1
|
Gustafsson J, Larsson E, Ljungberg M, Sjögreen Gleisner K. Pareto optimization of SPECT acquisition and reconstruction settings for 177Lu activity quantification. EJNMMI Phys 2024; 11:62. [PMID: 39004644 PMCID: PMC11247071 DOI: 10.1186/s40658-024-00667-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 07/05/2024] [Indexed: 07/16/2024] Open
Abstract
BACKGROUND The aim was to investigate the noise and bias properties of quantitative 177Lu-SPECT with respect to the number of projection angles, and the number of subsets and iterations in the OS-EM reconstruction, for different total acquisition times. METHODS Experimental SPECT acquisition of six spheres in a NEMA body phantom filled with 177Lu was performed, using medium-energy collimators and 120 projections with 180 s per projection. Bootstrapping was applied to generate data sets representing acquisitions with 20 to 120 projections for 10 min, 20 min, and 40 min, with 32 noise realizations per setting. Monte Carlo simulations were performed of 177Lu-DOTA-TATE in an anthropomorphic computer phantom with three tumours (2.8 mL to 40.0 mL). Projections representing 24 h and 168 h post administration were simulated, each with 32 noise realizations. Images were reconstructed using OS-EM with compensation for attenuation, scatter, and distance-dependent resolution. The number of subsets and iterations were varied within a constrained range of the product number of iterations × number of projections ≤ 2400 . Volumes-of-interest were defined following the physical size of the spheres and tumours, the mean activity-concentrations estimated, and the absolute mean relative error and coefficient of variation (CV) over noise realizations calculated. Pareto fronts were established by analysis of CV versus mean relative error. RESULTS Points at the Pareto fronts with low CV and high mean error resulted from using a low number of subsets, whilst points at the Pareto fronts associated with high CV but low mean error resulted from reconstructions with a high number of subsets. The number of projection angles had limited impact. CONCLUSIONS For accurate estimation of the 177Lu activity-concentration from SPECT images, the number of projection angles has limited importance, whilst the total acquisition time and the number of subsets and iterations are parameters of importance.
Collapse
Affiliation(s)
| | - Erik Larsson
- Radiation Physics, Skåne University Hospital, Lund, Sweden
| | | | | |
Collapse
|
2
|
Li Z, Benabdallah N, Luo J, Wahl RL, Thorek DLJ, Jha AK. ISIT-QA: In Silico Imaging Trial to Evaluate a Low-Count Quantitative SPECT Method Across Multiple Scanner-Collimator Configurations for 223Ra-Based Radiopharmaceutical Therapies. J Nucl Med 2024; 65:810-817. [PMID: 38575187 PMCID: PMC11064831 DOI: 10.2967/jnumed.123.266719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 02/13/2024] [Indexed: 04/06/2024] Open
Abstract
Personalized dose-based treatment planning requires accurate and reproducible noninvasive measurements to ensure safety and effectiveness. Dose estimation using SPECT is possible but challenging for alpha (α)-particle-emitting radiopharmaceutical therapy (α-RPT) because of complex γ-emission spectra, extremely low counts, and various image-degrading artifacts across a plethora of scanner-collimator configurations. Through the incorporation of physics-based considerations and skipping of the potentially lossy voxel-based reconstruction step, a recently developed projection-domain low-count quantitative SPECT (LC-QSPECT) method has the potential to provide reproducible, accurate, and precise activity concentration and dose measures across multiple scanners, as is typically the case in multicenter settings. To assess this potential, we conducted an in silico imaging trial to evaluate the LC-QSPECT method for a 223Ra-based α-RPT, with the trial recapitulating patient and imaging system variabilities. Methods: A virtual imaging trial titled In Silico Imaging Trial for Quantitation Accuracy (ISIT-QA) was designed with the objectives of evaluating the performance of the LC-QSPECT method across multiple scanner-collimator configurations and comparing performance with a conventional reconstruction-based quantification method. In this trial, we simulated 280 realistic virtual patients with bone-metastatic castration-resistant prostate cancer treated with 223Ra-based α-RPT. The trial was conducted with 9 simulated SPECT scanner-collimator configurations. The primary objective of this trial was to evaluate the reproducibility of dose estimates across multiple scanner-collimator configurations using LC-QSPECT by calculating the intraclass correlation coefficient. Additionally, we compared the reproducibility and evaluated the accuracy of both considered quantification methods across multiple scanner-collimator configurations. Finally, the repeatability of the methods was evaluated in a test-retest study. Results: In this trial, data from 268 223RaCl2 treated virtual prostate cancer patients, with a total of 2,903 lesions, were used to evaluate LC-QSPECT. LC-QSPECT provided dose estimates with good reproducibility across the 9 scanner-collimator configurations (intraclass correlation coefficient > 0.75) and high accuracy (ensemble average values of recovery coefficients ranged from 1.00 to 1.02). Compared with conventional reconstruction-based quantification, LC-QSPECT yielded significantly improved reproducibility across scanner-collimator configurations, accuracy, and test-retest repeatability ([Formula: see text] Conclusion: LC-QSPECT provides reproducible, accurate, and repeatable dose estimations in 223Ra-based α-RPT as evaluated in ISIT-QA. These findings provide a strong impetus for multicenter clinical evaluations of LC-QSPECT in dose quantification for α-RPTs.
Collapse
Affiliation(s)
- Zekun Li
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri
| | - Nadia Benabdallah
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri
- Program in Quantitative Molecular Therapeutics, Washington University, St. Louis, Missouri
| | - Jingqin Luo
- Siteman Cancer Center, Washington University, St. Louis, Missouri
- Division of Public Health Sciences, Department of Surgery, Washington University, St. Louis, Missouri; and
- Division of Biostatistics, Washington University, St. Louis, Missouri
| | - Richard L Wahl
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri
- Siteman Cancer Center, Washington University, St. Louis, Missouri
| | - Daniel L J Thorek
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri
- Program in Quantitative Molecular Therapeutics, Washington University, St. Louis, Missouri
- Siteman Cancer Center, Washington University, St. Louis, Missouri
| | - Abhinav K Jha
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri;
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri
- Siteman Cancer Center, Washington University, St. Louis, Missouri
| |
Collapse
|
3
|
Gape PMD, Schultz MK, Stasiuk GJ, Terry SYA. Towards Effective Targeted Alpha Therapy for Neuroendocrine Tumours: A Review. Pharmaceuticals (Basel) 2024; 17:334. [PMID: 38543120 PMCID: PMC10974115 DOI: 10.3390/ph17030334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 02/22/2024] [Accepted: 02/26/2024] [Indexed: 04/01/2024] Open
Abstract
This review article explores the evolving landscape of Molecular Radiotherapy (MRT), emphasizing Peptide Receptor Radionuclide Therapy (PRRT) for neuroendocrine tumours (NETs). The primary focus is on the transition from β-emitting radiopharmaceuticals to α-emitting agents in PRRT, offering a critical analysis of the radiobiological basis, clinical applications, and ongoing developments in Targeted Alpha Therapy (TAT). Through an extensive literature review, the article delves into the mechanisms and effectiveness of PRRT in targeting somatostatin subtype 2 receptors, highlighting both its successes and limitations. The discussion extends to the emerging paradigm of TAT, underlining its higher potency and specificity with α-particle emissions, which promise enhanced therapeutic efficacy and reduced toxicity. The review critically evaluates preclinical and clinical data, emphasizing the need for standardised dosimetry and a deeper understanding of the dose-response relationship in TAT. The review concludes by underscoring the significant potential of TAT in treating SSTR2-overexpressing cancers, especially in patients refractory to β-PRRT, while also acknowledging the current challenges and the necessity for further research to optimize treatment protocols.
Collapse
Affiliation(s)
- Paul M. D. Gape
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London SE1 7EP, UK; (G.J.S.); (S.Y.A.T.)
| | - Michael K. Schultz
- Departments of Radiology, Radiation Oncology, Free Radical and Radiation Biology Program, University of Iowa, Iowa City, IA 52242, USA;
- Perspective Therapeutics, Coralville, IA 52241, USA
| | - Graeme J. Stasiuk
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London SE1 7EP, UK; (G.J.S.); (S.Y.A.T.)
| | - Samantha Y. A. Terry
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London SE1 7EP, UK; (G.J.S.); (S.Y.A.T.)
| |
Collapse
|
4
|
Benabdallah N, Lu P, Abou DS, Zhang H, Ulmert D, Hobbs RF, Gay HA, Simons BW, Saeed MA, Rogers BE, Jha AK, Tai YC, Malone CD, Ippolito JE, Michalski J, Jennings JW, Baumann BC, Pachynski RK, Thorek DLJ. Beyond Average: α-Particle Distribution and Dose Heterogeneity in Bone Metastatic Prostate Cancer. J Nucl Med 2024; 65:245-251. [PMID: 38124163 PMCID: PMC10858382 DOI: 10.2967/jnumed.123.266571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/23/2023] [Indexed: 12/23/2023] Open
Abstract
α-particle emitters are emerging as a potent modality for disseminated cancer therapy because of their high linear energy transfer and localized absorbed dose profile. Despite great interest and pharmaceutical development, there is scant information on the distribution of these agents at the scale of the α-particle pathlength. We sought to determine the distribution of clinically approved [223Ra]RaCl2 in bone metastatic castration-resistant prostate cancer at this resolution, for the first time to our knowledge, to inform activity distribution and dose at the near-cell scale. Methods: Biopsy specimens and blood were collected from 7 patients 24 h after administration. 223Ra activity in each sample was recorded, and the microstructure of biopsy specimens was analyzed by micro-CT. Quantitative autoradiography and histopathology were segmented and registered with an automated procedure. Activity distributions by tissue compartment and dosimetry calculations based on the MIRD formalism were performed. Results: We revealed the activity distribution differences across and within patient samples at the macro- and microscopic scales. Microdistribution analysis confirmed localized high-activity regions in a background of low-activity tissue. We evaluated heterogeneous α-particle emission distribution concentrated at bone-tissue interfaces and calculated spatially nonuniform absorbed-dose profiles. Conclusion: Primary patient data of radiopharmaceutical therapy distribution at the small scale revealed that 223Ra uptake is nonuniform. Dose estimates present both opportunities and challenges to enhance patient outcomes and are a first step toward personalized treatment approaches and improved understanding of α-particle radiopharmaceutical therapies.
Collapse
Affiliation(s)
- Nadia Benabdallah
- Mallinckrodt Institute of Radiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Peng Lu
- Mallinckrodt Institute of Radiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Diane S Abou
- Mallinckrodt Institute of Radiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Hanwen Zhang
- Mallinckrodt Institute of Radiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - David Ulmert
- Department of Molecular and Medical Pharmacology, UCLA, Los Angeles, California
- Division of Oncology and Pathology, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Robert F Hobbs
- Department of Radiation Oncology, Johns Hopkins University, Baltimore, Maryland
| | - Hiram A Gay
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Brian W Simons
- Center for Comparative Medicine, Baylor University, Houston, Texas
| | - Muhammad A Saeed
- Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Buck E Rogers
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Abhinav K Jha
- Mallinckrodt Institute of Radiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Yuan-Chuan Tai
- Mallinckrodt Institute of Radiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Christopher D Malone
- Mallinckrodt Institute of Radiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Joseph E Ippolito
- Mallinckrodt Institute of Radiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Jeff Michalski
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Jack W Jennings
- Mallinckrodt Institute of Radiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Brian C Baumann
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
- Department of Radiation Oncology, Springfield Clinic, Springfield, Illinois; and
| | - Russell K Pachynski
- Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Daniel L J Thorek
- Mallinckrodt Institute of Radiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri;
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
- Oncologic Imaging Program, Siteman Cancer Center, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| |
Collapse
|
5
|
Rahman MA, Li Z, Yu Z, Laforest R, Thorek DLJ, Jha AK. A list-mode multi-energy window low-count SPECT reconstruction method for isotopes with multiple emission peaks. EJNMMI Phys 2023; 10:40. [PMID: 37347319 PMCID: PMC10287621 DOI: 10.1186/s40658-023-00558-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 05/31/2023] [Indexed: 06/23/2023] Open
Abstract
BACKGROUND Single-photon emission computed tomography (SPECT) provides a mechanism to perform absorbed-dose quantification tasks for [Formula: see text]-particle radiopharmaceutical therapies ([Formula: see text]-RPTs). However, quantitative SPECT for [Formula: see text]-RPT is challenging due to the low number of detected counts, the complex emission spectrum, and other image-degrading artifacts. Towards addressing these challenges, we propose a low-count quantitative SPECT reconstruction method for isotopes with multiple emission peaks. METHODS Given the low-count setting, it is important that the reconstruction method extracts the maximal possible information from each detected photon. Processing data over multiple energy windows and in list-mode (LM) format provide mechanisms to achieve that objective. Towards this goal, we propose a list-mode multi energy window (LM-MEW) ordered-subsets expectation-maximization-based SPECT reconstruction method that uses data from multiple energy windows in LM format and include the energy attribute of each detected photon. For computational efficiency, we developed a multi-GPU-based implementation of this method. The method was evaluated using 2-D SPECT simulation studies in a single-scatter setting conducted in the context of imaging [[Formula: see text]Ra]RaCl[Formula: see text], an FDA-approved RPT for metastatic prostate cancer. RESULTS The proposed method yielded improved performance on the task of estimating activity uptake within known regions of interest in comparison to approaches that use a single energy window or use binned data. The improved performance was observed in terms of both accuracy and precision and for different sizes of the region of interest. CONCLUSIONS Results of our studies show that the use of multiple energy windows and processing data in LM format with the proposed LM-MEW method led to improved quantification performance in low-count SPECT of isotopes with multiple emission peaks. These results motivate further development and validation of the LM-MEW method for such imaging applications, including for [Formula: see text]-RPT SPECT.
Collapse
Affiliation(s)
- Md Ashequr Rahman
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, USA
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, USA
| | - Zekun Li
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, USA
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, USA
| | - Zitong Yu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, USA
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, USA
| | - Richard Laforest
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, USA
| | - Daniel L. J. Thorek
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, USA
| | - Abhinav K. Jha
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, USA
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, USA
| |
Collapse
|
6
|
Li Z, Benabdallah N, Abou DS, Baumann BC, Dehdashti F, Ballard DH, Liu J, Jammalamadaka U, Laforest R, Wahl RL, Thorek DLJ, Jha AK. A Projection-Domain Low-Count Quantitative SPECT Method for α-Particle-Emitting Radiopharmaceutical Therapy. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2023; 7:62-74. [PMID: 37201111 PMCID: PMC10191330 DOI: 10.1109/trpms.2022.3175435] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
Single-photon emission-computed tomography (SPECT) provides a mechanism to estimate regional isotope uptake in lesions and at-risk organs after administration of α-particle-emitting radiopharmaceutical therapies (α-RPTs). However, this estimation task is challenging due to the complex emission spectra, the very low number of detected counts (~20 times lower than in conventional SPECT), the impact of stray-radiation-related noise at these low counts, and the multiple image-degrading processes in SPECT. The conventional reconstruction-based quantification methods are observed to be erroneous for α-RPT SPECT. To address these challenges, we developed a low-count quantitative SPECT (LC-QSPECT) method that directly estimates the regional activity uptake from the projection data (obviating the reconstruction step), compensates for stray-radiation-related noise, and accounts for the radioisotope and SPECT physics, including the isotope spectra, scatter, attenuation, and collimator-detector response, using a Monte Carlo-based approach. The method was validated in the context of 3-D SPECT with 223Ra, a commonly used radionuclide for α-RPT. Validation was performed using both realistic simulation studies, including a virtual clinical trial, and synthetic and 3-D-printed anthropomorphic physical-phantom studies. Across all studies, the LC-QSPECT method yielded reliable regional-uptake estimates and outperformed the conventional ordered subset expectation-maximization (OSEM)-based reconstruction and geometric transfer matrix (GTM)-based post-reconstruction partial-volume compensation methods. Furthermore, the method yielded reliable uptake across different lesion sizes, contrasts, and different levels of intralesion heterogeneity. Additionally, the variance of the estimated uptake approached the Cramér-Rao bound-defined theoretical limit. In conclusion, the proposed LC-QSPECT method demonstrated the ability to perform reliable quantification for α-RPT SPECT.
Collapse
Affiliation(s)
- Zekun Li
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63130 USA
| | - Nadia Benabdallah
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO 63110 USA
| | - Diane S Abou
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO 63110 USA
| | - Brian C Baumann
- Department of Radiation Oncology, Washington University, St. Louis, MO 63110 USA
| | - Farrokh Dehdashti
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO 63110 USA
| | - David H Ballard
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO 63110 USA
| | - Jonathan Liu
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO 63110 USA
| | - Uday Jammalamadaka
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO 63110 USA
| | - Richard Laforest
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO 63110 USA
| | - Richard L Wahl
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO 63110 USA
| | - Daniel L J Thorek
- Department of Biomedical Engineering, the Mallinckrodt Institute of Radiology, and the Program in Quantitative Molecular Therapeutics, Washington University, St. Louis, MO 63110 USA
| | - Abhinav K Jha
- Department of Biomedical Engineering and the Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO 63130 USA
| |
Collapse
|
7
|
Gear J. Milestones in dosimetry for nuclear medicine therapy. Br J Radiol 2022; 95:20220056. [PMID: 35451857 PMCID: PMC10996314 DOI: 10.1259/bjr.20220056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/31/2022] [Accepted: 04/14/2022] [Indexed: 11/05/2022] Open
Abstract
Nuclear Medicine therapy has reached a critical juncture with an unprecedented number of patients being treated and an extensive list of new radiopharmaceuticals under development. Since the early applications of these treatments dosimetry has played a vital role in their development, in both aiding optimisation and enhancing safety and efficacy. To inform the future direction of this field, it is useful to reflect on the scientific and technological advances that have occurred since those early uses. In this review, we explore how dosimetry has evolved over the years and discuss why such initiatives were conceived and the importance of maintaining standards within our practise. Specific milestones and landmark publications are highlighted and a thematic review and significant outcomes during each decade are presented.
Collapse
Affiliation(s)
- Jonathan Gear
- The Joint Department of Physics, The Royal Marsden NHS
Foundation Trust & Institute of Cancer Research,
Sutton, United Kingdom
| |
Collapse
|
8
|
Pettinato C, Richetta E, Cremonesi M. Dosimetry with single photon emission tomography (SPECT). Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00173-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
9
|
Graves SA, Bageac A, Crowley JR, Merlino DAM. Reimbursement Approaches for Radiopharmaceutical Dosimetry: Current Status and Future Opportunities. J Nucl Med 2021; 62:48S-59S. [PMID: 34857622 DOI: 10.2967/jnumed.121.262752] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 09/22/2021] [Indexed: 11/16/2022] Open
Abstract
Interest in performing dosimetry for clinical radiopharmaceutical therapy procedures has grown in recent years. Several approved therapies include dosimetry in the Food and Drug Administration-approved label instructions, and other therapies are best used under a patient-tailored paradigm. This paper, which is a product of the Society of Nuclear Medicine and Molecular Imaging Dosimetry Task Force, presents motivations and general workflows for radiopharmaceutical therapy dosimetry, as well as existing strategies for obtaining reimbursement for clinical activities related to dosimetry. Several specific patient examples are provided, including suggested codes for reimbursement. In addition to current reimbursement approaches, key dosimetry services that are not supported under the current coding structure are presented and suggested as areas of focus in the coming years.
Collapse
Affiliation(s)
| | | | - James R Crowley
- Diagnostic Radiology, Carilion Clinic, Roanoke, Virginia; and
| | | |
Collapse
|
10
|
Pandit-Taskar N, Iravani A, Lee D, Jacene H, Pryma D, Hope T, Saboury B, Capala J, Wahl RL. Dosimetry in Clinical Radiopharmaceutical Therapy of Cancer: Practicality Versus Perfection in Current Practice. J Nucl Med 2021; 62:60S-72S. [PMID: 34857623 DOI: 10.2967/jnumed.121.262977] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 10/22/2021] [Indexed: 12/25/2022] Open
Abstract
The use of radiopharmaceutical therapies (RPTs) in the treatment of cancers is growing rapidly, with more agents becoming available for clinical use in last few years and many new RPTs being in development. Dosimetry assessment is critical for personalized RPT, insofar as administered activity should be assessed and optimized in order to maximize tumor-absorbed dose while keeping normal organs within defined safe dosages. However, many current clinical RPTs do not require patient-specific dosimetry based on current Food and Drug Administration-labeled approvals, and overall, dosimetry for RPT in clinical practice and trials is highly varied and underutilized. Several factors impede rigorous use of dosimetry, as compared with the more convenient and less resource-intensive practice of empiric dosing. We review various approaches to applying dosimetry for the assessment of activity in RPT and key clinical trials, the extent of dosimetry use, the relative pros and cons of dosimetry-based versus fixed activity, and practical limiting factors pertaining to current clinical practice.
Collapse
Affiliation(s)
| | - Amir Iravani
- Washington University School of Medicine, St. Louis, Missouri
| | - Dan Lee
- Ochsner Medical Center, New Orleans, Louisiana
| | | | - Dan Pryma
- Penn Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Thomas Hope
- University of San Francisco, San Francisco, California; and
| | | | - Jacek Capala
- National Institutes of Health, Bethesda, Maryland
| | - Richard L Wahl
- Washington University School of Medicine, St. Louis, Missouri
| |
Collapse
|
11
|
Benabdallah N, Scheve W, Dunn N, Silvestros D, Schelker P, Abou D, Jammalamadaka U, Laforest R, Li Z, Liu J, Ballard DH, Maughan NM, Gay H, Baumann BC, Hobbs RF, Rogers B, Iravani A, Jha AK, Dehdashti F, Thorek DLJ. Practical considerations for quantitative clinical SPECT/CT imaging of alpha particle emitting radioisotopes. Theranostics 2021; 11:9721-9737. [PMID: 34815780 PMCID: PMC8581409 DOI: 10.7150/thno.63860] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/15/2021] [Indexed: 02/05/2023] Open
Abstract
Rationale: Alpha particle emitting radiopharmaceuticals are generating considerable interest for the treatment of disseminated metastatic disease. Molecular imaging of the distribution of these agents is critical to safely and effectively maximize the clinical potential of this emerging drug class. The present studies aim to investigate the feasibility and limitations of quantitative SPECT for 223Ra, 225Ac and 227Th. Methods: Three state-of-the-art SPECT/CT systems were investigated: the GE Discovery NM/CT 670, the GE Optima NM/CT 640, and the Siemens Symbia T6. A series of phantoms, including the NEMA IEC Body phantom, were used to compare and calibrate each camera. Additionally, anthropomorphic physical tumor and vertebrae phantoms were developed and imaged to evaluate the quantitative imaging protocol. Results: This work describes and validates a methodology to calibrate each clinical system. The efficiency of each gamma camera was analyzed and compared. Using the calibration factors obtained with the NEMA phantom, we were able to quantify the activity in 3D-printed tissue phantoms with an error of 2.1%, 3.5% and 11.8% for 223Ra, 225Ac, and 227Th, respectively. Conclusion: The present study validates that quantitative SPECT/CT imaging of 223Ra, 225Ac, and 227Th is achievable but that careful considerations for camera configuration are required. These results will aid in future implementation of SPECT-based patient studies and will help to identify the limiting factors for accurate image-based quantification with alpha particle emitting radionuclides.
Collapse
Affiliation(s)
- Nadia Benabdallah
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
- Program in Quantitative Molecular Therapeutics, Washington University School of Medicine, St. Louis, Missouri
| | | | | | | | | | - Diane Abou
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
- Program in Quantitative Molecular Therapeutics, Washington University School of Medicine, St. Louis, Missouri
| | - Uday Jammalamadaka
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Richard Laforest
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Zekun Li
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri
| | - Jonathan Liu
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - David H. Ballard
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Nichole M. Maughan
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri
| | - Hiram Gay
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri
| | - Brian C. Baumann
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri
| | - Robert F. Hobbs
- Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Buck Rogers
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri
| | - Amir Iravani
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Abhinav K. Jha
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri
- Oncologic Imaging Program, Alvin J. Siteman Cancer Center, Washington University School of Medicine, St. Louis, Missouri
| | - Farrokh Dehdashti
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
- Oncologic Imaging Program, Alvin J. Siteman Cancer Center, Washington University School of Medicine, St. Louis, Missouri
| | - Daniel L. J. Thorek
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
- Program in Quantitative Molecular Therapeutics, Washington University School of Medicine, St. Louis, Missouri
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri
- Oncologic Imaging Program, Alvin J. Siteman Cancer Center, Washington University School of Medicine, St. Louis, Missouri
| |
Collapse
|