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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] [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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Krokos G, Kotwal T, Malaih A, Barrington S, Jackson P, Hicks RJ, Marsden PK, Fischer BM. Evaluation of manual and automated approaches for segmentation and extraction of quantitative indices from [ 18F]FDG PET-CT images. Biomed Phys Eng Express 2024; 10:025007. [PMID: 38100790 PMCID: PMC10767880 DOI: 10.1088/2057-1976/ad160e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/28/2023] [Accepted: 12/15/2023] [Indexed: 12/17/2023]
Abstract
Utilisation of whole organ volumes to extract anatomical and functional information from computed tomography (CT) and positron emission tomography (PET) images may provide key information for the treatment and follow-up of cancer patients. However, manual organ segmentation, is laborious and time-consuming. In this study, a CT-based deep learning method and a multi-atlas method were evaluated for segmenting the liver and spleen on CT images to extract quantitative tracer information from Fluorine-18 fluorodeoxyglucose ([18F]FDG) PET images of 50 patients with advanced Hodgkin lymphoma (HL). Manual segmentation was used as the reference method. The two automatic methods were also compared with a manually defined volume of interest (VOI) within the organ, a technique commonly performed in clinical settings. Both automatic methods provided accurate CT segmentations, with the deep learning method outperforming the multi-atlas with a DICE coefficient of 0.93 ± 0.03 (mean ± standard deviation) in liver and 0.87 ± 0.17 in spleen compared to 0.87 ± 0.05 (liver) and 0.78 ± 0.11 (spleen) for the multi-atlas. Similarly, a mean relative error of -3.2% for the liver and -3.4% for the spleen across patients was found for the mean standardized uptake value (SUVmean) using the deep learning regions while the corresponding errors for the multi-atlas method were -4.7% and -9.2%, respectively. For the maximum SUV (SUVmax), both methods resulted in higher than 20% overestimation due to the extension of organ boundaries to include neighbouring, high-uptake regions. The conservative VOI method which did not extend into neighbouring tissues, provided a more accurate SUVmaxestimate. In conclusion, the automatic, and particularly the deep learning method could be used to rapidly extract information of the SUVmeanwithin the liver and spleen. However, activity from neighbouring organs and lesions can lead to high biases in SUVmaxand current practices of manually defining a volume of interest in the organ should be considered instead.
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Affiliation(s)
- Georgios Krokos
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
| | - Tejas Kotwal
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
| | - Afnan Malaih
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
| | - Sally Barrington
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
| | | | - Rodney J Hicks
- Department of Medicine, St Vincent’s Hospital Medical School, the University of Melbourne, Australia
| | - Paul K Marsden
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
| | - Barbara Malene Fischer
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
- Dept. Clinical Physiology and Nuclear Medicine, Rigshospitalet, Copenhagen, Denmark
- Dept. of Clinical Medicine, University of Copenhagen, Denmark
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Gustafsson J, Taprogge J. Future trends for patient-specific dosimetry methodology in molecular radiotherapy. Phys Med 2023; 115:103165. [PMID: 37880071 DOI: 10.1016/j.ejmp.2023.103165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 10/03/2023] [Accepted: 10/17/2023] [Indexed: 10/27/2023] Open
Abstract
Molecular radiotherapy is rapidly expanding, and new radiotherapeutics are emerging. The majority of treatments is still performed using empirical fixed activities and not tailored for individual patients. Molecular radiotherapy dosimetry is often seen as a promising candidate that would allow personalisation of treatments as outcome should ultimately depend on the absorbed doses delivered and not the activities administered. The field of molecular radiotherapy dosimetry has made considerable progress towards the feasibility of routine clinical dosimetry with reasonably accurate absorbed-dose estimates for a range of molecular radiotherapy dosimetry applications. A range of challenges remain with respect to the accurate quantification, assessment of time-integrated activity and absorbed dose estimation. In this review, we summarise a range of technological and methodological advancements, mainly focussed on beta-emitting molecular radiotherapeutics, that aim to improve molecular radiotherapy dosimetry to achieve accurate, reproducible, and streamlined dosimetry. We describe how these new technologies can potentially improve the often time-consuming considered process of dosimetry and provide suggestions as to what further developments might be required.
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Affiliation(s)
| | - Jan Taprogge
- National Radiotherapy Trials Quality Assurance (RTTQA) Group, Joint Department of Physics, Royal Marsden NHSFT, Downs Road, Sutton SM2 5PT, United Kingdom; The Institute of Cancer Research, 123 Old Brompton Road, London SW7 3RP, United Kingdom
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Reed MB, Ponce de León M, Vraka C, Rausch I, Godbersen GM, Popper V, Geist BK, Komorowski A, Nics L, Schmidt C, Klug S, Langsteger W, Karanikas G, Traub-Weidinger T, Hahn A, Lanzenberger R, Hacker M. Whole-body metabolic connectivity framework with functional PET. Neuroimage 2023; 271:120030. [PMID: 36925087 DOI: 10.1016/j.neuroimage.2023.120030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 02/22/2023] [Accepted: 03/13/2023] [Indexed: 03/15/2023] Open
Abstract
The nervous and circulatory system interconnects the various organs of the human body, building hierarchically organized subsystems, enabling fine-tuned, metabolically expensive brain-body and inter-organ crosstalk to appropriately adapt to internal and external demands. A deviation or failure in the function of a single organ or subsystem could trigger unforeseen biases or dysfunctions of the entire network, leading to maladaptive physiological or psychological responses. Therefore, quantifying these networks in healthy individuals and patients may help further our understanding of complex disorders involving body-brain crosstalk. Here we present a generalized framework to automatically estimate metabolic inter-organ connectivity utilizing whole-body functional positron emission tomography (fPET). The developed framework was applied to 16 healthy subjects (mean age ± SD, 25 ± 6 years; 13 female) that underwent one dynamic 18F-FDG PET/CT scan. Multiple procedures of organ segmentation (manual, automatic, circular volumes) and connectivity estimation (polynomial fitting, spatiotemporal filtering, covariance matrices) were compared to provide an optimized thorough overview of the workflow. The proposed approach was able to estimate the metabolic connectivity patterns within brain regions and organs as well as their interactions. Automated organ delineation, but not simplified circular volumes, showed high agreement with manual delineation. Polynomial fitting yielded similar connectivity as spatiotemporal filtering at the individual subject level. Furthermore, connectivity measures and group-level covariance matrices did not match. The strongest brain-body connectivity was observed for the liver and kidneys. The proposed framework offers novel opportunities towards analyzing metabolic function from a systemic, hierarchical perspective in a multitude of physiological pathological states.
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Affiliation(s)
- Murray Bruce Reed
- Department of Psychiatry and Psychotherapy, Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Austria
| | - Magdalena Ponce de León
- Department of Psychiatry and Psychotherapy, Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Austria
| | - Chrysoula Vraka
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Austria
| | - Ivo Rausch
- QIMP Team, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Godber Mathis Godbersen
- Department of Psychiatry and Psychotherapy, Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Austria
| | - Valentin Popper
- Department of Psychiatry and Psychotherapy, Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Austria
| | - Barbara Katharina Geist
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Austria
| | - Arkadiusz Komorowski
- Department of Psychiatry and Psychotherapy, Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Austria
| | - Lukas Nics
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Austria
| | - Clemens Schmidt
- Department of Psychiatry and Psychotherapy, Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Austria
| | - Sebastian Klug
- Department of Psychiatry and Psychotherapy, Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Austria
| | - Werner Langsteger
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Austria
| | - Georgios Karanikas
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Austria
| | - Tatjana Traub-Weidinger
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Austria
| | - Andreas Hahn
- Department of Psychiatry and Psychotherapy, Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Austria
| | - Rupert Lanzenberger
- Department of Psychiatry and Psychotherapy, Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Austria.
| | - Marcus Hacker
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Austria
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Krache A, Fontan C, Pestourie C, Bardiès M, Bouvet Y, Payoux P, Chatelut E, White-Koning M, Salabert AS. Preclinical Pharmacokinetics and Dosimetry of an 89Zr Labelled Anti-PDL1 in an Orthotopic Lung Cancer Murine Model. Front Med (Lausanne) 2022; 8:741855. [PMID: 35174180 PMCID: PMC8841431 DOI: 10.3389/fmed.2021.741855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 12/06/2021] [Indexed: 12/24/2022] Open
Abstract
Anti-PDL1 is a monoclonal antibody targeting the programmed death-cell ligand (PD-L1) by blocking the programmed death-cell (PD-1)/PD-L1 axis. It restores the immune system response in several tumours, such as non-small cell lung cancer (NSCLC). Anti-PDL1 or anti-PD1 treatments rely on PD-L1 tumoural expression assessed by immunohistochemistry on biopsy tissue. However, depending on the biopsy extraction site, PD-L1 expression can vary greatly. Non-invasive imaging enables whole-body mapping of PD-L1 sites and could improve the assessment of tumoural PD-L1 expression.MethodsPharmacokinetics (PK), biodistribution and dosimetry of a murine anti-PDL1 radiolabelled with zirconium-89, were evaluated in both healthy mice and immunocompetent mice with lung cancer. Preclinical PET (μPET) imaging was used to analyse [89Zr]DFO-Anti-PDL1 distribution in both groups of mice. Non-compartmental (NCA) and compartmental (CA) PK analyses were performed in order to describe PK parameters and assess area under the concentration-time curve (AUC) for dosimetry evaluation in humans.ResultsOrgan distribution was correctly estimated using PK modelling in both healthy mice and mice with lung cancer. Tumoural uptake occurred within 24 h post-injection of [89Zr]DFO-Anti-PDL1, and the best imaging time was at 48 h according to the signal-to-noise ratio (SNR) and image quality. An in vivo blocking study confirmed that [89Zr]DFO-anti-PDL1 specifically targeted PD-L1 in CMT167 lung tumours in mice. AUC in organs was estimated using a 1-compartment PK model and extrapolated to human (using allometric scaling) in order to estimate the radiation exposure in human. Human-estimated effective dose was 131 μSv/MBq.ConclusionThe predicted dosimetry was similar or lower than other antibodies radiolabelled with zirconium-89 for immunoPET imaging.
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Affiliation(s)
- Anis Krache
- CRCT, UMR 1037, Université de Toulouse, INSERM, Université Paul-Sabatier, Toulouse, France
- ToNIC, Toulouse NeuroImaging Center, UMR 1214, Université de Toulouse, INSERM, Université Paul-Sabatier, Toulouse, France
- General-Electric - Zionexa, Targeting Imaging and Therapy, Buc, France
- Anis Krache
| | - Charlotte Fontan
- General-Electric - Zionexa, Targeting Imaging and Therapy, Buc, France
| | - Carine Pestourie
- CREFRE (Centre Régional D'Exploration Fonctionnelle et Ressources Expérimentales) – INSERM UMS006, Plateforme GénoToul-Anexplo, Toulouse, France
- ENVT (Ecole Nationale Vétérinaire de Toulouse), Toulouse, France
| | - Manuel Bardiès
- IRCM (Institut de Recherche en Cancérologie de Montpellier), UMR 1194 INSERM, Université de Montpellier and ICM, Montpellier, France
- Département de Médecine Nucléaire, ICM (Institut du Cancer de Montpellier), Montpellier, France
| | - Yann Bouvet
- General-Electric - Zionexa, Targeting Imaging and Therapy, Buc, France
| | - Pierre Payoux
- ToNIC, Toulouse NeuroImaging Center, UMR 1214, Université de Toulouse, INSERM, Université Paul-Sabatier, Toulouse, France
- Centre Hospitalo-Universitaire de Toulouse, Toulouse, France
| | - Etienne Chatelut
- CRCT, UMR 1037, Université de Toulouse, INSERM, Université Paul-Sabatier, Toulouse, France
| | - Melanie White-Koning
- CRCT, UMR 1037, Université de Toulouse, INSERM, Université Paul-Sabatier, Toulouse, France
| | - Anne-Sophie Salabert
- ToNIC, Toulouse NeuroImaging Center, UMR 1214, Université de Toulouse, INSERM, Université Paul-Sabatier, Toulouse, France
- Centre Hospitalo-Universitaire de Toulouse, Toulouse, France
- *Correspondence: Anne-Sophie Salabert
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6
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Roncali E, Capala J, Benedict SH, Akabani G, Bednarz B, Bhadrasain V, Bolch WE, Buchsbaum JC, Coleman NC, Dewaraja YK, Frey E, Ghaly M, Grudzinski J, Hobbs RF, Howell RW, Humm JL, Kunos CA, Larson S, Lin FI, Madsen M, Mirzadeh S, Morse D, Pryma D, Sgouros G, St James S, Wahl RL, Xiao Y, Zanzonico P, Zukotynski K. Overview of the First NRG Oncology-National Cancer Institute Workshop on Dosimetry of Systemic Radiopharmaceutical Therapy. J Nucl Med 2021; 62:1133-1139. [PMID: 33277396 PMCID: PMC8833877 DOI: 10.2967/jnumed.120.255547] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/20/2021] [Indexed: 11/16/2022] Open
Abstract
In 2018, the National Cancer Institute and NRG Oncology partnered for the first time to host a joint workshop on systemic radiopharmaceutical therapy (RPT) to specifically address dosimetry issues and strategies for future clinical trials. The workshop focused on current dosimetric approaches for clinical trials, strategies under development that would optimize dose reporting, and future desired or optimized approaches for novel emerging radionuclides and carriers in development. In this article, we review the main approaches that are applied clinically to calculate the absorbed dose. These include absorbed doses calculated over a variety of spatial scales, including whole body, organ, suborgan, and voxel, the last 3 of which are achievable within the MIRD schema (S value) and can be calculated with analytic methods or Monte Carlo methods, the latter in most circumstances. This article will also contrast currently available methods and tools with those used in the past, to propose a pathway whereby dosimetry helps the field by optimizing the biologic effect of the treatment and trial design in the drug approval process to reduce financial and logistical costs. We also briefly discuss the dosimetric equivalent of biomarkers to help bring a precision medicine approach to RPT implementation when merited by evidence collected during early-phase trial investigations. Advances in the methodology and related tools have made dosimetry the optimum biomarker for RPT.
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Affiliation(s)
| | | | | | | | - Bryan Bednarz
- University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | | | - Wesley E Bolch
- Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | | | | | | | - Eric Frey
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland
| | - Michael Ghaly
- Radiopharmaceutical Imaging and Dosimetry LLC (Rapid), Baltimore, Maryland
| | | | - Robert F Hobbs
- Department of Radiation Oncology, Johns Hopkins University, Baltimore, Maryland
| | - Roger W Howell
- Department of Radiology, Rutgers University, Newark, New Jersey
| | - John L Humm
- Memorial Sloan Kettering Cancer Center, New York, New York
| | | | - Steve Larson
- Memorial Sloan Kettering Cancer Center, New York, New York
| | | | | | | | | | - Daniel Pryma
- University of Pennsylvania, Philadelphia, Pennsylvania
| | - George Sgouros
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland
| | - Sara St James
- University of California San Francisco, San Francisco, California
| | - Richard L Wahl
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Ying Xiao
- University of Pennsylvania, Philadelphia, Pennsylvania
| | - Pat Zanzonico
- Memorial Sloan Kettering Cancer Center, New York, New York
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Prospective SPECT-CT Organ Dosimetry-Driven Radiation-Absorbed Dose Escalation Using the In-111 ( 111In)/Yttrium 90 ( 90Y) Ibritumomab Tiuxetan (Zevalin ®) Theranostic Pair in Patients with Lymphoma at Myeloablative Dose Levels. Cancers (Basel) 2021; 13:cancers13112828. [PMID: 34204102 PMCID: PMC8201215 DOI: 10.3390/cancers13112828] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 12/25/2022] Open
Abstract
Simple Summary We prospectively evaluated the feasibility of SPECT-CT/planar organ dosimetry-based radiation dose escalation radioimmunotherapy in patients with recurrent non-Hodgkin’s lymphoma using the theranostic pair of 111In and 90Y anti-CD20 ibritumomab tiuxetan (Zevalin®) at myeloablative radiation-absorbed doses with autologous stem cell support. Unlike most routine dose escalation approaches, our approach used patient-individualized measurements of organ radiation absorbed dose from the tracer study, with patient-specific adjustments of the injected therapy dose to deliver a pre-specified radiation absorbed dose to the liver. Our approach was feasible, stem cell engraftment was swift, resulted in an 89% tumor response rate in treated patients, demonstrated over 3 fold variability in liver dosimetry/injected activity among patients, allowed us to exceed the FDA approved administered activity by over 5 fold and demonstrated the normal liver maximum tolerated dose to exceed 28 Gy. Dose escalation was not continued due to lack of drug availability. With modern dosimetry approaches, patient specific dosimetry-driven radiation dose escalation is feasible, allows adjustment of administered activity for heterogeneous pharmacokinetics and allows marked dose escalation vs. non-dosimetry driven approaches. Abstract Purpose: We prospectively evaluated the feasibility of SPECT-CT/planar organ dosimetry-based radiation dose escalation radioimmunotherapy in patients with recurrent non-Hodgkin’s lymphoma using the theranostic pair of 111In and 90Y anti-CD20 ibritumomab tiuxetan (Zevalin®) at myeloablative radiation-absorbed doses with autologous stem cell support. We also assessed acute non-hematopoietic toxicity and early tumor response in this two-center outpatient study. Methods: 24 patients with CD20-positive relapsed or refractory rituximab-sensitive, low-grade, mantle cell, or diffuse large-cell NHL, with normal organ function, platelet counts > 75,000/mm3, and <35% tumor involvement in the marrow were treated with Rituximab (375 mg/m2) weekly for 4 consecutive weeks, then one dose of cyclophosphamide 2.5 g/m2 with filgrastim 10 mcg/kg/day until stem cell collection. Of these, 18 patients with successful stem cell collection (at least 2 × 106 CD34 cells/kg) proceeded to RIT. A dosimetric administration of 111In ibritumomab tiuxetan (185 MBq) followed by five sequential quantitative planar and one SPECT/CT scan was used to determine predicted organ radiation-absorbed dose. Two weeks later, 90Y ibritumomab tiuxetan was administered in an outpatient setting at a cohort- and patient-specific predicted organ radiation-absorbed dose guided by a Continuous Response Assessment (CRM) methodology with the following cohorts for dose escalation: 14.8 MBq/kg, and targeted 18, 24, 28, and 30.5 Gy to the liver. Autologous stem cell infusion occurred when the estimated marrow radiation-absorbed dose rate was predicted to be <1 cGy/h. Feasibility, short-term toxicities, and tumor response were assessed. Results: Patient-specific hybrid SPECT/CT + planar organ dosimetry was feasible in all 18 cases and used to determine the patient-specific therapeutic dose and guide dose escalation (26.8 ± 7.3 MBq/kg (mean), 26.3 MBq/kg (median) of 90Y (range: 12.1–41.4 MBq/kg)) of ibritumomab tiuxetan that was required to deliver 10 Gy to the liver. Infused stem cells engrafted rapidly. The most common treatment-related toxicities were hematological and were reversible following stem cell infusion. No significant hepatotoxicity was seen. One patient died from probable treatment-related causes—pneumonia at day 27 post-transplant. One patient at dose level 18 Gy developed myelodysplastic syndrome (MDS), 4 patients required admission post-90Y RIT for febrile neutropenia, 16/18 patients receiving 90Y ibritumomab tiuxetan (89%) responded to the therapy, with 13 CR (72%) and 3/18 PR (17%), at 60 days post-treatment. Two patients had progressive disease at sixty days. One patient was lost to follow-up. Median time to progression was estimated to be at least 13 months. MTD to the liver is greater than 28 Gy, but the MTD was not reached as the study was terminated due to unexpected discontinuation of availability of the therapeutic agent. Conclusions: Patient-specific outpatient 90Y ibritumomab tiuxetan RIT with myeloablative doses of RIT up to a targeted 30.5 Gy to the liver is feasible, guided by prospective SPECT/CT + planar imaging with the theranostic pair of 111In and 90Y anti-CD20, with outpatient autologous stem cell transplant support. Administered activity over 5 times the standard FDA-approved activity was well-tolerated. The non-hematopoietic MTD in this study exceeds 28 Gy to the liver. Initial tumor responses were common at all dose levels. This study supports the feasibility of organ dosimetry-driven patient-specific dose escalation in the treatment of NHL with stem cell transplant and provides additional information on the radiation tolerance of the normal liver to radiopharmaceutical therapy.
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Asmi H, Bentayeb F, Bouzekraoui Y, Bonutti F. Optimization of Scatter Correction Method in Samarium-153 Single-photon Emission Computed Tomography using Triple-Energy Window: A Monte Carlo Simulation Study. Indian J Nucl Med 2020; 35:210-215. [PMID: 33082676 PMCID: PMC7537924 DOI: 10.4103/ijnm.ijnm_11_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/20/2020] [Accepted: 03/21/2020] [Indexed: 11/04/2022] Open
Abstract
PURPOSE In single-photon emission computed tomography imaging, the presence of scatter degrades image quality. The goal of this study is to optimize the main- and sub-energy windows for triple-energy window (TEW) method using Monte Carlo SImulating Medical Imaging Nuclear Detectors (SIMIND) code for samarium-153 (Sm-153) imaging. MATERIALS AND METHODS The comparison is based on the Monte Carlo simulation data with the results estimated using TEW method. Siemens Symbia gamma-camera equipped with low-energy high-resolution collimator was simulated for Sm-153 point source located in seven positions in water cylindrical phantom. Three different main-energy window widths (10%, 15%, and 20%) and three different sub-energy window widths (2, 4, and 6 keV) were evaluated. We compared the true scatter fraction determined by SIMIND and scatter fraction estimated using TEW scatter correction method at each position. In order to evaluate the image quality, we used the full width at half maximum (FWHM) computed on the PSF and image contrast using Jaszczak phantom. RESULTS The scatter fraction using TEW method is similar to the true scatter fraction for 20% of the main-energy window and 6 keV sub-energy windows. For these windows, the results show that the resolution and contrast were improved. CONCLUSION TEW method could be a useful scatter correction method to remove the scatter event in the image for Sm-153 imaging.
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Affiliation(s)
- Hicham Asmi
- Department of Physics, LPHE, Modeling and Simulations, Faculty of Science, Mohammed V University, Rabat, Morocco
| | - Farida Bentayeb
- Department of Physics, LPHE, Modeling and Simulations, Faculty of Science, Mohammed V University, Rabat, Morocco
| | - Youssef Bouzekraoui
- Department of Physics, LPHE, Modeling and Simulations, Faculty of Science, Mohammed V University, Rabat, Morocco
| | - Faustino Bonutti
- Department of Medical Physics, Academic Hospital of Udine, Udine, Italy
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9
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Abstract
The continuous development of SPECT over the past 50 years has led to improved image quality and increased diagnostic confidence. The most influential developments include the realization of hybrid SPECT/CT devices, as well as the implementation of attenuation correction and iterative image reconstruction techniques. These developments have led to a preference for SPECT/CT devices over SPECT-only systems and to the widespread adoption of the former, strengthening the role of SPECT/CT as the workhorse of Nuclear Medicine imaging. New trends in the ongoing development of SPECT/CT are diverse. For example, whole-body SPECT/CT images, consisting of acquisitions from multiple consecutive bed positions in the manner of PET/CT, are increasingly performed. Additionally, in recent years, some interesting approaches in detector technology have found their way into commercial products. For example, some SPECT cameras dedicated to specific organs employ semiconductor detectors made of cadmium telluride or cadmium zinc telluride, which have been shown to increase the obtainable image quality by offering a higher sensitivity and energy resolution. However, the advent of quantitative SPECT/CT which, like PET, can quantify the amount of tracer in terms of Bq/mL or as a standardized uptake value could be regarded as most important development. It is a major innovation that will lead to increased diagnostic accuracy and confidence, especially in longitudinal studies and in the monitoring of treatment response. The current work comprises two main aspects. At first, physical and technical fundamentals of SPECT image formation are described and necessary prerequisites of quantitative SPECT/CT are reviewed. Additionally, the typically achievable quantitative accuracy based on reports from the literature is given. Second, an extensive list of studies reporting on clinical applications of quantitative SPECT/CT is provided and reviewed.
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Affiliation(s)
- Philipp Ritt
- Clinic of Nuclear Medicine, University Hospital Erlangen, Ulmenweg 18, 91054, Erlangen, Germany.
| | - Torsten Kuwert
- Clinic of Nuclear Medicine, University Hospital Erlangen, Ulmenweg 18, 91054, Erlangen, Germany
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Marin G, Vanderlinden B, Karfis I, Guiot T, Wimana Z, Reynaert N, Vandenberghe S, Flamen P. A dosimetry procedure for organs-at-risk in 177Lu peptide receptor radionuclide therapy of patients with neuroendocrine tumours. Phys Med 2018; 56:41-49. [PMID: 30527088 DOI: 10.1016/j.ejmp.2018.11.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 10/05/2018] [Accepted: 11/02/2018] [Indexed: 01/25/2023] Open
Abstract
PURPOSE Peptide receptor radionuclide therapy with 177Lu-DOTATATE has become a standard treatment modality in neuroendocrine tumours (NETs). No consensus has yet been reached however regarding the absorbed dose threshold for lesion response, the absorbed dose limit to organs-at-risk, and the optimal fractionation and activity to be administered. This is partly due to a lack of uniform and comparable dosimetry protocols. The present article details the development of an organ-at-risk dosimetry procedure, which could be implemented and used routinely in a clinical context. METHODS Forty-seven patients with NETs underwent 177Lu-DOTATATE therapy. Three SPECT/CT images were acquired at 4, 24 and 144-192 h post-injection. Three blood samples were obtained together with the SPECT/CT acquisitions and 2 additional samples were obtained around 30 min and 1 h post-injection. A bi-exponential fit was used to compute the source organ time-integrated activity coefficients. Coefficients were introduced into OLINDA/EXM software to compute organ-at-risk absorbed doses. Median values for all patients were computed for absorbed dose coefficient D/A0 and for late effective half-life T1/2eff for kidneys, spleen and red marrow. RESULTS Dosimetry resulted in a median[interquartile range] of 0.78[0.35], 1.07[0.58] and 0.028[0.010] Gy/GBq for D/A0 and of 55[9], 71[9] and 52[18] h for T1/2eff for kidneys, spleen and red marrow respectively. CONCLUSIONS A dosimetry procedure for organs-at-risk in 177Lu-DOTATATE therapy based on serial SPECT/CT images and blood samples can be implemented routinely in a clinical context with limited patient burden. The results obtained were in accordance with those of other centres.
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Affiliation(s)
- Gwennaëlle Marin
- Department of Medical Physics, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium; Medical Imaging and Signal Processing (MEDISIP), Department of Electronics and Information Systems (ELIS), Faculty of Engineering and Architecture (FEA), Ghent University (UGent), 185 De Pintelaan, 9000 Gent, Belgium.
| | - Bruno Vanderlinden
- Department of Medical Physics, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
| | - Ioannis Karfis
- Department of Nuclear Medicine, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
| | - Thomas Guiot
- Department of Medical Physics, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
| | - Zena Wimana
- Department of Nuclear Medicine, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
| | - Nick Reynaert
- Department of Medical Physics, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
| | - Stefaan Vandenberghe
- Medical Imaging and Signal Processing (MEDISIP), Department of Electronics and Information Systems (ELIS), Faculty of Engineering and Architecture (FEA), Ghent University (UGent), 185 De Pintelaan, 9000 Gent, Belgium.
| | - Patrick Flamen
- Department of Nuclear Medicine, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
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