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Cicone F, Gnesin S, Santo G, Stokke C, Bartolomei M, Cascini GL, Minniti G, Paganelli G, Verger A, Cremonesi M. Do we need dosimetry for the optimization of theranostics in CNS tumors? Neuro Oncol 2024; 26:S242-S258. [PMID: 39351795 PMCID: PMC11631076 DOI: 10.1093/neuonc/noae200] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2024] Open
Abstract
Radiopharmaceutical theranostic treatments have grown exponentially worldwide, and internal dosimetry has attracted attention and resources. Despite some similarities with chemotherapy, radiopharmaceutical treatments are essentially radiotherapy treatments, as the release of radiation into tissues is the determinant of the observed clinical effects. Therefore, absorbed dose calculations are key to explaining dose-effect correlations and individualizing radiopharmaceutical treatments. The present article introduces the basic principles of internal dosimetry and provides an overview of available loco-regional and systemic radiopharmaceutical treatments for central nervous system (CNS) tumors. The specific characteristics of dosimetry as applied to these treatments are highlighted, along with their limitations and most relevant results. Dosimetry is performed with higher precision and better reproducibility than in the past, and dosimetric data should be systematically collected, as treatment planning and verification may help exploit the full potential of theranostic of CNS tumors.
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Affiliation(s)
- Francesco Cicone
- Nuclear Medicine Unit, Department of Experimental and Clinical Medicine, “Magna Graecia” University of Catanzaro, Catanzaro, Italy
| | - Silvano Gnesin
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Giulia Santo
- Nuclear Medicine Unit, Department of Experimental and Clinical Medicine, “Magna Graecia” University of Catanzaro, Catanzaro, Italy
| | - Caroline Stokke
- Department of Physics, University of Oslo, Oslo, Norway
- Department of Diagnostic Physics and Computational Radiology, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Mirco Bartolomei
- Nuclear Medicine Unit, Department of Oncology and Haematology, Azienda Ospedaliero-Universitaria di Ferrara, Ferrara, Italy
| | - Giuseppe Lucio Cascini
- Nuclear Medicine Unit, Department of Experimental and Clinical Medicine, “Magna Graecia” University of Catanzaro, Catanzaro, Italy
| | - Giuseppe Minniti
- IRCCS Neuromed, Pozzilli (IS), Italy
- Radiation Oncology Unit, Department of Radiological Sciences, Oncology and Anatomical Pathology, “Sapienza” University of Rome, Rome, Italy
| | - Giovanni Paganelli
- IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori,”Meldola, Italy
| | - Antoine Verger
- Department of Nuclear Medicine and Nancyclotep Imaging Platform, CHRU-Nancy, IADI, INSERM, UMR 1254, Université de Lorraine, Nancy, France
| | - Marta Cremonesi
- Unit of Radiation Research, IEO, European Institute of Oncology IRCCS, Milan, Italy
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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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Musa AS, Abdul Hadi MFR, Hashikin NAA, Ashour NI, Ying CK. Dosimetric assessment of Gadolinium-159 for hepatic radioembolization: Tomographic images and Monte Carlo simulation. Appl Radiat Isot 2023; 199:110916. [PMID: 37393764 DOI: 10.1016/j.apradiso.2023.110916] [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: 10/06/2022] [Revised: 06/03/2023] [Accepted: 06/26/2023] [Indexed: 07/04/2023]
Abstract
A common therapeutic radionuclide used in hepatic radioembolization is yttrium-90 (90Y). However, the absence of gamma emissions makes it difficult to verify the post-treatment distribution of 90Y microspheres. Gadolinium-159 (159Gd) has physical properties that are suitable for therapy and post-treatment imaging in hepatic radioembolization procedures. The current study is innovative for conducting a dosimetric investigation of the use of 159Gd in hepatic radioembolization by simulating tomographic images using the Geant4 application for tomographic emission (GATE) Monte Carlo (MC) simulation. For registration and segmentation, tomographic images of five patients with hepatocellular carcinoma (HCC) who had undergone transarterial radioembolization (TARE) therapy were processed using a 3D slicer. The tomographic images with 159Gd and 90Y separately were simulated using the GATE MC Package. The output of simulation (dose image) was uploaded to 3D slicer to compute the absorbed dose for each organ of interests. 159Gd were able to provide a recommended dose of 120 Gy to the tumour, with normal liver and lungs absorbed doses close to that of 90Y and less than the respective maximum permitted doses of 70 Gy and 30 Gy, respectively. Compared to 90Y, 159Gd requires higher administered activity approximately 4.92 times to achieve a tumour dose of 120 Gy. Thus; this research gives new insights into the use of 159Gd as a theranostic radioisotope, with the potential to be used as a90Y alternative for liver radioembolization.
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Affiliation(s)
- Ahmed Sadeq Musa
- School of Physics, Universiti Sains Malaysia, 11800, USM, Penang, Malaysia; Department of Physiology and Medical Physics, College of Medicine, University of Kerbala, 56001, Kerbala, Iraq
| | | | | | - Nabeel Ibrahim Ashour
- School of Physics, Universiti Sains Malaysia, 11800, USM, Penang, Malaysia; Department of Physics, College of Science, University of Kerbala, 56001, Kerbala, Iraq
| | - Chee Keat Ying
- Oncological & Radiological Science Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200, Kepala Batas, Penang, Malaysia
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Italiano A, Pistone D, Amato E, Baldari S, Auditore L. Internal Bremsstrahlung, the missing process in beta decay Monte Carlo simulation: The relevance in 32P Dose-Point-Kernel estimation. Phys Med 2023; 110:102585. [PMID: 37119675 DOI: 10.1016/j.ejmp.2023.102585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 03/03/2023] [Accepted: 04/07/2023] [Indexed: 05/01/2023] Open
Abstract
PURPOSE In nuclear medicine, Dose Point Kernels (DPKs), representing the energy deposited all around a point isotropic source, are extensively used for dosimetry and are usually obtained by Monte Carlo (MC) simulations. For beta-decaying nuclides, DPK is usually estimated neglecting Internal Bremsstrahlung (IB) emission, a process always accompanying the beta decay and consisting in the emission of photons having a continuous spectral distribution. This work aims to study the significance of IB emission for DPK estimation in the case of 32P and provide DPK values corrected for the IB photon contribution. METHODS DPK, in terms of the scaled absorbed dose fraction, F(R/X90), was first estimated by GAMOS MC simulation using the standard beta decay spectrum of 32P, Fβ(R/X90). Subsequently, an additional source term accounting for IB photons and their spectral distribution was defined and used for a further MC simulation, thus evaluating the contribution of IB emission to DPK values, Fβ+IB(R/X90). The relative percent difference, δ, between the DPKs obtained by the two approaches, Fβ+IB vs. Fβ, was studied as a function of the radial distance, R. RESULTS As far as the energy deposition is mainly due to the beta particles, IB photons does not significantly contribute to DPK; conversely, for larger R, Fβ+IB values are higher by 30-40% than Fβ. CONCLUSIONS The inclusion of IB emission in the MC simulations for DPK estimations is recommended, as well as the use of the DPK values corrected for IB photons, here provided.
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Affiliation(s)
- Antonio Italiano
- INFN, National Institute for Nuclear Physics, Section of Catania, Italy; MIFT Department, University of Messina, Italy
| | - Daniele Pistone
- INFN, National Institute for Nuclear Physics, Section of Catania, Italy; Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Italy.
| | - Ernesto Amato
- INFN, National Institute for Nuclear Physics, Section of Catania, Italy; Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Italy; Health Physics Unit, University Hospital 'Gaetano Martino', Messina, Italy
| | - Sergio Baldari
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Italy; Nuclear Medicine Unit, University Hospital 'Gaetano Martino', Messina, Italy
| | - Lucrezia Auditore
- INFN, National Institute for Nuclear Physics, Section of Catania, Italy; Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Italy
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Pistone D, Italiano A, Auditore L, Mandaglio G, Campenní A, Baldari S, Amato E. Relevance of artefacts in 99mTc-MAA SPECT scans on pre-therapy patient-specific 90Y TARE internal dosimetry: a GATE Monte Carlo study. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac6b0f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 04/27/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. The direct Monte Carlo (MC) simulation of radiation transport exploiting morphological and functional tomographic imaging as input data is considered the gold standard for internal dosimetry in nuclear medicine, and it is increasingly used in studies regarding trans-arterial radio-embolization (TARE). However, artefacts affecting the functional scans, such as reconstruction artefacts and motion blurring, decrease the accuracy in defining the radionuclide distribution in the simulations and consequently lead to errors in absorbed dose estimations. In this study, the relevance of such artefacts in patient-specific three-dimensional MC dosimetry was investigated in three cases of 90Y TARE. Approach. The pre-therapy 99mTc MacroAggregate Albumin (Tc-MAA) SPECTs and CTs of patients were used as input for simulations performed with the GEANT4-based toolkit GATE. Several pre-simulation SPECT-masking techniques were implemented, with the aim of zeroing the decay probability in air, in lungs, or in the whole volume outside the liver. Main results. Increments in absorbed dose up to about +40% with respect to the native-SPECT simulations were found in liver-related volumes of interest (VOIs), depending on the masking procedure adopted. Regarding lungs-related VOIs, decrements in absorbed doses in right lung as high as −90% were retrieved. Significance. These results highlight the relevant influence of SPECT artefacts, if not properly treated, on dosimetric outcomes for 90Y TARE cases. Well-designed SPECT-masking techniques appear to be a promising way to correct for such misestimations.
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Cicone F, Viertl D, Denoël T, Stabin MG, Prior JO, Gnesin S. Comparison of absorbed dose extrapolation methods for mouse-to-human translation of radiolabelled macromolecules. EJNMMI Res 2022; 12:21. [PMID: 35403982 PMCID: PMC9001797 DOI: 10.1186/s13550-022-00893-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 03/26/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Extrapolation of human absorbed doses (ADs) from biodistribution experiments on laboratory animals is used to predict the efficacy and toxicity profiles of new radiopharmaceuticals. Comparative studies between available animal-to-human dosimetry extrapolation methods are missing. We compared five computational methods for mice-to-human AD extrapolations, using two different radiopharmaceuticals, namely [111In]CHX-DTPA-scFv78-Fc and [68Ga]NODAGA-RGDyK. Human organ-specific time-integrated activity coefficients (TIACs) were derived from biodistribution studies previously conducted in our centre. The five computational methods adopted are based on simple direct application of mice TIACs to human organs (M1), relative mass scaling (M2), metabolic time scaling (M3), combined mass and time scaling (M4), and organ-specific allometric scaling (M5), respectively. For [68Ga]NODAGA-RGDyK, these methods for mice-to-human extrapolations were tested against the ADs obtained on patients, previously published by our group. Lastly, an average [68Ga]NODAGA-RGDyK-specific allometric parameter αnew was calculated from the organ-specific biological half-lives in mouse and humans and retrospectively applied to M3 and M4 to assess differences in human AD predictions with the α = 0.25 recommended by previous studies. RESULTS For both radiopharmaceuticals, the five extrapolation methods showed significantly different AD results (p < 0.0001). In general, organ ADs obtained with M3 were higher than those obtained with the other methods. For [68Ga]NODAGA-RGDyK, no significant differences were found between ADs calculated with M3 and those obtained directly on human subjects (H) (p = 0.99; average M3/H AD ratio = 1.03). All other methods for dose extrapolations resulted in ADs significantly different from those calculated directly on humans (all p ≤ 0.0001). Organ-specific allometric parameters calculated using combined experimental [68Ga]NODAGA-RGDyK mice and human biodistribution data varied significantly. ADs calculated with M3 and M4 after the application of αnew = 0.17 were significantly different from those obtained by the application of α = 0.25 (both p < 0.001). CONCLUSIONS Available methods for mouse-to-human dosimetry extrapolations provided significantly different results in two different experimental models. For [68Ga]NODAGA-RGDyK, the best approximation of human dosimetry was shown by M3, applying a metabolic scaling to the mouse organ TIACs. The accuracy of more refined extrapolation algorithms adopting model-specific metabolic scaling parameters should be further investigated.
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Affiliation(s)
- Francesco Cicone
- Department of Experimental and Clinical Medicine, and Neuroscience Research Centre, PET/MR Unit, “Magna Graecia” University of Catanzaro, Catanzaro, Italy
- Nuclear Medicine Unit, University Hospital “Mater Domini”, Catanzaro, Italy
- University of Lausanne, Lausanne, Switzerland
| | - David Viertl
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Rue du Bugnon 46, 1011 Lausanne, Switzerland
| | - Thibaut Denoël
- Department of Experimental and Clinical Medicine, and Neuroscience Research Centre, PET/MR Unit, “Magna Graecia” University of Catanzaro, Catanzaro, Italy
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Rue du Bugnon 46, 1011 Lausanne, Switzerland
| | | | - John O. Prior
- University of Lausanne, Lausanne, Switzerland
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Rue du Bugnon 46, 1011 Lausanne, Switzerland
| | - Silvano Gnesin
- University of Lausanne, Lausanne, Switzerland
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
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Auditore L, Pistone D, Amato E, Italiano A. Monte Carlo methods in nuclear medicine. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00136-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Ligonnet T, Pistone D, Auditore L, Italiano A, Amato E, Campennì A, Schaefer N, Boughdad S, Baldari S, Gnesin S. Simplified patient-specific renal dosimetry in 177Lu therapy: a proof of concept. Phys Med 2021; 92:75-85. [PMID: 34875425 DOI: 10.1016/j.ejmp.2021.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 11/17/2021] [Accepted: 11/20/2021] [Indexed: 12/25/2022] Open
Abstract
PURPOSE The aim of this proof-of-concept study is to propose a simplified personalized kidney dosimetry procedure in 177Lu peptide receptor radionuclide therapy (PRRT) for neuroendocrine tumors and metastatic prostate cancer. It relies on a single quantitative SPECT/CT acquisition and multiple radiometric measurements executed with a collimated external probe, properly directed on kidneys. METHODS We conducted a phantom study involving external count-rate measurements in an abdominal phantom setup filled with activity concentrations of 99mTc, reproducing patient-relevant organ effective half-lives occurring in 177Lu PRRT. GATE Monte Carlo (MC) simulations of the experiment, using 99mTc and 177Lu as sources, were performed. Furthermore, we tested this method via MC on a clinical case of 177Lu-DOTATATE PRRT with SPECT/CT images at three time points (2, 20 and 70 hrs), comparing a simplified kidney dosimetry, employing a single SPECT/CT and probe measurements at three time points, with the complete MC dosimetry. RESULTS The experimentally estimated kidney half-life with background subtraction applied was compatible within 3% with the expected value. The MC simulations of the phantom study, both with 99mTc and 177Lu, confirmed a similar level of accuracy. Concerning the clinical case, the simplified dosimetric method led to a kidney dose estimation compatible with the complete MC dosimetry within 6%, 12% and 2%, using respectively the SPECT/CT at 2, 20 and 70 hrs. CONCLUSIONS The proposed simplified procedure provided a satisfactory accuracy and would reduce the imaging required to derive the kidney absorbed dose to a unique quantitative SPECT/CT, with consequent benefits in terms of clinic workflows and patient comfort.
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Affiliation(s)
- Thomas Ligonnet
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Daniele Pistone
- MIFT Department, Università degli Studi di Messina, Messina, Italy; INFN Sezione di Catania, Catania, Italy.
| | - Lucrezia Auditore
- BIOMORF Department, Università degli Studi di Messina, Messina, Italy
| | - Antonio Italiano
- MIFT Department, Università degli Studi di Messina, Messina, Italy; INFN Sezione di Catania, Catania, Italy
| | - Ernesto Amato
- INFN Sezione di Catania, Catania, Italy; BIOMORF Department, Università degli Studi di Messina, Messina, Italy
| | - Alfredo Campennì
- BIOMORF Department, Università degli Studi di Messina, Messina, Italy; Nuclear Medicine Unit, University Hospital "G. Martino", Messina, Italy
| | - Niklaus Schaefer
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Sarah Boughdad
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Sergio Baldari
- BIOMORF Department, Università degli Studi di Messina, Messina, Italy; Nuclear Medicine Unit, University Hospital "G. Martino", Messina, Italy
| | - Silvano Gnesin
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
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Brosch-Lenz J, Uribe C, Gosewisch A, Kaiser L, Todica A, Ilhan H, Gildehaus FJ, Bartenstein P, Rahmim A, Celler A, Ziegler S, Böning G. Influence of dosimetry method on bone lesion absorbed dose estimates in PSMA therapy: application to mCRPC patients receiving Lu-177-PSMA-I&T. EJNMMI Phys 2021; 8:26. [PMID: 33709253 PMCID: PMC7952490 DOI: 10.1186/s40658-021-00369-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 02/23/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Patients with metastatic, castration-resistant prostate cancer (mCRPC) present with an increased tumor burden in the skeleton. For these patients, Lutetium-177 (Lu-177) radioligand therapy targeting the prostate-specific membrane antigen (PSMA) has gained increasing interest with promising outcome data. Patient-individualized dosimetry enables improvement of therapy success with the aim of minimizing absorbed dose to organs at risk while maximizing absorbed dose to tumors. Different dosimetric approaches with varying complexity and accuracy exist for this purpose. The Medical Internal Radiation Dose (MIRD) formalism applied to tumors assumes a homogeneous activity distribution in a sphere with unit density for derivation of tumor S values (TSV). Voxel S value (VSV) approaches can account for heterogeneous activities but are simulated for a specific tissue. Full patient-individual Monte Carlo (MC) absorbed dose simulation addresses both, heterogeneous activity and density distributions. Subsequent CT-based density weighting has the potential to overcome the assumption of homogeneous density in the MIRD formalism with TSV and VSV methods, which could be a major limitation for the application in bone metastases with heterogeneous density. The aim of this investigation is a comparison of these methods for bone lesion dosimetry in mCRPC patients receiving Lu-177-PSMA therapy. RESULTS In total, 289 bone lesions in 15 mCRPC patients were analyzed. Percentage difference (PD) of average absorbed dose per lesion compared to MC, averaged over all lesions, was + 14 ± 10% (min: - 21%; max: + 56%) for TSVs. With lesion-individual density weighting using Hounsfield Unit (HU)-to-density conversion on the patient's CT image, PD was reduced to - 8 ± 1% (min: - 10%; max: - 3%). PD on a voxel level for three-dimensional (3D) voxel-wise dosimetry methods, averaged per lesion, revealed large PDs of + 18 ± 11% (min: - 27%; max: + 58%) for a soft tissue VSV approach compared to MC; after voxel-wise density correction, this was reduced to - 5 ± 1% (min: - 12%; max: - 2%). CONCLUSION Patient-individual MC absorbed dose simulation is capable to account for heterogeneous densities in bone lesions. Since the computational effort prevents its routine clinical application, TSV or VSV dosimetry approaches are used. This study showed the necessity of lesion-individual density weighting for TSV or VSV in Lu-177-PSMA therapy bone lesion dosimetry.
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Affiliation(s)
- Julia Brosch-Lenz
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Carlos Uribe
- PET Functional Imaging, BC Cancer, 600 West 10th Avenue, Vancouver, BC V5Z 4E6 Canada
- Department of Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9 Canada
| | - Astrid Gosewisch
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Lena Kaiser
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Andrei Todica
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Harun Ilhan
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Franz Josef Gildehaus
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Arman Rahmim
- PET Functional Imaging, BC Cancer, 600 West 10th Avenue, Vancouver, BC V5Z 4E6 Canada
- Department of Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9 Canada
- Department of Integrative Oncology, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC V5Z 1L3 Canada
| | - Anna Celler
- Department of Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9 Canada
| | - Sibylle Ziegler
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Guido Böning
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
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Auditore L, Amato E, Boughdad S, Meyer M, Testart N, Cicone F, Beigelman-Aubry C, Prior JO, Schaefer N, Gnesin S. Monte Carlo 90Y PET/CT dosimetry of unexpected focal radiation-induced lung damage after hepatic radioembolisation. Phys Med Biol 2020; 65:235014. [PMID: 33245055 DOI: 10.1088/1361-6560/abbc80] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Transarterial radioembolization (TARE) with 90Y-loaded microspheres is an established therapeutic option for inoperable hepatic tumors. Increasing knowledge regarding TARE hepatic dose-response and dose-toxicity correlation is available but few studies have investigated dose-toxicity correlation in extra-hepatic tissues. We investigated absorbed dose levels for the appearance of focal lung damage in a case of off-target deposition of 90Y microspheres and compared them with the corresponding thresholds recommended to avoiding radiation induced lung injury following TARE. A 64-year-old male patient received 1.6 GBq of 90Y-labelled glass microspheres for an inoperable left lobe hepatocellular carcinoma. A focal off-target accumulation of radiolabeled microspheres was detected in the left lung upper lobe at the post-treatment 90Y-PET/CT, corresponding to a radiation-induced inflammatory lung lesion at the 3-months 18F-FDG PET/CT follow-up. 90Y-PET/CT data were used as input for Monte-Carlo based absorbed dose estimations. Dose-volume-histograms were computed to characterize the heterogeneity of absorbed dose distribution. The dose level associated with the appearance of lung tissue damage was estimated as the median absorbed dose measured at the edge of the inflammatory nodule. To account for respiratory movements and possible inaccuracy of image co-registration, three different methods were evaluated to define the irradiated off-target volume. Monte Carlo-derived absorbed dose distribution showed a highly heterogeneous absorbed dose pattern at the site of incidental microsphere deposition (volume = 2.13 ml) with a maximum dose of 630 Gy. Absorbed dose levels ranging from 119 Gy to 133 Gy, were estimated at the edge of the inflammatory nodule, depending on the procedure used to define the target volume. This report describes an original Monte Carlo based patient-specific dosimetry methodology for the study of the radiation-induced damage in a focal lung lesion after TARE. In our patient, radiation-induced focal lung damage occurred at significantly higher absorbed doses than those considered for single administration or cumulative lung dose delivered during TARE.
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Affiliation(s)
- Lucrezia Auditore
- Section of Radiological Sciences, Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Italy
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Italiano A, Auditore L, Amato E. Enhancement of radiation exposure risk from β-emitter radionuclides due to Internal Bremsstrahlung effect: A Monte Carlo study of 90Y case. Phys Med 2020; 76:159-165. [PMID: 32682293 DOI: 10.1016/j.ejmp.2020.06.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/09/2020] [Accepted: 06/23/2020] [Indexed: 11/29/2022] Open
Abstract
Employment of β-decaying radionuclides, used in many fields (industrial, clinical, research) requires a correct assessment of the operators' radiological exposure. Usually, in the dosimetric evaluation, the contribution coming from Internal Bremsstrahlung (IB) accompanying the β-decay is not kept into account; nevertheless, this negligibility does not always appear justified, at least for high-energy β-emitters. By means of Monte Carlo (MC) simulations, we showed how the contribution from IB photons is noteworthy for the evaluation of the overall radiation absorbed dose in the case of 90Y source. We evaluated an increase of the absorbed doses, respectively for a point source and the considered receptacles, up to + 34% and + 60% or + 15% and + 28%, depending on the adopted model of IB spectrum. These results demonstrate the relevance of IB phenomenon in radiation protection estimations and suggest extending future theoretical and experimental studies to other β-decaying radionuclides.
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Affiliation(s)
- Antonio Italiano
- Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Italy; MIFT Department, University of Messina, Italy
| | - Lucrezia Auditore
- Section of Radiological Sciences, Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Italy.
| | - Ernesto Amato
- Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Italy; Section of Radiological Sciences, Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Italy
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Gnesin S, Müller J, Burger IA, Meisel A, Siano M, Früh M, Choschzick M, Müller C, Schibli R, Ametamey SM, Kaufmann PA, Treyer V, Prior JO, Schaefer N. Radiation dosimetry of 18F-AzaFol: A first in-human use of a folate receptor PET tracer. EJNMMI Res 2020; 10:32. [PMID: 32270313 PMCID: PMC7142191 DOI: 10.1186/s13550-020-00624-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 03/27/2020] [Indexed: 12/21/2022] Open
Abstract
Background The folate receptor alpha (FRα) is an interesting target for imaging and therapy of different cancers. We present the first in-human radiation dosimetry and radiation safety results acquired within a prospective, multicentric trial (NCT03242993) evaluating the 18F-AzaFol (3′-aza-2′-[18F]fluorofolic acid) as the first clinically assessed PET tracer targeting the FRα. Material and methods Six eligible patients presented a histologically confirmed adenocarcinoma of the lung with measurable lesions (≥ 10 mm according to RECIST 1.1). TOF-PET images were acquired at 3, 11, 18, 30, 40, 50, and 60 min after the intravenous injection of 327 MBq (range 299–399 MBq) of 18F-AzaFol to establish dosimetry. Organ absorbed doses (AD), tumor AD, and patient effective doses (E) were assessed using the OLINDA/EXM v.2.0 software and compared with pre-clinical results. Results No serious related adverse events were observed. The highest AD were in the liver, the kidneys, the urinary bladder, and the spleen (51.9, 45.8, 39.1, and 35.4 μGy/MBq, respectively). Estimated patient and gender-averaged E were 18.0 ± 2.6 and 19.7 ± 1.4 μSv/MBq, respectively. E in-human exceeded the value of 14.0 μSv/MBq extrapolated from pre-clinical data. Average tumor AD was 34.8 μGy/MBq (range 13.6–60.5 μGy/MBq). Conclusions 18F-Azafol is a PET agent with favorable dosimetric properties and a reasonable radiation dose burden for patients which merits further evaluation to assess its performance. Trial registration ClinicalTrial.gov, NCT03242993, posted on August 8, 2017
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Affiliation(s)
- Silvano Gnesin
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Joachim Müller
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Irene A Burger
- Department of Nuclear Medicine, University Hospital of Zurich, Zurich, Switzerland.,Department of Nuclear Medicine, Kantonsspital Baden, Baden, Switzerland
| | - Alexander Meisel
- Department of Nuclear Medicine, University Hospital of Zurich, Zurich, Switzerland.,Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland.,Department of Internal Medicine-Hematology & Oncology, Stadtspital Waid, Zurich, Switzerland
| | - Marco Siano
- Department of Oncology and Hematology, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Martin Früh
- Department of Oncology and Hematology, Cantonal Hospital St. Gallen, St. Gallen, Switzerland.,University of Bern, Bern, Switzerland
| | - Matthias Choschzick
- Institute for Pathology and Molecular Pathology, University Hospital of Zurich, Zurich, Switzerland
| | - Cristina Müller
- Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland.,Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI, Villigen, Switzerland
| | - Roger Schibli
- Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland.,Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI, Villigen, Switzerland
| | - Simon M Ametamey
- Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Philipp A Kaufmann
- Department of Nuclear Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Valerie Treyer
- Department of Nuclear Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - John O Prior
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital and University of Lausanne, Rue du Bugnon 46, CH-1011, Lausanne, Switzerland.
| | - Niklaus Schaefer
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital and University of Lausanne, Rue du Bugnon 46, CH-1011, Lausanne, Switzerland
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Auditore L, Amato E, Italiano A, Arce P, Campennì A, Baldari S. Internal dosimetry for TARE therapies by means of GAMOS Monte Carlo simulations. Phys Med 2019; 64:245-251. [DOI: 10.1016/j.ejmp.2019.07.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/26/2019] [Accepted: 07/27/2019] [Indexed: 11/24/2022] Open
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