclusion: Treatment of a disseminated model of prostate cancer with simultaneous 225Ac- and 177Lu-PSMA-617 results in significantly decreased tumor growth compared with 177Lu, which was ineffective as a single agent against microscopic lesions. Mice treated later in the disease progression and bearing macroscopic, millimeter-sized lesions experienced significant tumor growth retardation and survival benefit in both monoisotopic and tandem regimens of 177Lu and 225Ac. Although the greatest benefits were observed with the single agent 225Ac, the tandem arm experienced no significant difference in disease burden or survival benefit, suggesting that the reduced activity of 225Ac was adequately compensated in the tandem arm. The superior therapeutic efficacy of 225Ac in this model suggests a preference for α-emitters alone, or possibly in combination, in the microscopic disease setting.
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Affiliation(s)
- Catherine Meyer
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California; and
| | - Andreea Stuparu
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California; and
| | - Katharina Lueckerath
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California; and
- Clinic for Nuclear Medicine, University Hospital Essen, Essen, Germany
| | - Jeremie Calais
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California; and
| | - Johannes Czernin
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California; and
| | - Roger Slavik
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California; and
| | - Magnus Dahlbom
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California; and
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11
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Carter LM, Zanzonico PB. MIB Guides: Preclinical radiopharmaceutical dosimetry. RESEARCH SQUARE 2023:rs.3.rs-3225362. [PMID: 37645915 PMCID: PMC10462246 DOI: 10.21203/rs.3.rs-3225362/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Preclinical dosimetry is essential for guiding the design of animal radiopharmaceutical biodistribution, imaging, and therapy experiments, evaluating efficacy and/or toxicities in such experiments, ensuring compliance with ethical standards for animal research, and providing reasonable initial estimates of normal-organ doses in humans, required for clinical translation of new radiopharmaceuticals. This MIB guide provides a basic protocol for obtaining preclinical dosimetry estimates with organ-level dosimetry software.
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Affiliation(s)
- Lukas M Carter
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Pat B Zanzonico
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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12
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Li J, Ni B, Yu X, Wang C, Li L, Zhou Y, Gu Y, Huang G, Hou J, Liu J, Chen Y. Metabolic kinetic modeling of [ 11C]methionine based on total-body PET in multiple myeloma. Eur J Nucl Med Mol Imaging 2023; 50:2683-2691. [PMID: 37039900 DOI: 10.1007/s00259-023-06219-y] [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: 08/09/2022] [Accepted: 04/02/2023] [Indexed: 04/12/2023]
Abstract
PURPOSE Multiple myeloma (MM) is a malignant disease characterized by the secretion of monoclonal immunoglobulins and has a high demand for amino acids. [11C]methionine total-body PET is capable of noninvasive dynamic monitoring of radiotracer in vivo, thus providing a way to reveal the dynamic changes of myeloma metabolism. This study aims to analyze the metabolic process of [11C]methionine based on kinetic modeling, and to preliminary reveal its application value in MM. METHODS Dynamic total-body [11C]methionine PET/CT was conducted with uEXPLORER in 12 subjects (9 MM patients and 3 controls). The tissue time activity curves (TACs) of organs and bone marrows were extracted. Model fitting of TACs was operated using PMOD Kinetic Modeling. After validation by Goodness of fit (GOF), the reversible two-tissue compartment model (2T4k) was used to further analysis. R software was used to analyze the correlation between kinetic parameters and clinical indicators. RESULTS The 2T4k has passed the criterion of GOF and was used to fit the data of 0-20 minutes. The [11C]methionine net uptake rate (Ki) was significantly higher in the MM lesions than in the non-myeloma controls (control: 0.040±0.007 mL/g/min, MM: 0.171±0.108 mL/g/min, p=0.009). The Ki values were found to be correlated with M protein levels in MM patients. MM patients with t(4;14) translocations had an elevated k4 value compared with t(4;14) negative patients. CONCLUSION MM lesions have a propensity for uptake of [11C]methionine. The serum levels of M protein are correlated with [11C]methionine uptake rate in myeloma. Metabolic classification based on the k4 value may be a promising strategy for risk stratification in MM.
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Affiliation(s)
- Jiajin Li
- Department of Nuclear Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Beiwen Ni
- Department of Hematology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Xiaofeng Yu
- Department of Nuclear Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Cheng Wang
- Department of Nuclear Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Lianghua Li
- Department of Nuclear Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Yun Zhou
- Central Research Institute, United Imaging Healthcare Group Co., Ltd, Shanghai, 200032, China
| | - Yue Gu
- Central Research Institute, United Imaging Healthcare Group Co., Ltd, Shanghai, 200032, China
| | - Gang Huang
- Department of Nuclear Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
- Shanghai Key Laboratory of Molecular Imaging, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, China
| | - Jian Hou
- Department of Hematology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
| | - Jianjun Liu
- Department of Nuclear Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
| | - Yumei Chen
- Department of Nuclear Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
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13
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Hardiansyah D, Riana A, Eiber M, Beer AJ, Glatting G. Population-based model selection for an accurate estimation of time-integrated activity using non-linear mixed-effects modelling. Z Med Phys 2023:S0939-3889(23)00007-7. [PMID: 36813594 DOI: 10.1016/j.zemedi.2023.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 12/23/2022] [Accepted: 01/13/2023] [Indexed: 02/22/2023]
Abstract
PURPOSE Personalized treatment planning in Molecular Radiotherapy (MRT) with accurately determining the absorbed dose is highly desirable. The absorbed dose is calculated based on the Time-Integrated Activity (TIA) and the dose conversion factor. A crucial unresolved issue in MRT dosimetry is which fit function to use for the TIA calculation. A data-driven population-based fitting function selection could help solve this problem. Therefore, this project aims to develop and evaluate a method for accurately determining TIAs in MRT, which performs a Population-Based Model Selection within the framework of the Non-Linear Mixed-Effects (NLME-PBMS) model. METHODS Biokinetic data of a radioligand for the Prostate-Specific Membrane Antigen (PSMA) for cancer treatment were used. Eleven fit functions were derived from various parameterisations of mono-, bi-, and tri-exponential functions. The functions' fixed and random effects parameters were fitted (in the NLME framework) to the biokinetic data of all patients. The goodness of fit was assumed acceptable based on the visual inspection of the fitted curves and the coefficients of variation of the fitted fixed effects. The Akaike weight, the probability that the model is the best among the whole set of considered models, was used to select the fit function most supported by the data from the set of functions with acceptable goodness of fit. NLME-PBMS Model Averaging (MA) was performed with all functions having acceptable goodness of fit. The Root-Mean-Square Error (RMSE) of the calculated TIAs from individual-based model selection (IBMS), a shared-parameter population-based model selection (SP-PBMS) reported in the literature, and the functions from NLME-PBMS method to the TIAs from MA were calculated and analysed. The NLME-PBMS (MA) model was used as the reference as this model considers all relevant functions with corresponding Akaike weights. RESULTS The function [Formula: see text] was selected as the function most supported by the data with an Akaike weight of (54 ± 11) %. Visual inspection of the fitted graphs and the RMSE values show that the NLME model selection method has a relatively better or equivalent performance than the IBMS or SP-PBMS methods. The RMSEs of the IBMS, SP-PBMS, and NLME-PBMS (f3a) methods are 7.4%, 8.8%, and 2.4%, respectively. CONCLUSION A procedure including fitting function selection in a population-based method was developed to determine the best fit function for calculating TIAs in MRT for a given radiopharmaceutical, organ and set of biokinetic data. The technique combines standard practice approaches in pharmacokinetics, i.e. an Akaike-weight-based model selection and the NLME model framework.
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Affiliation(s)
- Deni Hardiansyah
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia; Research Collaboration Center for Theranostic Radiopharmaceuticals, BRIN, Bandung, Indonesia.
| | - Ade Riana
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia
| | - Matthias Eiber
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, München, Germany
| | - Ambros J Beer
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Gerhard Glatting
- Department of Nuclear Medicine, Ulm University, Ulm, Germany; Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
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14
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Hardiansyah D, Riana A, Beer AJ, Glatting G. Single-time-point dosimetry using model selection and nonlinear mixed-effects modelling: a proof of concept. EJNMMI Phys 2023; 10:12. [PMID: 36759362 PMCID: PMC9911583 DOI: 10.1186/s40658-023-00530-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 02/01/2023] [Indexed: 02/11/2023] Open
Abstract
PURPOSE This project aims to develop and evaluate a method for accurately determining time-integrated activities (TIAs) in single-time-point (STP) dosimetry for molecular radiotherapy. It performs a model selection (MS) within the framework of the nonlinear mixed-effects (NLME) model (MS-NLME). METHODS Biokinetic data of [111In]In-DOTATATE activity in kidneys at T1 = (2.9 ± 0.6) h, T2 = (4.6 ± 0.4) h, T3 = (22.8 ± 1.6) h, T4 = (46.7 ± 1.7) h, and T5 = (70.9 ± 1.0) h post injection were obtained from eight patients using planar imaging. Eleven functions were derived from various parameterisations of mono-, bi-, and tri-exponential functions. The functions' fixed and random effects parameters were fitted simultaneously (in the NLME framework) to the biokinetic data of all patients. The Akaike weights were used to select the fit function most supported by the data. The relative deviations (RD) and the root-mean-square error (RMSE) of the calculated TIAs for the STP dosimetry at T3 = (22.8 ± 1.6) h and T4 = (46.7 ± 1.7) h p.i. were determined for all functions passing the goodness-of-fit test. RESULTS The function [Formula: see text] with four adjustable parameters and [Formula: see text] was selected as the function most supported by the data with an Akaike weight of (45 ± 6) %. RD and RMSE values show that the MS-NLME method performs better than functions with three or five adjustable parameters. The RMSEs of TIANLME-PBMS and TIA3-parameters were 7.8% and 10.9% (for STP at T3), and 4.9% and 10.7% (for STP at T4), respectively. CONCLUSION An MS-NLME method was developed to determine the best fit function for calculating TIAs in STP dosimetry for a given radiopharmaceutical, organ, and patient population. The proof of concept was demonstrated for biokinetic 111In-DOTATATE data, showing that four-parameter functions perform better than three- and five-parameter functions.
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Affiliation(s)
- Deni Hardiansyah
- grid.9581.50000000120191471Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia ,Research Collaboration Centre for Theranostic Radiopharmaceuticals, BRIN, Bandung, Indonesia
| | - Ade Riana
- grid.9581.50000000120191471Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia
| | - Ambros J. Beer
- grid.6582.90000 0004 1936 9748Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Gerhard Glatting
- Department of Nuclear Medicine, Ulm University, Ulm, Germany. .,Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Albert-Einstein-Allee 23, 89081, Ulm, Germany.
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15
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Resch S, Takayama Fouladgar S, Zacherl M, Sheikh GT, Liubchenko G, Rumiantcev M, Unterrainer LM, Wenter V, Bartenstein P, Ziegler SI, Ilhan H, Beyer L, Böning G, Delker A. Investigation of image-based lesion and kidney dosimetry protocols for 177Lu-PSMA-I&T therapy with and without a late SPECT/CT acquisition. EJNMMI Phys 2023; 10:11. [PMID: 36757516 PMCID: PMC9911578 DOI: 10.1186/s40658-023-00529-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 01/26/2023] [Indexed: 02/10/2023] Open
Abstract
BACKGROUND 177Lu-PSMA therapy has been successfully used to prolong the survival of patients with metastatic castration-resistant prostate cancer. Patient-specific dosimetry based on serial quantitative SPECT/CT imaging can support the understanding of dose-effect relationships. However, multiple SPECT/CT measurements can be challenging for patients, which motivates the investigation of efficient sampling schedules and their impact on dosimetry. In this study, different time samplings with respect to the number and timing of SPECT/CT acquisitions with and without a late measurement were investigated. MATERIALS AND METHODS In total, 43 lesions and 10 kidneys of 5 patients receiving 177Lu-PSMA-I&T therapy were investigated. Whole-body SPECT/CT measurements were performed at 1, 2, 3 and 7 days post-injection. For both lesions (isocontour-based segmentation) and kidneys (CT-based segmentation), a reference model was employed including all four time points. To identify the best-matching fit function out of a pre-defined set of models, visual inspection, coefficients of variation and sum of squared errors were considered as goodness-of-fit criteria. Biologically effective doses (BEDs) calculated with different time samplings (days 1, 2, 3/1, 2, 7/1, 3, 7/2, 3, 7 and 1, 2/1, 3/1, 7) were compared to the reference. RESULTS The best-fit function was found to be a mono-exponential model for lesions and a bi-exponential model with a population-based parameter and two free parameters for kidneys. The BEDs calculated with the time sampling 1, 3, 7 days showed the lowest deviations from the reference for lesions with 4 ± 5%. Without day 7, still 86% of all lesions showed deviations from the reference < 10%. The outlier deviations showed a positive correlation with the effective half-life of the respective lesions. For kidneys, including days 1, 2, 3 achieved the best results with 0 ± 1%. Generally, deviations for kidneys were found to be small for all time samplings (max. 13%). CONCLUSIONS For combined optimization of the SPECT/CT time sampling for kidney and lesion dosimetry during 177Lu-PSMA-I&T therapy, the sampling with days 1, 3, 7 showed the smallest deviation from the reference. Without a late acquisition, using the schedule with days 1, 2, 3 is likewise feasible.
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Affiliation(s)
- Sandra Resch
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany.
| | - Sarah Takayama Fouladgar
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Mathias Zacherl
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Gabriel T. Sheikh
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Grigory Liubchenko
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Mikhail Rumiantcev
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Lena M. Unterrainer
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Vera Wenter
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Peter Bartenstein
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Sibylle I. Ziegler
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Harun Ilhan
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Leonie Beyer
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Guido Böning
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Astrid Delker
- grid.5252.00000 0004 1936 973XDepartment of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
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16
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Hardiansyah D, Riana A, Beer AJ, Glatting G. Single-time-point estimation of absorbed doses in PRRT using a non-linear mixed-effects model. Z Med Phys 2023; 33:70-81. [PMID: 35961809 PMCID: PMC10082376 DOI: 10.1016/j.zemedi.2022.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/26/2022] [Accepted: 06/28/2022] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Estimation of accurate time-integrated activity coefficients (TIACs) and radiation absorbed doses (ADs) is desirable for treatment planning in peptide-receptor radionuclide therapy (PRRT). This study aimed to investigate the accuracy of a simplified dosimetry using a physiologically-based pharmacokinetic (PBPK) model, a nonlinear mixed effect (NLME) model, and single-time-point imaging to calculate the TIACs and ADs of 90Y-DOTATATE in various organs of dosimetric interest and tumors. MATERIALS & METHODS Biokinetic data of 111In-DOTATATE in tumors, kidneys, liver, spleen, and whole body were obtained from eight patients using planar scintigraphic imaging at T1 = (2.9 ± 0.6), T2 = (4.6 ± 0.4), T3 = (22.8 ± 1.6), T4 = (46.7 ± 1.7) and T5 = (70.9 ± 1.0) h post injection. Serum activity concentration was measured at 5 and 15 min; 0.5, 1, 2, and 4 h; and 1, 2, and 3 d p.i.. A published PBPK model for PRRT, NLME, and a single-time-point imaging datum at different time points were used to calculate TIACs in tumors, kidneys, liver, spleen, whole body, and serum. Relative deviations (RDs) (median [min, max]) between the calculated TIACs from single-time-point imaging were compared to the TIACs calculated from the all-time-points fit. The root mean square error (RMSE) of the difference between the computed ADs from the single-time-point imaging and reference ADs from the all-time point fittings were analyzed. A joint root mean square error RMSEjoint of the ADs was calculated with the RSME from both the tumor and kidneys to sort the time points concerning accurate results for the kidneys and tumor dosimetry. The calculations of TIACs and ADs from the single-time-point dosimetry were repeated using the sum of exponentials (SOE) approach introduced in the literature. The RDs and the RSME of the PBPK approach in our study were compared to the SOE approach. RESULTS Using the PBPK and NLME models and the biokinetic measurements resulted in a good fit based on visual inspection of the fitted curves and the coefficient of variation CV of the fitted parameters (<50%). T4 was identified being the time point with a relatively low median and range of TIACs RDs, i.e., 5 [1, 21]% and 2 [-15, 21]% for kidneys and tumors, respectively. T4 was found to be the time point with the lowest joint root mean square error RMSEjoint of the ADs. Based on the RD and RMSE, our results show a similar performance as the SOE and NLME model approach. SUMMARY In this study, we introduced a simplified calculation of TIACs/ADs using a PBPK model, an NLME model, and a single-time-point measurement. Our results suggest a single measurement might be used to calculate TIACs/ADs in the kidneys and tumors during PRRT.
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Affiliation(s)
- Deni Hardiansyah
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia
| | - Ade Riana
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia
| | - Ambros J Beer
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Gerhard Glatting
- Department of Nuclear Medicine, Ulm University, Ulm, Germany; Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany.
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SPECT/CT-based dosimetry of salivary glands and iodine-avid lesions following 131I therapy. HEALTH AND TECHNOLOGY 2023; 13:101-110. [PMID: 36628262 PMCID: PMC9817440 DOI: 10.1007/s12553-022-00718-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 12/19/2022] [Indexed: 01/07/2023]
Abstract
Objective The purpose was to provide uptake and radiation dose estimates to salivary glands (SG) and pathologic lesions following radioiodine therapy (RIT) of differentiated thyroid cancer patients (DTC). Methods A group of DTC patients (n = 25) undergoing 131I therapy joined this study with varying amounts of therapeutic activity. Sequential SPECT/CT scans were acquired at 4 ± 2, 24 ± 2, and 168 ± 3 h following administration of 3497-9250 MBq 131I. An earlier experiment with Acrylic glass body phantom (PET Phantom NEMA 2012 / IEC 2008) was conducted for system calibration including scatter, partial volume effect and count loss correction. Dose calculation was made via IDAC-Dose 2.1 code. Results The absorbed dose to parotid glands was 0.04-0.97 Gy/GBq (median: 0.26 Gy/GBq). The median absorbed dose to submandibular glands was 0.14 Gy/GBq (0.05 to 0.56 Gy/GBq). The absorbed dose to thyroid residues was from 0.55 to 399.5 Gy/GBq (median: 21.8 Gy/GBq), and that to distal lesions ranged from 0.78 to 28.0 Gy/GBq (median: 3.12 Gy/GBq). 41% of the thyroid residues received dose > 80 Gy, 18% between 70-80 Gy, 18% between 40-70 Gy, and 23% has dose < 40 Gy. In contrast, 18% of the metastases exhibited a dose > 80 Gy, 9% between 40-60 Gy, and the dose to the vast majority of lesions (64%) was < 40 Gy. Conclusion It was inferred that dose estimation after RIT with SPECT/CT is feasible to apply, together with good agreement with published 124I PET/CT dose estimates. A broad and sub-effective dose range was estimated for thyroid residues and distal lesions. Moreover, the current methodology might be useful for establishing a dose-effect relationship and radiation-induced salivary glands damage after RIT.
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Cassano B, Pizzoferro M, Valeri S, Polito C, Donatiello S, Altini C, Villani MF, Serra A, Castellano A, Garganese MC, Cannatà V. Personalized dosimetry for a deeper understanding of metastatic response to high activity 131I-mIBG therapy in high risk relapsed refractory neuroblastoma. Quant Imaging Med Surg 2022; 12:1299-1310. [PMID: 35111625 DOI: 10.21037/qims-21-548] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 09/06/2021] [Indexed: 12/19/2022]
Abstract
Background Dosimetry in molecular radiotherapy for personalized treatment is assuming a central role in clinical management of aggressive/relapsed tumors. Relapsed/refractory metastatic high-risk neuroblastoma (rrmHR-NBL) has a poor prognosis and high-activity 131I-mIBG therapy could represent a promising strategy. The primary aim of this case series study was to report the absorbed doses to whole-body (DWB ), red marrow (DRM ) and lesions (DLesion ). A secondary aim was to correlate DLesion values to clinical outcome. Methods Fourteen patients affected by rrmHR-NBL were treated with high-activity 131I-mIBG therapy (two administrations separated by 15 days). The first administration was weight-based whereas the second one was dosimetry-based (achieving DWB equals to 4 Gy). In all patients DWB and DRM was assessed; 9/14 patients were selected for DLesion evaluation using planar dosimetric approach (13 lesions evaluated). Treatment response was classified as progressive and stable disease (PD and SD), partial and complete response (PR and CR) according to the International Neuroblastoma Response Criteria. Patients were divided into two groups: Responder (CR, PR, SD) and Non-Responder (PD), correlating treatment response to DLesion value. Results The cumulative DWB , DRM and DLesion ranged from (1.5; 4.5), (1.0; 2.6) and (44.2; 585.8) Gy. A linear correlation between DWB and DRM and a power law correlation between the absorbed dose to WB normalized for administered activity and the mass of the patient were observed. After treatment 3, 2, 4 and 5 patients showed CR, PR, SD and PD respectively, showing a correlation between DLesion and the two response group. Conclusions Our experience demonstrated feasibility of high activity therapy of 131I-mIBG in rrmHR-NBL children as two administration intensive strategy. Dosimetric approach allowed a tailored high dose treatment maximizing the benefits of radionuclide therapy for pediatric patients while maintaining a safety profile. The assesment of DLesion contributed to have a deeper understaning of metabolic treatment effects.
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Affiliation(s)
- Bartolomeo Cassano
- Medical Physics Unit, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Milena Pizzoferro
- Nuclear Medicine Unit/Imaging Department, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Silvio Valeri
- Medical Physics Unit, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Claudia Polito
- Medical Physics Unit, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | | | - Claudio Altini
- Nuclear Medicine Unit/Imaging Department, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Maria Felicia Villani
- Nuclear Medicine Unit/Imaging Department, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Annalisa Serra
- Department of Pediatric Hematology and Oncology, IRCCS Ospedale Pediatrico Bambino Gesu, Rome, Italy
| | - Aurora Castellano
- Nuclear Medicine Unit/Imaging Department, IRCCS Bambino Gesù Children's Hospital, Rome, Italy.,Department of Pediatric Hematology and Oncology, IRCCS Ospedale Pediatrico Bambino Gesu, Rome, Italy
| | - Maria Carmen Garganese
- Nuclear Medicine Unit/Imaging Department, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Vittorio Cannatà
- Medical Physics Unit, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
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19
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Hardiansyah D, Riana A, Kletting P, Zaid NRR, Eiber M, Pawiro SA, Beer AJ, Glatting G. A population-based method to determine the time-integrated activity in molecular radiotherapy. EJNMMI Phys 2021; 8:82. [PMID: 34905131 PMCID: PMC8671591 DOI: 10.1186/s40658-021-00427-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 11/30/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The calculation of time-integrated activities (TIAs) for tumours and organs is required for dosimetry in molecular radiotherapy. The accuracy of the calculated TIAs is highly dependent on the chosen fit function. Selection of an adequate function is therefore of high importance. However, model (i.e. function) selection works more accurately when more biokinetic data are available than are usually obtained in a single patient. In this retrospective analysis, we therefore developed a method for population-based model selection that can be used for the determination of individual time-integrated activities (TIAs). The method is demonstrated at an example of [177Lu]Lu-PSMA-I&T kidneys biokinetics. It is based on population fitting and is specifically advantageous for cases with a low number of available biokinetic data per patient. METHODS Renal biokinetics of [177Lu]Lu-PSMA-I&T from thirteen patients with metastatic castration-resistant prostate cancer acquired by planar imaging were used. Twenty exponential functions were derived from various parameterizations of mono- and bi-exponential functions. The parameters of the functions were fitted (with different combinations of shared and individual parameters) to the biokinetic data of all patients. The goodness of fits were assumed as acceptable based on visual inspection of the fitted curves and coefficients of variation CVs < 50%. The Akaike weight (based on the corrected Akaike Information Criterion) was used to select the fit function most supported by the data from the set of functions with acceptable goodness of fit. RESULTS The function [Formula: see text] with shared parameter [Formula: see text] was selected as the function most supported by the data with an Akaike weight of 97%. Parameters [Formula: see text] and [Formula: see text] were fitted individually for every patient while parameter [Formula: see text] was fitted as a shared parameter in the population yielding a value of 0.9632 ± 0.0037. CONCLUSIONS The presented population-based model selection allows for a higher number of parameters of investigated fit functions which leads to better fits. It also reduces the uncertainty of the obtained Akaike weights and the selected best fit function based on them. The use of the population-determined shared parameter for future patients allows the fitting of more appropriate functions also for patients for whom only a low number of individual data are available.
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Affiliation(s)
- Deni Hardiansyah
- Medical Physics and Biophysics Division, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, 16424, Depok, Indonesia
| | - Ade Riana
- Medical Physics and Biophysics Division, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, 16424, Depok, Indonesia
| | - Peter Kletting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Albert-Einstein-Allee 23, 89081, Ulm, Germany.,Department of Nuclear Medicine, Ulm University, 89081, Ulm, Germany
| | - Nouran R R Zaid
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Albert-Einstein-Allee 23, 89081, Ulm, Germany
| | - Matthias Eiber
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, 81675, Munich, Germany
| | - Supriyanto A Pawiro
- Medical Physics and Biophysics Division, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, 16424, Depok, Indonesia
| | - Ambros J Beer
- Department of Nuclear Medicine, Ulm University, 89081, Ulm, Germany
| | - Gerhard Glatting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Albert-Einstein-Allee 23, 89081, Ulm, Germany. .,Department of Nuclear Medicine, Ulm University, 89081, Ulm, Germany.
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20
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Kennedy J, Chicheportiche A, Keidar Z. Quantitative SPECT/CT for dosimetry of peptide receptor radionuclide therapy. Semin Nucl Med 2021; 52:229-242. [PMID: 34911637 DOI: 10.1053/j.semnuclmed.2021.11.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Neuroendocrine tumors (NETs) are uncommon malignancies of increasing incidence and prevalence. As these slow growing tumors usually overexpress somatostatin receptors (SSTRs), the use of 68Ga-DOTA-peptides (gallium-68 chelated with dodecane tetra-acetic acid to somatostatin), which bind to the SSTRs, allows for PET based imaging and selection of patients for peptide receptor radionuclide therapy (PRRT). PRRT with radiolabeled somatostatin analogues such as 177Lu-DOTATATE (lutetium-177-[DOTA,Tyr3]-octreotate), is mainly used for the treatment of metastatic or inoperable NETs. However, PRRT is generally administered at a fixed injected activity in order not to exceed dose limits in critical organs, which is suboptimal given the variability in radiopharmaceutical uptake among patients. Advances in SPECT (single photon emission computed tomography) imaging enable the absolute quantitative measure of the true radiopharmaceutical distribution providing for PRRT dosimetry in each patient. Personalized PRRT based on patient-specific dosimetry could improve therapeutic efficacy by optimizing effective tumor absorbed dose while limiting treatment related radiotoxicity.
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Affiliation(s)
- John Kennedy
- Department of Nuclear Medicine, Rambam Health Care Campus, Haifa, Israel; B. Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
| | - Alexandre Chicheportiche
- Department of Nuclear Medicine and Biophysics, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Zohar Keidar
- Department of Nuclear Medicine, Rambam Health Care Campus, Haifa, Israel; B. Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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21
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A Physiologically Based Pharmacokinetic Model for In Vivo Alpha Particle Generators Targeting Neuroendocrine Tumors in Mice. Pharmaceutics 2021; 13:pharmaceutics13122132. [PMID: 34959413 PMCID: PMC8703774 DOI: 10.3390/pharmaceutics13122132] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/04/2021] [Accepted: 12/07/2021] [Indexed: 12/13/2022] Open
Abstract
In vivo alpha particle generators have great potential for the treatment of neuroendocrine tumors in alpha-emitter-based peptide receptor radionuclide therapy (α-PRRT). Quantitative pharmacokinetic analyses of the in vivo alpha particle generator and its radioactive decay products are required to address concerns about the efficacy and safety of α-PRRT. A murine whole-body physiologically based pharmacokinetic (PBPK) model was developed for 212Pb-labeled somatostatin analogs (212Pb-SSTA). The model describes pharmacokinetics of 212Pb-SSTA and its decay products, including specific and non-specific glomerular and tubular uptake. Absorbed dose coefficients (ADC) were calculated for bound and unbound radiolabeled SSTA and its decay products. Kidneys received the highest ADC (134 Gy/MBq) among non-target tissues. The alpha-emitting 212Po contributes more than 50% to absorbed doses in most tissues. Using this model, it is demonstrated that α-PRRT based on 212Pb-SSTA results in lower absorbed doses in non-target tissue than α-PRRT based on 212Bi-SSTA for a given kidneys absorbed dose. In both approaches, the energies released in the glomeruli and proximal tubules account for 54% and 46%, respectively, of the total energy absorbed in kidneys. The 212Pb-SSTA-PBPK model accelerates the translation from bench to bedside by enabling better experimental design and by improving the understanding of the underlying mechanisms.
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22
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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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23
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Zaid NRR, Kletting P, Winter G, Beer AJ, Glatting G. A Whole-Body Physiologically Based Pharmacokinetic Model for Alpha Particle Emitting Bismuth in Rats. Cancer Biother Radiopharm 2021; 37:41-46. [PMID: 34185608 DOI: 10.1089/cbr.2021.0028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Introduction/Aim: α particle emitting bismuth (212Bi) as decay product of 212Pb-labeled pharmaceuticals has been effective in targeted α particle therapy (TAT). Estimating the contribution of 212Bi released from its chelator to the absorbed doses in nontarget tissues is challenging in TAT. Physiologically based pharmacokinetic (PBPK) modeling can help overcome this limitation. Therefore, a whole-body 212Bi-PBPK model was developed to describe the pharmacokinetics (PKs) of 212Bi in rats. Materials and Methods: The rat 212Bi-PBPK model was implemented using the modeling software SAAM II with data and parameter values from the literature. Besides other mechanisms, 212Bi interactions with red blood cells, high molecular weight plasma protein, and intracellular biological thiols are described. Important PK parameters were fitted to time-activity data. Absorbed dose coefficients (ADCs) were calculated for injecting 0.774 fmol of 212Bi. Results: 212Bi uptake rates of liver, bone, small intestine, bone marrow, skin, and muscle were (0.86 ± 0.13), (3.85 ± 0.63), (0.27 ± 0.05), (1.44 ± 0.29), (0.04 ± 0.01), and (0.007 ± 0.007) per min with corresponding ADCs of 0.09, 0.03, 0.03, 0.07, 0.01, and 0.003 mGy/kBq, respectively. An ADC of 0.70 mGy/kBq was determined for kidneys. Conclusion: Kidneys are the dose-limiting organs in 212Bi-based TAT. The 212Bi-PBPK model is an effective tool to investigate the 212Bi biodistribution in murine models. Integrating the 212Bi-PBPK model into other murine and human PBPK models of α particle generators can help study the efficacy and safety of TAT.
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Affiliation(s)
- Nouran R R Zaid
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany.,Department of Biomedical Sciences, Biophysics and Medical Imaging Program, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
| | - Peter Kletting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany.,Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Gordon Winter
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Ambros J Beer
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Gerhard Glatting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany.,Department of Nuclear Medicine, Ulm University, Ulm, Germany
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24
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Hardiansyah D, Kletting P, Begum NJ, Eiber M, Beer AJ, Pawiro SA, Glatting G. Important pharmacokinetic parameters for individualization of 177 Lu-PSMA therapy: A global sensitivity analysis for a physiologically-based pharmacokinetic model. Med Phys 2020; 48:556-568. [PMID: 33244792 DOI: 10.1002/mp.14622] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/26/2020] [Accepted: 11/13/2020] [Indexed: 11/06/2022] Open
Abstract
PURPOSE The knowledge of the contribution of anatomical and physiological parameters to interindividual pharmacokinetic differences could potentially be used to improve individualized treatment planning for radionuclide therapy. The aim of this study was therefore to identify the physiologically based pharmacokinetic (PBPK) model parameters that determine the interindividual variability of absorbed doses (ADs) to kidneys and tumor lesions in therapy with 177 Lu-labeled PSMA-targeting radioligands. METHODS A global sensitivity analysis (GSA) with the extended Fourier Amplitude Sensitivity Test (eFAST) algorithm was performed. The whole-body PBPK model for PSMA-targeting radioligand therapy from our previous studies was used in this study. The model parameters of interest (input of the GSA) were the organ receptor densities [R0 ], the organ blood flows f, and the organ release rates λ. These parameters were systematically sampled NE times according to their distribution in the patient population. The corresponding pharmacokinetics were simulated and the ADs (model output) to kidneys and tumor lesions were collected. The main effect S i and total effect S Ti were calculated using the eFAST algorithm based on the variability of the model output: The main effect S i of input parameter i represents the reduction in variance of the output if the "true" value of parameter i would be known. The total effect S Ti of an input parameter i represents the proportion of variance remaining if the "true" values of all other input parameters except for i are known. The numbers of samples NE were increased up to 8193 to check the stability (i.e., convergence) of the calculated main effects S i and total effects S Ti . RESULTS From the simulations, the relative interindividual variability of ADs in the kidneys (coefficient of variation CV = 31%) was lower than that of ADs in the tumors (CV up to 59%). Based on the GSA, the most important parameters that determine the ADs to the kidneys were kidneys flow ( S i = 0.36, S Ti = 0.43) and kidneys receptor density ( S i = 0.25, S Ti = 0.30). Tumor receptor density was identified as the most important parameter determining the ADs to tumors ( S i and S Ti up to 0.72). CONCLUSIONS The results suggest that an accurate measurement of receptor density and flow before therapy could be a promising approach for developing an individualized treatment with 177 Lu-labeled PSMA-targeting radioligands.
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Affiliation(s)
- Deni Hardiansyah
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424, Indonesia
| | - Peter Kletting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, 89081, Germany.,Department of Nuclear Medicine, Ulm University, Ulm, 89081, Germany
| | - Nusrat J Begum
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, 89081, Germany
| | - Matthias Eiber
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, München, 81675, Germany
| | - Ambros J Beer
- Department of Nuclear Medicine, Ulm University, Ulm, 89081, Germany
| | - Supriyanto A Pawiro
- Medical Physics and Biophysics, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424, Indonesia
| | - Gerhard Glatting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, 89081, Germany.,Department of Nuclear Medicine, Ulm University, Ulm, 89081, Germany
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25
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Mora-Ramirez E, Santoro L, Cassol E, Ocampo-Ramos JC, Clayton N, Kayal G, Chouaf S, Trauchessec D, Pouget JP, Kotzki PO, Deshayes E, Bardiès M. Comparison of commercial dosimetric software platforms in patients treated with 177 Lu-DOTATATE for peptide receptor radionuclide therapy. Med Phys 2020; 47:4602-4615. [PMID: 32632928 PMCID: PMC7589428 DOI: 10.1002/mp.14375] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/21/2020] [Accepted: 06/22/2020] [Indexed: 12/17/2022] Open
Abstract
Purpose The aim of this study was to quantitatively compare five commercial dosimetric software platforms based on the analysis of clinical datasets of patients who benefited from peptide receptor radionuclide therapy (PRRT) with 177Lu‐DOTATATE (LUTATHERA®). Methods The dosimetric analysis was performed on two patients during two cycles of PRRT with 177Lu. Single photon emission computed tomography/computed tomography images were acquired at 4, 24, 72, and 192 h post injection. Reconstructed images were generated using Dosimetry Toolkit® (DTK) from Xeleris™ and HybridRecon‐Oncology version_1.3_Dicom (HROD) from HERMES. Reconstructed images using DTK were analyzed using the same software to calculate time‐integrated activity coefficients (TIAC), and mean absorbed doses were estimated using OLINDA/EXM V1.0 with mass correction. Reconstructed images from HROD were uploaded into PLANET® OncoDose from DOSIsoft, STRATOS from Phillips, Hybrid Dosimetry Module™ from HERMES, and SurePlan™ MRT from MIM. Organ masses, TIACs, and mean absorbed doses were calculated from each application using their recommendations. Results The majority of organ mass estimates varied by <9.5% between all platforms. The highest variability for TIAC results between platforms was seen for the kidneys (28.2%) for the two patients and the two treatment cycles. Relative standard deviations in mean absorbed doses were slightly higher compared with those observed for TIAC, but remained of the same order of magnitude between all platforms. Conclusions When applying a similar processing approach, results obtained were of the same order of magnitude regardless of the platforms used. However, the comparison of the performances of currently available platforms is still difficult as they do not all address the same parts of the dosimetric analysis workflow. In addition, the way in which data are handled in each part of the chain from data acquisition to absorbed doses may be different, which complicates the comparison exercise. Therefore, the dissemination of commercial solutions for absorbed dose calculation calls for the development of tools and standards allowing for the comparison of the performances between dosimetric software platforms.
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Affiliation(s)
- Erick Mora-Ramirez
- Centre de Recherches en Cancérologie de Toulouse, UMR 1037, Toulouse, F-31037, France.,INSERM, UMR 1037, Université Toulouse III Paul Sabatier, Toulouse, F-31062, France.,Escuela de Física - CICANUM, Universidad de Costa Rica, San José, 11501-2060, Costa Rica
| | - Lore Santoro
- Département de Médecine Nucléaire, Institut Régional du Cancer de Montpellier, Montpellier, F-34298, France
| | - Emmanuelle Cassol
- Centre de Recherches en Cancérologie de Toulouse, UMR 1037, Toulouse, F-31037, France.,INSERM, UMR 1037, Université Toulouse III Paul Sabatier, Toulouse, F-31062, France.,Département de Médecine Nucléaire, Hôpitaux Toulouse, Toulouse, F-31059, France.,Faculté de Médecine Rangueil, Université Toulouse III Paul Sabatier, Toulouse, F-31062, France
| | - Juan C Ocampo-Ramos
- Centre de Recherches en Cancérologie de Toulouse, UMR 1037, Toulouse, F-31037, France.,INSERM, UMR 1037, Université Toulouse III Paul Sabatier, Toulouse, F-31062, France
| | - Naomi Clayton
- Centre de Recherches en Cancérologie de Toulouse, UMR 1037, Toulouse, F-31037, France.,INSERM, UMR 1037, Université Toulouse III Paul Sabatier, Toulouse, F-31062, France
| | - Gunjan Kayal
- Centre de Recherches en Cancérologie de Toulouse, UMR 1037, Toulouse, F-31037, France.,INSERM, UMR 1037, Université Toulouse III Paul Sabatier, Toulouse, F-31062, France.,SCK CEN, Belgian Nuclear Research Centre, Boeretang 200, Mol, BE-2400, Belgium
| | - Soufiane Chouaf
- Département de Médecine Nucléaire, Institut Régional du Cancer de Montpellier, Montpellier, F-34298, France
| | - Dorian Trauchessec
- Département de Médecine Nucléaire, Institut Régional du Cancer de Montpellier, Montpellier, F-34298, France
| | - Jean-Pierre Pouget
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier (ICM), Montpellier, F-34298, France
| | - Pierre-Olivier Kotzki
- Département de Médecine Nucléaire, Institut Régional du Cancer de Montpellier, Montpellier, F-34298, France.,Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier (ICM), Montpellier, F-34298, France
| | - Emmanuel Deshayes
- Département de Médecine Nucléaire, Institut Régional du Cancer de Montpellier, Montpellier, F-34298, France.,Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier (ICM), Montpellier, F-34298, France
| | - Manuel Bardiès
- Centre de Recherches en Cancérologie de Toulouse, UMR 1037, Toulouse, F-31037, France.,INSERM, UMR 1037, Université Toulouse III Paul Sabatier, Toulouse, F-31062, France
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26
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Rinscheid A, Kletting P, Eiber M, Beer AJ, Glatting G. Influence of sampling schedules on [ 177Lu]Lu-PSMA dosimetry. EJNMMI Phys 2020; 7:41. [PMID: 32556844 PMCID: PMC7300169 DOI: 10.1186/s40658-020-00311-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 06/03/2020] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Individualized dosimetry is recommended for [177Lu]Lu-PSMA radioligand therapy (RLT) which is resource-intensive and protocols are often not optimized. Therefore, a simulation study was performed focusing on the determination of efficient optimal sampling schedules (OSS) for renal and tumour dosimetry by investigating different numbers of time points (TPs). METHODS Sampling schedules with 1-4 TPs were investigated. Time-activity curves of the kidneys and two tumour lesions were generated based on a physiologically based pharmacokinetic (PBPK) model and biokinetic data of 13 patients who have undergone [177Lu]Lu-PSMA I&T therapy. Systematic and stochastic noise of different ratios was considered when modelling time-activity data sets. Time-integrated activity coefficients (TIACs) were estimated by simulating the hybrid planar/SPECT method for schedules comprising at least two TPs. TIACs based on one single SPECT/CT measurement were estimated using an approximation for reducing the number of fitted parameters. For each sampling schedule, the root-mean-squared error (RMSE) of the deviations of the simulated TIACs from the ground truths for 1000 replications was used as a measure for accuracy and precision. RESULTS All determined OSS included a late measurement at 192 h p.i., which was necessary for accurate and precise tumour TIACs. OSS with three TPs were identified to be 3-4, 96-100 and 192 h with an additional SPECT/CT measurement at the penultimate TP. Kidney and tumour RMSE of 6.4 to 7.7% and 6.3 to 7.8% were obtained, respectively. Shortening the total time for dosimetry to e.g. 96 h resulted in kidney and tumour RMSE of 6.8 to 8.3% and 9.1 to 11%, respectively. OSS with four TPs showed similar results as with three TPs. Planar images at 4 and 68 h and a SPECT/CT shortly after the 68 h measurement led to kidney and tumour RMSE of 8.4 to 12% and 12 to 16%, respectively. One single SPECT/CT measurement at 52 h yielded good approximations for the kidney TIACs (RMSE of 7.0%), but led to biased tumour TIACs. CONCLUSION OSS allow improvements in accuracy and precision of renal and tumour dosimetry for [177Lu]Lu-PSMA therapy with potentially less effort. A late TP is important regarding accurate tumour TIACs.
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Affiliation(s)
- Andreas Rinscheid
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Albert-Einstein-Allee 23, 89081, Ulm, Germany. .,Department of Nuclear Medicine, Ulm University, 89081, Ulm, Germany.
| | - Peter Kletting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Albert-Einstein-Allee 23, 89081, Ulm, Germany.,Department of Nuclear Medicine, Ulm University, 89081, Ulm, Germany
| | - Matthias Eiber
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technische Universität München, 81675, München, Germany
| | - Ambros J Beer
- Department of Nuclear Medicine, Ulm University, 89081, Ulm, Germany
| | - Gerhard Glatting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Albert-Einstein-Allee 23, 89081, Ulm, Germany.,Department of Nuclear Medicine, Ulm University, 89081, Ulm, Germany
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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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Yonekura Y, Mattsson S, Flux G, Bolch WE, Dauer LT, Fisher DR, Lassmann M, Palm S, Hosono M, Doruff M, Divgi C, Zanzonico P. ICRP Publication 140: Radiological Protection in Therapy with Radiopharmaceuticals. Ann ICRP 2019; 48:5-95. [PMID: 31565950 DOI: 10.1177/0146645319838665] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Radiopharmaceuticals are increasingly used for the treatment of various cancers with novel radionuclides, compounds, tracer molecules, and administration techniques. The goal of radiation therapy, including therapy with radiopharmaceuticals, is to optimise the relationship between tumour control probability and potential complications in normal organs and tissues. Essential to this optimisation is the ability to quantify the radiation doses delivered to both tumours and normal tissues. This publication provides an overview of therapeutic procedures and a framework for calculating radiation doses for various treatment approaches. In radiopharmaceutical therapy, the absorbed dose to an organ or tissue is governed by radiopharmaceutical uptake, retention in and clearance from the various organs and tissues of the body, together with radionuclide physical half-life. Biokinetic parameters are determined by direct measurements made using techniques that vary in complexity. For treatment planning, absorbed dose calculations are usually performed prior to therapy using a trace-labelled diagnostic administration, or retrospective dosimetry may be performed on the basis of the activity already administered following each therapeutic administration. Uncertainty analyses provide additional information about sources of bias and random variation and their magnitudes; these analyses show the reliability and quality of absorbed dose calculations. Effective dose can provide an approximate measure of lifetime risk of detriment attributable to the stochastic effects of radiation exposure, principally cancer, but effective dose does not predict future cancer incidence for an individual and does not apply to short-term deterministic effects associated with radiopharmaceutical therapy. Accident prevention in radiation therapy should be an integral part of the design of facilities, equipment, and administration procedures. Minimisation of staff exposures includes consideration of equipment design, proper shielding and handling of sources, and personal protective equipment and tools, as well as education and training to promote awareness and engagement in radiological protection. The decision to hold or release a patient after radiopharmaceutical therapy should account for potential radiation dose to members of the public and carers that may result from residual radioactivity in the patient. In these situations, specific radiological protection guidance should be provided to patients and carers.
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A simulation-based method to determine optimal sampling schedules for dosimetry in radioligand therapy. Z Med Phys 2019; 29:314-325. [PMID: 30611606 DOI: 10.1016/j.zemedi.2018.12.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 11/13/2018] [Accepted: 12/03/2018] [Indexed: 11/20/2022]
Abstract
AIM For dosimetry in radioligand therapy, the time-integrated activity coefficients (TIACs) for organs at risk and for tumour lesions have to be determined. The used sampling scheme affects the TIACs and therefore the calculated absorbed doses. The aim of this work was to develop a general and flexible method, which analyses numerous clinically applicable sampling schedules using true time-activity curves (TACs) of virtual patients. METHOD Nine virtual patients with true TACs of the tumours were created using a physiologically-based pharmacokinetic (PBPK) model and individual biokinetic data of five patients with neuroendocrine tumours and four with meningioma. 111In-DOTATATE was used for pre-therapeutic dosimetry. In total, 15,120 sampling schemes, each consisting of 4 time points, were investigated. Gaussian noise of different levels was added to the corresponding true time-activity points. A bi-exponential function was used to fit the simulated time-activity data. For each investigated sampling schedule, 1000 replications were performed. Patient-specific and population-specific optimal sampling schedules were determined using the relative root-mean-square error (rRMSE). Furthermore, the fractions of TIACs a˜ deviating >5% (fΔa˜>5%) and >10% (fΔa˜>10%) from the true TIAC a˜true were used for additional evaluations e.g. to investigate the effect of varying single time points. RESULTS Almost all patient-specific and all population-specific optimal sampling schedules have t4≥96h for all noise levels. Changing the latest time point from the population-specific optimal time to e.g. 48h leads to a median increase of fΔa˜>10% from 0.1% to 88% for the lowest investigated noise level. Using the determined population-specific optimal schedules, results in more accurate and precise results than established schedules from the literature. CONCLUSION A method of determining the optimal sampling schedule for dosimetry, which considers clinical working hours and measurement uncertainties, has been developed and applied. The simulation study shows that optimised sampling schedules result in high accuracy and precision of the determined TIACs.
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In Vivo Biokinetics of 177Lu-OPS201 in Mice and Pigs as a Model for Predicting Human Dosimetry. CONTRAST MEDIA & MOLECULAR IMAGING 2019; 2019:6438196. [PMID: 30733648 PMCID: PMC6348830 DOI: 10.1155/2019/6438196] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 10/25/2018] [Accepted: 11/21/2018] [Indexed: 12/31/2022]
Abstract
Introduction 177Lu-OPS201 is a high-affinity somatostatin receptor subtype 2 antagonist for PRRT in patients with neuroendocrine tumors. The aim is to find the optimal scaling for dosimetry and to compare the biokinetics of 177Lu-OPS201 in animals and humans. Methods Data on biokinetics of 177Lu-OPS201 were analyzed in athymic nude Foxn1nu mice (28 F, weight: 26 ± 1 g), Danish Landrace pigs (3 F-1 M, weight: 28 ± 2 kg), and patients (3 F-1 M, weight: 61 ± 17 kg) with administered activities of 0.19–0.27 MBq (mice), 97–113 MBq (pigs), and 850–1086 MBq (patients). After euthanizing mice (up to 168 h), the organ-specific activity contents (including blood) were measured. Multiple planar and SPECT/CT scans were performed until 250 h (pigs) and 72 h (patients) to quantify the uptake in the kidneys and liver. Blood samples were taken up to 23 h (patients) and 300 h (pigs). In pigs and patients, kidney protection was applied. Time-dependent uptake data sets were created for each species and organ/tissue. Biexponential fits were applied to compare the biokinetics in the kidneys, liver, and blood of each species. The time-integrated activity coefficients (TIACs) were calculated by using NUKFIT. To determine the optimal scaling, several methods (relative mass scaling, time scaling, combined mass and time scaling, and allometric scaling) were compared. Results A fast blood clearance of the compound was observed in the first phase (<56 h) for all species. In comparison with patients, pigs showed higher liver retention. Based on the direct comparison of the TIACs, an underestimation in mice (liver and kidneys) and an overestimation in pigs' kidneys compared to the patient data (kidney TIAC: mice = 1.4 h, pigs = 7.7 h, and patients = 5.8 h; liver TIAC: mice = 0.7 h, pigs = 4.1 h, and patients = 5.3 h) were observed. Most similar TIACs were obtained by applying time scaling (mice) and combined scaling (pigs) (kidney TIAC: mice = 3.9 h, pigs = 4.8 h, and patients = 5.8 h; liver TIAC: mice = 0.9 h, pigs = 4.7 h, and patients = 5.3 h). Conclusion If the organ mass ratios between the species are high, the combined mass and time scaling method is optimal to minimize the interspecies differences. The analysis of the fit functions and the TIACs shows that pigs are better mimicking human biokinetics.
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Gear JI, Cox MG, Gustafsson J, Gleisner KS, Murray I, Glatting G, Konijnenberg M, Flux GD. EANM practical guidance on uncertainty analysis for molecular radiotherapy absorbed dose calculations. Eur J Nucl Med Mol Imaging 2018; 45:2456-2474. [PMID: 30218316 PMCID: PMC6208822 DOI: 10.1007/s00259-018-4136-7] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 08/14/2018] [Indexed: 11/30/2022]
Abstract
A framework is proposed for modelling the uncertainty in the measurement processes constituting the dosimetry chain that are involved in internal absorbed dose calculations. The starting point is the basic model for absorbed dose in a site of interest as the product of the cumulated activity and a dose factor. In turn, the cumulated activity is given by the area under a time-activity curve derived from a time sequence of activity values. Each activity value is obtained in terms of a count rate, a calibration factor and a recovery coefficient (a correction for partial volume effects). The method to determine the recovery coefficient and the dose factor, both of which are dependent on the size of the volume of interest (VOI), are described. Consideration is given to propagating estimates of the quantities concerned and their associated uncertainties through the dosimetry chain to obtain an estimate of mean absorbed dose in the VOI and its associated uncertainty. This approach is demonstrated in a clinical example.
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Affiliation(s)
- Jonathan I Gear
- The Royal Marsden NHS Foundation Trust & Institute of Cancer Research, Downs Road, Sutton, SM2 5PT, UK.
| | - Maurice G Cox
- National Physical Laboratory, Teddington, TW11 0LW, UK
| | - Johan Gustafsson
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | | | - Iain Murray
- The Royal Marsden NHS Foundation Trust & Institute of Cancer Research, Downs Road, Sutton, SM2 5PT, UK
| | - Gerhard Glatting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | | | - Glenn D Flux
- The Royal Marsden NHS Foundation Trust & Institute of Cancer Research, Downs Road, Sutton, SM2 5PT, UK
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Demirci E, Toklu T, Yeyin N, Ocak M, Alan-Selcuk N, Araman A, Kabasakal L. ESTIMATION OF THE ORGAN ABSORBED DOSES AND EFFECTIVE DOSE FROM 68Ga-PSMA-11 PET SCAN. RADIATION PROTECTION DOSIMETRY 2018; 182:518-524. [PMID: 30137614 DOI: 10.1093/rpd/ncy111] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 06/27/2018] [Indexed: 06/08/2023]
Abstract
68Ga-PSMA-11 PET/CT has been proven to have high clinical value for imaging of prostate cancer and rapidly gained popularity. In this study, we aimed to investigate absorbed doses of 68Ga-PSMA-11. Seven patients (mean age = 66.9 ± 6.6 years, range: 57-79 years) were enrolled in the study. Whole body PET images were acquired with multiple time points. MIRD method, NUKFIT and OLINDA/EXM software were used for dosimetry calculations. Kidneys, bladder wall, salivary and lacrimal glands received the highest absorbed dose. Estimated absorbed doses to these organs after injection of 150 MBq 68Ga-PSMA-11 were 37.0, 12.6, 14.4 and 6.3 mSv, respectively. Effective dose from PET scanning with 150 MBq injected 68Ga-PSMA-11 was 2.5 mSv. In conclusion, 68Ga-PSMA-11 has a favorable dosimetry profile similar to the 68Ga labeled octreotide analogs, which are used safely in routine clinical practices for many years. No adverse effects were reported. The kidneys were the dose-limiting organs.
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Affiliation(s)
- Emre Demirci
- Department of Nuclear Medicine, Yeditepe University School of Medicine, Istanbul, Turkey
| | - Türkay Toklu
- Department of Nuclear Medicine, Yeditepe University School of Medicine, Istanbul, Turkey
| | - Nami Yeyin
- Department of Nuclear Medicine, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Meltem Ocak
- Department of Pharmaceutical Technology, Pharmacy Faculty, Istanbul University, Istanbul, Turkey
| | - Nalan Alan-Selcuk
- Department of Nuclear Medicine, Yeditepe University School of Medicine, Istanbul, Turkey
| | - Ahmet Araman
- Department of Pharmaceutical Technology, Pharmacy Faculty, Istanbul University, Istanbul, Turkey
| | - Levent Kabasakal
- Department of Nuclear Medicine, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey
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Teles P, Costa J, Costa D, Matela N, Vaz P. Activity estimation and biokinetic analysis of 99mTc-DMSA in renal infant patients using a gamma camera. Phys Med 2018; 52:9-17. [PMID: 30139615 DOI: 10.1016/j.ejmp.2018.06.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/08/2018] [Accepted: 06/09/2018] [Indexed: 10/28/2022] Open
Abstract
Biokinetic data from the administration of radiopharmaceuticals is essential in nuclear medicine dosimetry. It has particular significance in children, as their metabolism is very different from adults. Biokinetic models for paediatric patients could therefore need to be adapted to better reflect their absorption, retention and excretion functions, when compared to adults. Obtaining quality in vivo infant or paediatric biokinetic data is then essential to improve the available reference models, which in turn can lead to the optimization of paediatric procedures and protocols in clinical practice. This study analyses the biokinetic behaviour of 99mTc-dimercaptosuccinic acid (DMSA), in 8 infants aged 4 months to 2 years old, through an imaging study using a gamma camera, and compares the obtained values with those obtained with the reference ICRP biokinetic model. The in vivo data was treated using an adapted methodology from the MIRD 16 pamphlet. Activity curves for the liver, the kidney and the whole body, were built, and new effective absorption, retention and excretion half-lives were estimated, and compared with the reference biokinetic parameters of ICRP 128. The obtained residence time in the kidneys of 2.56 h, has a deviation of 30.8% to the ICRP 128 value of 3.70 h. The obtained maximum uptake in the kidneys was of 0.22/A0, which compares to the value of 0.31/A0 for ICRP. The obtained biokinetic parameters were used to estimate the absorbed dose. The obtained dose values are smaller than the reference ICRP 128 ones by 32.1% in the kidneys, and 18.4% in the liver.
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Affiliation(s)
- P Teles
- Grupo de Protecção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), CTN/IST, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal.
| | - J Costa
- Grupo de Protecção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), CTN/IST, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal; Departamento de Física, Faculdade de Ciências e Tecnologias da Universidade Nova de Lisboa, Quinta da Torre, Campus Universitário, 2829-516 Caparica, Portugal
| | - D Costa
- Serviço de Medicina Nuclear, Champalimaud Centre for the Unknown, Av. Brasília, 1400-038 Lisboa, Portugal
| | - N Matela
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências da Universidade de Lisboa, Campo Grande 1749-016 Lisboa, Portugal
| | - P Vaz
- Grupo de Protecção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), CTN/IST, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
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Alan Selcuk N, Toklu T, Beykan S, Karaaslan SI. Evaluation of the dosimetry approaches in ablation treatment of thyroid cancer. J Appl Clin Med Phys 2018; 19:134-140. [PMID: 29858536 PMCID: PMC6036368 DOI: 10.1002/acm2.12350] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 01/05/2018] [Accepted: 04/10/2018] [Indexed: 11/09/2022] Open
Abstract
In this study, we aimed to evaluate dosimetric approaches in ablation treatment of Differentiated Thyroid Carcinoma (DTC) without interrupting the clinical routine. Prior to therapy, 10.7 MBq 131I in average was orally given to 24 patients suffering from DTC. MIRD formalism was used for dosimetric calculations. For blood and bone marrow dosimetry, blood samples and whole‐body counts were collected at 2, 24, 72, and 120 h after I‐131 administration. For remnant tissue dosimetry, uptake measurements were performed at the same time intervals. To estimate the remnant volume, anterior and lateral planar gamma camera images were acquired with a reference source within the field of view at 24 h after I‐131 administration. Ultrasound imaging was also performed. Treatment activities determined with the fixed activity method were administered to the patients. Secondary cancer risk relative to applied therapy was evaluated for dosimetric approaches. The average dose to blood and bone marrow were determined as 0.15 ± 0.04 and 0.11 ± 0.04 Gy/GBq, respectively. The average remnant tissue dose was 0.58 ± 0.52 Gy/MBq and the corresponding required activity to ablate the remnant was approximately 1.3 GBq of 131I. A strong correlation between 24th‐hour uptake and time‐integrated activity coefficient values was obtained. Compared to fixed activity method, approximately five times higher secondary cancer risk was determined in bone marrow dosimetry, while the risk was about three times lower in lesion‐based dosimetry.
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Affiliation(s)
- Nalan Alan Selcuk
- Department of Nuclear Medicine, Yeditepe University Hospital, Istanbul, Turkey
| | - Turkay Toklu
- Department of Nuclear Medicine, Yeditepe University Hospital, Istanbul, Turkey
| | - Seval Beykan
- Department of Physics, Yeditepe University, Istanbul, Turkey.,Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany
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Kletting P, Thieme A, Eberhardt N, Rinscheid A, D’Alessandria C, Allmann J, Wester HJ, Tauber R, Beer AJ, Glatting G, Eiber M. Modeling and Predicting Tumor Response in Radioligand Therapy. J Nucl Med 2018; 60:65-70. [DOI: 10.2967/jnumed.118.210377] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 05/08/2018] [Indexed: 11/16/2022] Open
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Lisova K, Sergeev M, Evans-Axelsson S, Stuparu AD, Beykan S, Collins J, Jones J, Lassmann M, Herrmann K, Perrin D, Lee JT, Slavik R, van Dam RM. Microscale radiosynthesis, preclinical imaging and dosimetry study of [ 18F]AMBF 3-TATE: A potential PET tracer for clinical imaging of somatostatin receptors. Nucl Med Biol 2018; 61:36-44. [PMID: 29747035 DOI: 10.1016/j.nucmedbio.2018.04.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 03/28/2018] [Accepted: 04/01/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND Peptides labeled with positron-emitting isotopes are emerging as a versatile class of compounds for the development of highly specific, targeted imaging agents for diagnostic imaging via positron-emission tomography (PET) and for precision medicine via theranostic applications. Despite the success of peptides labeled with gallium-68 (for imaging) or lutetium-177 (for therapy) in the clinical management of patients with neuroendocrine tumors or prostate cancer, there are significant advantages of using fluorine-18 for imaging. Recent developments have greatly simplified such labeling: in particular, labeling of organotrifluoroborates via isotopic exchange can readily be performed in a single-step under aqueous conditions and without the need for HPLC purification. Though an automated synthesis has not yet been explored, microfluidic approaches have emerged for 18F-labeling with high speed, minimal reagents, and high molar activity compared to conventional approaches. As a proof-of-concept, we performed microfluidic labeling of an octreotate analog ([18F]AMBF3-TATE), a promising 18F-labeled analog that could compete with [68Ga]Ga-DOTATATE with the advantage of providing a greater number of patient doses per batch produced. METHODS Both [18F]AMBF3-TATE and [68Ga]Ga-DOTATATE were labeled, the former by microscale methods adapted from manual labeling, and were imaged in mice bearing human SSTR2-overexpressing, rat SSTR2 wildtype, and SSTR2-negative xenografts. Furthermore, a dosimetry analysis was performed for [18F]AMBF3-TATE. RESULTS The micro-synthesis exhibited highly-repeatable performance with radiochemical conversion of 50 ± 6% (n = 15), overall decay-corrected radiochemical yield of 16 ± 1% (n = 5) in ~40 min, radiochemical purity >99%, and high molar activity. Preclinical imaging with [18F]AMBF3-TATE in SSTR2 tumor models correlated well with [68Ga]Ga-DOTATATE. The favorable biodistribution, with the highest tracer accumulation in the bladder followed distantly by gastrointestinal tissues, resulted in 1.26 × 10-2 mSv/MBq maximal estimated effective dose in human, a value lower than that reported for current clinical 18F- and 68Ga-labeled compounds. CONCLUSIONS The combination of novel chemical approaches to 18F-labeling and microdroplet radiochemistry have the potential to serve as a platform for greatly simplified development and production of 18F-labeled peptide tracers. Favorable preclinical imaging and dosimetry of [18F]AMBF3-TATE, combined with a convenient synthesis, validate this assertion and suggest strong potential for clinical translation.
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Affiliation(s)
- Ksenia Lisova
- Physics in Biology and Medicine Interdepartmental Graduate Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Maxim Sergeev
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Susan Evans-Axelsson
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Andreea D Stuparu
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Seval Beykan
- Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany
| | - Jeffrey Collins
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Jason Jones
- Physics in Biology and Medicine Interdepartmental Graduate Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Michael Lassmann
- Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany
| | - Ken Herrmann
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center (JCCC), UCLA, Los Angeles, CA, USA
| | - David Perrin
- Department of Chemistry, University of British Columbia, Vancouver, BC, Canada
| | - Jason T Lee
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center (JCCC), UCLA, Los Angeles, CA, USA.
| | - Roger Slavik
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center (JCCC), UCLA, Los Angeles, CA, USA.
| | - R Michael van Dam
- Physics in Biology and Medicine Interdepartmental Graduate Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center (JCCC), UCLA, Los Angeles, CA, USA.
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Begum NJ, Thieme A, Eberhardt N, Tauber R, D'Alessandria C, Beer AJ, Glatting G, Eiber M, Kletting P. The Effect of Total Tumor Volume on the Biologically Effective Dose to Tumor and Kidneys for 177Lu-Labeled PSMA Peptides. J Nucl Med 2018; 59:929-933. [PMID: 29419479 DOI: 10.2967/jnumed.117.203505] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/20/2018] [Indexed: 11/16/2022] Open
Abstract
The aim of this work was to simulate the effect of prostate-specific membrane antigen (PSMA)-positive total tumor volume (TTV) on the biologically effective doses (BEDs) to tumors and organs at risk in patients with metastatic castration-resistant prostate cancer who are undergoing 177Lu-PSMA radioligand therapy. Methods: A physiologically based pharmacokinetic model was fitted to the data of 13 patients treated with 177Lu-PSMA I&T (a PSMA inhibitor for imaging and therapy). The tumor, kidney, and salivary gland BEDs were simulated for TTVs of 0.1-10 L. The activity and peptide amounts leading to an optimal tumor-to-kidneys BED ratio were also investigated. Results: When the TTV was increased from 0.3 to 3 L, the simulated BEDs to tumors, kidneys, parotid glands, and submandibular glands decreased from 22 ± 15 to 11.0 ± 6.0 Gy1.49, 6.5 ± 2.3 to 3.7 ± 1.4 Gy2.5, 11.0 ± 2.7 to 6.4 ± 1.9 Gy4.5, and 10.9 ± 2.7 to 6.3 ± 1.9 Gy4.5, respectively (where the subscripts denote that an α/β of 1.49, 2.5, or 4.5 Gy was used to calculate the BED). The BED to the red marrow increased from 0.17 ± 0.05 to 0.32 ± 0.11 Gy15 For patients with a TTV of more than 0.3 L, the optimal amount of peptide was 273 ± 136 nmol and the optimal activity was 10.4 ± 4.4 GBq. Conclusion: This simulation study suggests that in patients with large PSMA-positive tumor volumes, higher activities and peptide amounts can be safely administered to maximize tumor BEDs without exceeding the tolerable BED to the organs at risk.
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Affiliation(s)
- Nusrat J Begum
- Department of Nuclear Medicine, Universität Ulm, Ulm, Germany
| | - Anne Thieme
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany; and
| | - Nina Eberhardt
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany; and
| | - Robert Tauber
- Department of Urology, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Calogero D'Alessandria
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany; and
| | - Ambros J Beer
- Department of Nuclear Medicine, Universität Ulm, Ulm, Germany
| | | | - Matthias Eiber
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany; and
| | - Peter Kletting
- Department of Nuclear Medicine, Universität Ulm, Ulm, Germany
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Hardiansyah D, Guo W, Attarwala AA, Kletting P, Mottaghy FM, Glatting G. Treatment planning in PRRT based on simulated PET data and a PBPK model. Nuklearmedizin 2018; 56:23-30. [DOI: 10.3413/nukmed-0819-16-04] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 11/07/2016] [Indexed: 11/20/2022]
Abstract
SummaryAim: To investigate the accuracy of treatment planning in peptide-receptor radionuclide therapy (PRRT) based on simulated PET data (using a PET noise model) and a physiologically based pharmacokinetic (PBPK) model. Methods: The parameters of a PBPK model were fitted to the biokinetic data of 15 patients. True mathematical phantoms of patients (MPPs) were the PBPK model with the fitted parameters. PET measurements after bolus injection of 150 MBq 68Ga-DOTATATE were simulated for the true MPPs. PET noise with typical noise levels was added to the data (i.e. c=0.3 [low], 3, 30 and 300 [high]). Organ activity data in the kidneys, tumour, liver and spleen were simulated at 0.5, 1 and 4 h p.i. PBPK model parameters were fitted to the simulated noisy PET data to derive the PET-predicted MPPs. Therapy was simulated assuming an infusion of 3.3 GBq of 90Y-DOTATATE over 30 min. Time-integrated activity coefficients (TIACs) of simulated therapy in tumour, kidneys, liver, spleen and remainder were calculated from both, true MPPs (true TIACs) and predicted MPPs (predicted TIACs). Variability v between true TIACs and predicted TIACs were calculated and analysed. Variability< 10 % was considered to be an accurate prediction. Results: For all noise level, variabilities for the kidneys, liver, and spleen showed an accurate prediction for TIACs, e.g. c=300: vkidney=(5 ± 2)%, vliver=(5 ± 2)%, vspleen=(4 ± 2)%. However, tumour TIAC predictions were not accurate for all noise levels, e.g. c=0.3: vtumour=(8 ± 5)%. Conclusion: PET based treatment planning with kidneys as the dose limiting organ seems possible for all reported noise levels using an adequate PBPK model and previous knowledge about the individual patient.
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Sarrut D, Halty A, Badel JN, Ferrer L, Bardiès M. Voxel-based multimodel fitting method for modeling time activity curves in SPECT images. Med Phys 2017; 44:6280-6288. [PMID: 28921613 DOI: 10.1002/mp.12586] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 08/22/2017] [Accepted: 08/22/2017] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Estimating the biodistribution and the pharmacokinetics from time-sequence SPECT images on a per-voxel basis is useful for studying activity nonuniformity or computing absorbed dose distributions by convolution of voxel kernels or Monte-Carlo radiation transport. Current approaches are either region-based, thus assuming uniform activity within the region, or voxel-based but using the same fitting model for all voxels. METHODS We propose a voxel-based multimodel fitting method (VoMM) that estimates a fitting function for each voxel by automatically selecting the most appropriate model among a predetermined set with Akaike criteria. This approach can be used to compute the time integrated activity (TIA) for all voxels in the image. To control fitting optimization that may fail due to excessive image noise, an approximated version based on trapezoid integration, named restricted method, is also studied. From this comparison, the number of failed fittings within images was estimated and analyzed. Numerical experiments were used to quantify uncertainties and feasibility was demonstrated with real patient data. RESULTS Regarding numerical experiments, root mean square errors of TIA obtained with VoMM were similar to those obtained with bi-exponential fitting functions, and were lower (< 5% vs. > 10%) than with single model approaches that consider the same fitting function for all voxels. Failure rates were lower with VoMM and restricted approaches than with single-model methods. On real clinical data, VoMM was able to fit 90% of the voxels and led to less failed fits than single-model approaches. On regions of interest (ROI) analysis, the difference between ROI-based and voxel-based TIA estimations was low, less than 4%. However, the computation of the mean residence time exhibited larger differences, up to 25%. CONCLUSIONS The proposed voxel-based multimodel fitting method, VoMM, is feasible on patient data. VoMM leads organ-based TIA estimations similar to conventional ROI-based method. However, for pharmacokinetics analysis, studies of spatial heterogeneity or voxel-based absorbed dose assessment, VoMM could be used preferentially as it prevents model overfitting.
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Affiliation(s)
- David Sarrut
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Centre Léon Bérard, Lyon, France
| | - Adrien Halty
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Centre Léon Bérard, Lyon, France
| | - Jean-Noel Badel
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Centre Léon Bérard, Lyon, France
| | - Ludovic Ferrer
- Medical Physics Department, ICO René Gauducheau, St Herblain, France.,CRCINA UMR 892, Nantes, France
| | - Manuel Bardiès
- Inserm UMR1037, CRCT, Université Toulouse III-Paul Sabatier, F-31000, Toulouse, France
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Nicolas GP, Beykan S, Bouterfa H, Kaufmann J, Bauman A, Lassmann M, Reubi JC, Rivier JE, Maecke HR, Fani M, Wild D. Safety, Biodistribution, and Radiation Dosimetry of 68Ga-OPS202 in Patients with Gastroenteropancreatic Neuroendocrine Tumors: A Prospective Phase I Imaging Study. J Nucl Med 2017; 59:909-914. [DOI: 10.2967/jnumed.117.199737] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 09/30/2017] [Indexed: 12/24/2022] Open
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Eberlein U, Cremonesi M, Lassmann M. Individualized Dosimetry for Theranostics: Necessary, Nice to Have, or Counterproductive? J Nucl Med 2017; 58:97S-103S. [PMID: 28864620 DOI: 10.2967/jnumed.116.186841] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 03/10/2017] [Indexed: 11/16/2022] Open
Abstract
In 2005, the term theragnostics (theranostics) was introduced for describing the use of imaging for therapy planning in radiation oncology. In nuclear medicine, this expression describes the use of tracers for predicting the absorbed doses in molecular radiotherapy and, thus, the safety and efficacy of a treatment. At present, the most successful groups of isotopes for this purpose are 123I/124I/131I, 68Ga/177Lu, and 111In/86Y/90Y. The purpose of this review is to summarize available data on the dosimetry and dose-response relationships of several theranostic compounds, with a special focus on radioiodine therapy for differentiated thyroid cancer and peptide receptor radionuclide therapy. These are treatment modalities for which dose-response relationships for healthy tissues and tumors have been demonstrated. In addition, available data demonstrate that posttherapeutic dosimetry after a first treatment cycle predicts the absorbed doses in further cycles. Both examples show the applicability of the concept of theranostics in molecular radiotherapies. Nevertheless, unanswered questions need to be addressed in clinical trials incorporating dosimetry-related concepts for determining the amount of therapeutic activity to be administered.
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Affiliation(s)
- Uta Eberlein
- Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Würzburg, Würzburg, Germany; and
| | - Marta Cremonesi
- Radiation Research Unit, Istituto Europeo di Oncologia, Milano, Italy
| | - Michael Lassmann
- Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Würzburg, Würzburg, Germany; and
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Nwankwo O, Glatting G, Wenz F, Fleckenstein J. A single-source photon source model of a linear accelerator for Monte Carlo dose calculation. PLoS One 2017; 12:e0183486. [PMID: 28886048 PMCID: PMC5590861 DOI: 10.1371/journal.pone.0183486] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 08/05/2017] [Indexed: 11/18/2022] Open
Abstract
PURPOSE To introduce a new method of deriving a virtual source model (VSM) of a linear accelerator photon beam from a phase space file (PSF) for Monte Carlo (MC) dose calculation. MATERIALS AND METHODS A PSF of a 6 MV photon beam was generated by simulating the interactions of primary electrons with the relevant geometries of a Synergy linear accelerator (Elekta AB, Stockholm, Sweden) and recording the particles that reach a plane 16 cm downstream the electron source. Probability distribution functions (PDFs) for particle positions and energies were derived from the analysis of the PSF. These PDFs were implemented in the VSM using inverse transform sampling. To model particle directions, the phase space plane was divided into a regular square grid. Each element of the grid corresponds to an area of 1 mm2 in the phase space plane. The average direction cosines, Pearson correlation coefficient (PCC) between photon energies and their direction cosines, as well as the PCC between the direction cosines were calculated for each grid element. Weighted polynomial surfaces were then fitted to these 2D data. The weights are used to correct for heteroscedasticity across the phase space bins. The directions of the particles created by the VSM were calculated from these fitted functions. The VSM was validated against the PSF by comparing the doses calculated by the two methods for different square field sizes. The comparisons were performed with profile and gamma analyses. RESULTS The doses calculated with the PSF and VSM agree to within 3% /1 mm (>95% pixel pass rate) for the evaluated fields. CONCLUSION A new method of deriving a virtual photon source model of a linear accelerator from a PSF file for MC dose calculation was developed. Validation results show that the doses calculated with the VSM and the PSF agree to within 3% /1 mm.
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Affiliation(s)
- Obioma Nwankwo
- Department of Radiation Oncology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Medical Radiation Physics/Radiation Protection, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- * E-mail:
| | - Gerhard Glatting
- Medical Radiation Physics/Radiation Protection, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Frederik Wenz
- Department of Radiation Oncology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Jens Fleckenstein
- Department of Radiation Oncology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Hardiansyah D, Attarwala AA, Kletting P, Mottaghy FM, Glatting G. Prediction of time-integrated activity coefficients in PRRT using simulated dynamic PET and a pharmacokinetic model. Phys Med 2017; 42:298-304. [PMID: 28739143 DOI: 10.1016/j.ejmp.2017.06.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 06/27/2017] [Accepted: 06/28/2017] [Indexed: 10/19/2022] Open
Abstract
PURPOSE To investigate the accuracy of predicted time-integrated activity coefficients (TIACs) in peptide-receptor radionuclide therapy (PRRT) using simulated dynamic PET data and a physiologically based pharmacokinetic (PBPK) model. METHODS PBPK parameters were estimated using biokinetic data of 15 patients after injection of (152±15)MBq of 111In-DTPAOC (total peptide amount (5.78±0.25)nmol). True mathematical phantoms of patients (MPPs) were the PBPK model with the estimated parameters. Dynamic PET measurements were simulated as being done after bolus injection of 150MBq 68Ga-DOTATATE using the true MPPs. Dynamic PET scans around 35min p.i. (P1), 4h p.i. (P2) and the combination of P1 and P2 (P3) were simulated. Each measurement was simulated with four frames of 5min each and 2 bed positions. PBPK parameters were fitted to the PET data to derive the PET-predicted MPPs. Therapy was simulated assuming an infusion of 5.1GBq of 90Y-DOTATATE over 30min in both true and PET-predicted MPPs. TIACs of simulated therapy were calculated, true MPPs (true TIACs) and predicted MPPs (predicted TIACs) followed by the calculation of variabilities v. RESULTS For P1 and P2 the population variabilities of kidneys, liver and spleen were acceptable (v<10%). For the tumours and the remainders, the values were large (up to 25%). For P3, population variabilities for all organs including the remainder further improved, except that of the tumour (v>10%). CONCLUSION Treatment planning of PRRT based on dynamic PET data seems possible for the kidneys, liver and spleen using a PBPK model and patient specific information.
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Affiliation(s)
- Deni Hardiansyah
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Electrical Engineering, Universitas Padjadjaran, Bandung, Indonesia
| | - Ali Asgar Attarwala
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Peter Kletting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Felix M Mottaghy
- Klinik für Nuklearmedizin, University Hospital, RWTH Aachen University, Aachen, Germany; Department of Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
| | - Gerhard Glatting
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany.
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Hardiansyah D, Guo W, Kletting P, Mottaghy FM, Glatting G. Time-integrated activity coefficient estimation for radionuclide therapy using PET and a pharmacokinetic model: A simulation study on the effect of sampling schedule and noise. Med Phys 2017; 43:5145. [PMID: 27587044 DOI: 10.1118/1.4961012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The aim of this study was to investigate the accuracy of PET-based treatment planning for predicting the time-integrated activity coefficients (TIACs). METHODS The parameters of a physiologically based pharmacokinetic (PBPK) model were fitted to the biokinetic data of 15 patients to derive assumed true parameters and were used to construct true mathematical patient phantoms (MPPs). Biokinetics of 150 MBq (68)Ga-DOTATATE-PET was simulated with different noise levels [fractional standard deviation (FSD) 10%, 1%, 0.1%, and 0.01%], and seven combinations of measurements at 30 min, 1 h, and 4 h p.i. PBPK model parameters were fitted to the simulated noisy PET data using population-based Bayesian parameters to construct predicted MPPs. Therapy simulations were performed as 30 min infusion of (90)Y-DOTATATE of 3.3 GBq in both true and predicted MPPs. Prediction accuracy was then calculated as relative variability vorgan between TIACs from both MPPs. RESULTS Large variability values of one time-point protocols [e.g., FSD = 1%, 240 min p.i., vkidneys = (9 ± 6)%, and vtumor = (27 ± 26)%] show inaccurate prediction. Accurate TIAC prediction of the kidneys was obtained for the case of two measurements (1 and 4 h p.i.), e.g., FSD = 1%, vkidneys = (7 ± 3)%, and vtumor = (22 ± 10)%, or three measurements, e.g., FSD = 1%, vkidneys = (7 ± 3)%, and vtumor = (22 ± 9)%. CONCLUSIONS (68)Ga-DOTATATE-PET measurements could possibly be used to predict the TIACs of (90)Y-DOTATATE when using a PBPK model and population-based Bayesian parameters. The two time-point measurement at 1 and 4 h p.i. with a noise up to FSD = 1% allows an accurate prediction of the TIACs in kidneys.
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Affiliation(s)
- Deni Hardiansyah
- Medical Radiation Physics/Radiation Protection, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim 68167, Germany and Department of Radiation Oncology, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim 68167, Germany
| | - Wei Guo
- Medical Radiation Physics/Radiation Protection, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim 68167, Germany
| | - Peter Kletting
- Department of Nuclear Medicine, Ulm University, Ulm 89081, Germany
| | - Felix M Mottaghy
- Department of Nuclear Medicine, University Hospital, RWTH Aachen University, Aachen 52074, Germany and Department of Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht 6229, The Netherlands
| | - Gerhard Glatting
- Medical Radiation Physics/Radiation Protection, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim 68167, Germany
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Boschi S, Lee JT, Beykan S, Slavik R, Wei L, Spick C, Eberlein U, Buck AK, Lodi F, Cicoria G, Czernin J, Lassmann M, Fanti S, Herrmann K. Synthesis and preclinical evaluation of an Al 18F radiofluorinated GLU-UREA-LYS(AHX)-HBED-CC PSMA ligand. Eur J Nucl Med Mol Imaging 2016; 43:2122-2130. [PMID: 27329046 PMCID: PMC5050145 DOI: 10.1007/s00259-016-3437-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 06/02/2016] [Indexed: 11/28/2022]
Abstract
PURPOSE The aim of this study was to synthesize and preclinically evaluate an 18F-PSMA positron emission tomography (PET) tracer. Prostate-specific membrane antigen (PSMA) specificity, biodistribution, and dosimetry in healthy and tumor-bearing mice were determined. METHODS Several conditions for the labeling of 18F-PSMA-11 via 18F-AlF-complexation were screened to study the influence of reaction temperature, peptide amount, ethanol volume, and reaction time. After synthesis optimization, biodistribution and dosimetry studies were performed in C57BL6 mice. For proof of PSMA-specificity, mice were implanted with PSMA-negative (PC3) and PSMA-positive (LNCaP) tumors in contralateral flanks. Static and dynamic microPET/computed tomography (CT) imaging was performed. RESULTS Quantitative labeling yields could be achieved with >97 % radiochemical purity. The 18F-PSMA-11 uptake was more than 24-fold higher in PSMA-high LNCaP than in PSMA-low PC3 tumors (18.4 ± 3.3 %ID/g and 0.795 ± 0.260 %ID/g, respectively; p < 4.2e-5). Results were confirmed by ex vivo gamma counter analysis of tissues after the last imaging time point. The highest absorbed dose was reported for the kidneys. The maximum effective dose for an administered activity of 200 MBq was 1.72 mSv. CONCLUSION 18F-PSMA-11 using direct labeling of chelate-attached peptide with aluminum-fluoride detected PSMA-expressing tumors with high tumor-to-liver ratios. The kidneys were the dose-limiting organs. Even by applying the most stringent dosimetric calculations, injected activities of up to 0.56 GBq are feasible.
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Affiliation(s)
- Stefano Boschi
- Department of Nuclear Medicine, S.Orsola-Malpighi University Hospital, Via Massarenti 9, 40138, Bologna, Italy
| | - Jason T Lee
- Crump Institute for Molecular Imaging, David Geffen School of Medicine at UCLA, Los Angeles, USA
| | - Seval Beykan
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Roger Slavik
- Ahmanson Translational Imaging Division, David Geffen School of Medicine at UCLA, 10833 Le Conte Ave. CHS AR-255, Los Angeles, CA, 90095, USA
| | - Liu Wei
- Ahmanson Translational Imaging Division, David Geffen School of Medicine at UCLA, 10833 Le Conte Ave. CHS AR-255, Los Angeles, CA, 90095, USA
| | - Claudio Spick
- Ahmanson Translational Imaging Division, David Geffen School of Medicine at UCLA, 10833 Le Conte Ave. CHS AR-255, Los Angeles, CA, 90095, USA
| | - Uta Eberlein
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Andreas K Buck
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Filippo Lodi
- Department of Nuclear Medicine, S.Orsola-Malpighi University Hospital, Via Massarenti 9, 40138, Bologna, Italy
| | - Gianfranco Cicoria
- Department of Medical Physics, S. Orsola-Malpighi University Hospital, Bologna, Italy
| | - Johannes Czernin
- Ahmanson Translational Imaging Division, David Geffen School of Medicine at UCLA, 10833 Le Conte Ave. CHS AR-255, Los Angeles, CA, 90095, USA
| | - Michael Lassmann
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Stefano Fanti
- Department of Nuclear Medicine, S.Orsola-Malpighi University Hospital, Via Massarenti 9, 40138, Bologna, Italy
| | - Ken Herrmann
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany.
- Ahmanson Translational Imaging Division, David Geffen School of Medicine at UCLA, 10833 Le Conte Ave. CHS AR-255, Los Angeles, CA, 90095, USA.
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Sijbesma JWA, Zhou X, Vállez García D, Houwertjes MC, Doorduin J, Kwizera C, Maas B, Meerlo P, Dierckx RA, Slart RHJA, Elsinga PH, van Waarde A. Novel Approach to Repeated Arterial Blood Sampling in Small Animal PET: Application in a Test-Retest Study with the Adenosine A1 Receptor Ligand [(11)C]MPDX. Mol Imaging Biol 2016; 18:715-23. [PMID: 27091332 PMCID: PMC5010612 DOI: 10.1007/s11307-016-0954-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
PURPOSE Small animal positron emission tomography (PET) can be used to detect small changes in neuroreceptor availability. This often requires rapid arterial blood sampling. However, current catheterization procedures do not allow repeated blood sampling. We have developed a procedure which allows arterial sampling on repeated occasions in the same animal. PROCEDURES Eleven male Wistar rats were two times catheterized via a superficial branch of a femoral artery and scanned with [(11)C]MPDX and blood sampling. PET images were co-registered to a magnetic resonance imaging (MRI) template. Regional tracer distribution volumes (V T) in the brain were calculated by the Logan analysis. The procedure was repeated after 1 week. RESULTS Surgery was successful in 90 % of the cases, and discomfort was minor. The V T data showed small differences between test and retest, low between subject variability, and a strong agreement between and within subjects. CONCLUSION Repeated quantitative imaging with a high reproducibility is possible with this approach.
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Affiliation(s)
- Jürgen W A Sijbesma
- University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Xiaoyun Zhou
- University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - David Vállez García
- University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Martin C Houwertjes
- Experimental Anesthesiology and Clinical Pharmacology Research Group, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Janine Doorduin
- University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Chantal Kwizera
- University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Bram Maas
- University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Peter Meerlo
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747AG, Groningen, The Netherlands
| | - Rudi A Dierckx
- University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Riemer H J A Slart
- University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
- Department of Biomedical Photonic Imaging, University of Twente, P.O. Box 217, 7500AE, Enschede, The Netherlands
| | - Philip H Elsinga
- University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Aren van Waarde
- University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.
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Kletting P, Schuchardt C, Kulkarni HR, Shahinfar M, Singh A, Glatting G, Baum RP, Beer AJ. Investigating the Effect of Ligand Amount and Injected Therapeutic Activity: A Simulation Study for 177Lu-Labeled PSMA-Targeting Peptides. PLoS One 2016; 11:e0162303. [PMID: 27611841 PMCID: PMC5017739 DOI: 10.1371/journal.pone.0162303] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 08/19/2016] [Indexed: 11/19/2022] Open
Abstract
In molecular radiotherapy with 177Lu-labeled prostate specific membrane antigen (PSMA) peptides, kidney and/or salivary glands doses limit the activity which can be administered. The aim of this work was to investigate the effect of the ligand amount and injected activity on the tumor-to-normal tissue biologically effective dose (BED) ratio for 177Lu-labeled PSMA peptides. For this retrospective study, a recently developed physiologically based pharmacokinetic model was adapted for PSMA targeting peptides. General physiological parameters were taken from the literature. Individual parameters were fitted to planar gamma camera measurements (177Lu-PSMA I&T) of five patients with metastasizing prostate cancer. Based on the estimated parameters, the pharmacokinetics of tumor, salivary glands, kidneys, total body and red marrow was simulated and time-integrated activity coefficients were calculated for different peptide amounts. Based on these simulations, the absorbed doses and BEDs for normal tissue and tumor were calculated for all activities leading to a maximal tolerable kidney BED of 10 Gy2.5/cycle, a maximal salivary gland absorbed dose of 7.5 Gy/cycle and a maximal red marrow BED of 0.25 Gy15/cycle. The fits yielded coefficients of determination > 0.85, acceptable relative standard errors and low parameter correlations. All estimated parameters were in a physiologically reasonable range. The amounts (for 25−29 nmol) and pertaining activities leading to a maximal tumor dose, considering the defined maximal tolerable doses to organs of risk, were calculated to be 272±253 nmol (452±420 μg) and 7.3±5.1 GBq. Using the actually injected amount (235±155 μg) and the same maximal tolerable doses, the potential improvement for the tumor BED was 1–3 fold. The results suggest that currently given amounts for therapy are in the appropriate order of magnitude for many lesions. However, for lesions with high binding site density or lower perfusion, optimizing the peptide amount and activity might improve the tumor-to-kidney and tumor-to-salivary glands BED ratio considerably.
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Affiliation(s)
- Peter Kletting
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
- * E-mail:
| | - Christiane Schuchardt
- THERANOSTICS Center for Molecular Radiotherapy and Molecular Imaging (PET/CT), Zentralklinik Bad Berka, Bad Berka, Germany
| | - Harshad R. Kulkarni
- THERANOSTICS Center for Molecular Radiotherapy and Molecular Imaging (PET/CT), Zentralklinik Bad Berka, Bad Berka, Germany
| | - Mostafa Shahinfar
- THERANOSTICS Center for Molecular Radiotherapy and Molecular Imaging (PET/CT), Zentralklinik Bad Berka, Bad Berka, Germany
| | - Aviral Singh
- THERANOSTICS Center for Molecular Radiotherapy and Molecular Imaging (PET/CT), Zentralklinik Bad Berka, Bad Berka, Germany
| | - Gerhard Glatting
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Richard P. Baum
- THERANOSTICS Center for Molecular Radiotherapy and Molecular Imaging (PET/CT), Zentralklinik Bad Berka, Bad Berka, Germany
| | - Ambros J. Beer
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
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48
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Hardiansyah D, Begum NJ, Kletting P, Mottaghy FM, Glatting G. Sensitivity Analysis of a Physiologically Based Pharmacokinetic Model Used for Treatment Planning in Peptide Receptor Radionuclide Therapy. Cancer Biother Radiopharm 2016; 31:217-24. [PMID: 27403777 DOI: 10.1089/cbr.2016.2012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The aim of this work was to evaluate the sensitivity of time-integrated activity coefficients (TIACs) on the erroneously chosen prior knowledge in a physiologically based pharmacokinetic (PBPK) model used for treatment planning in peptide receptor radionuclide therapy (PRRT). Parameters of the PBPK model were fitted to the biokinetic data of 15 patients after the injection of (111)In-DTPAOC. The fittings were performed using fixed parameter values taken from literature as prior knowledge (reference case, Ref). The fixed parameters were gender, physical information (e.g., body weight), dissociation rate koff, dissociation constant KD, fraction of blood flow, and spleen and liver volumes. The fittings were repeated with changed fixed parameters (Changed). The relative deviations (RDs) of TIACs calculated from Changed and Ref were analyzed for kidneys, tumor, liver, spleen, remainder, whole body, and serum. A changed koff has the largest effect on RD, the largest RD values were found for changed koff = 0.001 L/min: RDkidneys = (3 ± 3)%, RDtumor = (0.5 ± 4)%, RDliver = (6 ± 9)%, RDspleen = (5 ± 5)%, RDremainder = (2 ± 31)%, RDserum = (-4 ± 25)%, and RDwholebody = (3 ± 16)%. For other changed parameters, the maximum RDs were <1%. The calculation of organ TIACs in PRRT using the PBPK model was little affected by assigning wrong prior knowledge to the evaluated patients. The calculation of bone marrow-absorbed doses could be affected by the inaccurate TIACs of serum and remainder in the case of an inadequate koff.
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Affiliation(s)
- Deni Hardiansyah
- 1 Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University , Mannheim, Germany .,2 Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University , Mannheim, Germany
| | - Nusrat Jihan Begum
- 1 Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University , Mannheim, Germany .,3 Digitale Signalverarbeitung , Information Technology Faculty, Hochschule Mannheim, Mannheim, Germany
| | - Peter Kletting
- 4 Department of Nuclear Medicine, University Hospital Ulm , Ulm, Germany
| | - Felix M Mottaghy
- 5 Klinik für Nuklearmedizin, University Hospital, RWTH Aachen University , Aachen, Germany .,6 Department of Nuclear Medicine, Maastricht University Medical Center (MUMC+) , Maastricht, The Netherlands
| | - Gerhard Glatting
- 1 Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University , Mannheim, Germany
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49
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Delker A, Ilhan H, Zach C, Brosch J, Gildehaus FJ, Lehner S, Bartenstein P, Böning G. The Influence of Early Measurements Onto the Estimated Kidney Dose in [(177)Lu][DOTA(0),Tyr(3)]Octreotate Peptide Receptor Radiotherapy of Neuroendocrine Tumors. Mol Imaging Biol 2016; 17:726-34. [PMID: 25790773 DOI: 10.1007/s11307-015-0839-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE Multiple measurements have been required to estimate the radiation dose to the kidneys resulting from [(177)Lu]DOTATATE therapy for neuroendocrine tumors. The aim of this study was to investigate the influence of early time-point measurement in the renal dose calculation. PROCEDURES Anterior/posterior whole-body planar scintigraphy images were acquired at approx. 1, 24, 48, and 72 h after administration of [(177)Lu]DOTATATE. Furthermore, we acquired planar 1-bed dynamic recordings in 12 frames (5 min each) during the first hour. We assessed kidney exposure with a three-phase model consisting of a linear increase to the maximum within the initial minutes p.i., followed a bi-exponential decline. This three-phase-model served as reference for evaluating accuracy of dose estimates in 105 kidneys calculated by conventional mono-exponential fitting of the final three and four whole-body images. RESULTS Mean effective half-life times for the reference model were 25.8 ± 12.0 min and 63.9 ± 17.6 h, predicting a mean renal dose of 5.7 ± 2.1 Gy. The effective half-life time was 46.3 ± 15.4 h for the last four and 63.3 ± 17.0 h for the last three data points. The mean start of the first whole-body measurement was 1.2 ± 0.1 h p.i. The ratio of fast to slow phases was 28.1 ± 23.9% at this time point, which caused a mean absolute percentage dose deviation of 12.4% for four data points, compared to 3.1% for three data points. At a mean time of 2.4 h p.i. (max 5.1 h), the ratio of fast to slow phase declined below 5%. CONCLUSIONS Kinetic analysis of renal uptake using dynamic planar scans from the first hour after injection revealed a fast and a slow washout phase. Although the fast phase did not contribute substantially to the estimated renal dose, it could influence planar measurements performed within the first hours. We found that the presence of two clearance phases can hamper accurate dose estimation based on a single-phase model, resulting in approximately 12.4% dose underestimation, thus potentially resulting in overtreatment. In the absence of dynamic initial recordings, the first dosimetry measurements should therefore be obtained later than 3-5 h after [(177)Lu]DOTATATE injection. Omitting the early whole-body image reduced the dose estimation error to 3.1%.
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Affiliation(s)
- Andreas Delker
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Harun Ilhan
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Christian Zach
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Julia Brosch
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Franz Josef Gildehaus
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Sebastian Lehner
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Guido Böning
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany.
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Beykan S, Dam JS, Eberlein U, Kaufmann J, Kjærgaard B, Jødal L, Bouterfa H, Bejot R, Lassmann M, Jensen SB. 177Lu-OPS201 targeting somatostatin receptors: in vivo biodistribution and dosimetry in a pig model. EJNMMI Res 2016; 6:50. [PMID: 27294582 PMCID: PMC4906090 DOI: 10.1186/s13550-016-0204-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 05/27/2016] [Indexed: 11/10/2022] Open
Abstract
Background 177Lu is used in peptide receptor radionuclide therapies for the treatment of neuroendocrine tumors. Based on the recent literature, SST2 antagonists are superior to agonists in tumor uptake. The compound OPS201 is the novel somatostatin antagonist showing the highest SST2 affinity. The aim of this study was to measure the in vivo biodistribution and dosimetry of 177Lu-OPS201 in five anesthetized Danish Landrace pigs as an appropriate substitute for humans to quantitatively assess the absorbed doses for future clinical applications. Results 177Lu-OPS201 was obtained with a specific activity ranging from 10 to 17 MBq/μg. Prior to administration, the radiochemical purity was measured as s > 99.7 % in all cases. After injection, fast clearance of the compound from the blood stream was observed. Less than 5 % of the injected activity was presented in blood 10 min after injection. A series of SPECT/CT and whole-body scans conducted until 10 days after intravenous injection showed uptake mostly in the liver, spine, and kidneys. There was no visible uptake in the spleen. Blood samples were taken to determine the time-activity curve in the blood. Time-activity curves and time-integrated activity coefficients were calculated for the organs showing visible uptake. Based on these data, the absorbed organ dose coefficients for a 70-kg patient were calculated with OLINDA/EXM. For humans after an injection of 5 GBq 177Lu-OPS201, the highest predicted absorbed doses are obtained for the kidneys (13.7 Gy), the osteogenic cells (3.9 Gy), the urinary bladder wall (1.8 Gy), and the liver (1.0 Gy). No metabolites of 177Lu-OPS201 were found by radio HPLC analysis. None of the absorbed doses calculated will exceed organ toxicity levels. Conclusions The 177Lu-OPS201 was well tolerated and caused no abnormal physiological or behavioral signs. In vivo distributions and absorbed doses of pigs are comparable to those observed in other publications. According to the biodistribution data in pigs, presented in this work, the expected radiation exposure in humans will be within the acceptable range. Electronic supplementary material The online version of this article (doi:10.1186/s13550-016-0204-9) contains supplementary material, which is available to authorized users.
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