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Hammersen N, Jentzen W, Stawitzki F, Herrmann K, Kersting D, Fragoso Costa P, Moraitis A. PET quantification performance of the oversize-volume-of-interest approach in the context of tumour dosimetry in radionuclide therapy planning. Phys Med Biol 2024; 69:165007. [PMID: 38925139 DOI: 10.1088/1361-6560/ad5c36] [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: 03/10/2024] [Accepted: 06/26/2024] [Indexed: 06/28/2024]
Abstract
Objective.The partial-volume effect (PVE) is an important factor impairing tumour quantification in molecular imaging. The commonly used contour-volume-of-interest (contour-VOI) approach to correct for this effect employs phantom-based recovery coefficients. Applying oversize-VOIs could offer superior quantification accuracy in small lesions. The oversize-VOI approach uses a large oversize volume to determine the total tumour activity after applying a background correction. Aims of this study were to provide a procedure for the application of the oversize-VOI approach and to compare its performance to the contour-VOI approach in PET imaging.Approach.A sphere tumour model was simulated to determine the oversize diameter that contained 90%, 95%, and 98% of the total activity as a function of the tumour size. Experimental investigations involving phantom and clinical data were conducted on a digital PET/CT scanner. In the phantom investigation, 12 spherical tumour inserts (diameters ranging from 3.7 to 37.4 mm) containing18F-solution were used. The accuracy of the contour- and oversize-VOI approach was evaluated for different signal-to-background ratios (20-3). Clinically, both approaches were applied on PET/CT images acquired with18F-labelled prostate-specific membrane antigen in prostate cancer patients.Main results.From the tumour model, we deduced that an oversize-VOI of two PET spatial resolutions larger than the physical lesion diameter contains at least 98% of the total activity for lesions with diameters down to one PET spatial resolution, while minimizing the background contribution. Both approaches were robust against varying phantom and clinical imaging conditions. Performance of the oversize-VOI approach was favorable for lesions below 10 mm in diameter, whereas the contour-VOI approach was slightly more accurate for sizes above 10 mm.Significance.The oversize-VOI approach facilitates image quantification of small tumours. It is simple and effective to correct for the PVE and may be used in pre-therapeutic (small) tumour dosimetry.
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Affiliation(s)
- Noah Hammersen
- Department of Nuclear Medicine, West German Cancer Center (WTZ), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, Essen, Germany
| | - Walter Jentzen
- Department of Nuclear Medicine, West German Cancer Center (WTZ), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, Essen, Germany
| | - Florian Stawitzki
- Department of Nuclear Medicine, West German Cancer Center (WTZ), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, Essen, Germany
| | - Ken Herrmann
- Department of Nuclear Medicine, West German Cancer Center (WTZ), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, Essen, Germany
| | - David Kersting
- Department of Nuclear Medicine, West German Cancer Center (WTZ), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, Essen, Germany
| | - Pedro Fragoso Costa
- Department of Nuclear Medicine, West German Cancer Center (WTZ), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, Essen, Germany
| | - Alexandros Moraitis
- Department of Nuclear Medicine, West German Cancer Center (WTZ), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, Essen, Germany
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Kayal G, Barbosa N, Marín CC, Ferrer L, Fragoso-Negrín JA, Grosev D, Gupta SK, Hidayati NR, Moalosi TCG, Poli GL, Thakral P, Tsapaki V, Vauclin S, Vergara-Gil A, Knoll P, Hobbs RF, Bardiès M. Quality Assurance Considerations in Radiopharmaceutical Therapy Dosimetry Using PLANETDose: An International Atomic Energy Agency Study. J Nucl Med 2024; 65:125-131. [PMID: 37884334 PMCID: PMC10755524 DOI: 10.2967/jnumed.122.265340] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 07/25/2023] [Indexed: 10/28/2023] Open
Abstract
Implementation of radiopharmaceutical therapy dosimetry varies depending on the clinical application, dosimetry protocol, software, and ultimately the operator. Assessing clinical dosimetry accuracy and precision is therefore a challenging task. This work emphasizes some pitfalls encountered during a structured analysis, performed on a single-patient dataset consisting of SPECT/CT images by various participants using a standard protocol and clinically approved commercial software. Methods: The clinical dataset consisted of the dosimetric study of a patient administered with [177Lu]Lu-DOTATATE at Tygerberg Hospital, South Africa, as a part of International Atomic Energy Agency-coordinated research project E23005. SPECT/CT images were acquired at 5 time points postinjection. Patient and calibration images were reconstructed on a workstation, and a calibration factor of 122.6 Bq/count was derived independently and provided to the participants. A standard dosimetric protocol was defined, and PLANETDose (version 3.1.1) software was installed at 9 centers to perform the dosimetry of 3 treatment cycles. The protocol included rigid image registration, segmentation (semimanual for organs, activity threshold for tumors), and dose voxel kernel convolution of activity followed by absorbed dose (AD) rate integration to obtain the ADs. Iterations of the protocol were performed by participants individually and within collective training, the results of which were analyzed for dosimetric variability, as well as for quality assurance and error analysis. Intermediary checkpoints were developed to understand possible sources of variation and to differentiate user error from legitimate user variability. Results: Initial dosimetric results for organs (liver and kidneys) and lesions showed considerable interoperator variability. Not only was the generation of intermediate checkpoints such as total counts, volumes, and activity required, but also activity-to-count ratio, activity concentration, and AD rate-to-activity concentration ratio to determine the source of variability. Conclusion: When the same patient dataset was analyzed using the same dosimetry procedure and software, significant disparities were observed in the results despite multiple sessions of training and feedback. Variations due to human error could be minimized or avoided by performing intensive training sessions, establishing intermediate checkpoints, conducting sanity checks, and cross-validating results across physicists or with standardized datasets. This finding promotes the development of quality assurance in clinical dosimetry.
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Affiliation(s)
- Gunjan Kayal
- CRCT, UMR 1037, INSERM, Université Toulouse III Paul Sabatier, Toulouse, France
- SCK CEN, Belgian Nuclear Research Centre, Mol, Belgium
| | | | | | - Ludovic Ferrer
- Medical Physics Department, ICO René Gauducheau, Nantes, France
- CRCINA, UMR 1232, INSERM, France
| | - José-Alejandro Fragoso-Negrín
- DOSIsoft SA, Cachan, France
- IRCM, UMR 1194 INSERM, Universite de Montpellier and Institut Regional du Cancer de Montpellier, Montpellier, France
| | - Darko Grosev
- Department of Nuclear Medicine and Radiation Protection, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Santosh Kumar Gupta
- Department of Nuclear Medicine and PET, Mahamana Pandit Madanmohan Malviya Cancer Centre and Homi Bhabha Cancer Centre, Varanasi, India
| | - Nur Rahmah Hidayati
- Research Center and Technology for Radiation Safety and Metrology-National Research and Innovation Agency, Jakarta, Indonesia
| | - Tumelo C G Moalosi
- Department of Medical Imaging and Clinical Oncology, Medical Physics, Nuclear Medicine Division, Faculty of Medicine and Health Science, Stellenbosch University, Tygerberg Hospital, Cape Town, South Africa
| | - Gian Luca Poli
- Department of Medical Physics, ASST Papa Giovanni XXIII, Bergamo, Italy
| | - Parul Thakral
- Department of Nuclear Medicine, Fortis Memorial Research Institute, Gurugram, India
| | - Virginia Tsapaki
- Dosimetry and Medical Radiation Physics, International Atomic Energy Agency, Vienna, Austria
| | | | - Alex Vergara-Gil
- CRCT, UMR 1037, INSERM, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Peter Knoll
- Dosimetry and Medical Radiation Physics, International Atomic Energy Agency, Vienna, Austria
| | - Robert F Hobbs
- Johns Hopkins Medical Institute, Baltimore, Maryland; and
| | - Manuel Bardiès
- IRCM, UMR 1194 INSERM, Universite de Montpellier and Institut Regional du Cancer de Montpellier, Montpellier, France;
- Département de Médecine Nucléaire, Institut Régional du Cancer de Montpellier, Montpellier, France
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3
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Tran-Gia J, Denis-Bacelar AM, Ferreira KM, Robinson AP, Bobin C, Bonney LM, Calvert N, Collins SM, Fenwick AJ, Finocchiaro D, Fioroni F, Giannopoulou K, Grassi E, Heetun W, Jewitt SJ, Kotzasarlidou M, Ljungberg M, Lourenço V, McGowan DR, Mewburn-Crook J, Sabot B, Scuffham J, Sjögreen Gleisner K, Solc J, Thiam C, Tipping J, Wevrett J, Lassmann M. On the use of solid 133Ba sources as surrogate for liquid 131I in SPECT/CT calibration: a European multi-centre evaluation. EJNMMI Phys 2023; 10:73. [PMID: 37993667 PMCID: PMC10665282 DOI: 10.1186/s40658-023-00582-3] [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: 04/27/2023] [Accepted: 09/25/2023] [Indexed: 11/24/2023] Open
Abstract
INTRODUCTION Commissioning, calibration, and quality control procedures for nuclear medicine imaging systems are typically performed using hollow containers filled with radionuclide solutions. This leads to multiple sources of uncertainty, many of which can be overcome by using traceable, sealed, long-lived surrogate sources containing a radionuclide of comparable energies and emission probabilities. This study presents the results of a quantitative SPECT/CT imaging comparison exercise performed within the MRTDosimetry consortium to assess the feasibility of using 133Ba as a surrogate for 131I imaging. MATERIALS AND METHODS Two sets of four traceable 133Ba sources were produced at two National Metrology Institutes and encapsulated in 3D-printed cylinders (volume range 1.68-107.4 mL). Corresponding hollow cylinders to be filled with liquid 131I and a mounting baseplate for repeatable positioning within a Jaszczak phantom were also produced. A quantitative SPECT/CT imaging comparison exercise was conducted between seven members of the consortium (eight SPECT/CT systems from two major vendors) based on a standardised protocol. Each site had to perform three measurements with the two sets of 133Ba sources and liquid 131I. RESULTS As anticipated, the 131I pseudo-image calibration factors (cps/MBq) were higher than those for 133Ba for all reconstructions and systems. A site-specific cross-calibration reduced the performance differences between both radionuclides with respect to a cross-calibration based on the ratio of emission probabilities from a median of 12-1.5%. The site-specific cross-calibration method also showed agreement between 133Ba and 131I for all cylinder volumes, which highlights the potential use of 133Ba sources to calculate recovery coefficients for partial volume correction. CONCLUSION This comparison exercise demonstrated that traceable solid 133Ba sources can be used as surrogate for liquid 131I imaging. The use of solid surrogate sources could solve the radiation protection problem inherent in the preparation of phantoms with 131I liquid activity solutions as well as reduce the measurement uncertainties in the activity. This is particularly relevant for stability measurements, which have to be carried out at regular intervals.
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Affiliation(s)
- Johannes Tran-Gia
- Department of Nuclear Medicine, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany.
| | | | | | | | - Christophe Bobin
- Université Paris-Saclay, CEA, List, Laboratoire National Henri Becquerel (LNE-LNHB), 91120, Palaiseau, France
| | - Lara M Bonney
- Department of Medical Physics and Clinical Engineering, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Nicholas Calvert
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Manchester, UK
| | - Sean M Collins
- National Physical Laboratory, Hampton Road, Teddington, UK
- School of Mathematics and Physics, University of Surrey, Guildford, UK
| | | | - Domenico Finocchiaro
- Medical Physics Unit, Azienda Ospedaliero-Universitaria Policlinico di Modena, Modena, Italy
| | - Federica Fioroni
- Medical Physics Unit, Azienda USL-IRCCS Di Reggio Emilia, Reggio Emilia, Italy
| | | | - Elisa Grassi
- Medical Physics Unit, Azienda USL-IRCCS Di Reggio Emilia, Reggio Emilia, Italy
| | - Warda Heetun
- National Physical Laboratory, Hampton Road, Teddington, UK
| | - Stephanie J Jewitt
- Department of Medical Physics and Clinical Engineering, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Maria Kotzasarlidou
- Nuclear Medicine Department, "THEAGENIO" Anticancer Hospital, Thessaloniki, Greece
| | | | - Valérie Lourenço
- Université Paris-Saclay, CEA, List, Laboratoire National Henri Becquerel (LNE-LNHB), 91120, Palaiseau, France
| | - Daniel R McGowan
- Department of Medical Physics and Clinical Engineering, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- Department of Oncology, University of Oxford, Oxford, UK
| | | | - Benoit Sabot
- Université Paris-Saclay, CEA, List, Laboratoire National Henri Becquerel (LNE-LNHB), 91120, Palaiseau, France
| | - James Scuffham
- Royal Surrey County Hospital, Royal Surrey NHS Foundation Trust, Guildford, UK
| | | | - Jaroslav Solc
- Czech Metrology Institute, Okruzni 31, 638 00, Brno, Czech Republic
| | - Cheick Thiam
- Université Paris-Saclay, CEA, List, Laboratoire National Henri Becquerel (LNE-LNHB), 91120, Palaiseau, France
| | - Jill Tipping
- Department of Medical Physics and Clinical Engineering, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Jill Wevrett
- Royal Surrey County Hospital, Royal Surrey NHS Foundation Trust, Guildford, UK
| | - Michael Lassmann
- Department of Nuclear Medicine, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany
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Mancini-Terracciano C, Ambrosino A, Campana L, Cassano B, Collamati F, Faccini R, Iaccarino G, Mirabelli R, Morganti S, Nicolanti F, Pacilio M, Soriani A, Solfaroli Camillocci E. Experimental validation of an innovative approach in biokinetics study for personalised dosimetry of molecular radiation therapy treatments. Phys Med Biol 2023; 68:19NT02. [PMID: 37747087 DOI: 10.1088/1361-6560/acf910] [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: 05/09/2023] [Accepted: 09/12/2023] [Indexed: 09/26/2023]
Abstract
One of today's main challenges in molecular radiation therapy is to assess an individual dosimetry that allows treatment to be tailored to the specific patient, in accordance with the current paradigm of 'personalized medicine'. The evaluation of the absorbed doses for tumor and organs at risk in molecular radiotherapy is typically based on MIRD schema acquiring few experimental points for the assessement of biokinetic parameters. WIDMApp, the wearable individual dose monitoring apparatus, is an innovative approach for internal dosimetry based on a wearable radiation detecting system for individual biokinetics sampling, a Monte Carlo simulation for particle interaction, and an unfolding algorithm for data analysis and integrated activity determination at organ level. A prototype of a WIDMApp detector element was used to record the photon emissions in a body phantom containing 3 spheres with liquid sources (18F,64Cu and99mTc) to simulate organs having different washout. Modelling the phantom geometry on the basis of a CT scan imaging, the Monte Carlo simulation computed the contribution of each emitting sphere to the signal detected in 3 positions on the phantoms surface. Combining the simulated results with the data acquired for 120 h, the unfolding algorithm deconvolved the detected signal and assessed the decay half-life (T1/2) and initial activity values (A(0)) that best reproduces the observed exponential decays. A 3%-18% level of agreement is found between the actualA(0) andT1/2values and those obtained by means of the minimization procedure based on the Monte Carlo simulation. That resulted in an estimation of the cumulated activity <15%. Moreover, WIDMApp data redundancy has been used to mitigate some experimental occurrences that happened during data taking. A first experimental test of the WIDMApp approach to internal radiation dosimetry is presented. Studies with patients are foreseen to validate the technique in a real environment.
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Affiliation(s)
- C Mancini-Terracciano
- Department of Physics, Sapienza University of Rome, Italy
- National Institute of Nuclear Physics, INFN Rome, Italy
| | - A Ambrosino
- Department of Physics, Sapienza University of Rome, Italy
- National Institute of Nuclear Physics, INFN Rome, Italy
| | - L Campana
- Department of Physics, Sapienza University of Rome, Italy
- National Institute of Nuclear Physics, INFN Rome, Italy
- Specialty School of Medical Physics, Sapienza University of Rome, Italy
| | - B Cassano
- Medical Physics Division, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - F Collamati
- National Institute of Nuclear Physics, INFN Rome, Italy
| | - R Faccini
- Department of Physics, Sapienza University of Rome, Italy
- National Institute of Nuclear Physics, INFN Rome, Italy
| | - G Iaccarino
- Medical Physics Division, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - R Mirabelli
- National Institute of Nuclear Physics, INFN Rome, Italy
- Department of Scienze di Base e Applicate per l'Ingegneria (SBAI), Sapienza University of Rome, Italy
| | - S Morganti
- National Institute of Nuclear Physics, INFN Rome, Italy
| | - F Nicolanti
- Department of Physics, Sapienza University of Rome, Italy
- National Institute of Nuclear Physics, INFN Rome, Italy
| | - M Pacilio
- Medical Physics Division, Azienda Ospedaliera-Universitaria Policlinico Umberto I, Rome, Italy
| | - A Soriani
- Medical Physics Division, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - E Solfaroli Camillocci
- National Center for Radiation Protection and Computational Physics, Italian National Institute of Health, Rome, Italy
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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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Kessara A, Buyukcizmeci N, Gedik GK. ESTIMATION OF PATIENT ORGAN AND WHOLE-BODY DOSES IN [18F-FDG] PET/CT SCAN. RADIATION PROTECTION DOSIMETRY 2023; 199:61-68. [PMID: 36379473 DOI: 10.1093/rpd/ncac218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 09/15/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
The object of this study was to estimate organ doses and whole-body effective doses from positron emission tomography/computed tomography (PET/CT) scan using [fluorine-18]-fluoro-2-deoxy-d-glucose (18F-FDG) in adult patients and to assess the CT component contribution to organ and whole-body doses. The [18F-FDG] PET/CT scan was conducted on 204 adult patients (90 females and 114 males). For all patients, females and males, the whole-body effective doses were 20.54, 23.89 and 17.89 mSv, respectively. For all patients, females and males, the CT component contribution to the whole-body effective dose was 66, 71 and 62%, respectively. Since CT is the primary contributor to the effective dose in the [18F-FDG] PET/CT scan protocol, the significance of improving CT protocols to minimize patient dose is underscored. All attempts must be made, using available mechanisms and techniques, to reduce the patient's dose of PET/CT scan, especially in obese patients.
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Affiliation(s)
- Aida Kessara
- Department of physics, Institute of science, University of Selcuk, 42130 Konya, Türkiye
| | | | - Gonca Kara Gedik
- Department of Nuclear Medicine, Selcuk University, Medical Faculty, 42131 Konya, Türkiye
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Miszczyk J, Gałaś A, Panek A, Kowalska A, Kostkiewicz M, Borkowska E, Brudecki K. Genotoxicity Associated with 131I and 99mTc Exposure in Nuclear Medicine Staff: A Physical and Biological Monitoring Study. Cells 2022; 11:cells11101655. [PMID: 35626692 PMCID: PMC9139973 DOI: 10.3390/cells11101655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/12/2022] [Accepted: 05/14/2022] [Indexed: 12/10/2022] Open
Abstract
Nuclear medicine staff are constantly exposed to low doses of ionizing radiation. This study investigated the level of genotoxic effects in hospital employees exposed to routinely used 131I and 99mTc in comparison with a control group. The study compared the results of physical and biological monitoring in peripheral blood lymphocytes. The effects of confounding factors, such as smoking status and physical activity, were also considered. Physical dosimetry monitoring revealed differences in the individual annual effective dose as measured by finger ring dosimeter and whole-body dosimeter between the 131I- and 99mTc-exposed groups. The DNA damage studies revealed differences between the groups in terms of excess premature chromosome condensation (PCC) fragments and tail DNA. Physical activity and smoking status differentiated the investigated groups. When assessed by the level of physical activity, the highest mean values of tail DNA were observed for the 99mTc group. When assessed by work-related physical effort, excess PCC fragments were significantly higher in the 131I group than in the control group. In the investigated groups, the tail DNA values were significantly different between non-smokers and past or current smokers, but excess PCC fragments did not significantly differ by smoking status. It is important to measure exposure to low doses of ionizing radiation and assess the potential risk from this exposure. Such investigations support the need to continue epidemiological and experimental studies to improve our understanding of the mechanisms of the health effects of radionuclides and to develop predictive models of the behavior of these complex systems in response to low-dose radiation.
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Affiliation(s)
- Justyna Miszczyk
- Department of Experimental Physics of Complex Systems, Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Kraków, Poland;
- Correspondence:
| | - Aleksander Gałaś
- Chair of Epidemiology and Preventive Medicine, Department of Epidemiology, Jagiellonian University Medical College, 31-008 Kraków, Poland;
| | - Agnieszka Panek
- Department of Experimental Physics of Complex Systems, Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Kraków, Poland;
| | - Aldona Kowalska
- Department of Endocrinology and Nuclear Medicine, Holy Cross Cancer Center, 25-734 Kielce, Poland;
- Faculty of Health Sciences, Jan Kochanowski University, 25-369 Kielce, Poland
| | - Magdalena Kostkiewicz
- Heart and Vascular Diseases Department, Faculty of Medicine, Institute of Cardiology, Collegium Medicum, Jagiellonian University, 31-007 Kraków, Poland;
- Nuclear Medicine Department, John Paul II Hospital, 31-202 Kraków, Poland;
| | - Eliza Borkowska
- Nuclear Medicine Department, John Paul II Hospital, 31-202 Kraków, Poland;
| | - Kamil Brudecki
- Department of Mass Spectrometry, Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Kraków, Poland;
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Liu Z, Li Z, Mhlanga JC, Siegel BA, Jha AK. No-gold-standard evaluation of quantitative imaging methods in the presence of correlated noise. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2022; 12035:120350M. [PMID: 36465994 PMCID: PMC9717481 DOI: 10.1117/12.2605762] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Objective evaluation of quantitative imaging (QI) methods with patient data is highly desirable, but is hindered by the lack or unreliability of an available gold standard. To address this issue, techniques that can evaluate QI methods without access to a gold standard are being actively developed. These techniques assume that the true and measured values are linearly related by a slope, bias, and Gaussian-distributed noise term, where the noise between measurements made by different methods is independent of each other. However, this noise arises in the process of measuring the same quantitative value, and thus can be correlated. To address this limitation, we propose a no-gold-standard evaluation (NGSE) technique that models this correlated noise by a multi-variate Gaussian distribution parameterized by a covariance matrix. We derive a maximum-likelihood-based approach to estimate the parameters that describe the relationship between the true and measured values, without any knowledge of the true values. We then use the estimated slopes and diagonal elements of the covariance matrix to compute the noise-to-slope ratio (NSR) to rank the QI methods on the basis of precision. The proposed NGSE technique was evaluated with multiple numerical experiments. Our results showed that the technique reliably estimated the NSR values and yielded accurate rankings of the considered methods for 83% of 160 trials. In particular, the technique correctly identified the most precise method for ∼ 97% of the trials. Overall, this study demonstrates the efficacy of the NGSE technique to accurately rank different QI methods when correlated noise is present, and without access to any knowledge of the ground truth. The results motivate further validation of this technique with realistic simulation studies and patient data.
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Affiliation(s)
- Ziping Liu
- Department of Biomedical Engineering, Washington University, St. Louis, MO, USA
| | - Zekun Li
- Department of Biomedical Engineering, Washington University, St. Louis, MO, USA
| | - Joyce C. Mhlanga
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Barry A. Siegel
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Abhinav K. Jha
- Department of Biomedical Engineering, Washington University, St. Louis, MO, USA
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
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9
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Miller C, Rousseau J, Ramogida CF, Celler A, Rahmim A, Uribe CF. Implications of physics, chemistry and biology for dosimetry calculations using theranostic pairs. Theranostics 2022; 12:232-259. [PMID: 34987643 PMCID: PMC8690938 DOI: 10.7150/thno.62851] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 10/18/2021] [Indexed: 12/15/2022] Open
Abstract
Theranostics is an emerging paradigm that combines imaging and therapy in order to personalize patient treatment. In nuclear medicine, this is achieved by using radiopharmaceuticals that target identical molecular targets for both imaging (using emitted gamma rays) and radiopharmaceutical therapy (using emitted beta, alpha or Auger-electron particles) for the treatment of various diseases, such as cancer. If the therapeutic radiopharmaceutical cannot be imaged quantitatively, a “theranostic pair” imaging surrogate can be used to predict the absorbed radiation doses from the therapeutic radiopharmaceutical. However, theranostic dosimetry assumes that the pharmacokinetics and biodistributions of both radiopharmaceuticals in the pair are identical or very similar, an assumption that still requires further validation for many theranostic pairs. In this review, we consider both same-element and different-element theranostic pairs and attempt to determine if factors exist which may cause inaccurate dose extrapolations in theranostic dosimetry, either intrinsic (e.g. chemical differences) or extrinsic (e.g. injecting different amounts of each radiopharmaceutical) to the radiopharmaceuticals. We discuss the basis behind theranostic dosimetry and present common theranostic pairs and their therapeutic applications in oncology. We investigate general factors that could create alterations in the behavior of the radiopharmaceuticals or the quantitative accuracy of imaging them. Finally, we attempt to determine if there is evidence showing some specific pairs as suitable for theranostic dosimetry. We show that there are a variety of intrinsic and extrinsic factors which can significantly alter the behavior among pairs of radiopharmaceuticals, even if they belong to the same chemical element. More research is needed to determine the impact of these factors on theranostic dosimetry estimates and on patient outcomes, and how to correctly account for them.
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10
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Neira-Castro S, Guiu-Souto J, Pardo-Montero J. Dosimetry in positron emission tomography. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00026-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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11
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Lassmann M, Eberlein U, Gear J, Konijnenberg M, Kunikowska J. Dosimetry for Radiopharmaceutical Therapy: The European Perspective. J Nucl Med 2021; 62:73S-79S. [PMID: 34857624 DOI: 10.2967/jnumed.121.262754] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 10/13/2021] [Indexed: 11/16/2022] Open
Abstract
This review presents efforts in Europe over the last few years with respect to standardization of quantitative imaging and dosimetry and comprises the results of several European research projects on practices regarding radiopharmaceutical therapies (RPTs). Because the European Union has regulatory requirements concerning dosimetry in RPTs, the European Association of Nuclear Medicine released a position paper in 2021 on the use of dosimetry under these requirements. The importance of radiobiology for RPTs is elucidated in another position paper by the European Association of Nuclear Medicine. Furthermore, how dosimetry interacts with clinical requirements is described, with several clinical examples. In the future, more efforts need to be undertaken to increase teaching and standardization efforts and to incorporate radiobiology for further individualizing patient treatment, with the aim of improving the outcome and safety of RPTs.
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Affiliation(s)
- Michael Lassmann
- Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany
| | - Uta Eberlein
- Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany;
| | - Jonathan Gear
- Joint Department of Physics, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, London, United Kingdom
| | - Mark Konijnenberg
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands; and
| | - Jolanta Kunikowska
- Nuclear Medicine Department, Medical University of Warsaw, Warsaw, Poland
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12
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Morganti S, Collamati F, Faccini R, Iaccarino G, Mancini-Terracciano C, Mirabelli R, Nicolanti F, Pacilio M, Soriani A, Solfaroli-Camillocci E. A wearable radiation measurement system for collection of patient-specific time-activity data in radiopharmaceutical therapy: system design and Monte Carlo simulation results. Med Phys 2021; 48:8117-8126. [PMID: 34704618 PMCID: PMC9298698 DOI: 10.1002/mp.15311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 09/30/2021] [Accepted: 10/11/2021] [Indexed: 11/12/2022] Open
Abstract
Purpose: A high level of personalization in Molecular Radiotherapy (MRT) could bring advantages in terms of treatment effectiveness and toxicity reduction. Individual organ‐level dosimetry is crucial to describe the radiopharmaceutical biodistribution expressed by the patient, to estimate absorbed doses to normal organs and target tissue(s). This paper presents a proof‐of‐concept Monte Carlo simulation study of “WIDMApp” (Wearable Individual Dose Monitoring Apparatus), a multi‐channel radiation detector and data processing system for in vivo patient measurement and collection of radiopharmaceutical biokinetic data (i.e., time‐activity data). Potentially, such a system can increase the amount of such data that can be collected while reducing the need to derive it via nuclear medicine imaging. Methods: a male anthropomorphic MIRD phantom was used to simulate photons (i.e., gamma‐rays) propagation in a patient undergoing a 131I thyroid treatment. The administered activity was set to the amount usually administered for the treatment of differentiated carcinoma while its initial distribution in different organs was assigned following the ICRP indications for the 131I biokinetics. Using this information, the simulation computes the Time‐dependent Counts Curves (TCCs) that would have been measured by seven WIDMApp‐like sensors placed and oriented to face each one of five emitting organs plus two thyroid lobes. A deconvolution algorithm was then applied on this simulated data set to reconstruct the Time‐Activity Curve (TAC) of each organ. Deviations of the reconstructed TACs parameters from values used to generate them were studied as a function of the deconvolution algorithm initialization parameters and assuming non‐Poisson fluctuation of the TCCs data points. Results: This study demonstrates that it is possible, at least in the simple simulated scenario, to reconstruct the organ cumulated activity by measuring the time dependence of counts recorded by several detectors placed at selected positions on the patient's body. The ability to perform in vivo sampling more frequently than conventional biokinetic studies increases the number of time points and therefore the accuracy in TAC estimates. In this study, an accuracy on cumulated activity of 5% is obtained even with a 20% error on the TCC data points and a 50% error on the initial guess on the parameters of the deconvolution algorithm. Conclusions: the WIDMApp approach could provide an effective tool to characterize more accurately the radiopharmaceutical biokinetics in MRT patients, reducing the need of resources of nuclear medicine departments, such as technologist and scanner time, to perform individualized biokinetics studies. The relatively simple hardware for the approach proposed would allow its application to large numbers of patients. The results obtained justify development of an actual prototype system to characterize this technique under realistic conditions.
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Affiliation(s)
| | | | - Riccardo Faccini
- National Institute of Nuclear Physics, INFN, Rome, Italy.,Department of Physics, Sapienza University of Rome, Italy
| | - Giuseppe Iaccarino
- Laboratory of Medical Physics and Expert Systems, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Carlo Mancini-Terracciano
- National Institute of Nuclear Physics, INFN, Rome, Italy.,Department of Physics, Sapienza University of Rome, Italy
| | - Riccardo Mirabelli
- National Institute of Nuclear Physics, INFN, Rome, Italy.,Department of Physics, Sapienza University of Rome, Italy
| | - Francesca Nicolanti
- National Institute of Nuclear Physics, INFN, Rome, Italy.,Department of Physics, Sapienza University of Rome, Italy
| | - Massimiliano Pacilio
- Medical Physics Division, Azienda Ospedaliera-Universitaria Policlinico Umberto I, Rome, Italy
| | - Antonella Soriani
- Laboratory of Medical Physics and Expert Systems, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Elena Solfaroli-Camillocci
- National Institute of Nuclear Physics, INFN, Rome, Italy.,Department of Physics, Sapienza University of Rome, Italy.,Specialty School of Medical Physics, Sapienza University of Rome, Rome, Italy
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13
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Tran-Gia J, Denis-Bacelar AM, Ferreira KM, Robinson AP, Calvert N, Fenwick AJ, Finocchiaro D, Fioroni F, Grassi E, Heetun W, Jewitt SJ, Kotzassarlidou M, Ljungberg M, McGowan DR, Scott N, Scuffham J, Gleisner KS, Tipping J, Wevrett J, Lassmann M. A multicentre and multi-national evaluation of the accuracy of quantitative Lu-177 SPECT/CT imaging performed within the MRTDosimetry project. EJNMMI Phys 2021; 8:55. [PMID: 34297218 PMCID: PMC8302709 DOI: 10.1186/s40658-021-00397-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/21/2021] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Patient-specific dosimetry is required to ensure the safety of molecular radiotherapy and to predict response. Dosimetry involves several steps, the first of which is the determination of the activity of the radiopharmaceutical taken up by an organ/lesion over time. As uncertainties propagate along each of the subsequent steps (integration of the time-activity curve, absorbed dose calculation), establishing a reliable activity quantification is essential. The MRTDosimetry project was a European initiative to bring together expertise in metrology and nuclear medicine research, with one main goal of standardizing quantitative 177Lu SPECT/CT imaging based on a calibration protocol developed and tested in a multicentre inter-comparison. This study presents the setup and results of this comparison exercise. METHODS The inter-comparison included nine SPECT/CT systems. Each site performed a set of three measurements with the same setup (system, acquisition and reconstruction): (1) Determination of an image calibration for conversion from counts to activity concentration (large cylinder phantom), (2) determination of recovery coefficients for partial volume correction (IEC NEMA PET body phantom with sphere inserts), (3) validation of the established quantitative imaging setup using a 3D printed two-organ phantom (ICRP110-based kidney and spleen). In contrast to previous efforts, traceability of the activity measurement was required for each participant, and all participants were asked to calculate uncertainties for their SPECT-based activities. RESULTS Similar combinations of imaging system and reconstruction lead to similar image calibration factors. The activity ratio results of the anthropomorphic phantom validation demonstrate significant harmonization of quantitative imaging performance between the sites with all sites falling within one standard deviation of the mean values for all inserts. Activity recovery was underestimated for total kidney, spleen, and kidney cortex, while it was overestimated for the medulla. CONCLUSION This international comparison exercise demonstrates that harmonization of quantitative SPECT/CT is feasible when following very specific instructions of a dedicated calibration protocol, as developed within the MRTDosimetry project. While quantitative imaging performance demonstrates significant harmonization, an over- and underestimation of the activity recovery highlights the limitations of any partial volume correction in the presence of spill-in and spill-out between two adjacent volumes of interests.
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Affiliation(s)
- Johannes Tran-Gia
- Department of Nuclear Medicine, University of Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany.
| | | | | | - Andrew P Robinson
- National Physical Laboratory, Teddington, UK
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Manchester, UK
- The University of Manchester, Manchester, UK
| | - Nicholas Calvert
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Manchester, UK
| | - Andrew J Fenwick
- National Physical Laboratory, Teddington, UK
- Cardiff University, Cardiff, UK
| | - Domenico Finocchiaro
- Medical Physics Unit, Azienda Unità Sanitaria Locale di Reggio Emilia-IRCCS, Reggio Emilia, Italy
- Department of Physics and Astronomy, University of Bologna, Bologna, Italy
| | - Federica Fioroni
- Medical Physics Unit, Azienda Unità Sanitaria Locale di Reggio Emilia-IRCCS, Reggio Emilia, Italy
| | - Elisa Grassi
- Medical Physics Unit, Azienda Unità Sanitaria Locale di Reggio Emilia-IRCCS, Reggio Emilia, Italy
| | | | - Stephanie J Jewitt
- Radiation Physics and Protection, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Maria Kotzassarlidou
- Nuclear Medicine Department, "THEAGENIO" Anticancer Hospital, Thessaloniki, Greece
| | | | - Daniel R McGowan
- Radiation Physics and Protection, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- Department of Oncology, University of Oxford, Oxford, UK
| | - Nathaniel Scott
- Radiation Physics and Protection, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - James Scuffham
- National Physical Laboratory, Teddington, UK
- Royal Surrey County Hospital, Guildford, UK
- Department of Physics, University of Surrey, Guildford, UK
| | | | - Jill Tipping
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Manchester, UK
| | - Jill Wevrett
- National Physical Laboratory, Teddington, UK
- Royal Surrey County Hospital, Guildford, UK
- Department of Physics, University of Surrey, Guildford, UK
| | - Michael Lassmann
- Department of Nuclear Medicine, University of Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany
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14
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15
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Gupta A, Lee MS, Kim JH, Lee DS, Lee JS. Preclinical Voxel-Based Dosimetry in Theranostics: a Review. Nucl Med Mol Imaging 2020; 54:86-97. [PMID: 32377260 DOI: 10.1007/s13139-020-00640-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/27/2020] [Accepted: 03/31/2020] [Indexed: 12/22/2022] Open
Abstract
Due to the increasing use of preclinical targeted radionuclide therapy (TRT) studies for the development of novel theranostic agents, several studies have been performed to accurately estimate absorbed doses to mice at the voxel level using reference mouse phantoms and Monte Carlo (MC) simulations. Accurate dosimetry is important in preclinical theranostics to interpret radiobiological dose-response relationships and to translate results for clinical use. Direct MC (DMC) simulation is believed to produce more realistic voxel-level dose distribution with high precision because tissue heterogeneities and nonuniform source distributions in patients or animals are considered. Although MC simulation is considered to be an accurate method for voxel-based absorbed dose calculations, it is time-consuming, computationally demanding, and often impractical in daily practice. In this review, we focus on the current status of voxel-based dosimetry methods applied in preclinical theranostics and discuss the need for accurate and fast voxel-based dosimetry methods for pretherapy absorbed dose calculations to optimize the dose computation time in preclinical TRT.
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Affiliation(s)
- Arun Gupta
- 1Department of Radiology & Imaging, B.P. Koirala Institute of Health Sciences, Dharan, Nepal
| | - Min Sun Lee
- 2Department of Radiology, School of Medicine, Stanford University, Stanford, CA USA
| | - Joong Hyun Kim
- 3Center for Ionizing Radiation, Korea Research Institute of Standards and Science, Daejeon, South Korea
| | - Dong Soo Lee
- 4Department of Nuclear Medicine, College of Medicine, Seoul National University, 103 Daehak-ro, Jongno-gu, Seoul, 03080 South Korea
| | - Jae Sung Lee
- 4Department of Nuclear Medicine, College of Medicine, Seoul National University, 103 Daehak-ro, Jongno-gu, Seoul, 03080 South Korea.,5Interdisciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, South Korea.,6Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, South Korea
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16
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Vaughn BA, Ahn SH, Aluicio-Sarduy E, Devaraj J, Olson AP, Engle J, Boros E. Chelation with a twist: a bifunctional chelator to enable room temperature radiolabeling and targeted PET imaging with scandium-44. Chem Sci 2020; 11:333-342. [PMID: 32953004 PMCID: PMC7472660 DOI: 10.1039/c9sc04655k] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 11/17/2019] [Indexed: 01/16/2023] Open
Abstract
Scandium-44 has emerged as an attractive, novel PET radioisotope with ideal emission properties and half-life (t 1/2 = 3.97 h, E mean β+ = 632 keV) well matched to the pharmacokinetics of small molecules, peptides and small biologics. Conjugates of the current gold-standard chelator for 44Sc, 1,4,7,10-tetraaza-cyclododecane-1,4,7,10-tetraacetic acid (DOTA), require heating to achieve radiochemical complexation, limiting application of this isotope in conjunction with temperature-sensitive biologics. To establish Sc(iii) isotopes as broadly applicable tools for nuclear medicine, development of alternative bifunctional chelators is required. To address this need, we characterized the Sc(iii)-chelation properties of the small-cavity triaza-macrocycle-based, picolinate-functionalized chelator H3mpatcn. Spectroscopic and radiochemical studies establish the [Sc(mpatcn)] complex as kinetically inert and appropriate for biological applications. A proof-of-concept bifunctional conjugate targeting the prostate-specific membrane antigen (PSMA), picaga-DUPA, chelates 44Sc to form 44Sc(picaga)-DUPA at room temperature with an apparent molar activity of 60 MBq μmol-1 and formation of inert RRR-Λ and SSS-Δ-twist isomers. Sc(picaga)-DUPA exhibits a K i of 1.6 nM for PSMA, comparable to the 18F-based imaging probe DCFPyL (K i = 1.1 nM) currently in phase 3 clinical trials for imaging prostate cancer. Finally, we successfully employed 44Sc(picaga)-DUPA to image PSMA-expressing tumors in a preclinical mouse model, establishing the picaga bifunctional chelator as an optimal choice for the 44Sc PET nuclide.
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Affiliation(s)
- Brett A Vaughn
- Department of Chemistry , Stony Brook University , 100 Nicolls Road , Stony Brook , 11790 , New York , USA .
| | - Shin Hye Ahn
- Department of Chemistry , Stony Brook University , 100 Nicolls Road , Stony Brook , 11790 , New York , USA .
| | - Eduardo Aluicio-Sarduy
- Medical Physics Department , University of Wisconsin-Madison , 1111 Highland Avenue , Madison , 53705 , Wisconsin , USA
| | - Justin Devaraj
- Department of Chemistry , Stony Brook University , 100 Nicolls Road , Stony Brook , 11790 , New York , USA .
| | - Aeli P Olson
- Medical Physics Department , University of Wisconsin-Madison , 1111 Highland Avenue , Madison , 53705 , Wisconsin , USA
| | - Jonathan Engle
- Medical Physics Department , University of Wisconsin-Madison , 1111 Highland Avenue , Madison , 53705 , Wisconsin , USA
| | - Eszter Boros
- Department of Chemistry , Stony Brook University , 100 Nicolls Road , Stony Brook , 11790 , New York , USA .
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17
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Finessi M, Liberini V, Deandreis D. Major limits of dosimetrically determined activities in advanced differentiated thyroid carcinoma. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF RADIOPHARMACEUTICAL CHEMISTRY AND BIOLOGY 2019; 63:258-266. [PMID: 31560183 DOI: 10.23736/s1824-4785.19.03211-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The 2013/59 EURATOM directive defines all nuclear medicine applications for therapeutic purpose as a form of radiotherapy and underlines the need of both justification and optimization of these procedures, including radioactive iodine therapy (RAIT) with [131I] for metastatic differentiated thyroid cancer (DTC). In metastatic DTC, optimal activity to be administered to achieve the best response rate with limited toxicity is still a matter of debate and international guidelines do not provide univocal recommendations on the preferable use of empiric versus a dosimetry-based approach in these patients. The purpose of this literature review is to describe the possible limits of dosimetry in RAIT planning according to methodological aspects, tumoral heterogeneity and to report clinical data on the impact on patients' outcome of different approaches. Due to the lack of standardized dosimetry protocols and clinical data assessing the superiority of a dosimetry-based vs an empiric approach in these patients, there is a need of standardisation and prospective, properly conducted studies to validate and to assess the best approach.
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Affiliation(s)
- Monica Finessi
- Division of Nuclear Medicine, Department of Medical Sciences, AOU Città della Salute e della Scienza, University of Turin, Turin, Italy -
| | - Virginia Liberini
- Division of Nuclear Medicine, Department of Medical Sciences, AOU Città della Salute e della Scienza, University of Turin, Turin, Italy
| | - Désirée Deandreis
- Division of Nuclear Medicine, Department of Medical Sciences, AOU Città della Salute e della Scienza, University of Turin, Turin, Italy
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18
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Benabdallah N, Bernardini M, Bianciardi M, de Labriolle-Vaylet C, Franck D, Desbrée A. 223Ra-dichloride therapy of bone metastasis: optimization of SPECT images for quantification. EJNMMI Res 2019; 9:20. [PMID: 30790144 PMCID: PMC6384291 DOI: 10.1186/s13550-019-0488-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 02/04/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND 223Ra imaging is crucial to evaluate the successfulness of the therapy of bone metastasis of castration-resistant prostate cancer (CRPC). The goals of this study were to establish a quantitative tomographic 223Ra imaging protocol with clinically achievable conditions, as well as to investigate its usefulness and limitations. We performed several experiments using the Infinia Hawkeye 4 gamma camera (GE) and physical phantoms in order to assess the optimal image acquisition and reconstruction parameters, such as the windows setting, as well as the iteration number and filter of the reconstruction algorithm. Then, based on the MIRD pamphlet 23, we used a NEMA phantom and an anthropomorphic TORSO® phantom to calibrate the gamma camera and investigate the accuracy of quantification. RESULTS Experiences showed that the 85 keV ± 20%, 154 keV ± 10%, and 270 keV ± 10% energy windows are the most suitable for 223Ra imaging. The study with the NEMA phantom showed that the OSEM algorithm with 2 iterations, 10 subsets, and the Butterworth filter offered the best compromise between contrast and noise. Moreover, the calibration factors for different sphere sizes (26.5 ml, 11.5 ml, and 5.6 ml) were constant for 223Ra concentrations ranging between 6.5 and 22.8 kBq/ml. The values found are 73.7 cts/s/MBq, 43.8 cts/s/MBq, and 43.4 cts/s/MBq for 26.5 ml, 11.5 ml, and 5.6 ml sphere, respectively. For concentration lower than 6.5 kBq/ml, the calibration factors exhibited greater variability pointing out the limitations of SPECT/CT imaging for quantification. By the use of a TORSO® phantom, we simulated several tumors to normal tissue ratios as close as possible to clinical conditions. Using the calibration factors obtained with the NEMA phantom, for 223Ra concentrations higher than 8 kBq/ml, we were able to quantify the activity with an error inferior to 18.8% in a 5.6 ml lesion. CONCLUSIONS Absolute quantitative 223Ra SPECT imaging appears feasible once the dimension of the target is determined. Further evaluation should be needed to apply the calibration factor-based quantitation to clinical 223Ra SPECT/CT imaging. This will open the possibility for patient-specific 223Ra treatment planning and therapeutic outcome prediction in patients.
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Affiliation(s)
- Nadia Benabdallah
- Internal Dose Assessment Laboratory, Institute for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses, France
| | - Michela Bernardini
- Nuclear Medicine Department, European Hospital George Pompidou (HEGP), Paris, France
| | - Marta Bianciardi
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, USA
| | - Claire de Labriolle-Vaylet
- UPMC, Univ Paris 06 Biophysics, Paris, France
- Nuclear Medicine Department, Trousseau Hospital, Paris, France
| | - Didier Franck
- Internal Dose Assessment Laboratory, Institute for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses, France
| | - Aurélie Desbrée
- Internal Dose Assessment Laboratory, Institute for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses, France
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19
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Paiva FG, do Carmo Santana P, Mourão AP. Evaluation of patient effective dose in a PET/CT test. Appl Radiat Isot 2018; 145:137-141. [PMID: 30599383 DOI: 10.1016/j.apradiso.2018.12.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 11/01/2018] [Accepted: 12/19/2018] [Indexed: 11/29/2022]
Abstract
The positron emission tomography (PET)/computed tomography (CT) technique generates high doses in patients because two radiodiagnostic modalities are used in a single examination. In this study, the absorbed and effective doses generated by CT scans and by the incorporation of radiopharmaceutical solution were evaluated in 19 organs. It was found that 78.2% of the effective dose in PET/CT examinations comes from the CT scan. With an activity of 3.33 MBq/kg-1, 18F-FDG contributes 21.8% of the final effective dose.
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Affiliation(s)
- Fernanda Guerra Paiva
- Departamento de Engenharia Nuclear, Programa de Pós Graduação em Ciências e Técnicas Nucleares, Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos 6627, Belo Horizonte, MG 31270-901, Brazil.
| | - Priscila do Carmo Santana
- Faculdade de Medicina, Universidade Federal de Minas Gerais, Av. Professor Alfredo Balena 190, Belo Horizonte, MG 30123-970, Brazil
| | - Arnaldo Prata Mourão
- Departamento de Engenharia Nuclear, Programa de Pós Graduação em Ciências e Técnicas Nucleares, Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos 6627, Belo Horizonte, MG 31270-901, Brazil; Centro de Engenharia Biomédica, Centro Federal de Educação Tecnológica de Minas Gerais, Av. Amazonas 5253, Room 113, Belo Horizonte, MG 30421-169, Brazil
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Besemer AE, Grudzinski JJ, Weichert JP, Hall LT, Bednarz BP. Pretreatment CLR 124 Positron Emission Tomography Accurately Predicts CLR 131 Three-Dimensional Dosimetry in a Triple-Negative Breast Cancer Patient. Cancer Biother Radiopharm 2018; 34:13-23. [PMID: 30351218 DOI: 10.1089/cbr.2018.2568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
INTRODUCTION CLR1404 is a theranostic molecular agent that can be radiolabeled with 124I (CLR 124) for positron emission tomography (PET) imaging, or 131I (CLR 131) for single-photon emission computed tomography (SPECT) imaging and targeted radionuclide therapy. This pilot study evaluated a pretreatment dosimetry methodology in a triple-negative breast cancer patient who was uniquely enrolled in both a CLR 124 PET imaging clinical trial and a CLR 131 therapeutic dose escalation clinical trial. MATERIALS AND METHODS Three-dimensional PET/CT images were acquired at 1, 3, 24, 48, and 120 h postinjection of 178 MBq CLR 124. One month later, pretherapy 2D whole-body planar images were acquired at 0.25, 5, 24, 48, and 144 h postinjection of 370 MBq CLR 131. Following the therapeutic administration of 1990 MBq CLR 131, 3D SPECT/CT images were acquired at 74, 147, 334, and 505 h postinjection. The therapeutic CLR 131 voxel-level absorbed dose was estimated from PET (RAPID PET) and SPECT (RAPID SPECT) images using a Geant4-based Monte Carlo dosimetry platform called RAPID (Radiopharmaceutical Assessment Platform for Internal Dosimetry), and region of interest (ROI) mean doses were also estimated using the OLINDA/EXM software based on PET (OLINDA PET), SPECT (OLINDA SPECT), and planar (OLINDA planar) images. RESULTS The RAPID PET and OLINDA PET tracer-predicted ROI mean doses correlated well (m ≥ 0.631, R2 ≥ 0.694, p ≤ 0.01) with both the RAPID SPECT and OLINDA SPECT therapeutic mean doses. The 2D planar images did not have any significant correlations. The ROI mean doses differed by -4% to -43% between RAPID and OLINDA/EXM, and by -19% to 29% between PET and SPECT. The 3D dose distributions and dose volume histograms calculated with RAPID were similar for the PET/CT and SPECT/CT. CONCLUSIONS This pilot study demonstrated that CLR 124 pretreatment PET images can be used to predict CLR 131 3D therapeutic dosimetry better than CLR 131 2D planar images. In addition, unlike OLINDA/EXM, Monte Carlo dosimetry methods were capable of accurately predicting dose heterogeneity, which is important for predicting dose-response relationships and clinical outcomes.
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Affiliation(s)
- Abigail E Besemer
- 1 Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin.,2 Department of Human Oncology, University of Wisconsin-Madison, Madison, Wisconsin.,3 Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska
| | - Joseph J Grudzinski
- 1 Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin
| | - Jamey P Weichert
- 1 Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin.,4 Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin.,5 Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - Lance T Hall
- 4 Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin.,5 Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - Bryan P Bednarz
- 1 Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin
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Wevrett J, Fenwick A, Scuffham J, Johansson L, Gear J, Schlögl S, Segbers M, Sjögreen-Gleisner K, Solný P, Lassmann M, Tipping J, Nisbet A. Inter-comparison of quantitative imaging of lutetium-177 ( 177Lu) in European hospitals. EJNMMI Phys 2018; 5:17. [PMID: 30069805 PMCID: PMC6070453 DOI: 10.1186/s40658-018-0213-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 04/13/2018] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND This inter-comparison exercise was performed to demonstrate the variability of quantitative SPECT/CT imaging for lutetium-177 (177Lu) in current clinical practice. Our aim was to assess the feasibility of using international inter-comparison exercises as a means to ensure consistency between clinical sites whilst enabling the sites to use their own choice of quantitative imaging protocols, specific to their systems. Dual-compartment concentric spherical sources of accurately known activity concentrations were prepared and sent to seven European clinical sites. The site staff were not aware of the true volumes or activity within the sources-they performed SPECT/CT imaging of the source, positioned within a water-filled phantom, using their own choice of parameters and reported their estimate of the activities within the source. RESULTS The volumes reported by the participants for the inner section of the source were all within 29% of the true value and within 60% of the true value for the outer section. The activities reported by the participants for the inner section of the source were all within 20% of the true value, whilst those reported for the outer section were up to 83% different to the true value. CONCLUSIONS A variety of calibration and segmentation methods were used by the participants for this exercise which demonstrated the variability of quantitative imaging across clinical sites. This paper presents a method to assess consistency between sites using different calibration and segmentation methods.
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Affiliation(s)
- Jill Wevrett
- University of Surrey, Guildford, UK.
- National Physical Laboratory, Teddington, UK.
- Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK.
| | | | - James Scuffham
- University of Surrey, Guildford, UK
- Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK
| | | | | | | | - Marcel Segbers
- Erasmus University Medical Centre, Rotterdam, Netherlands
| | | | - Pavel Solný
- Motol University Hospital, Prague, Czech Republic
| | | | - Jill Tipping
- The Christie NHS Foundation Trust, Manchester, UK
| | - Andrew Nisbet
- University of Surrey, Guildford, UK
- Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK
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Lassmann M, Eberlein U. The Relevance of Dosimetry in Precision Medicine. J Nucl Med 2018; 59:1494-1499. [PMID: 30002109 DOI: 10.2967/jnumed.117.206649] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/29/2018] [Indexed: 11/16/2022] Open
Abstract
The aim of this review is to provide an overview of the most recent technologic developments in state-of-the-art equipment and tools for dosimetry in radionuclide therapies. This includes, but is not restricted to, calibration methods for imaging systems. In addition, a summary of new developments that consider the influence of small-scale dosimetry and of biologic effects on radionuclide therapies is given. Finally, the current limitations of patient-specific dosimetry such as bone-marrow dosimetry or dosimetry of α-emitters are discussed.
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Affiliation(s)
- Michael Lassmann
- Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Würzburg, Würzburg, Germany
| | - Uta Eberlein
- Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Würzburg, Würzburg, Germany
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23
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Tran-Gia J, Lassmann M. Characterization of Noise and Resolution for Quantitative 177Lu SPECT/CT with xSPECT Quant. J Nucl Med 2018; 60:50-59. [DOI: 10.2967/jnumed.118.211094] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/14/2018] [Indexed: 12/29/2022] Open
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Kesner AL, Bodei L. Modern Radiopharmaceutical Dosimetry Should Include Robust Biodistribution Reporting. J Nucl Med 2018; 59:1507-1509. [DOI: 10.2967/jnumed.118.208603] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 03/23/2018] [Indexed: 11/16/2022] Open
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25
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Wurzer A, Seidl C, Morgenstern A, Bruchertseifer F, Schwaiger M, Wester H, Notni J. Dual-Nuclide Radiopharmaceuticals for Positron Emission Tomography Based Dosimetry in Radiotherapy. Chemistry 2018; 24:547-550. [PMID: 28833667 PMCID: PMC5813229 DOI: 10.1002/chem.201702335] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Indexed: 01/15/2023]
Abstract
Improvement of the accuracy of dosimetry in radionuclide therapy has the potential to increase patient safety and therapeutic outcomes. Although positron emission tomography (PET) is ideally suited for acquisition of dosimetric data because PET is inherently quantitative and offers high sensitivity and spatial resolution, it is not directly applicable for this purpose because common therapeutic radionuclides lack the necessary positron emission. This work reports on the synthesis of dual-nuclide labeled radiopharmaceuticals with therapeutic and PET functionality, which are based on common and widely available metal radionuclides. Dual-chelator conjugates, featuring interlinked cyclen- and triazacyclononane-based polyphosphinates DOTPI and TRAP, allow for strictly regioselective complexation of therapeutic (e.g., 177 Lu, 90 Y, or 213 Bi) and PET (e.g., 68 Ga) radiometals in the same molecular framework by exploiting the orthogonal metal ion selectivity of these chelators (DOTPI: large cations, such as lanthanide(III) ions; TRAP: small trivalent ions, such as GaIII ). Such DOTPI-TRAP conjugates were decorated with 3 Gly-urea-Lys (KuE) motifs for targeting prostate-specific membrane antigen (PSMA), employing Cu-catalyzed (CuAAC) as well as strain-promoted (SPAAC) click chemistry. These were labeled with 177 Lu or 213 Bi and 68 Ga and used for in vivo imaging of LNCaP (human prostate carcinoma) tumor xenografts in SCID mice by PET, thus proving practical applicability of the concept.
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Affiliation(s)
- Alexander Wurzer
- Pharmaceutical RadiochemistryTechnische Universität MünchenWalther-Meißner-Strasse 385748GarchingGermany
| | - Christof Seidl
- Department of Nuclear MedicineTechnische Universität MünchenGermany
- Department of Obstetrics and GynecologyTechnische Universität MünchenGermany
| | - Alfred Morgenstern
- European Commission, Joint Research CentreDirectorate for Nuclear Safety and SecurityKarlsruheGermany
| | - Frank Bruchertseifer
- European Commission, Joint Research CentreDirectorate for Nuclear Safety and SecurityKarlsruheGermany
| | - Markus Schwaiger
- Department of Nuclear MedicineTechnische Universität MünchenGermany
| | - Hans‐Jürgen Wester
- Pharmaceutical RadiochemistryTechnische Universität MünchenWalther-Meißner-Strasse 385748GarchingGermany
| | - Johannes Notni
- Pharmaceutical RadiochemistryTechnische Universität MünchenWalther-Meißner-Strasse 385748GarchingGermany
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Notni J, Wester HJ. Re-thinking the role of radiometal isotopes: Towards a future concept for theranostic radiopharmaceuticals. J Labelled Comp Radiopharm 2017; 61:141-153. [PMID: 29143368 DOI: 10.1002/jlcr.3582] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 10/26/2017] [Accepted: 10/26/2017] [Indexed: 12/22/2022]
Abstract
The potential and future role of certain metal radionuclides, for example, 44 Sc, 89 Zr, 86 Y, 64 Cu, 68 Ga, 177 Lu, 225 Ac, and 213 Bi, and several terbium isotopes has been controversially discussed in the past decades. Furthermore, the possible benefits of "matched pairs" of isotopes for tandem applications of diagnostics and therapeutics (theranostics) have been emphasized, while such approaches still have not made their way into routine clinical practice. Analysis of bibliographical data illustrates how popularity of certain nuclides has been promoted by cycles of availability and applications. We furthermore discuss the different practical requirements for diagnostic and therapeutic radiopharmaceuticals and the resulting consequences for efficient development of clinically useful pairs of radionuclide theranostics, with particular emphasis on the underlying economical factors. Based on an exemplary assessment of overall production costs for 68 Ga and 18 F radiopharmaceuticals, we venture a look into the future of theranostics and predict that high-throughput PET applications, that is, diagnosis of frequent conditions, will ultimately rely on 18 F tracers. PET radiometals will occupy a niche in the clinical low-throughput sector (diagnosis of rare diseases), but above all, dominate preclinical research and clinical translation. Matched isotope pairs will be of lesser relevance for theranostics but may become important for future PET-based therapeutic dosimetry.
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Affiliation(s)
- Johannes Notni
- Pharmaceutical Radiochemistry, Technische Universität München, Garching, Germany
| | - Hans-Jürgen Wester
- Pharmaceutical Radiochemistry, Technische Universität München, Garching, Germany
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Parach AA, Rajabi H. A comparison between GATE4 results and MCNP4B published data for internal radiation dosimetry. Nuklearmedizin 2017; 50:122-33. [DOI: 10.3413/nukmed-0363-10-10] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Accepted: 01/13/2011] [Indexed: 11/20/2022]
Abstract
SummaryAim: GATE, has been designed as upper layer of the GEANT4 toolkit for nuclear medicine application including internal dosimetry. However, its results have not been fully compared to the well-developed codes and anthropomorphic voxel phantoms have never been used with GATE/GEANT for internal dosimetry. The aim of present study was to compare the internal dose calculated by GATE/GEANT with the MCNP4B published data. Methods: The Zubal phantom was used to model a typical adult male. Activity was assumed uniformly distributed in liver, kidneys, lungs, spleen, pancreas and adrenals. GATE/ GEANT Monte Carlo package was used for estimation of doses in the phantom. Simulations were performed for photon energy of 0.01–1 MeV and mono-energetic electrons of 935 keV. Specific absorbed fractions for photons and S-factors for electrons were calculated. Results: On average, GATE/GEANT produces higher photon SAF (Specific Absorbed Fraction) values (+2.7%) for self-absorption and lower values (-2.9%) for cross-absorption. The difference was higher for paired organs particularly lungs. Moreover the photon SAF values for lungs as source organ at the energy of 200 and 500 keV was considerably higher with MCNP4B compared to GATE. Conclusion: Despite of differences between the GATE4 and MCNP4B, the results can be considered ensuring. This may be considered as validation of GATE/GEANT as a proprietary code in nuclear medicine for radionuclide dosimetry applications.
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Tran-Gia J, Lassmann M. Optimizing Image Quantification for 177Lu SPECT/CT Based on a 3D Printed 2-Compartment Kidney Phantom. J Nucl Med 2017; 59:616-624. [PMID: 29097409 DOI: 10.2967/jnumed.117.200170] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/16/2017] [Indexed: 01/18/2023] Open
Abstract
The aim of this work was to find an optimal setup for activity determination of 177Lu-based SPECT/CT imaging reconstructed with 2 commercially available methods (xSPECT Quant and Flash3D). For this purpose, 3-dimensional (3D)-printed phantoms of different geometries were manufactured, different partial-volume correction (PVC) methods were applied, and the accuracy of the activity determination was evaluated. Methods: A 2-compartment kidney phantom (70% cortical and 30% medullary compartment), a sphere, and an ellipsoid of equal volumes were 3D printed, filled with 177Lu, and scanned with a SPECT/CT system. Reconstructions were performed with xSPECT and Flash3D. Different PVC methods were applied to find an optimal quantification setup: method 1 was a geometry-specific recovery coefficient based on the 3D printing model, method 2 was a geometry-specific recovery coefficient based on the low-dose CT scan, method 3 was an enlarged volume of interest including spilled-out counts, method 4 was activity concentration in the peak milliliter applied to the entire CT-based volume, and method 5 was a fixed threshold of 42% of the maximum in a large volume containing the object of interest. Additionally, the influence of postreconstruction gaussian filtering was investigated. Results: Although the recovery coefficients of sphere and ellipsoid differed by only 0.7%, a difference of 31.7% was observed between the sphere and the renal cortex phantoms. Without postfiltering, the model-based recovery coefficients (methods 1 and 2) resulted in the best accuracies (xSPECT, 1.5%; Flash3D, 10.3%), followed by the enlarged volume (method 3) (xSPECT, 8.5%; Flash3D, 13.0%). The peak-milliliter method (method 4) showed large errors only for sphere and ellipsoid (xSPECT, 23.4%; Flash3D, 21.6%). Applying a 42% threshold (method 5) led to the largest quantification errors (xSPECT, 32.3%; Flash3D, 46.7%). After postfiltering, a general increase in the errors was observed. Conclusion: In this work, 3D printing was used as a prototyping technique for a geometry-specific investigation of SPECT/CT reconstruction parameters and PVC methods. The optimal setup for activity determination was found to be an unsmoothed SPECT/CT reconstruction in combination with a recovery coefficient based on the low-dose CT. The difference between spheric and renal recovery coefficients suggests that the typically applied volume-dependent but only sphere-based recovery coefficient lookup tables should be replaced by a more geometry-specific alternative.
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Affiliation(s)
- Johannes Tran-Gia
- Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany
| | - Michael Lassmann
- Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany
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Bastiaannet R, Viergever MA, de Jong HWAM. Impact of respiratory motion and acquisition settings on SPECT liver dosimetry for radioembolization. Med Phys 2017; 44:5270-5279. [PMID: 28736826 DOI: 10.1002/mp.12483] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 05/29/2017] [Accepted: 07/11/2017] [Indexed: 12/22/2022] Open
Abstract
PURPOSE Respiratory motion may impose significant inaccuracies on emission activity estimation in quantitative SPECT. This effect may be a major issue in dosimetry as used in the management of liver radioembolization. The purpose of this study was to investigate the impact of respiratory motion on radioembolization liver dosimetry for different SPECT acquisition settings. METHODS In a series of SPECT/CT Monte Carlo simulations using several digital XCAT phantoms, the following parameters were varied: breathing/nonbreathing, liver tumor size (0.3-35 ml) and location, patient properties (body mass index ranging from underweight to obese; male and female), acquisition time (10-30 s/view), collimator setup (High Sensitivity, High Resolution, Ultra High Resolution) and tumor VOI. The effect of applying a respiratory gating scheme was examined as well. RESULTS Breathing decreased activity recovery and tumor/non-tumor (T/N) ratios on average from 90% to 66%. VOIs based on SPECT images instead of breath-hold CT improved T/N values significantly. The most accurate results were obtained using a gating scheme combined with SPECT-based VOIs. Scan duration, body mass index, sex, and location all had a minor effect. Lung shunt fraction estimations were relatively unaffected by any of the varied parameters. CONCLUSIONS Respiratory motion has a large effect on SPECT activity quantitation of liver tumors as used in radioembolization treatment planning and assessment. As compared with the other parameters that were varied in this study, respiration is the predominant degrading effect on image quantitation. Gating alleviates much of this detrimental effect.
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Affiliation(s)
- Remco Bastiaannet
- Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, 3508GA, The Netherlands
| | - Max A Viergever
- Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, 3508GA, The Netherlands
| | - Hugo W A M de Jong
- Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, 3508GA, The Netherlands
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Attarwala AA, Karanja YW, Hardiansyah D, Romanó C, Roscher M, Wängler B, Glatting G. Investigation of the imaging characteristics of the ALBIRA II small animal PET system for 18F, 68Ga and 64Cu. Z Med Phys 2017; 27:132-144. [PMID: 28412013 DOI: 10.1016/j.zemedi.2017.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 01/15/2017] [Accepted: 01/16/2017] [Indexed: 10/19/2022]
Abstract
AIM In this study the performance characteristics of the Albira II PET sub-system and the response of the system for the following radionuclides 18F, 68Ga and 64Cu was analyzed. MATERIALS AND METHODS The Albira II tri-modal system (Bruker BioSpin MRI GmbH, Ettlingen, Germany) is a pre-clinical device for PET, SPECT and CT. The PET sub-system uses single continuous crystal detectors of lutetium yttrium orthosilicate (LYSO). The detector assembly consists of three rings of 8 detector modules. The transaxial field of view (FOV) has a diameter of 80mm and the axial FOV is 148mm. A NEMA NU-4 image quality phantom (Data Spectrum Corporation, Durham, USA) having five rods with diameters of 1, 2, 3, 4 and 5mm and a uniform central region was used. Measurements with 18F, 68Ga and 64Cu were performed in list mode acquisition over 10h. Data were reconstructed using a maximum-likelihood expectation-maximization (MLEM) algorithm with iteration numbers between 5 and 50. System sensitivity, count rate linearity, convergence and recovery coefficients were analyzed. RESULTS The sensitivities for the entire FOV (non-NEMA method) for 18F, 68Ga and 64Cu were (3.78±0.05)%, (3.97±0.18)% and (3.79±0.37)%, respectively. The sensitivity based on the NEMA protocol using the 22Na point source yielded (5.53±0.06)%. Dead-time corrected true counts were linear for activities ≤7MBq (18F and 68Ga) and ≤17MBq (64Cu) in the phantom. The radial, tangential and axial full widths at half maximum (FWHMs) were 1.52, 1.47 and 1.48mm. Recovery coefficients for the uniform region with a total activity of 8MBq in the phantom were (0.97±0.05), (0.98±0.06), (0.98±0.06) for 18F, 68Ga and 64Cu, respectively. CONCLUSION The Albira II pre-clinical PET system has an adequate sensitivity range and the system linearity is suitable for the range of activities used for pre-clinical imaging. Overall, the system showed a favorable image quality for pre-clinical applications.
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Affiliation(s)
- 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.
| | - Yvonne Wanjiku Karanja
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Deni Hardiansyah
- 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
| | - Chiara Romanó
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Mareike Roscher
- Molecular Imaging and Radiochemistry, Institute for Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Institute for Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - 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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Traino AC, Piccinno M, Avigo C. Dosimetry of non-uniform activity distribution: possibility to use the local energy deposition approach at the voxel level in radionuclide therapy. Biomed Phys Eng Express 2016. [DOI: 10.1088/2057-1976/2/6/065001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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32
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Braad PEN, Andersen T, Hansen SB, Høilund-Carlsen PF. Strategies for CT tissue segmentation for Monte Carlo calculations in nuclear medicine dosimetry. Med Phys 2016; 43:6507. [DOI: 10.1118/1.4967267] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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33
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Treutwein M, Schad L. Highly cited articles in "Zeitschrift für Medizinische Physik". Z Med Phys 2016; 26:293-294. [PMID: 27765385 DOI: 10.1016/j.zemedi.2016.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Plyku D, Loeb DM, Prideaux AR, Baechler S, Wahl RL, Sgouros G, Hobbs RF. Strengths and Weaknesses of a Planar Whole-Body Method of (153)Sm Dosimetry for Patients with Metastatic Osteosarcoma and Comparison with Three-Dimensional Dosimetry. Cancer Biother Radiopharm 2016; 30:369-79. [PMID: 26560193 DOI: 10.1089/cbr.2014.1803] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Dosimetric accuracy depends directly upon the accuracy of the activity measurements in tumors and organs. The authors present the methods and results of a retrospective tumor dosimetry analysis in 14 patients with a total of 28 tumors treated with high activities of (153)Sm-ethylenediaminetetramethylenephosphonate ((153)Sm-EDTMP) for therapy of metastatic osteosarcoma using planar images and compare the results with three-dimensional dosimetry. MATERIALS AND METHODS Analysis of phantom data provided a complete set of parameters for dosimetric calculations, including buildup factor, attenuation coefficient, and camera dead-time compensation. The latter was obtained using a previously developed methodology that accounts for the relative motion of the camera and patient during whole-body (WB) imaging. Tumor activity values calculated from the anterior and posterior views of WB planar images of patients treated with (153)Sm-EDTMP for pediatric osteosarcoma were compared with the geometric mean value. The mean activities were integrated over time and tumor-absorbed doses were calculated using the software package OLINDA/EXM. RESULTS The authors found that it was necessary to employ the dead-time correction algorithm to prevent measured tumor activity half-lives from often exceeding the physical decay half-life of (153)Sm. Measured half-lives so long are unquestionably in error. Tumor-absorbed doses varied between 0.0022 and 0.27 cGy/MBq with an average of 0.065 cGy/MBq; however, a comparison with absorbed dose values derived from a three-dimensional analysis for the same tumors showed no correlation; moreover, the ratio of three-dimensional absorbed dose value to planar absorbed dose value was 2.19. From the anterior and posterior activity comparisons, the order of clinical uncertainty for activity and dose calculations from WB planar images, with the present methodology, is hypothesized to be about 70%. CONCLUSION The dosimetric results from clinical patient data indicate that absolute planar dosimetry is unreliable and dosimetry using three-dimensional imaging is preferable, particularly for tumors, except perhaps for the most sophisticated planar methods. The relative activity and patient kinetics derived from planar imaging show a greater level of reliability than the dosimetry.
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Affiliation(s)
- Donika Plyku
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - David M Loeb
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Andrew R Prideaux
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Sébastien Baechler
- 2 University Institute of Radiation Physics, University of Lausanne , Lausanne, Switzerland
| | - Richard L Wahl
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - George Sgouros
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Robert F Hobbs
- 1 Department of Radiation Oncology, Johns Hopkins University School of Medicine , Baltimore, Maryland
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Jha AK, Caffo B, Frey EC. A no-gold-standard technique for objective assessment of quantitative nuclear-medicine imaging methods. Phys Med Biol 2016; 61:2780-800. [PMID: 26982626 DOI: 10.1088/0031-9155/61/7/2780] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The objective optimization and evaluation of nuclear-medicine quantitative imaging methods using patient data is highly desirable but often hindered by the lack of a gold standard. Previously, a regression-without-truth (RWT) approach has been proposed for evaluating quantitative imaging methods in the absence of a gold standard, but this approach implicitly assumes that bounds on the distribution of true values are known. Several quantitative imaging methods in nuclear-medicine imaging measure parameters where these bounds are not known, such as the activity concentration in an organ or the volume of a tumor. We extended upon the RWT approach to develop a no-gold-standard (NGS) technique for objectively evaluating such quantitative nuclear-medicine imaging methods with patient data in the absence of any ground truth. Using the parameters estimated with the NGS technique, a figure of merit, the noise-to-slope ratio (NSR), can be computed, which can rank the methods on the basis of precision. An issue with NGS evaluation techniques is the requirement of a large number of patient studies. To reduce this requirement, the proposed method explored the use of multiple quantitative measurements from the same patient, such as the activity concentration values from different organs in the same patient. The proposed technique was evaluated using rigorous numerical experiments and using data from realistic simulation studies. The numerical experiments demonstrated that the NSR was estimated accurately using the proposed NGS technique when the bounds on the distribution of true values were not precisely known, thus serving as a very reliable metric for ranking the methods on the basis of precision. In the realistic simulation study, the NGS technique was used to rank reconstruction methods for quantitative single-photon emission computed tomography (SPECT) based on their performance on the task of estimating the mean activity concentration within a known volume of interest. Results showed that the proposed technique provided accurate ranking of the reconstruction methods for 97.5% of the 50 noise realizations. Further, the technique was robust to the choice of evaluated reconstruction methods. The simulation study pointed to possible violations of the assumptions made in the NGS technique under clinical scenarios. However, numerical experiments indicated that the NGS technique was robust in ranking methods even when there was some degree of such violation.
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Affiliation(s)
- Abhinav K Jha
- Division of Medical Imaging Physics, Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
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Yeong CH, Cheng MH, Ng KH. Therapeutic radionuclides in nuclear medicine: current and future prospects. J Zhejiang Univ Sci B 2015; 15:845-63. [PMID: 25294374 DOI: 10.1631/jzus.b1400131] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The potential use of radionuclides in therapy has been recognized for many decades. A number of radionuclides, such as iodine-131 ((131)I), phosphorous-32 ((32)P), strontium-90 ((90)Sr), and yttrium-90 ((90)Y), have been used successfully for the treatment of many benign and malignant disorders. Recently, the rapid growth of this branch of nuclear medicine has been stimulated by the introduction of a number of new radionuclides and radiopharmaceuticals for the treatment of metastatic bone pain and neuroendocrine and other malignant or non-malignant tumours. Today, the field of radionuclide therapy is enjoying an exciting phase and is poised for greater growth and development in the coming years. For example, in Asia, the high prevalence of thyroid and liver diseases has prompted many novel developments and clinical trials using targeted radionuclide therapy. This paper reviews the characteristics and clinical applications of the commonly available therapeutic radionuclides, as well as the problems and issues involved in translating novel radionuclides into clinical therapies.
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Affiliation(s)
- Chai-Hong Yeong
- Department of Biomedical Imaging & University of Malaya Research Imaging Centre, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; Department of Nuclear Medicine, the Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China
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Subacute haematotoxicity after PRRT with (177)Lu-DOTA-octreotate: prognostic factors, incidence and course. Eur J Nucl Med Mol Imaging 2015; 43:453-63. [PMID: 26419852 PMCID: PMC4731438 DOI: 10.1007/s00259-015-3193-4] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 09/04/2015] [Indexed: 10/28/2022]
Abstract
PURPOSE In peptide receptor radionuclide therapy (PRRT), the bone marrow (BM) is one of the dose-limiting organs. The accepted dose limit for BM is 2 Gy, adopted from (131)I treatment. We investigated the incidence and duration of haematological toxicity and its risk factors in patients treated with PRRT with (177)Lu-DOTA(0)-Tyr(3)-octreotate ((177)Lu-DOTATATE). Also, absorbed BM dose estimates were evaluated and compared with the accepted 2 Gy dose limit. METHODS The incidence and duration of grade 3 or 4 haematological toxicity (according to CTCAE v3.0) and risk factors were analysed. Mean BM dose per unit (gigabecquerels) of administered radioactivity was calculated and the correlations between doses to the BM and haematological risk factors were determined. RESULTS Haematological toxicity (grade 3/4) occurred in 34 (11 %) of 320 patients. In 15 of the 34 patients, this lasted more than 6 months or blood transfusions were required. Risk factors significantly associated with haematological toxicity were: poor renal function, white blood cell (WBC) count <4.0 × 10(9)/l, age over 70 years, extensive tumour mass and high tumour uptake on the OctreoScan. Previous chemotherapy was not associated. The mean BM dose per administered activity in 23 evaluable patients was 67 ± 7 mGy/GBq, resulting in a mean BM dose of 2 Gy in patients who received four cycles of 7.4 GBq (177)Lu-DOTATATE. Significant correlations between (cumulative) BM dose and platelet and WBC counts were found in a selected group of patients. CONCLUSION The incidence of subacute haematological toxicity after PRRT with (177)Lu-DOTATATE is acceptable (11 %). Patients with impaired renal function, low WBC count, extensive tumour mass, high tumour uptake on the OctreoScan and/or advanced age are more likely to develop grade 3/4 haematological toxicity. The BM dose limit of 2 Gy, adopted from (131)I, seems not to be valid for PRRT with (177)Lu-DOTATATE.
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Lee I, Paeng JC, Lee SJ, Shin CS, Jang JY, Cheon GJ, Lee DS, Chung JK, Kang KW. Comparison of Diagnostic Sensitivity and Quantitative Indices Between (68)Ga-DOTATOC PET/CT and (111)In-Pentetreotide SPECT/CT in Neuroendocrine Tumors: a Preliminary Report. Nucl Med Mol Imaging 2015; 49:284-90. [PMID: 26550047 DOI: 10.1007/s13139-015-0356-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 06/02/2015] [Accepted: 07/15/2015] [Indexed: 01/13/2023] Open
Abstract
PURPOSE In-pentetreotide has been used for neuroendocrine tumors expressing somatostatin receptors. Recently, (68)Ga-DOTATOC PET has been used with the advantage of high image quality. In this study, we compared quantitative indices between (111)In-pentetreotide SPECT/CT and (68)Ga-DOTATOC PET/CT. METHODS Thirteen patients diagnosed with neuroendocrine tumors were prospectively recruited. Patients underwent (111)In-pentetreotide scans with SPECT/CT and (68)Ga-DOTATOC PET/CT before treatment. The number and location of lesions were analyzed on both imaging techniques to compare lesion detectability. Additionally, the maximal uptake count of each lesion and mean uptake count of the lungs were measured on both imagings, and target-to-normal lung ratios (TNR) were calculated as quantitative indices. RESULTS Among 13 patients, 10 exhibited lesions with increased uptake on (111)In-pentetreotide SPECT/CT and/or (68)Ga-DOTATOC PET/CT. Scans with SPECT/CT detected 19 lesions, all of which were also detected on PET/CT. Moreover, 16 additional lesions were detected on PET/CT (6 in the liver, 9 in the pancreas and 1 in the spleen). PET/CT exhibited a significantly higher sensitivity than SPECT/CT (100 % vs. 54 %, P < 0.001). TNR was significantly higher on PET/CT than on SPECT/CT (99.9 ± 84.3 vs. 71.1 ± 114.9, P < 0.001) in spite of a significant correlation (r = 0.692, P = 0.01). CONCLUSION Ga-DOTATOC PET/CT has a higher diagnostic sensitivity than (111)In-pentetreotide scans with SPECT/CT. The TNR on PET/CT is higher than that of SPECT/CT, which also suggests the higher sensitivity of PET/CT. (111)In-pentetreotide SPECT/CT should be used carefully if it is used instead of (68)Ga-DOTATOC PET/CT.
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Affiliation(s)
- Inki Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 110-744 Korea
| | - Jin Chul Paeng
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 110-744 Korea
| | - Soo Jin Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 110-744 Korea
| | - Chan Soo Shin
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Jin-Young Jang
- Department of Surgery, Seoul National University College of Medicine, Seoul, Korea
| | - Gi Jeong Cheon
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 110-744 Korea ; Cancer Research Institute, Seoul National University, Seoul, Korea
| | - Dong Soo Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 110-744 Korea ; Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Gyeonggi-Do, Korea
| | - June-Key Chung
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 110-744 Korea ; Cancer Research Institute, Seoul National University, Seoul, Korea
| | - Keon Wook Kang
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 110-744 Korea ; Cancer Research Institute, Seoul National University, Seoul, Korea
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Gear JI, Long C, Rushforth D, Chittenden SJ, Cummings C, Flux GD. Development of patient-specific molecular imaging phantoms using a 3D printer. Med Phys 2014; 41:082502. [PMID: 25086556 DOI: 10.1118/1.4887854] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/16/2014] [Accepted: 06/26/2014] [Indexed: 02/11/2024] Open
Abstract
PURPOSE The aim of the study was to investigate rapid prototyping technology for the production of patient-specific, cost-effective liquid fillable phantoms directly from patient CT data. METHODS Liver, spleen, and kidney volumes were segmented from patient CT data. Each organ was converted to a shell and filling holes and leg supports were added using computer aided design software and prepared for printing. Additional fixtures were added to the liver to allow lesion inserts to be fixed within the structure. Phantoms were printed from an ultraviolet curable photopolymer using polyjet technology on an Objet EDEN 500V 3D printer. RESULTS The final print material is a clear solid acrylic plastic which is watertight, rigid, and sufficiently durable to withstand multiple assembly and scanning protocols. Initial scans of the phantoms have been performed with Tc-99m SPECT and F-18 PET/CT. CONCLUSIONS The organ geometry showed good correspondence with anatomical references. The methodology developed can be generally applied to other anatomical or geometrical phantoms for molecular imaging.
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Affiliation(s)
- J I Gear
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey SM2 5TL, United Kingdom
| | - C Long
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey SM2 5TL, United Kingdom
| | - D Rushforth
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey SM2 5TL, United Kingdom
| | - S J Chittenden
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey SM2 5TL, United Kingdom
| | - C Cummings
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey SM2 5TL, United Kingdom
| | - G D Flux
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey SM2 5TL, United Kingdom
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Belley MD, Wang C, Nguyen G, Gunasingha R, Chao NJ, Chen BJ, Dewhirst MW, Yoshizumi TT. Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators. Med Phys 2014; 41:034101. [PMID: 24593746 PMCID: PMC3987731 DOI: 10.1118/1.4864237] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 12/16/2013] [Accepted: 01/16/2014] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Accurate dosimetry is essential when irradiating mice to ensure that functional and molecular endpoints are well understood for the radiation dose delivered. Conventional methods of prescribing dose in mice involve the use of a single dose rate measurement and assume a uniform average dose throughout all organs of the entire mouse. Here, the authors report the individual average organ dose values for the irradiation of a 12, 23, and 33 g mouse on a 320 kVp x-ray irradiator and calculate the resulting error from using conventional dose prescription methods. METHODS Organ doses were simulated in the Geant4 application for tomographic emission toolkit using the MOBY mouse whole-body phantom. Dosimetry was performed for three beams utilizing filters A (1.65 mm Al), B (2.0 mm Al), and C (0.1 mm Cu + 2.5 mm Al), respectively. In addition, simulated x-ray spectra were validated with physical half-value layer measurements. RESULTS Average doses in soft-tissue organs were found to vary by as much as 23%-32% depending on the filter. Compared to filters A and B, filter C provided the hardest beam and had the lowest variation in soft-tissue average organ doses across all mouse sizes, with a difference of 23% for the median mouse size of 23 g. CONCLUSIONS This work suggests a new dose prescription method in small animal dosimetry: it presents a departure from the conventional approach of assigninga single dose value for irradiation of mice to a more comprehensive approach of characterizing individual organ doses to minimize the error and uncertainty. In human radiation therapy, clinical treatment planning establishes the target dose as well as the dose distribution, however, this has generally not been done in small animal research. These results suggest that organ dose errors will be minimized by calibrating the dose rates for all filters, and using different dose rates for different organs.
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Affiliation(s)
- Matthew D Belley
- Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705
| | - Chu Wang
- Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705
| | - Giao Nguyen
- Duke Radiation Dosimetry Laboratory, Duke University Medical Center, Durham, North Carolina 27710
| | - Rathnayaka Gunasingha
- Duke Radiation Dosimetry Laboratory, Duke University Medical Center, Durham, North Carolina 27710
| | - Nelson J Chao
- Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710 and Department of Immunology, Duke University Medical Center, Durham, North Carolina 27710
| | - Benny J Chen
- Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710
| | - Mark W Dewhirst
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710
| | - Terry T Yoshizumi
- Duke Radiation Dosimetry Laboratory, Duke University Medical Center, Durham, North Carolina 27710; Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710; and Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710
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Glatting G, Bardiès M, Lassmann M. Treatment planning in molecular radiotherapy. Z Med Phys 2013; 23:262-9. [PMID: 23597414 DOI: 10.1016/j.zemedi.2013.03.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 03/05/2013] [Accepted: 03/14/2013] [Indexed: 01/09/2023]
Abstract
In molecular radiotherapy a radionuclide or a radioactively labelled pharmaceutical is administered to the patient. Treatment planning therefore comprises the determination of activity to administer. This administered activity should maximize tumour cell sterilization while minimizing normal tissue damage. In this work we present different approaches that are frequently used for determining the suitable activity. These approaches may be cohort- based as in chemotherapy, or patient-specific using dosimetry based on individual biokinetics. The approaches are different with respect to the input complexity, the corresponding costs and - in consequence - the quality of the therapy. In addition, a general scheme for data collection and analysis is proposed. To develop an effective and safe treatment, elaborate data need to be obtained. The main challenges, however, are collecting these complex data and analyse them properly.
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Affiliation(s)
- Gerhard Glatting
- Medical Radiation Physics/Radiation Protection, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
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Schipper MJ, Koral KF, Avram AM, Kaminski MS, Dewaraja YK. Prediction of therapy tumor-absorbed dose estimates in I-131 radioimmunotherapy using tracer data via a mixed-model fit to time activity. Cancer Biother Radiopharm 2013; 27:403-11. [PMID: 22947086 DOI: 10.1089/cbr.2011.1053] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND For individualized treatment planning in radioimmunotherapy (RIT), correlations must be established between tracer-predicted and therapy-delivered absorbed doses. The focus of this work was to investigate this correlation for tumors. METHODS The study analyzed 57 tumors in 19 follicular lymphoma patients treated with I-131 tositumomab and imaged with SPECT/CT multiple times after tracer and therapy administrations. Instead of the typical least-squares fit to a single tumor's measured time-activity data, estimation was accomplished via a biexponential mixed model in which the curves from multiple subjects were jointly estimated. The tumor-absorbed dose estimates were determined by patient-specific Monte Carlo calculation. RESULTS The mixed model gave realistic tumor time-activity fits that showed the expected uptake and clearance phases even with noisy data or missing time points. Correlation between tracer and therapy tumor-residence times (r=0.98; p<0.0001) and correlation between tracer-predicted and therapy-delivered mean tumor-absorbed doses (r=0.86; p<0.0001) were very high. The predicted and delivered absorbed doses were within ± 25% (or within ± 75 cGy) for 80% of tumors. CONCLUSIONS The mixed-model approach is feasible for fitting tumor time-activity data in RIT treatment planning when individual least-squares fitting is not possible due to inadequate sampling points. The good correlation between predicted and delivered tumor doses demonstrates the potential of using a pretherapy tracer study for tumor dosimetry-based treatment planning in RIT.
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Affiliation(s)
- Matthew J Schipper
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109, USA.
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Traino AC, Marcatili S, Avigo C, Sollini M, Erba PA, Mariani G. Dosimetry for nonuniform activity distributions: A method for the calculation of 3D absorbed-dose distribution without the use of voxelS-values, point kernels, or Monte Carlo simulations. Med Phys 2013; 40:042505. [DOI: 10.1118/1.4794473] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Abstract
Conventional nuclear medical imaging uses radiopharmaceuticals labeled by single-photon emitters such as Tc-99m, I-123, or I-131 in vivo. Classical clinical examples are the study of bone metabolism by bone scintigraphy with the Tc-99m-labeled polyphosphonates or of iodine transport into the thyroid gland using Tc-99m-pertechnetate. With single-photon emission-computed tomography (SPECT), the distribution of these radiopharmaceuticals within the human body is three-dimensionally visualized. Contrary to positron emission tomography (PET), current SPECT technology does not allow the quantification of regional values of radioactivity tissue concentration as SPECT images are grossly compromised by artifacts caused by photon scatter and attenuation. With the advent of hybrid imaging systems combining a SPECT camera with an X-ray computerized (CT) scanner in one gantry, reliable corrections for these artifacts seem possible, allowing truly quantitative SPECT.
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Affiliation(s)
- Philipp Ritt
- Nuklearmedizinische Klinik, Universität Erlangen-Nürnberg, Erlangen, Germany.
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Dieudonné A, Hobbs RF, Lebtahi R, Maurel F, Baechler S, Wahl RL, Boubaker A, Le Guludec D, Sgouros G, Gardin I. Study of the impact of tissue density heterogeneities on 3-dimensional abdominal dosimetry: comparison between dose kernel convolution and direct Monte Carlo methods. J Nucl Med 2012; 54:236-43. [PMID: 23249540 DOI: 10.2967/jnumed.112.105825] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
UNLABELLED Dose kernel convolution (DK) methods have been proposed to speed up absorbed dose calculations in molecular radionuclide therapy. Our aim was to evaluate the impact of tissue density heterogeneities (TDH) on dosimetry when using a DK method and to propose a simple density-correction method. METHODS This study has been conducted on 3 clinical cases: case 1, non-Hodgkin lymphoma treated with (131)I-tositumomab; case 2, a neuroendocrine tumor treatment simulated with (177)Lu-peptides; and case 3, hepatocellular carcinoma treated with (90)Y-microspheres. Absorbed dose calculations were performed using a direct Monte Carlo approach accounting for TDH (3D-RD), and a DK approach (VoxelDose, or VD). For each individual voxel, the VD absorbed dose, D(VD), calculated assuming uniform density, was corrected for density, giving D(VDd). The average 3D-RD absorbed dose values, D(3DRD), were compared with D(VD) and D(VDd), using the relative difference Δ(VD/3DRD). At the voxel level, density-binned Δ(VD/3DRD) and Δ(VDd/3DRD) were plotted against ρ and fitted with a linear regression. RESULTS The D(VD) calculations showed a good agreement with D(3DRD). Δ(VD/3DRD) was less than 3.5%, except for the tumor of case 1 (5.9%) and the renal cortex of case 2 (5.6%). At the voxel level, the Δ(VD/3DRD) range was 0%-14% for cases 1 and 2, and -3% to 7% for case 3. All 3 cases showed a linear relationship between voxel bin-averaged Δ(VD/3DRD) and density, ρ: case 1 (Δ = -0.56ρ + 0.62, R(2) = 0.93), case 2 (Δ = -0.91ρ + 0.96, R(2) = 0.99), and case 3 (Δ = -0.69ρ + 0.72, R(2) = 0.91). The density correction improved the agreement of the DK method with the Monte Carlo approach (Δ(VDd/3DRD) < 1.1%), but with a lesser extent for the tumor of case 1 (3.1%). At the voxel level, the Δ(VDd/3DRD) range decreased for the 3 clinical cases (case 1, -1% to 4%; case 2, -0.5% to 1.5%, and -1.5% to 2%). No more linear regression existed for cases 2 and 3, contrary to case 1 (Δ = 0.41ρ - 0.38, R(2) = 0.88) although the slope in case 1 was less pronounced. CONCLUSION This study shows a small influence of TDH in the abdominal region for 3 representative clinical cases. A simple density-correction method was proposed and improved the comparison in the absorbed dose calculations when using our voxel S value implementation.
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Affiliation(s)
- Arnaud Dieudonné
- Department of Nuclear Medicine, Beaujon Hospital, Assistance Publique-Hôpitaux de Paris APHP, Clichy, France.
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Dewaraja YK, Frey EC, Sgouros G, Brill AB, Roberson P, Zanzonico PB, Ljungberg M. MIRD pamphlet No. 23: quantitative SPECT for patient-specific 3-dimensional dosimetry in internal radionuclide therapy. J Nucl Med 2012; 53:1310-25. [PMID: 22743252 DOI: 10.2967/jnumed.111.100123] [Citation(s) in RCA: 241] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In internal radionuclide therapy, a growing interest in voxel-level estimates of tissue-absorbed dose has been driven by the desire to report radiobiologic quantities that account for the biologic consequences of both spatial and temporal nonuniformities in these dose estimates. This report presents an overview of 3-dimensional SPECT methods and requirements for internal dosimetry at both regional and voxel levels. Combined SPECT/CT image-based methods are emphasized, because the CT-derived anatomic information allows one to address multiple technical factors that affect SPECT quantification while facilitating the patient-specific voxel-level dosimetry calculation itself. SPECT imaging and reconstruction techniques for quantification in radionuclide therapy are not necessarily the same as those designed to optimize diagnostic imaging quality. The current overview is intended as an introduction to an upcoming series of MIRD pamphlets with detailed radionuclide-specific recommendations intended to provide best-practice SPECT quantification-based guidance for radionuclide dosimetry.
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Affiliation(s)
- Yuni K Dewaraja
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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Willegaignon J, Sapienza MT, Buchpiguel CA. Comparison of different dosimetric methods for red marrow absorbed dose calculation in thyroid cancer therapy. RADIATION PROTECTION DOSIMETRY 2012; 149:138-146. [PMID: 21586539 DOI: 10.1093/rpd/ncr214] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Several dosimetric methods have been proposed for estimating red marrow absorbed dose (RMAD) when radionuclide therapy is planned for differentiated thyroid cancer, although to date, there is no consensus as to whether dose calculation should be based on blood-activity concentration or not. Our purpose was to compare RMADs derived from methods that require collecting patients' blood samples versus those involving OLINDA/EXM software, thereby precluding this invasive procedure. This is a retrospective study that included 34 patients under treatment for metastatic thyroid disease. A deviation of <10 % between RMADs was found, when comparing the doses from the most usual invasive dosimetric methods and those from OLINDA/EXM. No statistical difference between the methods was discovered, whereby the need for invasive procedures when calculating the dose is questioned. The use of OLINDA/EXM in clinical routine could possibly diminish data collection, thus giving rise to a simultaneous reduction in time and clinical costs, besides avoiding any kind of discomfort on the part of the patients involved.
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Affiliation(s)
- José Willegaignon
- Nuclear Medicine Center, Department of Radiology, School of Medicine, University of São Paulo, São Paulo, Brazil.
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Kao YH, Hock Tan AE, Burgmans MC, Irani FG, Khoo LS, Gong Lo RH, Tay KH, Tan BS, Hoe Chow PK, Eng Ng DC, Whatt Goh AS. Image-Guided Personalized Predictive Dosimetry by Artery-Specific SPECT/CT Partition Modeling for Safe and Effective 90Y Radioembolization. J Nucl Med 2012; 53:559-66. [DOI: 10.2967/jnumed.111.097469] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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Determination of individual organ masses for 90Y-anti-CD66 radioimmunotherapy: Influence on therapy planning. Z Med Phys 2011; 21:305-9. [DOI: 10.1016/j.zemedi.2011.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 05/12/2011] [Accepted: 05/13/2011] [Indexed: 11/18/2022]
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Wierts R, de Pont CD, Brans B, Mottaghy FM, Kemerink GJ. Dosimetry in molecular nuclear therapy. Methods 2011; 55:196-202. [DOI: 10.1016/j.ymeth.2011.09.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 09/11/2011] [Accepted: 09/13/2011] [Indexed: 01/06/2023] Open
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