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Curkic Kapidzic S, Gustafsson J, Larsson E, Jessen L, Sjögreen Gleisner K. Kidney dosimetry in [ 177Lu]Lu-DOTA-TATE therapy based on multiple small VOIs. Phys Med 2024; 120:103335. [PMID: 38555793 DOI: 10.1016/j.ejmp.2024.103335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/24/2024] [Accepted: 03/21/2024] [Indexed: 04/02/2024] Open
Abstract
PURPOSE The aim was to investigate the use of multiple small VOIs for kidney dosimetry in [177Lu]Lu-DOTA-TATE therapy. METHOD The study was based on patient and simulated SPECT images in anthropomorphic geometries. Images were reconstructed using two reconstruction programs (local LundaDose and commercial Hermia) using OS-EM with and without resolution recovery (RR). Five small VOIs were placed to determine the average activity concentration (AC) in each kidney. The study consisted of three steps: (i) determination of the number of iterations for AC convergence based on simulated images; (ii) determination of recovery-coefficients (RCs) for 2 mL VOIs using a separate set of simulated images; (iii) assessment of operator variability in AC estimates for simulated and patient images. Five operators placed the VOIs, using for guidance: a) SPECT/CT with RR, b) SPECT/CT without RR, and c) CT only. For simulated images, time-integrated ACs (TIACs) were evaluated. For patient images, estimated ACs were compared with results of a previous method based on whole-kidney VOIs. RESULTS Eight iterations and ten subsets were sufficient for both programs and reconstruction settings. Mean RCs (mean ± SD) with RR were 1.03 ± 0.02 (LundaDose) and 1.10 ± 0.03 (Hermia), and without RR 0.91 ± 0.03 (LundaDose) and 0.94 ± 0.03 (Hermia). Most stable and accurate estimates of the AC were obtained using five 2-mL VOIs guided by SPECT/CT with RR, applying them to images without RR, and including an explicit RC for recovery correction. CONCLUSION The small VOI method based on five 2-mL VOIs was found efficient and sufficiently accurate for kidney dosimetry in [177Lu]Lu-DOTA-TATE therapy.
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Affiliation(s)
- Selma Curkic Kapidzic
- Medical Radiation Physics, Lund, Lund University, Lund, Sweden; Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden.
| | | | - Erik Larsson
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden
| | - Lovisa Jessen
- Medical Radiation Physics, Lund, Lund University, Lund, Sweden
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Vasić V, Gustafsson J, Nowshahr EY, Stenvall A, Beer AJ, Gleisner KS, Glatting G. A PBPK model for PRRT with [ 177Lu]Lu-DOTA-TATE: Comparison of model implementations in SAAM II and MATLAB/SimBiology. Phys Med 2024; 119:103299. [PMID: 38367588 DOI: 10.1016/j.ejmp.2024.103299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/06/2023] [Accepted: 01/23/2024] [Indexed: 02/19/2024] Open
Abstract
Physiologically based pharmacokinetic (PBPK) models offer the ability to simulate and predict the biodistribution of radiopharmaceuticals and have the potential to enable individualised treatment planning in molecular radiotherapy. The objective of this study was to develop and implement a whole-body compartmental PBPK model for peptide receptor radionuclide therapy (PRRT) with [177Lu]Lu-DOTA-TATE in SimBiology to allow for more complex analyses. The correctness of the model implementation was ensured by comparing its outputs, such as the time-integrated activity (TIA), with those of a PBPK model implemented in SAAM II software. METHODS A combined PBPK model for [68Ga]Ga-DOTA-TATE and [177Lu]Lu-DOTA-TATE was developed and implemented in both SAAM II and SimBiology. A retrospective analysis of 12 patients with metastatic neuroendocrine tumours (NETs) was conducted. First, time-activity curves (TACs) and TIAs from the two software were calculated and compared for identical parameter values. Second, pharmacokinetic parameters were fitted to activity concentrations, analysed and compared. RESULTS The PBPK model implemented in SimBiology produced TIA results comparable to those generated by the model implemented in SAAM II, with a relative deviation of less than 0.5% when using the same input parameters. The relative deviation of the fitted TIAs was less than 5% when model parameter values were fitted to the measured activity concentrations. CONCLUSION The proposed PBPK model implemented in SimBiology can be used for dosimetry in radioligand therapy and TIA prediction. Its outputs are similar to those generated by the PBPK model implemented in SAAM II, confirming the correctness of the model implementation in SimBiology.
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Affiliation(s)
- Valentina Vasić
- Department of Nuclear Medicine, Ulm University, Ulm, Germany; Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany.
| | | | - Elham Yousefzadeh Nowshahr
- Department of Nuclear Medicine, Ulm University, Ulm, Germany; Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Anna Stenvall
- Medical Radiation Physics, Lund University, Lund, Sweden
| | - Ambros J Beer
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | | | - Gerhard Glatting
- Department of Nuclear Medicine, Ulm University, Ulm, Germany; Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
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Roth D, Larsson E, Strand J, Ljungberg M, Sjögreen Gleisner K. Feasibility of 177Lu activity quantification using a small portable CZT-based gamma-camera. EJNMMI Phys 2024; 11:2. [PMID: 38167976 PMCID: PMC10761658 DOI: 10.1186/s40658-023-00602-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 12/06/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND In image processing for activity quantification, the end goal is to produce a metric that is independent of the measurement geometry. Photon attenuation needs to be accounted for and can be accomplished utilizing spectral information, avoiding the need of additional image acquisitions. The aim of this work is to investigate the feasibility of 177Lu activity quantification with a small CZT-based hand-held gamma-camera, using such an attenuation correction method. METHODS A previously presented dual photopeak method, based on the differential attenuation for two photon energies, is adapted for the three photopeaks at 55 keV, 113 keV, and 208 keV for 177Lu. The measurement model describes the count rates in each energy window as a function of source depth and activity, accounting for distance-dependent system sensitivity, attenuation, and build-up. Parameter values are estimated from characterizing measurements, and the source depth and activity are obtained by minimizing the difference between measured and modelled count rates. The method is applied and evaluated in phantom measurements, in a clinical setting for superficial lesions in two patients, and in a pre-clinical setting for one human tumour xenograft. Evaluation is made for a LEHR and an MEGP collimator. RESULTS For phantom measurements at clinically relevant depths, the average (and standard deviation) in activity errors are 17% ± 9.6% (LEHR) and 2.9% ± 3.6% (MEGP). For patient measurements, deviations from activity estimates from planar images from a full-sized gamma-camera are 0% ± 21% (LEHR) and 16% ± 18% (MEGP). For mouse measurements, average deviations of - 16% (LEHR) and - 6% (MEGP) are obtained when compared to a small-animal SPECT/CT system. The MEGP collimator appears to be better suited for activity quantification, yielding a smaller variability in activity estimates, whereas the LEHR results are more severely affected by septal penetration. CONCLUSIONS Activity quantification for 177Lu using the hand-held camera is found to be feasible. The readily available nature of the hand-held camera may enable more frequent activity quantification in e.g., superficial structures in patients or in the pre-clinical setting.
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Affiliation(s)
- Daniel Roth
- Medical Radiation Physics, Lund, Lund University, Lund, Sweden.
| | - Erik Larsson
- Department of Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Joanna Strand
- Department of Clinical Sciences Lund, Oncology, Lund University, Lund, Sweden
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund University, Lund, Sweden
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Peters S, Tran-Gia J, Agius S, Ivashchenko OV, Badel JN, Cremonesi M, Kurth J, Gabiña PM, Richetta E, Gleisner KS, Tipping J, Bardiès M, Stokke C. Implementation of dosimetry for molecular radiotherapy; results from a European survey. Phys Med 2024; 117:103196. [PMID: 38104033 DOI: 10.1016/j.ejmp.2023.103196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 10/13/2023] [Accepted: 12/07/2023] [Indexed: 12/19/2023] Open
Abstract
PURPOSE The use of molecular radiotherapy (MRT) has been rapidly evolving over the last years. The aim of this study was to assess the current implementation of dosimetry for MRTs in Europe. METHODS A web-based questionnaire was open for treating centres between April and June 2022, and focused on 2020-2022. Questions addressed the application of 16 different MRTs, the availability and involvement of medical physicists, software used, quality assurance, as well as the target regions for dosimetry, whether treatment planning and/or verification were performed, and the dosimetric methods used. RESULTS A total of 173 responses suitable for analysis was received from centres performing MRT, geographically distributed over 27 European countries. Of these, 146 centres (84 %) indicated to perform some form of dosimetry, and 97 % of these centres had a medical physicist available and almost always involved in dosimetry. The most common MRTs were 131I-based treatments for thyroid diseases and thyroid cancer, and [223Ra]RaCl2 for bone metastases. The implementation of dosimetry varied widely between therapies, from almost all centres performing dosimetry-based planning for microsphere treatments to none for some of the less common treatments (like 32P sodium-phosphate for myeloproliferative disease and [89Sr]SrCl2 for bone metastases). CONCLUSIONS Over the last years, implementation of dosimetry, both for pre-therapeutic treatment planning and post-therapy absorbed dose verification, increased for several treatments, especially for microsphere treatments. For other treatments that have moved from research to clinical routine, the use of dosimetry decreased in recent years. However, there are still large differences both across and within countries.
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Affiliation(s)
- Steffie Peters
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Johannes Tran-Gia
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Sam Agius
- Medical Imaging Department and Radioisotope Unit, Mater Dei Hospital, Msida, Malta
| | - Oleksandra V Ivashchenko
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen, The Netherlands
| | - Jean Noël Badel
- Centre de Lutte Contre le Cancer Léon-Bérard, CREATIS CNRS UMR 5220 INSERM U 1044, Université de Lyon, INSA-Lyon, Lyon, France
| | - Marta Cremonesi
- Unit of Radiation Research, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Jens Kurth
- Department of Nuclear Medicine, Rostock University Medical Center, Rostock, Germany
| | - Pablo Minguez Gabiña
- Department of Medical Physics and Radiation Protection, Gurutzeta-Cruces University Hospital/Biocruces Bizkaia Health Research Institute, Barakaldo, Spain
| | - Elisa Richetta
- Medical Physics Department, AO Ordine Mauriziano, Turin, Italy
| | | | - Jill Tipping
- The Christie NHS Foundation Trust, Nuclear Medicine, Manchester, UK
| | - Manuel Bardiès
- IRCM, UMR 1194 INSERM, Université de Montpellier and Institut Régional du Cancer de Montpellier (ICM), France & Département de Médecine Nucléaire, Institut Régional du Cancer de Montpellier (ICM), France
| | - Caroline Stokke
- Department of Physics and Computational Radiology, Oslo University Hospital, Oslo, Norway; Department of Physics, University of Oslo, Oslo, Norway.
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Cicone F, Sjögreen Gleisner K, Sarnelli A, Indovina L, Gear J, Gnesin S, Kraeber-Bodéré F, Bischof Delaloye A, Valentini V, Cremonesi M. The contest between internal and external-beam dosimetry: The Zeno's paradox of Achilles and the tortoise. Phys Med 2024; 117:103188. [PMID: 38042710 DOI: 10.1016/j.ejmp.2023.103188] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/06/2023] [Accepted: 11/23/2023] [Indexed: 12/04/2023] Open
Abstract
Radionuclide therapy, also called molecular radiotherapy (MRT), has come of age, with several novel radiopharmaceuticals being approved for clinical use or under development in the last decade. External beam radiotherapy (EBRT) is a well-established treatment modality, with about half of all oncologic patients expected to receive at least one external radiation treatment over their disease course. The efficacy and the toxicity of both types of treatment rely on the interaction of radiation with biological tissues. Dosimetry played a fundamental role in the scientific and technological evolution of EBRT, and absorbed doses to the target and to the organs at risk are calculated on a routine basis. In contrast, in MRT the usefulness of internal dosimetry has long been questioned, and a structured path to include absorbed dose calculation is missing. However, following a similar route of development as EBRT, MRT treatments could probably be optimized in a significant proportion of patients, likely based on dosimetry and radiobiology. In the present paper we describe the differences and the similarities between internal and external-beam dosimetry in the context of radiation treatments, and we retrace the main stages of their development over the last decades.
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Affiliation(s)
- Francesco Cicone
- Department of Experimental and Clinical Medicine, "Magna Graecia" University of Catanzaro, Catanzaro, Italy; Nuclear Medicine Unit, "Mater Domini" University Hospital, Catanzaro, Italy.
| | | | - Anna Sarnelli
- Medical Physics Unit, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) "Dino Amadori", Meldola, Italy
| | - Luca Indovina
- Department of Diagnostic Imaging, Oncological Radiotherapy and Hematology, Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy
| | - Jonathan Gear
- Joint Department of Physics, Royal Marsden NHSFT & Institute of Cancer Research, Sutton, UK
| | - Silvano Gnesin
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland; University of Lausanne, Lausanne, Switzerland
| | - Françoise Kraeber-Bodéré
- Nantes Université, Université Angers, CHU Nantes, INSERM, CNRS, CRCI2NA, Médecine Nucléaire, F-44000 Nantes, France
| | | | - Vincenzo Valentini
- Department of Diagnostic Imaging, Oncological Radiotherapy and Hematology, Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy; Università Cattolica del Sacro Cuore, Rome, Italy
| | - Marta Cremonesi
- Unit of Radiation Research, IEO, European Institute of Oncology IRCCS, Milan, Italy
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Hindorf C, Jessen L, Kapidzic SC, Blakkisrud J, Dalmo J, Engelsen O, Gustafsson J, Sandström M, Sæterstøl J, Gleisner KS. Traceable calibration with 177Lu and comparison of activity meters at hospitals in Norway and Sweden. Phys Med 2023; 116:103170. [PMID: 37989044 DOI: 10.1016/j.ejmp.2023.103170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/05/2023] [Accepted: 11/06/2023] [Indexed: 11/23/2023] Open
Abstract
INTRODUCTION The activity meter is used to determine the activity of delivered radiopharmaceuticals, administered activity to patients and reference activity when gamma-cameras are calibrated prior to imaged-based dosimetry. The aim is to describe a procedure for cross-calibration of activity meters at different clinical sites, and report on 177Lu activity results when using factory-set calibration factors compared to when calibration is performed with traceability to a primary standard. METHODS Thirty activity meters placed at seven hospitals in Norway and Sweden from four manufacturers: Capintec, Commecer, NuviaTech and Veenstra were included. A stock solution with 177Lu was prepared at the local sites and measured in each activity meter with factory settings. The solution was shipped to the reference site at Lund University for measurements in a secondary standard activity meter. Deviations between local and reference activity measurements were determined for three geometries: 25-mL vial, 10-mL syringe and 1-mL syringe. RESULTS The median of the deviations was 6.4 % for the 25 mL vial, 5.9 % for the 10 mL syringe and 6.8 % for the 1 mL syringe. The median of the deviations for the 25 mL vial, was 1.5 % for activity meters from Capintec, 7.0 % for Comecer, 11.0 % for NuviaTech and 2.4 % for Veenstra. The majority of the deviations were positive and the maximum deviation was 14.5 %. CONCLUSION The activity of 177Lu measured in an activity meter with factory-set dial settings may yield deviations up to 14.5%, compared to activities measured with traceability to a primary standard. This would imply an undertreatment of patients.
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Affiliation(s)
- Cecilia Hindorf
- Department of Medical Radiation Physics, Lund University, Lund, Sweden; Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden.
| | - Lovisa Jessen
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Selma Curkic Kapidzic
- Department of Medical Radiation Physics, Lund University, Lund, Sweden; Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden
| | - Johan Blakkisrud
- Department of Physics and Computational Radiology, Oslo University Hospital, Oslo, Norway
| | - Johanna Dalmo
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Ola Engelsen
- PET Imaging Center, University Hospital North Norway (UNN), Tromsø, Norway
| | - Johan Gustafsson
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Mattias Sandström
- Section of Nuclear Medicine and PET, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Jostein Sæterstøl
- Department of Radiology, Haukeland University Hospital, Bergen, Norway
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Gustafsson J, Ljungberg M, Alm Carlsson G, Larsson E, Warfvinge CF, Asp P, Sjögreen Gleisner K. Averaging of absorbed doses: How matter matters. Med Phys 2023; 50:6600-6613. [PMID: 37272586 DOI: 10.1002/mp.16528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 04/05/2023] [Accepted: 05/10/2023] [Indexed: 06/06/2023] Open
Abstract
BACKGROUND Dosimetry in radionuclide therapy often requires the calculation of average absorbed doses within and between spatial regions, for example, for voxel-based dosimetry methods, for paired organs, or across multiple tumors. Formation of such averages can be made in different ways, starting from different definitions. PURPOSE The aim of this study is to formally specify different averaging strategies for absorbed doses, and to compare their results when applied to absorbed dose distributions that are non-uniform within and between regions. METHODS For averaging within regions, two definitions of the average absorbed dose are considered: the simple average over the region (the region average) and the average when weighting by the mass density (density-weighted region average). The latter is shown to follow from the definition of mean absorbed dose according to the ICRU, and to be consistent with the MIRD formalism. For averaging between different spatial regions, three definitions follow: the volume-weighted, the mass-weighted, and the unweighted average. With respect to characterizing non-uniformity, the different average definitions lead to the use of dose-volume histograms (DVHs) (region average), dose-mass histograms (DMHs) (density-weighted region average), and unweighted histograms (unweighted average). Average absorbed doses are calculated for three worked examples, starting from the different definitions. The first, schematic, example concerns the calculation of the average absorbed dose between two regions with different volumes or mass densities. The second, stylized, example concerns voxel-based dosimetry, for which the average absorbed-dose rate within a region is calculated. The geometries studied include three 177 Lu-filled voxelized spheres, where the sphere masses are held constant while the material compositions, densities, and volumes are varied. For comparison, the mean absorbed-dose rates obtained using unit-density sphere S-values are also included. The third example concerns SPECT/CT-based tumor dosimetry for five patients undergoing therapy with 177 Lu-PSMA and six patients undergoing therapy with 177 Lu-DOTA-TATE, for which the average absorbed-dose rates across multiple tumors are calculated. For the second and third examples, analyses also include representations by histograms. RESULTS Example 1 shows that the average absorbed doses, calculated using different definitions, can differ considerably if the masses and absorbed doses for two regions are markedly different. From example 2 it is seen that the density-weighted region average is stable under different activity and density distributions and is also in line with results using S-values. In contrast, the region average varies as function of the activity distribution. In example 3, the absorbed dose rates for individual tumors differ by (1.1 ± 4.3)% and (-0.1 ± 0.4)% with maximum deviations of +34.4% and -1.4% for 177 Lu-PSMA and 177 Lu-DOTA-TATE, respectively, when calculated as region averages or density-weighted region averages, with largest deviations obtained when the density is non-uniform. The average absorbed doses calculated across all tumors are similar when comparing mass-weighted and volume-weighted averages but these differ substantially from unweighted averages. CONCLUSION Different strategies for averaging of absorbed doses within and between regions can lead to substantially different absorbed-dose estimates. At reporting of radionuclide therapy dosimetry, it is important to specify the averaging strategy applied.
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Affiliation(s)
| | | | - Gudrun Alm Carlsson
- Department of Radiation Physics, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Erik Larsson
- Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Carl Fredrik Warfvinge
- Division of Oncology and Pathology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Pernilla Asp
- Division of Oncology and Pathology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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Gabiña PM, Gleisner KS, Cremonesi M, Stokke C, Flux G, Cicone F, Konijnenberg M, Aldridge M, Sandstrom M, Chiesa C, Paphiti M, Hippeläinen E, Uribe C, Solny P, Gnesin S, Bernhardt P, Chouin N, Costa PF, Glatting G, Verburg F, Gear J. Results from an EANM survey on time estimates and personnel responsible for main tasks in molecular radiotherapy dosimetry. Eur J Nucl Med Mol Imaging 2023; 50:2595-2604. [PMID: 37129712 DOI: 10.1007/s00259-023-06215-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Affiliation(s)
- Pablo Mínguez Gabiña
- Department of Medical Physics and Radiation Protection, Gurutzeta-Cruces University Hospital/Biocruces Bizkaia Health Research Institute, Plaza Cruces S/N, 48903, Barakaldo, Spain
- Faculty of Engineering, Department of Applied Physics, UPV/EHU, Bilbao, Spain
| | | | - Marta Cremonesi
- Radiation Research Unit, Department of Medical Imaging and Radiation Sciences, Istituto Europeo Di Oncologia, Milan, Italy
| | - Caroline Stokke
- Department of Physics and Computational Radiology, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
- Department of Physics, University of Oslo, Oslo, Norway
| | - Glenn Flux
- Joint Department of Physics, Royal Marsden NHSFT and Institute of Cancer Research, Sutton, UK
| | - Francesco Cicone
- Department of Experimental and Clinical Medicine, "Magna Graecia" University of Catanzaro, Catanzaro, Italy
- Nuclear Medicine Unit, University Hospital "Mater Domini", Catanzaro, Italy
| | - Mark Konijnenberg
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Matt Aldridge
- Maidstone and Tunbridge Wells NHS Trust, Maidstone Hospital, Maidstone, ME16 9QQ, UK
| | - Mattias Sandstrom
- Section of Nuclear Medicine and PET, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Carlo Chiesa
- Nuclear Medicine Division, Foundation IRCCS Istituto Nazionale Tumori, Via Giacomo Venezian 1, 20133, Milan, Italy
| | - Maria Paphiti
- Medical Physics Department, Pammakaristos Hospital of Divine Providence, Iakovaton 43, 11144, Athens, Greece
| | - Eero Hippeläinen
- Department of Clinical Physiology and Nuclear Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Carlos Uribe
- Functional Imaging, BC Cancer, Vancouver, BC, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
| | - Pavel Solny
- National Radiation Protection Institute, Bartoskova 1450/28, 140 00, Praha 4, Nusle, Czech Republic
| | - Silvano Gnesin
- Institute of Radiation Physics, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Peter Bernhardt
- Department of Medical Radiation Sciences, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Gothenburg, University, Gothenburg, Sweden
- Department of Medical Physics and Biomedical Engineering (MFT), Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Nicolas Chouin
- Nantes Université, Inserm, CNRS, Université d'Angers, Oniris, CRCI2NA, Nantes, France
| | - Pedro Fragoso Costa
- Department of Nuclear Medicine, West German Cancer Center, University of Duisburg-Essen, Essen, Germany
- Cancer Consortium (DKTK), University Hospital Essen, Essen, Germany
| | - Gerhard Glatting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | - Frederik Verburg
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Jonathan Gear
- Joint Department of Physics, Royal Marsden NHSFT and Institute of Cancer Research, Sutton, UK.
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10
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Stenvall A, Gustafsson J, Larsson E, Roth D, Sundlöv A, Jönsson L, Hindorf C, Ohlsson T, Sjögreen Gleisner K. Relationships between uptake of [ 68Ga]Ga-DOTA-TATE and absorbed dose in [ 177Lu]Lu-DOTA-TATE therapy. EJNMMI Res 2022; 12:75. [PMID: 36534192 PMCID: PMC9763525 DOI: 10.1186/s13550-022-00947-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Somatostatin receptor 68Ga PET imaging is standard for evaluation of a patient's suitability for 177Lu peptide receptor radionuclide therapy of neuroendocrine tumours (NETs). The 68Ga PET serves to ensure sufficient somatostatin receptor expression, commonly evaluated qualitatively. The aim of this study is to investigate the quantitative relationships between uptake in 68Ga PET and absorbed doses in 177Lu therapy. METHOD Eighteen patients underwent [68Ga]Ga-DOTA-TATE PET imaging within 20 weeks prior to their first cycle of [177Lu]Lu-DOTA-TATE. Absorbed doses for therapy were estimated for tumours, kidney, spleen, and normal liver parenchyma using a hybrid SPECT/CT-planar method. Gallium-68 activity concentrations were retrieved from PET images and also used to calculate SUVs and normalized SUVs, using blood and tissue for normalization. The 68Ga activity concentrations per injected activity, SUVs, and normalized SUVs were compared with 177Lu activity concentrations 1 d post-injection and 177Lu absorbed doses. For tumours, for which there was a variable number per patient, both inter- and intra-patient correlations were analysed. Furthermore, the prediction of 177Lu tumour absorbed doses based on a combination of tumour-specific 68Ga activity concentrations and group-based estimates of the effective half-lives for grade 1 and 2 NETs was explored. RESULTS For normal organs, only spleen showed a significant correlation between the 68Ga activity concentration and 177Lu absorbed dose (r = 0.6). For tumours, significant, but moderate, correlations were obtained, with respect to both inter-patient (r = 0.7) and intra-patient (r = 0.45) analyses. The correlations to absorbed doses did not improve when using 68Ga SUVs or normalized SUVs. The relationship between activity uptakes for 68Ga PET and 177Lu SPECT was stronger, with correlation coefficients r = 0.8 for both inter- and intra-patient analyses. The 177Lu absorbed dose to tumour could be predicted from the 68Ga activity concentrations with a 95% coverage interval of - 65% to 248%. CONCLUSIONS On a group level, a high uptake of [68Ga]Ga-DOTA-TATE is associated with high absorbed doses at 177Lu-DOTA-TATE therapy, but the relationship has a limited potential with respect to individual absorbed dose planning. Using SUV or SUV normalized to reference tissues do not improve correlations compared with using activity concentration per injected activity.
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Affiliation(s)
- Anna Stenvall
- grid.4514.40000 0001 0930 2361Medical Radiation Physics, Lund, Lund University, Lund, Sweden ,grid.411843.b0000 0004 0623 9987Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Johan Gustafsson
- grid.4514.40000 0001 0930 2361Medical Radiation Physics, Lund, Lund University, Lund, Sweden
| | - Erik Larsson
- grid.411843.b0000 0004 0623 9987Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Daniel Roth
- grid.4514.40000 0001 0930 2361Medical Radiation Physics, Lund, Lund University, Lund, Sweden
| | - Anna Sundlöv
- grid.4514.40000 0001 0930 2361Division of Oncology, Department of Clinical Sciences, Lund, Lund University, Lund, Sweden
| | - Lena Jönsson
- grid.4514.40000 0001 0930 2361Medical Radiation Physics, Lund, Lund University, Lund, Sweden ,grid.411843.b0000 0004 0623 9987Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Cecilia Hindorf
- grid.4514.40000 0001 0930 2361Medical Radiation Physics, Lund, Lund University, Lund, Sweden ,grid.24381.3c0000 0000 9241 5705Department of Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Tomas Ohlsson
- grid.411843.b0000 0004 0623 9987Radiation Physics, Skåne University Hospital, Lund, Sweden
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11
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Roth D, Larsson E, Ljungberg M, Sjögreen Gleisner K. Monte Carlo modelling of a compact CZT-based gamma camera with application to 177Lu imaging. EJNMMI Phys 2022; 9:35. [PMID: 35526172 PMCID: PMC9081070 DOI: 10.1186/s40658-022-00463-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 04/20/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Semiconductor gamma-camera systems based on cadmium zinc telluride (CZT) detectors present new challenges due to an energy-response that includes effects of low-energy tailing. In particular, such energy tails produce effects that need to be considered when imaging radionuclides with multiple emissions such as $$^{177}{\mathrm {Lu}}$$
177
Lu
. Monte Carlo simulation can be used to investigate the behaviour of such systems and optimise their use, provided that the detector model closely reflects the real physical detector. The aim of this work is to develop a CZT model applicable for simulation of CZT-based gamma cameras.
Methods
The equations describing the charge transport and signal induction are considered in three dimensions and are solved numerically, and the CZT model is then realised by coupling the detector-response to the photon-transport handled by the SIMIND Monte Carlo program. The CZT model is tuned to reproduce experimentally measured energy spectra of a hand-held gamma camera system for multiple radionuclides ($$^{99\mathrm {m}}{\mathrm {Tc}}$$
99
m
Tc
, $$^{123}{\mathrm {I}}$$
123
I
and $$^{177}{\mathrm {Lu}}$$
177
Lu
) and parallel-hole collimators (MEGP, LEHR) as well as an uncollimated system.
Results
Overall, the model results agree well with measurements across the range of experimental conditions. The applicability of the model is demonstrated by separating energy spectra into components to investigate the interference of high-energy photons on lower energy-windows, where pronounced effects of low-energy tailing for $$^{177}{\mathrm {Lu}}$$
177
Lu
are observed.
Conclusions
The developed model provides understanding of the specifics of the camera response and is expected to be helpful for future optimisation of gamma camera applications.
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12
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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: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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13
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Roth D, Gustafsson JR, Warfvinge CF, Sundlöv A, Åkesson A, Tennvall J, Sjögreen Gleisner K. Dosimetric quantities of neuroendocrine tumors over treatment cycles with 177Lu-DOTA-TATE. J Nucl Med 2021; 63:399-405. [PMID: 34272319 DOI: 10.2967/jnumed.121.262069] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/25/2021] [Indexed: 11/16/2022] Open
Abstract
Tumor dosimetry was performed for 177Lu-DOTA-TATE with the aims of better understanding i) the range and variation of the tumor absorbed doses (ADs), ii) how different dosimetric quantities evolve over the treatment cycles, and iii) whether this evolution differs depending on the tumor grade. Such information is important for radiobiological interpretation and may inform the design of alternative administration schemes. Methods: Data come from 41 patients with neuroendocrine tumors (NETs) of grade 1 (n = 23) or 2 (n = 18), that had received between 2 and 9 treatment cycles. Dosimetry was performed for 182 individual lesions, giving in total 880 individual AD assessments across all cycles. Hybrid planar-SPECT/CT imaging was used, including quantitative SPECT reconstruction, voxel-based absorbed-dose-rate calculation, semi-automatic image segmentation, and partial-volume correction. Linear mixed-effect models were used to analyze changes over cycles in tumor ADs, absorbed-dose rates and activity concentrations at day-1, effective half-times, and tumor volumes. Tumors smaller than 8 ml were excluded from analyses. Results: Tumor ADs ranged between 2 and 77 Gy per cycle. On average the AD decreased over the cycles, with significantly different rates (P < 0.05) for grade 1 and 2 NETs of 6% and 14% per cycle, respectively. The absorbed-dose rates and activity concentrations at day-1 decreased by similar amounts. The effective half-times were less variable but shorter for grade 2 than grade 1 (P < 0.001). For grade 2 NETS the tumor volumes decreased, with a similar tendency in grade 1. Conclusion: The tumor AD, absorbed-dose rate and activity uptake decrease, in parallel with tumor volumes, between 177Lu-DOTA-TATE treatment cycles, particularly for grade 2 NETs. The effective half-times vary less but are lower for grade 2 than grade 1 NETs. These results may indicate the development of radiation-induced fibrosis and could have implications for the design of future treatment and dosimetry protocols.
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Affiliation(s)
- Daniel Roth
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Sweden
| | - Johan Ruben Gustafsson
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Sweden
| | - Carl Fredrik Warfvinge
- Division of Oncology and Pathology, Department of Clinical Sciences Lund, Lund University, Sweden
| | - Anna Sundlöv
- Division of Oncology and Pathology, Department of Clinical Sciences Lund, Lund University, Sweden
| | - Anna Åkesson
- Clinical Studies Sweden - Forum South, Skåne University Hospital
| | - Jan Tennvall
- Division of Oncology and Pathology, Department of Clinical Sciences Lund, Lund University, Sweden
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14
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Roth D, Larsson E, Sundlöv A, Sjögreen Gleisner K. Characterisation of a hand-held CZT-based gamma camera for 177Lu imaging. EJNMMI Phys 2020; 7:46. [PMID: 32642884 PMCID: PMC7343677 DOI: 10.1186/s40658-020-00313-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 06/17/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Currently, hand-held gamma cameras are being developed for 99mTc imaging, mainly for sentinel lymph node detection. These cameras offer advantages, such as mobility and ease of access, and may be useful also for other applications such as biokinetic studies in animals or for imaging of small, superficial structures in patients. In this work, the suitability of a CZT-based hand-held camera for 177Lu imaging is investigated. The energy response of CZT-based detectors combined with the multiple photon emissions of 177Lu poses new challenges compared to 99mTc imaging, and a thorough camera characterisation is thus warranted. METHODS Three collimators (LEHR, LEHS, and MEGP) and three energy windows (55 keV, 113 keV, and 208 keV) are investigated. Characterised camera properties include the system spatial resolution, energy resolution, sensitivity, image uniformity, septal penetration, and temperature dependence. Characterisations are made starting from NEMA guidelines when applicable, with adjustments made when required. The applicability of the camera is demonstrated by imaging of a superficially located tumour in a patient undergoing [177 Lu]Lu-DOTA-TATE therapy. RESULTS Overall, the results are encouraging. Compared to a conventional gamma camera, the hand-held camera generally has a higher sensitivity for a given collimator. For source-collimator distances below 3 cm, the spatial resolution FWHM is within 6 mm for the LEHR and MEGP collimators. Before uniformity correction, the central field-of-view integral uniformity shows best results for the 113-keV window, with values obtained between 11 and 14%. The corresponding values after uniformity correction are within 3%. Effects of septal penetration are observed but are manageable with a proper combination of collimator and energy window setting. Septal penetration and collimator scatter not only affect the 208-keV window but also contribute with counts in lower windows due to energy-tailing effects. The patient study revealed non-uniform uptake patterns in a region that appeared uniform in a conventional gamma camera image. CONCLUSIONS The results show that the hand-held camera can be used for 177Lu imaging. A 113-keV energy window combined with LEHR or MEGP collimators provides the best image system characteristics.
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Affiliation(s)
- Daniel Roth
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden.
| | - Erik Larsson
- Department of Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Anna Sundlöv
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden.,Department of Oncology and Pathology, Clinical Sciences Lund, Lund University, Lund, Sweden.,Department of Oncology, Skåne University Hospital, Lund, Sweden
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15
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Mínguez P, Rodeño E, Genollá J, Domínguez M, Expósito A, Sjögreen Gleisner K. Analysis of activity uptake, effective half-life and time-integrated activity for low- and high-risk papillary thyroid cancer patients treated with 1.11 GBq and 3.7 GBq of 131I-NaI respectively. Phys Med 2019; 65:143-149. [DOI: 10.1016/j.ejmp.2019.08.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 08/21/2019] [Accepted: 08/23/2019] [Indexed: 11/16/2022] Open
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16
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Hagmarker L, Svensson J, Rydén T, van Essen M, Sundlöv A, Gleisner KS, Gjertsson P, Bernhardt P. Bone Marrow Absorbed Doses and Correlations with Hematologic Response During 177Lu-DOTATATE Treatments Are Influenced by Image-Based Dosimetry Method and Presence of Skeletal Metastases. J Nucl Med 2019; 60:1406-1413. [PMID: 30902877 PMCID: PMC6785794 DOI: 10.2967/jnumed.118.225235] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 03/13/2019] [Indexed: 12/15/2022] Open
Abstract
This study aimed to compare different image-based methods for bone marrow dosimetry and study the dose–response relationship during treatment with 177Lu-DOTATATE in patients with and without skeletal metastases. Methods: This study included 46 patients with advanced neuroendocrine tumors treated with at least 2 fractions of 177Lu-DOTATATE at Sahlgrenska University Hospital. High- and low-uptake compartments were automatically outlined in planar images collected at 2, 24, 48, and 168 h after injection. The bone marrow absorbed doses were calculated from the cross doses of the high- and low-uptake compartments and the self-dose, using the time–activity concentration curve for the low-uptake compartment. This time–activity concentration curve was adjusted using a fixed constant of 1.8 for the planar dosimetry method and using the activity concentrations in vertebral bodies in SPECT images at 24 h after injection of 177Lu-DOTATATE in 4 hybrid methods: L4-SPECT used the activity concentration in the L4 vertebra, whereas V-SPECT, L-SPECT, and T-SPECT used the median activity concentration in all visible vertebrae, lumbar vertebrae, and thoracic vertebrae, respectively. Results: Using the planar method, L4-SPECT, V-SPECT, L-SPECT, and T-SPECT, the estimated median bone marrow absorbed doses were 0.19, 0.36, 0.40, 0.39, and 0.46 Gy/7.4 GBq, respectively, with respective ranges of 0.12–0.33, 0.15–1.44, 0.19–1.71, 0.21–1.60, and 0.18–2.12 Gy/7.4 GBq. For all methods, the bone marrow absorbed dose significantly correlated with decreased platelet counts. This correlation increased after treatment fraction 2: the Spearman correlation (rs) were −0.49 for the planar method, −0.61 for L4-SPECT, −0.63 for V-SPECT, −0.63 for L-SPECT, and −0.57 for T-SPECT. A separate analysis revealed an increased correlation for patients without skeletal metastases using the planar method (rs = −0.67). In contrast, hybrid methods had poor correlations for patients without metastases and stronger correlations for patients with skeletal metastases (rs = −0.61 to −0.74). The mean bone marrow absorbed doses were 3%–69% higher for patients with skeletal metastases than for patients without. Conclusion: The estimated bone marrow absorbed doses by image-based techniques and the correlation with platelets are influenced by the choice of measured vertebrae and the presence of skeletal metastases.
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Affiliation(s)
- Linn Hagmarker
- Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Johanna Svensson
- Department of Oncology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Tobias Rydén
- Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Martijn van Essen
- Department of Clinical Physiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Anna Sundlöv
- Department of Oncology, Skåne University Hospital, Lund, Sweden.,Lund University, Division of Oncology and Pathology, Department of Clinical Sciences, Lund, Sweden; and
| | | | - Peter Gjertsson
- Department of Clinical Physiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Peter Bernhardt
- Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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17
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Gear JI, Cox MG, Gustafsson J, Gleisner KS, Murray I, Glatting G, Konijnenberg M, Flux GD. EANM practical guidance on uncertainty analysis for molecular radiotherapy absorbed dose calculations. Eur J Nucl Med Mol Imaging 2018; 45:2456-2474. [PMID: 30218316 PMCID: PMC6208822 DOI: 10.1007/s00259-018-4136-7] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 08/14/2018] [Indexed: 11/30/2022]
Abstract
A framework is proposed for modelling the uncertainty in the measurement processes constituting the dosimetry chain that are involved in internal absorbed dose calculations. The starting point is the basic model for absorbed dose in a site of interest as the product of the cumulated activity and a dose factor. In turn, the cumulated activity is given by the area under a time-activity curve derived from a time sequence of activity values. Each activity value is obtained in terms of a count rate, a calibration factor and a recovery coefficient (a correction for partial volume effects). The method to determine the recovery coefficient and the dose factor, both of which are dependent on the size of the volume of interest (VOI), are described. Consideration is given to propagating estimates of the quantities concerned and their associated uncertainties through the dosimetry chain to obtain an estimate of mean absorbed dose in the VOI and its associated uncertainty. This approach is demonstrated in a clinical example.
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Affiliation(s)
- Jonathan I Gear
- The Royal Marsden NHS Foundation Trust & Institute of Cancer Research, Downs Road, Sutton, SM2 5PT, UK.
| | - Maurice G Cox
- National Physical Laboratory, Teddington, TW11 0LW, UK
| | - Johan Gustafsson
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | | | - Iain Murray
- The Royal Marsden NHS Foundation Trust & Institute of Cancer Research, Downs Road, Sutton, SM2 5PT, UK
| | - Gerhard Glatting
- Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany
| | | | - Glenn D Flux
- The Royal Marsden NHS Foundation Trust & Institute of Cancer Research, Downs Road, Sutton, SM2 5PT, UK
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18
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Roth D, Gustafsson J, Sundlöv A, Sjögreen Gleisner K. A method for tumor dosimetry based on hybrid planar-SPECT/CT images and semiautomatic segmentation. Med Phys 2018; 45:5004-5018. [PMID: 30199102 DOI: 10.1002/mp.13178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 06/17/2018] [Accepted: 08/14/2018] [Indexed: 01/01/2023] Open
Abstract
PURPOSE A hybrid planar-SPECT/CT method for tumor dosimetry in 177 Lu-DOTATATE therapy, applicable to datasets consisting of multiple conjugate-view images and one SPECT/CT, is developed and evaluated. METHODS The imaging protocol includes conjugate-view imaging at 1, 24, 96, and 168 h post infusion (p.i.) and a SPECT/CT acquisition 24 h p.i. The dosimetry method uses the planar images to estimate the shape of the time-activity concentration curve, which is then rescaled to absolute units using the SPECT-derived activity concentration. The resulting time-integrated activity concentration coefficient (TIACC) is used to calculate the tumor-absorbed dose. Semiautomatic segmentation techniques are applied for tumor delineation in both planar and SPECT images, where the planar image segmentation is accomplished using an active-rays-based technique. The selection of tumors is done by visual inspection of planar and SPECT images and applying a set of criteria concerning the tumor visibility and possible interference from superimposed activity uptakes in the planar images. Five different strategies for determining values from planar regions of interest (ROIs), based on entire or partial ROIs, and with and without background correction, are evaluated. Evaluation is performed against a SPECT/CT-based method on data from six patients where sequential conjugate-view and SPECT/CT imaging have been performed in parallel and against ground truths in Monte Carlo simulated images. The patient data are also used to evaluate the interoperator variability and to assess the validity of the developed criteria for tumor selection. RESULTS For patient images, the hybrid method produces TIACCs that are on average 6% below those of the SPECT/CT only method, with standard deviations for the relative TIACC differences of 8%-11%. Simulations show that the hybrid and SPECT-based methods estimate the TIACCs to within approximately 10% for tumors larger than around 10 ml, while for smaller tumors, all methods underestimate the TIACCs due to underestimations of the activity concentrations in the SPECT images. The planar image segmentation has a low operator dependence, with a median Dice similarity coefficient of 0.97 between operators. The adopted criteria for tumor selection manage to discriminate the tumors for which the absorbed-dose deviations between the hybrid and SPECT methods are the highest. CONCLUSIONS The hybrid method is found suitable for studies of tumor-absorbed doses in radionuclide therapy, provided that selection criteria regarding the visibility and overlapping activities in the planar images are applied.
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Affiliation(s)
- Daniel Roth
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Johan Gustafsson
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Anna Sundlöv
- Division of Oncology and Pathology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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Sundlöv A, Gustafsson J, Brolin G, Mortensen N, Hermann R, Bernhardt P, Svensson J, Ljungberg M, Tennvall J, Sjögreen Gleisner K. Feasibility of simplifying renal dosimetry in 177Lu peptide receptor radionuclide therapy. EJNMMI Phys 2018; 5:12. [PMID: 29974391 PMCID: PMC6031553 DOI: 10.1186/s40658-018-0210-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Accepted: 03/21/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Recently, 177Lu-dotatate therapy for neuroendocrine tumours has received regulatory approval. Dosimetry can be used to optimize treatment on an individual basis, but there is no international consensus as to how it should be done. The aim of this study is to determine a feasible and accurate dosimetry method to guide individualized peptide receptor radionuclide therapy (PRRT) for patients with neuroendocrine tumours. As part of a clinical trial on 177Lu-dotatate therapy, renal dosimetry was performed for all patients in each treatment cycle, using a hybrid planar-SPECT/CT method. In the present study, we use the image data acquired from 22 patients and 119 cycles and define a set of alternative treatment planning strategies, each representing a simplification in terms of image acquisition and dosimetric calculations. The results from the simplified strategies are compared to the results from the protocol-prescribed hybrid planar-SPECT/CT-based method by analysing differences both in per-cycle and total cumulative absorbed dose (AD) analyses. RESULTS In general, the SPECT-based methods gave results that were largely consistent with the protocol-specified hybrid method, both in the per-cycle and cumulative AD analyses. Notably, performing one SPECT/CT per cycle at 96 h yielded ADs that were very similar to the protocol method. The methods using planar dosimetry resulted in larger variations, as expected, while giving 4 cycles to all patients resulted in the largest inter-individual differences in cumulative AD. CONCLUSIONS Performing one SPECT/CT at 96 h in every treatment cycle gives sufficiently reliable dosimetric results to base individualized treatment planning on, with a reasonable demand on resources.
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Affiliation(s)
- Anna Sundlöv
- Oncology and Pathology, Department of Clinical Sciences Lund, Skåne University Hospital, Lund University, Lund, Sweden.
- Department of Oncology, Skåne University Hospital, SE-221 85, Lund, Sweden.
| | - Johan Gustafsson
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Gustav Brolin
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Nadja Mortensen
- Oncology and Pathology, Department of Clinical Sciences Lund, Skåne University Hospital, Lund University, Lund, Sweden
| | - Rebecca Hermann
- Department of Radiation Physics, University of Gothenburg, Gothenburg, Sweden
| | - Peter Bernhardt
- Department of Radiation Physics, University of Gothenburg, Gothenburg, Sweden
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Johanna Svensson
- Department of Oncology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Michael Ljungberg
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Jan Tennvall
- Oncology and Pathology, Department of Clinical Sciences Lund, Skåne University Hospital, Lund University, Lund, Sweden
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Sjögreen Gleisner K, Spezi E, Solny P, Gabina PM, Cicone F, Stokke C, Chiesa C, Paphiti M, Brans B, Sandström M, Tipping J, Konijnenberg M, Flux G. Variations in the practice of molecular radiotherapy and implementation of dosimetry: results from a European survey. EJNMMI Phys 2017; 4:28. [PMID: 29199391 PMCID: PMC5712507 DOI: 10.1186/s40658-017-0193-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 11/06/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Currently, the implementation of dosimetry in molecular radiotherapy (MRT) is not well investigated, and in view of the Council Directive (2013/59/Euratom), there is a need to understand the current availability of dosimetry-based MRT in clinical practice and research studies. The aim of this study was to assess the current practice of MRT and dosimetry across European countries. METHODS An electronic questionnaire was distributed to European countries. This addressed 18 explicitly considered therapies, and for each therapy, a similar set of questions were included. Questions covered the number of patients and treatments during 2015, involvement of medical specialties and medical physicists, implementation of absorbed dose planning, post-therapy imaging and dosimetry, and the basis of therapy prescription. RESULTS Responses were obtained from 26 countries and 208 hospitals, administering in total 42,853 treatments. The most common therapies were 131I-NaI for benign thyroid diseases and thyroid ablation of adults. The involvement of a medical physicist (mean over all 18 therapies) was reported to be either minority or never by 32% of the responders. The percentage of responders that reported that dosimetry was included on an always/majority basis differed between the therapies and showed a median value of 36%. The highest percentages were obtained for 177Lu-PSMA therapy (100%), 90Y microspheres of glass (84%) and resin (82%), 131I-mIBG for neuroblastoma (59%), and 131I-NaI for benign thyroid diseases (54%). The majority of therapies were prescribed based on fixed-activity protocols. The highest number of absorbed-dose based prescriptions were reported for 90Y microsphere treatments in the liver (64% and 96% of responses for resin and glass, respectively), 131I-NaI treatment of benign thyroid diseases (38% of responses), and for 131I-mIBG treatment of neuroblastoma (18% of responses). CONCLUSIONS There is a wide variation in MRT practice across Europe and for different therapies, including the extent of medical-physicist involvement and the implementation of dosimetry-guided treatments.
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Affiliation(s)
| | | | - Pavel Solny
- Department of Nuclear Medicine and Endocrinology, Motol University Hospital, 2nd Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Pablo Minguez Gabina
- Department of Medical Physics and Radiation Protection, Gurutzeta/Cruces University Hospital, Barakaldo, Spain
| | - Francesco Cicone
- Nuclear Medicine, Sant’Andrea Hospital, Department of Surgical and Medical Sciences and Translational Medicine, Sapienza University of Rome, Rome, Italy
| | - Caroline Stokke
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
| | - Carlo Chiesa
- Nuclear Medicine Division, Foundation IRCCS Istituto Nazionale Tumori, Milan, Italy
| | - Maria Paphiti
- Department of Medical Physics, Pammakaristos Hospital, Athens, Greece
| | - Boudewijn Brans
- Department of Nuclear Medicine and PET Center, University Hospital, Ghent, Belgium
| | - Mattias Sandström
- Department of Surgical Sciences, Radiology, Uppsala University Hospital, Uppsala, Sweden
| | - Jill Tipping
- The Christie NHS Foundation Trust, Nuclear Medicine, Manchester, UK
| | - Mark Konijnenberg
- Department of Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Glenn Flux
- Joint Department of Physics, Royal Marsden Hospital and Institute of Cancer Research, Sutton, UK
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Stokke C, Gabiña PM, Solný P, Cicone F, Sandström M, Gleisner KS, Chiesa C, Spezi E, Paphiti M, Konijnenberg M, Aldridge M, Tipping J, Wissmeyer M, Brans B, Bacher K, Kobe C, Flux G. Dosimetry-based treatment planning for molecular radiotherapy: a summary of the 2017 report from the Internal Dosimetry Task Force. EJNMMI Phys 2017; 4:27. [PMID: 29164483 PMCID: PMC5698234 DOI: 10.1186/s40658-017-0194-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 11/06/2017] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND The European directive on basic safety standards (Council directive 2013/59 Euratom) mandates dosimetry-based treatment planning for radiopharmaceutical therapies. The directive comes into operation February 2018, and the aim of a report produced by the Internal Dosimetry Task Force of the European Association of Nuclear Medicine is to address this aspect of the directive. A summary of the report is presented. RESULTS A brief review of five of the most common therapy procedures is included in the current text, focused on the potential to perform patient-specific dosimetry. In the full report, 11 different therapeutic procedures are included, allowing additional considerations of effectiveness, references to specific literature on quantitative imaging and dosimetry, and existing evidence for absorbed dose-effect correlations for each treatment. Individualized treatment planning with tracer diagnostics and verification of the absorbed doses delivered following therapy is found to be scientifically feasible for almost all procedures investigated, using quantitative imaging and/or external monitoring. Translation of this directive into clinical practice will have significant implications for resource requirements. CONCLUSIONS Molecular radiotherapy is undergoing a significant expansion, and the groundwork for dosimetry-based treatment planning is already in place. The mandated individualization is likely to improve the effectiveness of the treatments, although must be adequately resourced.
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Affiliation(s)
- Caroline Stokke
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway.
| | - Pablo Minguez Gabiña
- Department of Medical Physics and Radiation Protection, Gurutzeta/Cruces University Hospital, Barakaldo, Spain
| | - Pavel Solný
- Department of Dosimetry and Application of Ionizing Radiation, Czech Technical University in Prague, Prague, Czech Republic
| | - Francesco Cicone
- Nuclear Medicine, Sant'Andrea Hospital, Department of Surgical and Medical Sciences and Translational Medicine, Sapienza University of Rome, Rome, Italy
| | - Mattias Sandström
- Section of Nuclear Medicine and PET, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | | | - Carlo Chiesa
- Nuclear Medicine Division, Foundation IRCCS istituto nazionale Tumori, Milan, Italy
| | | | - Maria Paphiti
- Department of Medical Physics, Pammakaristos Hospital, Athens, Greece
| | - Mark Konijnenberg
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Matt Aldridge
- Nuclear Medicine/Radiotherapy Physics, UCL Institute of Nuclear Medicine and UCL Hospitals NHS Foundation Trust, London, UK
| | - Jill Tipping
- The Christie NHS Foundation Trust, Nuclear Medicine, Manchester, UK
| | - Michael Wissmeyer
- Department of Nuclear Medicine, University Hospital of Geneva, Geneva, Switzerland
| | - Boudewijn Brans
- Department of Nuclear Medicine and PET Center, University Hospital, Ghent, Belgium
| | - Klaus Bacher
- Department of Basic Medical Sciences, Division of Medical Physics, Ghent University, Ghent, Belgium
| | - Carsten Kobe
- Department for Nuclear Medicine, University Hospital of Cologne, Cologne, Germany
| | - Glenn Flux
- Joint Department of Physics, Royal Marsden Hospital and Institute of Cancer Research, Sutton, UK
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Flux GD, Verburg FA, Chiesa C, Bardiès M, Gleisner KS, Hertz B, Konijnenberg M, Lassmann M, Ljungberg M, Luster M, Stabin M, Strigari L. Comparison of Empiric Versus Dosimetry-Guided Radioiodine Therapy: The Devil Is in the Details. J Nucl Med 2017; 58:862. [PMID: 28183989 DOI: 10.2967/jnumed.116.186643] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Glenn D Flux
- Royal Marsden Hospital Downs Rd. Sutton, Su SM2 5PT, United Kingdom E-mail:
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Gustafsson J, Sundlöv A, Sjögreen Gleisner K. SPECT image segmentation for estimation of tumour volume and activity concentration in 177Lu-DOTATATE radionuclide therapy. EJNMMI Res 2017; 7:18. [PMID: 28233160 PMCID: PMC5323339 DOI: 10.1186/s13550-017-0262-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 01/31/2017] [Indexed: 11/23/2022] Open
Abstract
Background Dosimetry in radionuclide therapy has the potential to allow for a treatment tailored to the individual patient. One therapeutic radiopharmaceutical where patient-specific dosimetry is feasible is 177Lu-DOTATATE, used for the treatment of neuroendocrine tumours. The emission of gamma photons by 177Lu allows for imaging with SPECT (single photon emission computed tomography). One important step for dosimetry using this imaging technique is the SPECT image segmentation, which needs to be robust and accurate for the estimated quantities to be reliable. This work investigates different methods for automatic tumour delineation in 177Lu-DOTATATE SPECT images. Three segmentation methods are considered: a fixed 42% threshold (FT), the Otsu method (OM) and a method based on Fourier surfaces (FS). Effects of including resolution compensation in the iterative SPECT image reconstruction are also studied. Evaluation is performed based on Monte Carlo-simulated SPECT images from 24 h and 336 h post injection (p.i.), for determination of the volume, activity concentration and dice similarity coefficient. In addition, patient data are used to investigate the correspondence of tumour volumes when delineated in SPECT or morphological CT or MR images. Patient data are also used to examine the sensitivity to the operator-dependent initialization. Results For simulated images from 24 h p.i. reconstructed without resolution compensation, a volume and activity-concentration root-mean-square error below 15% is typically obtained for tumours above approximately 10 cm3 when using OM or FS, while FT performs considerably worse. When including resolution compensation, the tumour volume becomes underestimated and the activity concentration overestimated. The FS method appears to be robust to noise, as seen for the 336 h images. The differences between the tumour volumes estimated from the SPECT images and the volumes estimated from morphological images are generally larger than the discrepancies seen for the simulated data sets. Conclusions Segmentation results are encouraging for future dosimetry of tumours with volumes above approximately 10 cm3. Using resolution compensation in the reconstruction may have a negative effect on volume estimation.
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Affiliation(s)
- Johan Gustafsson
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden.
| | - Anna Sundlöv
- Department of Oncology and Pathology, Clinical Sciences Lund, Lund University, Lund, Sweden.,Department of Oncology, Skåne University Hospital, Lund, Sweden
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Mínguez P, Flux G, Genollá J, Delgado A, Rodeño E, Sjögreen Gleisner K. Whole-remnant and maximum-voxel SPECT/CT dosimetry in 131 I-NaI treatments of differentiated thyroid cancer. Med Phys 2016; 43:5279-5287. [PMID: 28105713 DOI: 10.1118/1.4961742] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 08/08/2016] [Accepted: 08/13/2016] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To investigate the possible differences between SPECT/CT based whole-remnant and maximum-voxel dosimetry in patients receiving radio-iodine ablation treatment of differentiated thyroid cancer (DTC). METHODS Eighteen DTC patients were administered 1.11 GBq of 131 I-NaI after near-total thyroidectomy and rhTSH stimulation. Two patients had two remnants, so in total dosimetry was performed for 20 sites. Three SPECT/CT scans were performed for each patient at 1, 2, and 3-7 days after administration. The activity, the remnant mass, and the maximum-voxel activity were determined from these images and from a recovery-coefficient curve derived from experimental phantom measurements. The cumulated activity was estimated using trapezoidal-exponential integration. Finally, the absorbed dose was calculated using S-values for unit-density spheres in whole-remnant dosimetry and S-values for voxels in maximum-voxel dosimetry. RESULTS The mean absorbed dose obtained from whole-remnant dosimetry was 40 Gy (range 2-176 Gy) and from maximum-voxel dosimetry 34 Gy (range 2-145 Gy). For any given patient, the activity concentrations for each of the three time-points were approximately the same for the two methods. The effective half-lives varied (R = 0.865), mainly due to discrepancies in estimation of the longer effective half-lives. On average, absorbed doses obtained from whole-remnant dosimetry were 1.2 ± 0.2 (1 SD) higher than for maximum-voxel dosimetry, mainly due to differences in theS-values. The method-related differences were however small in comparison to the wide range of absorbed doses obtained in patients. CONCLUSIONS Simple and consistent procedures for SPECT/CT based whole-volume and maximum-voxel dosimetry have been described, both based on experimentally determined recovery coefficients. Generally the results from the two approaches are consistent, although there is a small, systematic difference in the absorbed dose due to differences in the S-values, and some variability due to differences in the estimated effective half-lives, especially when the effective half-life is long. Irrespective of the method used, the patient absorbed doses obtained span over two orders of magnitude.
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Affiliation(s)
- Pablo Mínguez
- Department of Medical Radiation Physics, LundUniversity, Lund 22185, Sweden and Department of Medical Physics, Gurutzeta/Cruces University Hospital, Barakaldo 48903, Spain
| | - Glenn Flux
- Joint Department of Physics, Royal Marsden NHS Foundation Trust andInstitute of Cancer Research, Sutton SM2 5PT, United Kingdom
| | - José Genollá
- Department of Nuclear Medicine, Gurutzeta/Cruces UniversityHospital, Barakaldo 48903, Spain
| | - Alejandro Delgado
- Department of Nuclear Medicine, Gurutzeta/Cruces UniversityHospital, Barakaldo 48903, Spain
| | - Emilia Rodeño
- Department of Nuclear Medicine, Gurutzeta/Cruces UniversityHospital, Barakaldo 48903, Spain
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Mínguez P, Gustafsson J, Flux G, Gleisner KS. Biologically effective dose in fractionated molecular radiotherapy--application to treatment of neuroblastoma with (131)I-mIBG. Phys Med Biol 2016; 61:2532-51. [PMID: 26948833 DOI: 10.1088/0031-9155/61/6/2532] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In this work, the biologically effective dose (BED) is investigated for fractionated molecular radiotherapy (MRT). A formula for the Lea-Catcheside G-factor is derived which takes the possibility of combinations of sub-lethal damage due to radiation from different administrations of activity into account. In contrast to the previous formula, the new G-factor has an explicit dependence on the time interval between administrations. The BED of tumour and liver is analysed in MRT of neuroblastoma with (131)I-mIBG, following a common two-administration protocol with a mass-based activity prescription. A BED analysis is also made for modified schedules, when due to local regulations there is a maximum permitted activity for each administration. Modifications include both the simplistic approach of delivering this maximum permitted activity in each of the two administrations, and also the introduction of additional administrations while maintaining the protocol-prescribed total activity. For the cases studied with additional (i.e. more than two) administrations, BED of tumour and liver decreases at most 12% and 29%, respectively. The decrease in BED of the tumour is however modest compared to the two-administration schedule using the maximum permitted activity, where the decrease compared to the original schedule is 47%.
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Affiliation(s)
- Pablo Mínguez
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, 22185 Lund, Sweden. Department of Medical Physics, Gurutzeta/Cruces University Hospital, 48903 Barakaldo, Spain
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Gustafsson J, Brolin G, Cox M, Ljungberg M, Johansson L, Gleisner KS. Uncertainty propagation for SPECT/CT-based renal dosimetry in177Lu peptide receptor radionuclide therapy. Phys Med Biol 2015; 60:8329-46. [DOI: 10.1088/0031-9155/60/21/8329] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Brolin G, Gustafsson J, Ljungberg M, Gleisner KS. Pharmacokinetic digital phantoms for accuracy assessment of image-based dosimetry in (177)Lu-DOTATATE peptide receptor radionuclide therapy. Phys Med Biol 2015. [PMID: 26215085 DOI: 10.1088/0031-9155/60/15/6131] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Patient-specific image-based dosimetry is considered to be a useful tool to limit toxicity associated with peptide receptor radionuclide therapy (PRRT). To facilitate the establishment and reliability of absorbed-dose response relationships, it is essential to assess the accuracy of dosimetry in clinically realistic scenarios. To this end, we developed pharmacokinetic digital phantoms corresponding to patients treated with (177)Lu-DOTATATE. Three individual voxel phantoms from the XCAT population were generated and assigned a dynamic activity distribution based on a compartment model for (177)Lu-DOTATATE, designed specifically for this purpose. The compartment model was fitted to time-activity data from 10 patients, primarily acquired using quantitative scintillation camera imaging. S values for all phantom source-target combinations were calculated based on Monte-Carlo simulations. Combining the S values and time-activity curves, reference values of the absorbed dose to the phantom kidneys, liver, spleen, tumours and whole-body were calculated. The phantoms were used in a virtual dosimetry study, using Monte-Carlo simulated gamma-camera images and conventional methods for absorbed-dose calculations. The characteristics of the SPECT and WB planar images were found to well represent those of real patient images, capturing the difficulties present in image-based dosimetry. The phantoms are expected to be useful for further studies and optimisation of clinical dosimetry in (177)Lu PRRT.
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Affiliation(s)
- Gustav Brolin
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Sweden
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Ljungberg M, Gleisner KS. Hybrid Imaging for Patient-Specific Dosimetry in Radionuclide Therapy. Diagnostics (Basel) 2015; 5:296-317. [PMID: 26854156 PMCID: PMC4665601 DOI: 10.3390/diagnostics5030296] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 06/29/2015] [Accepted: 07/01/2015] [Indexed: 11/16/2022] Open
Abstract
Radionuclide therapy aims to treat malignant diseases by systemic administration of radiopharmaceuticals, often using carrier molecules such as peptides and antibodies. The radionuclides used emit electrons or alpha particles as a consequence of radioactive decay, thus leading to local energy deposition. Administration to individual patients can be tailored with regards to the risk of toxicity in normal organs by using absorbed dose planning. The scintillation camera, employed in planar imaging or single-photon emission computed tomography (SPECT), generates images of the spatially and temporally varying activity distribution. Recent commercially available combined SPECT and computed tomography (CT) systems have dramatically increased the possibility of performing accurate dose planning by using the CT information in several steps of the dose-planning calculation chain. This paper discusses the dosimetry chain used for individual absorbed-dose planning and highlights the areas where hybrid imaging makes significant contributions.
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Affiliation(s)
- Michael Ljungberg
- Department of Medical Radiation Physics, Lund University, 221 85 Lund, Sweden.
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Mínguez P, Flux G, Genollá J, Guayambuco S, Delgado A, Fombellida JC, Sjögreen Gleisner K. Dosimetric results in treatments of neuroblastoma and neuroendocrine tumors with (131)I-metaiodobenzylguanidine with implications for the activity to administer. Med Phys 2015; 42:3969-78. [PMID: 26133597 DOI: 10.1118/1.4921807] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2024] Open
Abstract
PURPOSE The aim was to investigate whole-body and red marrow absorbed doses in treatments of neuroblastoma (NB) and adult neuroendocrine tumors (NETs) with (131)I-metaiodobenzylguanidine and to propose a simple method for determining the activity to administer when dosimetric data for the individual patient are not available. METHODS Nine NB patients and six NET patients were included, giving in total 19 treatments as four patients were treated twice. Whole-body absorbed doses were determined from dose-rate measurements and planar gamma-camera imaging. For six NB and five NET treatments, red marrow absorbed doses were also determined using the blood-based method. RESULTS Dosimetric data from repeated administrations in the same patient were consistent. In groups of NB and NET patients, similar whole-body residence times were obtained, implying that whole-body absorbed dose per unit of administered activity could be reasonably well described as a power function of the patient mass. For NB, this functional form was found to be consistent with dosimetric data from previously published studies. The whole-body to red marrow absorbed dose ratio was similar among patients, with values of 1.4 ± 0.6-1.7 ± 0.7 (1 standard deviation) in NB treatments and between 1.5 ± 0.6 and 1.7 ± 0.7 (1 standard deviation) in NET treatments. CONCLUSIONS The consistency of dosimetric results between administrations for the same patient supports prescription of the activity based on dosimetry performed in pretreatment studies, or during the first administration in a fractionated schedule. The expressions obtained for whole-body absorbed doses per unit of administered activity as a function of patient mass for NB and NET treatments are believed to be a useful tool to estimate the activity to administer at the stage when the individual patient biokinetics has not yet been measured.
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Affiliation(s)
- Pablo Mínguez
- Department of Medical Radiation Physics, Lund University, Lund 22185, Sweden and Department of Medical Physics, Gurutzeta/Cruces University Hospital, Barakaldo 48903, Spain
| | - Glenn Flux
- Joint Department of Physics, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton SM2 5PT, United Kingdom
| | - José Genollá
- Department of Nuclear Medicine, Gurutzeta/Cruces University Hospital, Barakaldo 48903, Spain
| | - Sonía Guayambuco
- Department of Nuclear Medicine, Gurutzeta/Cruces University Hospital, Barakaldo 48903, Spain
| | - Alejandro Delgado
- Department of Nuclear Medicine, Gurutzeta/Cruces University Hospital, Barakaldo 48903, Spain
| | - José Cruz Fombellida
- Department of Nuclear Medicine, Gurutzeta/Cruces University Hospital, Barakaldo 48903, Spain
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Sjögreen Gleisner K, Brolin G, Sundlöv A, Mjekiqi E, Östlund K, Tennvall J, Larsson E. Long-Term Retention of 177Lu/177mLu-DOTATATE in Patients Investigated by γ-Spectrometry and γ-Camera Imaging. J Nucl Med 2015; 56:976-84. [DOI: 10.2967/jnumed.115.155390] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 04/28/2015] [Indexed: 11/16/2022] Open
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Strigari L, Konijnenberg M, Chiesa C, Bardies M, Du Y, Gleisner KS, Lassmann M, Flux G. The evidence base for the use of internal dosimetry in the clinical practice of molecular radiotherapy. Eur J Nucl Med Mol Imaging 2014; 41:1976-88. [PMID: 24915892 DOI: 10.1007/s00259-014-2824-5] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 05/19/2014] [Indexed: 01/10/2023]
Abstract
Molecular radiotherapy (MRT) has demonstrated unique therapeutic advantages in the treatment of an increasing number of cancers. As with other treatment modalities, there is related toxicity to a number of organs at risk. Despite the large number of clinical trials over the past several decades, considerable uncertainties still remain regarding the optimization of this therapeutic approach and one of the vital issues to be answered is whether an absorbed radiation dose-response exists that could be used to guide personalized treatment. There are only limited and sporadic data investigating MRT dosimetry. The determination of dose-effect relationships for MRT has yet to be the explicit aim of a clinical trial. The aim of this article was to collate and discuss the available evidence for an absorbed radiation dose-effect relationships in MRT through a review of published data. Based on a PubMed search, 92 papers were found. Out of 79 studies investigating dosimetry, an absorbed dose-effect correlation was found in 48. The application of radiobiological modelling to clinical data is of increasing importance and the limited published data on absorbed dose-effect relationships based on these models are also reviewed. Based on National Cancer Institute guideline definition, the studies had a moderate or low rate of clinical relevance due to the limited number of studies investigating overall survival and absorbed dose. Nevertheless, the evidence strongly implies a correlation between the absorbed doses delivered and the response and toxicity, indicating that dosimetry-based personalized treatments would improve outcome and increase survival.
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Affiliation(s)
- Lidia Strigari
- Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, via E. Chianesi 53, 00144, Rome, Italy,
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Gleisner KS, Ljungberg M. Patient-specific whole-body attenuation correction maps from a CT system for conjugate-view-based activity quantification: method development and evaluation. Cancer Biother Radiopharm 2013; 27:652-64. [PMID: 23210927 DOI: 10.1089/cbr.2011.1082] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
For activity quantification based on planar scintillation camera measurements, photon attenuation is an important factor that needs to be corrected for in a patient- and organ-specific manner. One possibility for obtaining attenuation correction maps is to use X-ray CT scout images. Since the intensity of scout images is in relative numbers, their image values need to be multiplied by a factor to become quantitative and thus useful for attenuation correction. The calibration factor can for our current imaging system be obtained from a scanner system file, but is generally not available. For this purpose, a method based on the patient weight has been developed. Results based on 79 patient scout images show that the calibration factor thus determined correlates well with values that, in this case, are independently specified by the system. The accuracy of attenuation correction factors (ACFs) derived from the scout-based attenuation correction maps is evaluated by comparison to ACFs derived from three-dimensional CT studies. For photon energies of 208, 245, and 364 keV, scout-based ACFs are on average 1.2% and 0.5% from the CT-derived values, using the system-based and the weight-based values of the scout-image calibration factor, respectively. The imprecision is somewhat higher for the weight-based method, due to variability in the delineation of the patient contour used as a part of this method. In conclusion, X-ray scouts are found useful for attenuation correction with a satisfactory accuracy obtained, both using the new, weight-based method, and using the previous, system-based method, for determining the required calibration factor.
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Brolin G, Gleisner KS, Ljungberg M. Dynamic (99m)Tc-MAG3 renography: images for quality control obtained by combining pharmacokinetic modelling, an anthropomorphic computer phantom and Monte Carlo simulated scintillation camera imaging. Phys Med Biol 2013; 58:3145-61. [PMID: 23603770 DOI: 10.1088/0031-9155/58/10/3145] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In dynamic renal scintigraphy, the main interest is the radiopharmaceutical redistribution as a function of time. Quality control (QC) of renal procedures often relies on phantom experiments to compare image-based results with the measurement setup. A phantom with a realistic anatomy and time-varying activity distribution is therefore desirable. This work describes a pharmacokinetic (PK) compartment model for (99m)Tc-MAG3, used for defining a dynamic whole-body activity distribution within a digital phantom (XCAT) for accurate Monte Carlo (MC)-based images for QC. Each phantom structure is assigned a time-activity curve provided by the PK model, employing parameter values consistent with MAG3 pharmacokinetics. This approach ensures that the total amount of tracer in the phantom is preserved between time points, and it allows for modifications of the pharmacokinetics in a controlled fashion. By adjusting parameter values in the PK model, different clinically realistic scenarios can be mimicked, regarding, e.g., the relative renal uptake and renal transit time. Using the MC code SIMIND, a complete set of renography images including effects of photon attenuation, scattering, limited spatial resolution and noise, are simulated. The obtained image data can be used to evaluate quantitative techniques and computer software in clinical renography.
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Affiliation(s)
- Gustav Brolin
- Department of Medical Radiation Physics, Lund University, Sweden.
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Gustafsson J, Nilsson P, Gleisner KS. On the biologically effective dose (BED)—using convolution for calculating the effects of repair: I. Analytical considerations. Phys Med Biol 2013; 58:1507-27. [DOI: 10.1088/0031-9155/58/5/1507] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Gustafsson J, Nilsson P, Gleisner KS. On the biologically effective dose (BED)-using convolution for calculating the effects of repair: II. Numerical considerations. Phys Med Biol 2013; 58:1529-48. [PMID: 23406832 DOI: 10.1088/0031-9155/58/5/1529] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We have previously shown analytically that the biologically effective dose (BED), including effects of repair during irradiation and of incomplete repair between fractions, can be formulated using a convolution between the absorbed dose rate function and the function describing repair. In this work, a discrete formalism is derived along with its implementation via the fast Fourier transform. The implementation takes the intrinsic periodicity of the discrete Fourier transform into consideration, as well as possible inconsistencies that may arise due to discretization and truncation of the functions describing the absorbed dose rate and repair. Numerically and analytically calculated BED values are compared for various situations in external beam radiotherapy, brachytherapy and radionuclide therapy, including the use of different repair models. The numerical method is shown to be accurate and versatile since it can be applied to any kind of absorbed dose rate function and allows for the incorporation of different repair models. Typical accuracies for clinically realistic examples are in the order of 10(-3)% to 10(-5)%. The method has thus the potential of being a useful tool for the calculation of BED, also in situations with complicated irradiation patterns or repair functions.
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Affiliation(s)
- Johan Gustafsson
- Department of Medical Radiation Physics, Lund University, Lund, Sweden.
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Toporski J, Garkavij M, Tennvall J, Ora I, Gleisner KS, Dykes JH, Lenhoff S, Juliusson G, Scheding S, Turkiewicz D, Békássy AN. High-dose iodine-131-metaiodobenzylguanidine with haploidentical stem cell transplantation and posttransplant immunotherapy in children with relapsed/refractory neuroblastoma. Biol Blood Marrow Transplant 2009; 15:1077-85. [PMID: 19660720 DOI: 10.1016/j.bbmt.2009.05.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2009] [Accepted: 05/07/2009] [Indexed: 10/20/2022]
Abstract
We evaluated the feasibility and efficacy of using high-dose iodine-131-metaiodobenzylguanidine ((131)I-MIBG) followed by reduced-intensity conditioning (RIC) and transplantation of T cell-depleted haploidentical peripheral blood stem cells (designated haplo-SCT) to treat relapsing/refractory neuroblastoma (RRNB). Five RRNB patients were enrolled: 4 with relapse (3 after autologous SCT) and 1 with induction therapy failure. The preparative regimen included high-dose (131)I-MIBG on day -20, followed by fludarabine (Flu), thiotepa, and melphalan (Mel) from day -8 to -1. Granulocyte-colony stimulating factor (G-CSF)-mobilized, T cell-depleted haploidentical paternal stem cells were infused on day 0 together with cultured donor mesenchymal stem cells. A single dose of rituximab was given on day +1. After cessation of short immunosuppression (mycophenolate, OKT3), 4 children received donor lymphocyte infusion (DLI). (131)I-MIBG infusion and RIC were well tolerated. All patients engrafted. No primary acute graft-versus-host disease (aGVHD) was observed. Four children developed aGVHD after DLI and were successfully treated. Analysis of immunologic recovery showed fast reappearance of potentially immunocompetent natural killer (NK) and T cells, which might have acted as effector cells responsible for the graft-versus-tumor (GVT) effect. Two children are alive and well, with no evidence of disease 40 and 42 months after transplantation. One patient experienced late progression with new bone lesions (sternum) 38 months after haplo-SCT, and is being treated with local irradiation and reinstituted DLI. One patient rejected the graft, was rescued with autologous backup, and died of progressive disease 5 months after transplantation. Another child relapsed 7 months after transplantation and died 5 months later. High-dose (131)I-MIBG followed by RIC and haplo-SCT for RRNB is feasible and promising, because 2 of 5 children on that regimen achieved long-lasting remission. Further studies are needed to evaluate targeted therapy and immune-mediated tumor control in high-risk neuroblastoma.
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Affiliation(s)
- Jacek Toporski
- Department of Pediatric Oncology, University Hospital, Lund, Sweden.
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Nickel M, Strand SE, Lindén O, Wingårdh K, Tennwall J, Gleisner KS. Development and Evaluation of a Pharmacokinetic Model for Prediction of Radioimmunotherapy Based on Pretherapy Data. Cancer Biother Radiopharm 2009; 24:111-22. [DOI: 10.1089/cbr.2008.0530] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Mattias Nickel
- Department of Medical Radiation Physics, Clinical Sciences, Lund University, Lund, Sweden
| | - Sven-Erik Strand
- Department of Medical Radiation Physics, Clinical Sciences, Lund University, Lund, Sweden
| | - Ola Lindén
- Department of Oncology, Clinical Sciences, Lund University, Lund, Sweden
| | - Karin Wingårdh
- Department of Medical Radiation Physics, Clinical Sciences, Lund University, Lund, Sweden
| | - Jan Tennwall
- Department of Oncology, Clinical Sciences, Lund University, Lund, Sweden
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Berg G, Jacobsson L, Nyström E, Gleisner KS, Tennvall J. Consequences of inadvertent radioiodine treatment of Graves' disease and thyroid cancer in undiagnosed pregnancy. Can we rely on routine pregnancy testing? Acta Oncol 2008; 47:145-9. [PMID: 17851865 DOI: 10.1080/02841860701558807] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Radioiodine and most cytostatic treatments are contraindicated in pregnancy. Still, inadvertent therapy does occur. Radioiodine was given to two pregnant women with Graves' disease and thyroid cancer respectively, both in their 20th gestational week. Routine pregnancy tests based on urinary beta-hCG had failed to indicate pregnancy in both cases. METHODS Estimation of doses to the foetuses and foetal thyroids. Scrutiny of pregnancy testing. RESULTS AND CONCLUSIONS Doses to foetal thyroids were ablative (250-600 Gy). Total foetal dose in the Graves' patient was 100 mGy and compatible with survival, whereas a foetal dose of approximately 700 mGy together with induced hypothyroidism was fatal for the foetus of the cancer patient. Routine pregnancy tests may fail early and late in pregnancy. The possibility of pregnancy should be considered in all fertile women before therapy with radionuclides or cytostatic regimens, and a clinical investigation undertaken on wide indications with determination of serum beta-hCG, preferably together with an ultrasound examination.
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Affiliation(s)
- Gertrud Berg
- Department of Oncology, Sahlgrenska University Hospital, Sahlgrenska Academy, Göteborg, Sweden.
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Gleisner KS, Nickel M, Lindén O, Erlandsson K, Wingårdh K, Strand SE. Parametric images of antibody pharmacokinetics based on serial quantitative whole-body imaging and blood sampling. J Nucl Med 2007; 48:1369-78. [PMID: 17673426 DOI: 10.2967/jnumed.107.039503] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED We present a method for pharmacokinetic modeling of distributions of (111)In-labeled monoclonal antibodies (mAbs) on individual pixels of planar scintillation-camera images. METHODS The method is applied to 2 sets of clinical whole-body images, each consisting of 6 consecutive images acquired over a week. Quantification is performed on a pixel basis, yielding images in units of Bq/pixel. The images acquired on the different occasions are registered using a nonrigid method, and for each pixel location a time-activity curve is obtained for which kinetic modeling is performed. The (111)In-mAb is assumed to be located in either the vascular or the extravascular space. The vascular content is assumed to follow the global blood kinetics as determined from blood samples, together with a model parameter alpha that describes the fraction of the whole-body blood volume present in the particular pixel. The rate of change of the extravascular compartment is described by a linear 1-tissue-compartment model with 2 rate constants, K'1 and k2, reflecting extravasation and washout, respectively. The model is optimized for each pixel position with regard to the values of the 3 parameters (alpha, K'1, and k2), resulting in 3 parametric images. From these, images of the cumulated activity in vascular and extravascular spaces are calculated, as is an image of the rate-constants ratio, which is closely related to the volume of distribution. RESULTS The resulting parametric images are analyzed in terms of the appearance of the time-activity curves at various locations. Results also include interpretation of the parametric images in their clinical context, and the location of regions that exhibit high extravasation and a low washout rate is compared with confirmed malignant sites. CONCLUSION Parametric imaging allows the study and analysis of the spatial and temporal distributions of mAbs simultaneously. Parametric imaging enhances regions where the pharmacokinetics differ from the surrounding tissue and provides a tool to detect and locate unexpected kinetic behavior, which is sometimes characteristic of malignant tissue. For dosimetry in radionuclide therapy, parametric imaging offers a less biased means of analyzing serial mAb images than traditional region-of-interest-based analysis.
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