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Jin Y, Meng LJ. Exploration of Coincidence Detection of Cascade Photons to Enhance Preclinical Multi-Radionuclide SPECT Imaging. IEEE TRANSACTIONS ON MEDICAL IMAGING 2024; 43:1766-1781. [PMID: 38163304 DOI: 10.1109/tmi.2023.3348756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
We proposed a technique of coincidence detection of cascade photons (CDCP) to enhance preclinical SPECT imaging of therapeutic radionuclides emitting cascade photons, such as Lu-177, Ac-225, Ra-223, and In-111. We have carried out experimental studies to evaluate the proposed CDCP-SPECT imaging of low-activity radionuclides using a prototype coincidence detection system constructed with large-volume cadmium zinc telluride (CZT) imaging spectrometers and a pinhole collimator. With In-111 in experimental studies, the CDCP technique allows us to improve the signal-to-contamination in the projection (Projection-SCR) by ~53 times and reduce ~98% of the normalized contamination. Compared to traditional scatter correction, which achieves a Projection-SCR of 1.00, our CDCP method boosts it to 15.91, showing enhanced efficacy in reducing down-scattered contamination, especially at lower activities. The reconstructed images of a line source demonstrated the dramatic enhancement of the image quality with CDCP-SPECT compared to conventional and triple-energy-window-corrected SPECT data acquisition. We also introduced artificial energy blurring and Monte Carlo simulation to quantify the impact of detector performance, especially its energy resolution and timing resolution, on the enhancement through the CDCP technique. We have further demonstrated the benefits of the CDCP technique with simulation studies, which shows the potential of improving the signal-to-contamination ratio by 300 times with Ac-225, which emits cascade photons with a decay constant of ~0.1 ns. These results have demonstrated the potential of CDCP-enhanced SPECT for imaging a super-low level of therapeutic radionuclides in small animals.
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Kästner D, Braune A, Brogsitter C, Freudenberg R, Kotzerke J, Michler E. Gamma camera imaging characteristics of 166Ho and 99mTc used in Selective Internal Radiation Therapy. EJNMMI Phys 2024; 11:35. [PMID: 38581559 PMCID: PMC10998827 DOI: 10.1186/s40658-024-00633-3] [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: 08/03/2023] [Accepted: 03/20/2024] [Indexed: 04/08/2024] Open
Abstract
BACKGROUND The administration of a 166Ho scout dose is available as an alternative to 99mTc particles for pre-treatment imaging in Selective Internal Radiation Therapy (SIRT). It has been reported that the 166Ho scout dose may be more accurate for the prediction of microsphere distribution and the associated therapy planning. The aim of the current study is to compare the scintigraphic imaging characteristics of both isotopes, considering the objectives of the pre-treatment imaging using clinically geared phantoms. METHODS Planar and SPECT/CT images were obtained using a NEMA image quality phantom in different phantom setups and another body-shaped phantom with several inserts. The influence of collimator type, count statistics, dead time effects, isotope properties and patient obesity on spatial resolution, contrast recovery and the detectability of small activity accumulations was investigated. Furthermore, the effects of the imaging characteristics on personalized dosimetry are discussed. RESULTS The images with 99mTc showed up to 3 mm better spatial resolution, up to two times higher contrast recovery and significantly lower image noise than those with 166Ho. The contrast-to-noise ratio was up to five times higher for 99mTc than for 166Ho. Only when using 99mTc all activity-filled spheres could be distinguished from the activity-filled background. The measurements mimicking an obese patient resulted in a degraded image quality for both isotopes. CONCLUSIONS Our measurements demonstrate better scintigraphic imaging properties for 99mTc compared to 166Ho in terms of spatial resolution, contrast recovery, image noise, and lesion detectability. While the 166Ho scout dose promises better prediction of the microsphere distribution, it is important to consider the inferior imaging characteristics of 166Ho, which may affect individualized treatment planning in SIRT.
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Affiliation(s)
- David Kästner
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307, Dresden, Germany.
| | - Anja Braune
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Claudia Brogsitter
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Robert Freudenberg
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Jörg Kotzerke
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307, Dresden, Germany
- Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Enrico Michler
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307, Dresden, Germany
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Collette B, Mannie-Corbisier M, Bucalau AM, Pauly N, Verset G, Moreno-Reyes R, Flamen P, Trotta N. Impact of scatter correction on personalized dosimetry in selective internal radiotherapy using 166Ho-PLLA: a single-center study including Monte-Carlo simulation, phantom and patient imaging. EJNMMI Phys 2024; 11:33. [PMID: 38564100 PMCID: PMC10987418 DOI: 10.1186/s40658-024-00639-x] [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: 11/16/2023] [Accepted: 03/28/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Developments in transarterial radioembolization led to the conception of new microspheres loaded with holmium-166 (166Ho). However, due to the complexity of the scatter components in 166Ho single photon emission computed tomography (SPECT), questions about image quality and dosimetry are emerging. The aims of this work are to investigate the scatter components and correction methods to propose a suitable solution, and to evaluate the impact on image quality and dosimetry including Monte-Carlo (MC) simulations, phantom, and patient data. METHODS Dual energy window (DEW) and triple energy window (TEW) methods were investigated for scatter correction purposes and compared using Contrast Recovery Coefficients (CRC) and Contrast to Noise Ratios (CNR). First, MC simulations were carried out to assess all the scatter components in the energy windows used, also to confirm the choice of the parameter needed for the DEW method. Then, MC simulations of acquisitions of a Jaszczak phantom were conducted with conditions mimicking an ideal scatter correction. These simulated projections can be reconstructed and compared with real acquisitions corrected by both methods and then reconstructed. Finally, both methods were applied on patient data and their impact on personalized dosimetry was evaluated. RESULTS MC simulations confirmed the use of k = 1 for the DEW method. These simulations also confirmed the complexity of scatter components in the main energy window used with a high energy gamma rays component of about half of the total counts detected, together with a negligible X rays component and a negligible presence of fluorescence. CRC and CNR analyses, realized on simulated scatter-free projections of the phantom and on scatter corrected acquisitions of the same phantom, suggested an increased efficiency of the TEW method, even at the price of higher level of noise. Finally, these methods, applied on patient data, showed significant differences in terms of non-tumoral liver absorbed dose, non-tumoral liver fraction under 50 Gy, tumor absorbed dose, and tumor fraction above 150 Gy. CONCLUSIONS This study demonstrated the impact of scatter correction on personalized dosimetry on patient data. The use of a TEW method is proposed for scatter correction in 166Ho SPECT imaging.
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Affiliation(s)
- Benoît Collette
- Department of Nuclear Medicine, Hôpital Universitaire de Bruxelles (HUB), Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Brussels, Belgium.
- Laboratory of Image Synthesis and Analysis, Brussels School of Engineering, Université Libre de Bruxelles (ULB), Brussels, Belgium.
| | - Marie Mannie-Corbisier
- Department of Nuclear Metrology, Brussels School of Engineering, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Ana-Maria Bucalau
- Department of Gastroenterolgy, Hepatopancreatology and Digestive Oncology, Hôpital Universitaire de Bruxelles (HUB), Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Nicolas Pauly
- Department of Nuclear Metrology, Brussels School of Engineering, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Gontran Verset
- Department of Gastroenterolgy, Hepatopancreatology and Digestive Oncology, Hôpital Universitaire de Bruxelles (HUB), Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Rodrigo Moreno-Reyes
- Department of Nuclear Medicine, Hôpital Universitaire de Bruxelles (HUB), Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Brussels, Belgium
| | - Patrick Flamen
- Department of Nuclear Medicine, Hôpital Universitaire de Bruxelles (HUB), Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Brussels, Belgium
| | - Nicola Trotta
- Department of Nuclear Medicine, Hôpital Universitaire de Bruxelles (HUB), Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Brussels, Belgium
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Morsink NC, Nijsen JFW, Grinwis GCM, Hesselink JW, Kirpensteijn J, van Nimwegen SA. Intratumoral injection of holmium-166 microspheres as neoadjuvant therapy of soft tissue sarcomas in dogs. Front Vet Sci 2022; 9:1015248. [PMID: 36387397 PMCID: PMC9664058 DOI: 10.3389/fvets.2022.1015248] [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: 08/09/2022] [Accepted: 10/10/2022] [Indexed: 01/24/2023] Open
Abstract
INTRODUCTION Minimally invasive microbrachytherapy is in development to treat solid tumors by intratumoral injection of (radioactive) holmium-166 (166Ho) microspheres (MS). A high local dose can be administered with minimal damage to surrounding tissue because of the short soft tissue penetration depth of 166Ho beta radiation. We aimed to prospectively evaluate the safety and efficacy of 166Ho microbrachytherapy in client-owned canine patients with soft tissue sarcomas (STS). METHODS We included seven dogs with STS not suitable for local excision due to tumor size and/or location. 166HoMS were suspended in a carrier fluid and multiple needle-injections were performed in predetermined tumor segments to maximize tumor coverage. Tumor response was evaluated using 3D caliper and CT measurements. Follow-up further included monitoring for potential side effects and registration of subsequent treatments and survival, until at least two years after treatment. RESULTS Delivered radioactive doses ranged from 70 to 969 Gy resulting in a mean tumor volume reduction of 49.0 ± 21.3% after 33 ± 25 days. Treatment-related side effects consisted of local necrosis (n = 1) and ulceration of the skin covering the tumor (n = 1), which resolved with basic wound care, and surgical excision of residual tumor, respectively. Residual tumor was surgically resected in six patients after 22-93 days. After a mean follow-up of 1,005 days, four patients were alive, two patients were euthanized because of unrelated causes, and one patient was euthanized because of disease progression after the owner(s) declined subsequent surgical treatment. CONCLUSION 166Ho microbrachytherapy was a safe and effective neoadjuvant treatment option for canine patients with STS.
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Affiliation(s)
- Nino Chiron Morsink
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands,*Correspondence: Nino Chiron Morsink
| | - Johannes Frank Wilhelmus Nijsen
- Department of Medical Imaging, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Jan Willem Hesselink
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Jolle Kirpensteijn
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
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de Vries M, Klaassen NJM, Morsink NC, van Nimwegen SA, Nijsen JFW, van den Dobbelsteen JJ. Dedicated holmium microsphere administration device for MRI-guided interstitial brain microbrachytherapy. Med Eng Phys 2021; 96:13-21. [PMID: 34565548 DOI: 10.1016/j.medengphy.2021.07.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 07/15/2021] [Accepted: 07/21/2021] [Indexed: 01/22/2023]
Abstract
Microbrachytherapy with radioactive holmium-166 (166Ho) microspheres (MS) has the potential to be an effective treatment method for brain malignancies. Direct intratumoural delivery of 166Ho-MS and dose coverage of the whole tumour are crucial requirements. However, currently no dedicated instruments for controlled intratumoural delivery exist. This study presents an administration device that facilitates this novel magnetic resonance imaging (MRI) -guided intervention. The bioceramic alumina oxide cannula creates a straight channel for a superelastic nitinol precurved stylet to control spatial deposition of Ho-MS. End-point accuracy of the stylet was measured during insertions in phantoms. Imaging tests were performed in a 3 Tesla MRI-scanner to quantify instrument-induced artefacts. Additionally, the feasibility of non-radioactive holmium-165 (165Ho)-MS delivery with the administration device was evaluated in a brain tumour simulant. Absolute stylet tip error was 0.88 ± 0.61 mm, instrument distortion in MRI depended on needle material and orientation and dose delivery of 165Ho-MS in a brain tumour phantom was possible. This study shows that the administration device can accurately place the stylet for injection of Ho-MS and that visualization can be performed with MRI.
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Affiliation(s)
- M de Vries
- Department of BioMechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Mekelweg 2, Delft 2628 CD, the Netherlands.
| | - N J M Klaassen
- Department of Medical Imaging, Radboud Institute for Health Sciences, Radboud university Medical Center, Geert Grooteplein Zuid 10, Nijmegen 6525 GA, the Netherlands
| | - N C Morsink
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, Utrecht 3508 TD, the Netherlands
| | - S A van Nimwegen
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, Utrecht 3508 TD, the Netherlands
| | - J F W Nijsen
- Department of Medical Imaging, Radboud Institute for Health Sciences, Radboud university Medical Center, Geert Grooteplein Zuid 10, Nijmegen 6525 GA, the Netherlands; Quirem Medical B.V., Zutphenseweg 55, Deventer 7418 AH, the Netherlands
| | - J J van den Dobbelsteen
- Department of BioMechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Mekelweg 2, Delft 2628 CD, the Netherlands
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Ramonaheng K, van Staden JA, du Raan H. The effect of calibration factors and recovery coefficients on 177Lu SPECT activity quantification accuracy: a Monte Carlo study. EJNMMI Phys 2021; 8:27. [PMID: 33738605 PMCID: PMC7973313 DOI: 10.1186/s40658-021-00365-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 02/08/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Different gamma camera calibration factor (CF) geometries have been proposed to convert SPECT data into units of activity concentration. However, no consensus has been reached on a standardised geometry. The CF is dependent on the selected geometry and is further affected by partial volume effects. This study investigated the effect of two CF geometries and their corresponding recovery coefficients (RCs) on the quantification accuracy of 177Lu SPECT images using Monte Carlo simulations. METHODS The CF geometries investigated were (i) a radioactive-sphere surrounded by non-radioactive water (sphere-CF) and (ii) a cylindrical phantom uniformly filled with radioactive water (cylinder-CF). Recovery coefficients were obtained using the sphere-CF and cylinder-CF, yielding the sphere-RC and cylinder-RC values, respectively, for partial volume correction (PVC). The quantification accuracy was evaluated using four different-sized spheres (15.6-65.4 ml) and a kidney model with known activity concentrations inside a cylindrical, torso and patient phantom. Images were reconstructed with the 3D OS-EM algorithm incorporating attenuation, scatter and detector-response corrections. Segmentation was performed using the physical size and a small cylindrical volume inside the cylinder for the sphere-CF and cylinder-CF, respectively. RESULTS The sphere quantification error (without PVC) was better for the sphere-CF (≤ - 5.54%) compared to the cylinder-CF (≤ - 20.90%), attributed to the similar geometry of the quantified and CF spheres. Partial volume correction yielded comparable results for the sphere-CF-RC (≤ 3.47%) and cylinder-CF-RC (≤ 3.53%). The accuracy of the kidney quantification was poorer (≤ 22.34%) for the sphere-CF without PVC compared to the cylinder-CF (≤ 2.44%). With PVC, the kidney quantification results improved and compared well for the sphere-CF-RC (≤ 3.50%) and the cylinder-CF-RC (≤ 3.45%). CONCLUSION The study demonstrated that upon careful selection of CF-RC combinations, comparable quantification errors (≤ 3.53%) were obtained between the sphere-CF-RC and cylinder-CF-RC, when all corrections were applied.
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Affiliation(s)
- Keamogetswe Ramonaheng
- Department of Medical Physics, Faculty of Health Sciences, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa.
| | - Johannes A van Staden
- Department of Medical Physics, Faculty of Health Sciences, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa
| | - Hanlie du Raan
- Department of Medical Physics, Faculty of Health Sciences, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa
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Stella M, Braat AJAT, Lam MGEH, de Jong HWAM, van Rooij R. Gamma camera characterization at high holmium-166 activity in liver radioembolization. EJNMMI Phys 2021; 8:22. [PMID: 33651253 PMCID: PMC7925770 DOI: 10.1186/s40658-021-00372-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 02/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND High activities of holmium-166 (166Ho)-labeled microspheres are used for therapeutic radioembolization, ideally directly followed by SPECT imaging for dosimetry purposes. The resulting high-count rate potentially impacts dead time, affecting the image quality and dosimetric accuracy. This study assesses gamma camera performance and SPECT image quality at high 166Ho activities of several GBq. To this purpose, the liver compartment, including two tumors, of an anthropomorphic phantom was filled with 166Ho-chloride, with a tumor to non-tumorous liver activity concentration ratio of 10:1. Multiple SPECT/CT scans were acquired over a range of activities up to 2.7 GBq. Images were reconstructed using a commercially available protocol incorporating attenuation and scatter correction. Dead time effects were assessed from the observed count rate in the photopeak (81 keV, 15% width) and upper scatter (118 keV, 12% width) window. Post reconstruction, each image was scaled with an individual conversion factor to match the known total activity in the phantom at scanning time. The resulting activity concentration was measured in the tumors and non-tumorous liver. The image quality as a function of activity was assessed by a visual check of the absence of artifacts by a nuclear medicine physician. The apparent lung shunt fraction (nonzero due to scatter) was estimated on planar and SPECT images. RESULTS A 20% count loss due to dead time was observed around 0.7 GBq in the photopeak window. Independent of the count losses, the measured activity concentration was up to 100% of the real value for non-tumorous liver, when reconstructions were normalized to the known activity at scanning time. However, for tumor spheres, activity concentration recovery was ~80% at the lowest activity, decreasing with increasing activity in the phantom. Measured lung shunt fractions were relatively constant over the considered activity range. CONCLUSIONS At high 166Ho count rate, all images, visually assessed, presented no artifacts, even at considerable dead time losses. A quantitative evaluation revealed the possibility of reliable dosimetry within the healthy liver, as long as a post-reconstruction scaling to scanning activity is applied. Reliable tumor dosimetry, instead, remained hampered by the dead time.
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Affiliation(s)
- Martina Stella
- Department of Radiology and Nuclear Medicine, UMC Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
| | - Arthur J A T Braat
- Department of Radiology and Nuclear Medicine, UMC Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Marnix G E H Lam
- Department of Radiology and Nuclear Medicine, UMC Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Hugo W A M de Jong
- Department of Radiology and Nuclear Medicine, UMC Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Rob van Rooij
- Department of Radiology and Nuclear Medicine, UMC Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
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Stella M, Braat A, Lam M, de Jong H, van Rooij R. Quantitative 166Ho-microspheres SPECT derived from a dual-isotope acquisition with 99mTc-colloid is clinically feasible. EJNMMI Phys 2020; 7:48. [PMID: 32666401 PMCID: PMC7359973 DOI: 10.1186/s40658-020-00317-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 07/03/2020] [Indexed: 11/19/2022] Open
Abstract
Purpose Accurate dosimetry is essential in radioembolization. To this purpose, an automatic protocol for healthy liver dosimetry based on dual isotope (DI) SPECT imaging, combining holmium-166 (166Ho)-microspheres, and technetium-99 m (99mTc)-colloid was developed: 166Ho-microspheres used as scout and therapeutic particles, and 99mTc-colloid to identify the healthy liver. DI SPECT allows for an automatic and accurate estimation of absorbed doses, introducing true personalized dosimetry. However, photon crosstalk between isotopes can compromise image quality. This study investigates the effect of 99mTc downscatter on 166Ho dosimetry, by comparing 166Ho-SPECT reconstructions of patient scans acquired before (166Ho-only) and after additional administration of 99mTc-colloid (166Ho-DI). Methods The 166Ho-only and 166Ho-DI scans were performed in short succession by injecting 99mTc-colloid on the scanner table. To compensate for 99mTc downscatter, its influence was accounted for in the DI image reconstruction using energy window-based scatter correction methods. The qualitative assessment was performed by independent blinded comparison by two nuclear medicine physicians assessing 65 pairs of SPECT/CT. Inter-observer agreement was tested by Cohen’s kappa coefficient. For the quantitative analysis, two volumes of interest within the liver, VOITUMOR, and VOIHEALTHY were manually delineated on the 166Ho-only reconstruction and transferred to the co-registered 166Ho-DI reconstruction. Absorbed dose within the resulting VOIs, and in the lungs (VOILUNGS), was calculated based on the administered therapeutic activity. Results The qualitative assessment showed no distinct clinical preference for either 166Ho-only or 166Ho-DI SPECT (kappa = 0.093). Quantitative analysis indicated that the mean absorbed dose difference between 166Ho-DI and 166Ho-only was − 2.00 ± 2.84 Gy (median 27 Gy; p value < 0.00001), − 5.27 ± 8.99 Gy (median 116 Gy; p value = 0.00035), and 0.80 ± 1.08 Gy (median 3 Gy; p value < 0.00001) for VOIHEALTHY, VOITUMOR, and VOILUNGS, respectively. The corresponding Pearson’s correlation coefficient between 166Ho-only and 166Ho-DI for absorbed dose was 0.97, 0.99, and 0.82, respectively. Conclusion The DI protocol enables automatic dosimetry with undiminished image quality and accuracy. Clinical trials The clinical study mentioned is registered with Clinicaltrials.gov (NCT02067988) on 20 February 2014.
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Affiliation(s)
- M Stella
- Department of Radiology and Nuclear Medicine, University Medical Center, Utrecht, Heidelberglaan 100, 3584, CX, Utrecht, The Netherlands.
| | - Ajat Braat
- Department of Radiology and Nuclear Medicine, University Medical Center, Utrecht, Heidelberglaan 100, 3584, CX, Utrecht, The Netherlands
| | - Mgeh Lam
- Department of Radiology and Nuclear Medicine, University Medical Center, Utrecht, Heidelberglaan 100, 3584, CX, Utrecht, The Netherlands
| | - Hwam de Jong
- Department of Radiology and Nuclear Medicine, University Medical Center, Utrecht, Heidelberglaan 100, 3584, CX, Utrecht, The Netherlands
| | - R van Rooij
- Department of Radiology and Nuclear Medicine, University Medical Center, Utrecht, Heidelberglaan 100, 3584, CX, Utrecht, The Netherlands
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Ramonaheng K, van Staden JA, du Raan H. Validation of a Monte Carlo modelled gamma camera for Lutetium-177 imaging. Appl Radiat Isot 2020; 163:109200. [PMID: 32561041 DOI: 10.1016/j.apradiso.2020.109200] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 02/11/2020] [Accepted: 04/08/2020] [Indexed: 10/24/2022]
Abstract
This study validated a model of the Siemens Symbia T16 dual-head SPECT/CT gamma camera created using the Monte Carlo program SIMIND for 177Lu. The validation was done by comparing experimental and simulated gamma camera performance criteria tests for the 177Lu 208 keV photopeak with a medium-energy collimator. Results showed good agreement between the experimental and simulated values. These results illustrated that SIMIND could emulate the Symbia T16 successfully and therefore, can be used with confidence to model 177Lu images.
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Affiliation(s)
- K Ramonaheng
- Department of Medical Physics, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa.
| | - J A van Staden
- Department of Medical Physics, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa
| | - H du Raan
- Department of Medical Physics, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa
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Brady SL, Shulkin BL. Analysis of quantitative [I-123] mIBG SPECT/CT in a phantom and in patients with neuroblastoma. EJNMMI Phys 2019; 6:31. [PMID: 31889238 PMCID: PMC6937351 DOI: 10.1186/s40658-019-0267-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 12/02/2019] [Indexed: 11/13/2022] Open
Abstract
Purpose To determine the accuracy of quantitative SPECT, intersystem and interpatient standardized uptake value (SUV) calculation consistency for a manufacturer-independent quantitative SPECT/CT reconstruction algorithm, and the range of SUVs of normal and neoplastic tissue. Methods A NEMA body phantom with 6 spheres (ranging 10–37 mm) was filled with a known activity-to-volume ratio and used to determine the contrast recovery coefficient (CRC) for each visible sphere, and the measured SUV accuracy of those spheres and background water solution. One hundred eleven 123I-metaiodobenzylguanidine ([I-123] mIBG) SPECT/CT examinations from 43 patients were reconstructed using SUV SPECT® (HERMES Medical Solutions Inc.); 42 examinations were acquired using a GE Infinia Hawkeye 4 SPECT/CT, and 69 were acquired on a Siemens Symbia Intevo SPECT/CT. Inter scanner SUV analysis of 9 regions of normal [I-123] mIBG tissue uptake was conducted. Intrapatient mean SUV variability was calculated by measuring normal liver uptake within patients scanned on both cameras. The intensity of uptake by neoplastic tissue in the images was quantified using maximum SUV and, if present, compared over time. Results The phantom results of the visible spheres and background resulted in accuracy calculations better than 5–10% with CRC correction. Interscanner SUV variability showed no statistical difference (average p value 0.559; range 0.066–1.0) among the 9 normal tissues analyzed. Intrapatient liver mean SUV varied ≤ 16% as calculated for 28 patients (87 examinations) studied on both scanners. In one patient, a thoracic tumor evaluated over 10 time points (18 months) underwent a 74% (3.1/12.0) reduction in maximum SUV with treatment. Conclusion The results demonstrate quantitative accuracy to better than 10%, and both consistent SUV calculation between 2 different SPECT/CT scanners for 9 tissues, and low intrapatient measurement variability for quantitative SPECT/CT analysis in a pediatric population with neuroblastoma. Quantitative SPECT/CT offers the opportunity for objective analysis of tumor response using [I-123] mIBG by normalizing the uptake to injected dose and patient weight, as is done for PET.
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Affiliation(s)
- Samuel L Brady
- Department of Radiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH, 45229, USA
| | - Barry L Shulkin
- Department of Diagnostic Imaging MS 220, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-3678, USA.
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Bastiaannet R, Kappadath SC, Kunnen B, Braat AJAT, Lam MGEH, de Jong HWAM. The physics of radioembolization. EJNMMI Phys 2018; 5:22. [PMID: 30386924 PMCID: PMC6212377 DOI: 10.1186/s40658-018-0221-z] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 06/19/2018] [Indexed: 12/11/2022] Open
Abstract
Radioembolization is an established treatment for chemoresistant and unresectable liver cancers. Currently, treatment planning is often based on semi-empirical methods, which yield acceptable toxicity profiles and have enabled the large-scale application in a palliative setting. However, recently, five large randomized controlled trials using resin microspheres failed to demonstrate a significant improvement in either progression-free survival or overall survival in both hepatocellular carcinoma and metastatic colorectal cancer. One reason for this might be that the activity prescription methods used in these studies are suboptimal for many patients.In this review, the current dosimetric methods and their caveats are evaluated. Furthermore, the current state-of-the-art of image-guided dosimetry and advanced radiobiological modeling is reviewed from a physics' perspective. The current literature is explored for the observation of robust dose-response relationships followed by an overview of recent advancements in quantitative image reconstruction in relation to image-guided dosimetry.This review is concluded with a discussion on areas where further research is necessary in order to arrive at a personalized treatment method that provides optimal tumor control and is clinically feasible.
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Affiliation(s)
- Remco Bastiaannet
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Room E01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - S. Cheenu Kappadath
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, 1155 Pressler St, Unit 1352, Houston, TX 77030 USA
| | - Britt Kunnen
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Room E01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Arthur J. A. T. Braat
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Room E01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Marnix G. E. H. Lam
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Room E01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Hugo W. A. M. de Jong
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Room E01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
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Determination of gamma camera calibration factors for quantitation of therapeutic radioisotopes. EJNMMI Phys 2018; 5:8. [PMID: 29717385 PMCID: PMC5930296 DOI: 10.1186/s40658-018-0208-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 02/23/2018] [Indexed: 01/23/2023] Open
Abstract
Background Camera calibration, which translates reconstructed count map into absolute activity map, is a prerequisite procedure for quantitative SPECT imaging. Both planar and tomographic scans using different phantom geometries have been proposed for the determination of the camera calibration factor (CF). However, there is no consensus on which approach is the best. The aim of this study is to evaluate all these calibration methods, compare their performance, and propose a practical and accurate calibration method for SPECT quantitation of therapeutic radioisotopes. Twenty-one phantom experiments (Siemens Symbia SPECT/CT) and 12 Monte Carlo simulations (GATE v6.1) using three therapy isotopes (131I, 177Lu, and 188Re) have been performed. The following phantom geometries were used: (1) planar scans of point source in air (PS), (2) tomographic scans of insert(s) filled with activity placed in non-radioactive water (HS + CB), (3) tomographic scans of hot insert(s) in radioactive water (HS + WB), and (4) tomographic scans of cylinders uniformly filled with activity (HC). Tomographic data were reconstructed using OSEM with CT-based attenuation correction and triple energy window (TEW) scatter correction, and CF was determined using total counts in the reconstructed image, while for planar scans, the photopeak counts, corrected for scatter and background with TEW, were used. Additionally, for simulated data, CF obtained from primary photons only was analyzed. Results For phantom experiments, CF obtained from PS and HS + WB agreed to within 6% (below 3% if experiments performed on the same day are considered). However, CF from HS + CB exceeded those from PS by 4–12%. Similar trend was found in simulation studies. Analysis of CFs from primary photons helped us to understand this discrepancy. It was due to underestimation of scatter by the TEW method, further enhanced by attenuation correction. This effect becomes less important when the source is distributed over the entire phantom volume (HS + WB and HC). Conclusions Camera CF could be determined using planar scans of a point source, provided that the scatter and background contributions are removed, for example using the clinically available TEW method. This approach is simple and yet provides CF with sufficient accuracy (~ 5%) to be used in clinics for radiotracer quantification.
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Shi L, Vedantham S, Karellas A, Zhu L. X-ray scatter correction for dedicated cone beam breast CT using a forward-projection model. Med Phys 2017; 44:2312-2320. [PMID: 28295375 DOI: 10.1002/mp.12213] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 01/25/2017] [Accepted: 03/07/2017] [Indexed: 12/25/2022] Open
Abstract
PURPOSE The quality of dedicated cone-beam breast CT (CBBCT) imaging is fundamentally limited by x-ray scatter contamination due to the large irradiation volume. In this paper, we propose a scatter correction method for CBBCT using a novel forward-projection model with high correction efficacy and reliability. METHOD We first coarsely segment the uncorrected, first-pass, reconstructed CBBCT images into binary-object maps and assign the segmented fibroglandular and adipose tissue with the correct attenuation coefficients based on the mean x-ray energy. The modified CBBCT are treated as the prior images toward scatter correction. Primary signals are first estimated via forward projection on the modified CBBCT. To avoid errors caused by inaccurate segmentation, only sparse samples of estimated primary are selected for scatter estimation. A Fourier-Transform based algorithm, herein referred to as local filtration hereafter, is developed to efficiently estimate the global scatter distribution on the detector. The scatter-corrected images are obtained by removing the estimated scatter distribution from measured projection data. RESULTS We evaluate the method performance on six patients with different breast sizes and shapes representing the general population. The results show that the proposed method effectively reduces the image spatial non-uniformity from 8.27 to 1.91% for coronal views and from 6.50 to 3.00% for sagittal views. The contrast-to-deviation ratio is improved by an average factor of 1.41. Comparisons on the image details reveal that the proposed scatter correction successfully preserves fine structures of fibroglandular tissues that are lost in the segmentation process. CONCLUSION We propose a highly practical and efficient scatter correction algorithm for CBBCT via a forward-projection model. The method is attractive in clinical CBBCT imaging as it is readily implementable on a clinical system without modifications in current imaging protocols or system hardware.
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Affiliation(s)
- Linxi Shi
- Nuclear and Radiological Engineering and Medical Physics Programs, The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Srinivasan Vedantham
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
| | - Andrew Karellas
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
| | - Lei Zhu
- Nuclear and Radiological Engineering and Medical Physics Programs, The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.,Department of Modern Physics, School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China
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Gamma camera calibration and validation for quantitative SPECT imaging with 177Lu. Appl Radiat Isot 2016; 112:156-64. [DOI: 10.1016/j.apradiso.2016.03.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 02/09/2016] [Accepted: 03/07/2016] [Indexed: 11/21/2022]
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Prince JF, van Rooij R, Bol GH, de Jong HWAM, van den Bosch MAAJ, Lam MGEH. Safety of a Scout Dose Preceding Hepatic Radioembolization with 166Ho Microspheres. J Nucl Med 2015; 56:817-23. [PMID: 25931477 DOI: 10.2967/jnumed.115.155564] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 04/15/2015] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Before (166)Ho radioembolization, a small batch of the same type of microspheres is administered as a scout dose instead of the conventional (99m)Tc-macroaggregated albumin ((99m)Tc-MAA). The (166)Ho scout dose provides a more accurate and precise lung shunt assessment. However, in contrast to (99m)Tc-MAA, an unintended extrahepatic deposition of this β-emitting scout dose could inflict radiation damage, the extent of which we aimed to quantify in this study. METHODS All patients eligible for radioembolization in our institute between January 2011 and March 2014 were reviewed. Of the extrahepatic depositions of (99m)Tc-MAA on SPECT, the amount and volume were measured. These were used to calculate the theoretic absorbed dose in the case a (166)Ho scout dose had been used. The extrahepatic activity was measured as the sum of all voxels of the deposition. Volumes were measured using a threshold technique including all voxels from the maximum voxel intensity up to a certain percentage. The threshold needed to obtain the true volume was studied in a phantom study. RESULTS In the phantom study, a threshold of 40% was found to overestimate the volume, with the consequence of underestimating the absorbed dose. Of 160 patients, 32 patients (34 cases) of extrahepatic deposition were identified. The depositions contained a median of 1.3% (range, 0.1%-19.5%) of the administered activity in a median volume of 6.8 mL (range, 1.1-42 mL). The use of a scout dose of 250 MBq of (166)Ho microspheres in these cases would theoretically have resulted in a median absorbed dose of 6.0 Gy (range, 0.9-374 Gy). The dose exceeded a limit of 49 Gy (reported in 2013) in 2 of 34 cases (5.9%; 95% confidence interval, 0.7%-20.1%) or 2 of 160 (1.3%; 95% confidence interval, 0.1%-4.7%) of all patients. In these 2 patients with a large absorbed dose (112 and 374 Gy), the culprit vessel was identified in 1 case. CONCLUSION Extrahepatic deposition of a (166)Ho scout dose seems to be theoretically safe in most patients. Its safety in clinical practice is being evaluated in ongoing clinical trials.
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Affiliation(s)
- Jip F Prince
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Rob van Rooij
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Gijsbert H Bol
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Hugo W A M de Jong
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Marnix G E H Lam
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
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Ao ECI, Wu NY, Wang SJ, Song N, Mok GSP. Improved dosimetry for targeted radionuclide therapy using nonrigid registration on sequential SPECT images. Med Phys 2015; 42:1060-70. [DOI: 10.1118/1.4906242] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Elschot M, Smits MLJ, Nijsen JFW, Lam MGEH, Zonnenberg BA, van den Bosch MAAJ, Viergever MA, de Jong HWAM. Quantitative Monte Carlo-based holmium-166 SPECT reconstruction. Med Phys 2014; 40:112502. [PMID: 24320461 DOI: 10.1118/1.4823788] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Quantitative imaging of the radionuclide distribution is of increasing interest for microsphere radioembolization (RE) of liver malignancies, to aid treatment planning and dosimetry. For this purpose, holmium-166 ((166)Ho) microspheres have been developed, which can be visualized with a gamma camera. The objective of this work is to develop and evaluate a new reconstruction method for quantitative (166)Ho SPECT, including Monte Carlo-based modeling of photon contributions from the full energy spectrum. METHODS A fast Monte Carlo (MC) simulator was developed for simulation of (166)Ho projection images and incorporated in a statistical reconstruction algorithm (SPECT-fMC). Photon scatter and attenuation for all photons sampled from the full (166)Ho energy spectrum were modeled during reconstruction by Monte Carlo simulations. The energy- and distance-dependent collimator-detector response was modeled using precalculated convolution kernels. Phantom experiments were performed to quantitatively evaluate image contrast, image noise, count errors, and activity recovery coefficients (ARCs) of SPECT-fMC in comparison with those of an energy window-based method for correction of down-scattered high-energy photons (SPECT-DSW) and a previously presented hybrid method that combines MC simulation of photopeak scatter with energy window-based estimation of down-scattered high-energy contributions (SPECT-ppMC+DSW). Additionally, the impact of SPECT-fMC on whole-body recovered activities (A(est)) and estimated radiation absorbed doses was evaluated using clinical SPECT data of six (166)Ho RE patients. RESULTS At the same noise level, SPECT-fMC images showed substantially higher contrast than SPECT-DSW and SPECT-ppMC+DSW in spheres ≥ 17 mm in diameter. The count error was reduced from 29% (SPECT-DSW) and 25% (SPECT-ppMC+DSW) to 12% (SPECT-fMC). ARCs in five spherical volumes of 1.96-106.21 ml were improved from 32%-63% (SPECT-DSW) and 50%-80% (SPECT-ppMC+DSW) to 76%-103% (SPECT-fMC). Furthermore, SPECT-fMC recovered whole-body activities were most accurate (A(est) = 1.06 × A - 5.90 MBq, R(2) = 0.97) and SPECT-fMC tumor absorbed doses were significantly higher than with SPECT-DSW (p = 0.031) and SPECT-ppMC+DSW (p = 0.031). CONCLUSIONS The quantitative accuracy of (166)Ho SPECT is improved by Monte Carlo-based modeling of the image degrading factors. Consequently, the proposed reconstruction method enables accurate estimation of the radiation absorbed dose in clinical practice.
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Affiliation(s)
- Mattijs Elschot
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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Elschot M, Nijsen JFW, Lam MGEH, Smits MLJ, Prince JF, Viergever MA, van den Bosch MAAJ, Zonnenberg BA, de Jong HWAM. (⁹⁹m)Tc-MAA overestimates the absorbed dose to the lungs in radioembolization: a quantitative evaluation in patients treated with ¹⁶⁶Ho-microspheres. Eur J Nucl Med Mol Imaging 2014; 41:1965-75. [PMID: 24819055 DOI: 10.1007/s00259-014-2784-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 04/15/2014] [Indexed: 01/19/2023]
Abstract
PURPOSE Radiation pneumonitis is a rare but serious complication of radioembolic therapy of liver tumours. Estimation of the mean absorbed dose to the lungs based on pretreatment diagnostic (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) imaging should prevent this, with administered activities adjusted accordingly. The accuracy of (99m)Tc-MAA-based lung absorbed dose estimates was evaluated and compared to absorbed dose estimates based on pretreatment diagnostic (166)Ho-microsphere imaging and to the actual lung absorbed doses after (166)Ho radioembolization. METHODS This prospective clinical study included 14 patients with chemorefractory, unresectable liver metastases treated with (166)Ho radioembolization. (99m)Tc-MAA-based and (166)Ho-microsphere-based estimation of lung absorbed doses was performed on pretreatment diagnostic planar scintigraphic and SPECT/CT images. The clinical analysis was preceded by an anthropomorphic torso phantom study with simulated lung shunt fractions of 0 to 30 % to determine the accuracy of the image-based lung absorbed dose estimates after (166)Ho radioembolization. RESULTS In the phantom study, (166)Ho SPECT/CT-based lung absorbed dose estimates were more accurate (absolute error range 0.1 to -4.4 Gy) than (166)Ho planar scintigraphy-based lung absorbed dose estimates (absolute error range 9.5 to 12.1 Gy). Clinically, the actual median lung absorbed dose was 0.02 Gy (range 0.0 to 0.7 Gy) based on posttreatment (166)Ho-microsphere SPECT/CT imaging. Lung absorbed doses estimated on the basis of pretreatment diagnostic (166)Ho-microsphere SPECT/CT imaging (median 0.02 Gy, range 0.0 to 0.4 Gy) were significantly better predictors of the actual lung absorbed doses than doses estimated on the basis of (166)Ho-microsphere planar scintigraphy (median 10.4 Gy, range 4.0 to 17.3 Gy; p < 0.001), (99m)Tc-MAA SPECT/CT imaging (median 2.5 Gy, range 1.2 to 12.3 Gy; p < 0.001), and (99m)Tc-MAA planar scintigraphy (median 5.5 Gy, range 2.3 to 18.2 Gy; p < 0.001). CONCLUSION In clinical practice, lung absorbed doses are significantly overestimated by pretreatment diagnostic (99m)Tc-MAA imaging. Pretreatment diagnostic (166)Ho-microsphere SPECT/CT imaging accurately predicts lung absorbed doses after (166)Ho radioembolization.
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Affiliation(s)
- Mattijs Elschot
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
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van den Hoven AF, Smits MLJ, Rosenbaum CENM, Verkooijen HM, van den Bosch MAAJ, Lam MGEH. The effect of intra-arterial angiotensin II on the hepatic tumor to non-tumor blood flow ratio for radioembolization: a systematic review. PLoS One 2014; 9:e86394. [PMID: 24466071 PMCID: PMC3895031 DOI: 10.1371/journal.pone.0086394] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 12/06/2013] [Indexed: 12/23/2022] Open
Abstract
PURPOSE Treatment efficacy of intra-arterial radioembolization for liver tumors depends on the selective targeting of tumorous tissue. Recent investigations have demonstrated that tumors may receive inadequate doses of radioactivity after radioembolization, due to unfavorable tumor to non-tumor (T/N) uptake ratios of radioactive microspheres. Hepatic arterial infusion of the vasoconstrictor angiotensin II (AT-II) is reported to increase the T/N blood flow ratio. The purpose of this systematic review was to provide a comprehensive overview of the effect of hepatic arterial AT-II on T/N blood flow ratio in patients with hepatic malignancies, and determine its clinical value for radioembolization. METHODS This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A structured search was performed in the PubMed, EMBASE and Cochrane databases. Only studies that presented data on T/N ratios before and after infusion of AT-II into the hepatic artery, in human patients with hepatic malignancies, were selected. Median T/N ratios before, during and after AT-II infusion, and the median T/N ratio improvement factor were extracted from the selected articles. All data on systemic blood pressure measurements and clinical symptoms were also extracted. RESULTS The search identified 524 titles of which 5 studies, including a total of 71 patients were considered relevant. Median T/N ratios before infusion of AT-II ranged from 0.4 to 3.4. All studies observed a substantial improvement of the T/N ratio after AT-II infusion, with median improvement factors ranging from 1.8 to 3.1. A transitory increase of systemic blood pressure was observed during AT-II infusion. CONCLUSIONS Infusion of AT-II into the hepatic artery leads to an increase of the tumor to non-tumor blood flow ratio, as measured by T/N uptake ratios. Clinical trials are warranted to assess safety aspects, optimal administration strategy and impact on treatment efficacy during radioembolization.
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Affiliation(s)
- Andor F. van den Hoven
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maarten L. J. Smits
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Helena M. Verkooijen
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Marnix G. E. H. Lam
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
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Vente MAD, Zonnenberg BA, Nijsen JFW. Microspheres for radioembolization of liver malignancies. Expert Rev Med Devices 2014; 7:581-3. [DOI: 10.1586/erd.10.48] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Shcherbinin S, Grimes J, Bator A, Cwikla JB, Celler A. Three-dimensional personalized dosimetry for 188Re liver selective internal radiation therapy based on quantitative post-treatment SPECT studies. Phys Med Biol 2013; 59:119-134. [PMID: 24334821 DOI: 10.1088/0031-9155/59/1/119] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We demonstrate that accurate patient-specific distributions of microspheres labeled with 188Re and resulting absorbed doses can be obtained from single-photon emission computed tomography (SPECT) studies performed after 188Re selective internal radiation therapy when accurate correction methods are employed in image reconstruction. Our quantitative image reconstruction algorithm includes corrections for attenuation, resolution degradations and scatter as well as a window-based compensation for contamination. The procedure has been validated using four phantom experiments containing an 18 ml cylindrical source (82-93 MBq of 188Re activity) simulating a liver tumor. In addition, we applied our approach to post-therapy SPECT studies of ten patients with progressive primary or metastatic liver carcinomas. Our quantitative algorithm accurately (within 9%) recovered 188Re activity from four phantom experiments. In addition, for two patients that received three scans, deviations remained consistent between the measured and the reconstructed activities that were determined from studies with differing severity of the dead-time effect. The analysis of absorbed doses for patient studies allowed us to hypothesize that D90 (the minimum dose received by 90% of the tumor volume) may be a reliable metric relating therapy outcomes to the calculated doses. Among several considered metrics, only D90 showed statistically significant correlation with the overall survival.
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Affiliation(s)
- S Shcherbinin
- Medical Imaging Research Group, University of British Columbia, 366-828 West 10th Avenue, Vancouver BC, V5Z 1M9, Canada
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Smits MLJ, Elschot M, van den Bosch MAAJ, van de Maat GH, van het Schip AD, Zonnenberg BA, Seevinck PR, Verkooijen HM, Bakker CJ, de Jong HWAM, Lam MGEH, Nijsen JFW. In vivo dosimetry based on SPECT and MR imaging of 166Ho-microspheres for treatment of liver malignancies. J Nucl Med 2013; 54:2093-100. [PMID: 24136931 DOI: 10.2967/jnumed.113.119768] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
UNLABELLED (166)Ho-poly(l-lactic acid) microspheres allow for quantitative imaging with MR imaging or SPECT for microsphere biodistribution assessment after radioembolization. The purpose of this study was to evaluate SPECT- and MR imaging-based dosimetry in the first patients treated with (166)Ho radioembolization. METHODS Fifteen patients with unresectable, chemorefractory liver metastases of any origin were enrolled in this phase 1 study and were treated with (166)Ho radioembolization according to a dose escalation protocol (20-80 Gy). The contours of all liver segments and all discernible tumors were manually delineated on T2-weighted posttreatment MR images and registered to the posttreatment SPECT images (n = 9) or SPECT/CT images (n = 6) and MR imaging-based R2* maps (n = 14). Dosimetry was based on SPECT (n = 15) and MR imaging (n = 9) for all volumes of interest, tumor-to-nontumor (T/N) activity concentration ratios were calculated, and correlation and agreement of MR imaging- and SPECT-based measurements were evaluated. RESULTS The median overall T/N ratio was 1.4 based on SPECT (range, 0.9-2.8) and 1.4 based on MR imaging (range, 1.1-3.1). In 6 of 15 patients (40%), all tumors had received an activity concentration equal to or higher than the normal liver (T/N ratio ≥ 1). Analysis of SPECT and MR imaging measurements for dose to liver segments yielded a high correlation (R(2) = 0.91) and a moderate agreement (mean bias, 3.7 Gy; 95% limits of agreement, -11.2 to 18.7). CONCLUSION With the use of (166)Ho-microspheres, in vivo dosimetry is feasible on the basis of both SPECT and MR imaging, which enables personalized treatment by selective targeting of inadequately treated tumors.
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Affiliation(s)
- Maarten L J Smits
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands; and
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Shcherbinin S, Chamoiseau S, Celler A. Simulation-based reconstruction of absolute activities from the99mTc/111In dual-isotope SPECT/CT: phantom experiments and imaging of neuroendocrine tumors. Phys Med Biol 2013; 58:3339-57. [DOI: 10.1088/0031-9155/58/10/3339] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Bult W, Kroeze SGC, Elschot M, Seevinck PR, Beekman FJ, de Jong HWAM, Uges DRA, Kosterink JGW, Luijten PR, Hennink WE, van het Schip AD, Bosch JLHR, Nijsen JFW, Jans JJM. Intratumoral administration of holmium-166 acetylacetonate microspheres: antitumor efficacy and feasibility of multimodality imaging in renal cancer. PLoS One 2013; 8:e52178. [PMID: 23320070 PMCID: PMC3540022 DOI: 10.1371/journal.pone.0052178] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 11/12/2012] [Indexed: 01/01/2023] Open
Abstract
Purpose The increasing incidence of small renal tumors in an aging population with comorbidities has stimulated the development of minimally invasive treatments. This study aimed to assess the efficacy and demonstrate feasibility of multimodality imaging of intratumoral administration of holmium-166 microspheres (166HoAcAcMS). This new technique locally ablates renal tumors through high-energy beta particles, while the gamma rays allow for nuclear imaging and the paramagnetism of holmium allows for MRI. Methods 166HoAcAcMS were administered intratumorally in orthotopic renal tumors (Balb/C mice). Post administration CT, SPECT and MRI was performed. At several time points (2 h, 1, 2, 3, 7 and 14 days) after MS administration, tumors were measured and histologically analyzed. Holmium accumulation in organs was measured using inductively coupled plasma mass spectrometry. Results 166HoAcAcMS were successfully administered to tumor bearing mice. A striking near-complete tumor-control was observed in 166HoAcAcMS treated mice (0.10±0.01 cm3 vs. 4.15±0.3 cm3 for control tumors). Focal necrosis and inflammation was present from 24 h following treatment. Renal parenchyma outside the radiated region showed no histological alterations. Post administration CT, MRI and SPECT imaging revealed clear deposits of 166HoAcAcMS in the kidney. Conclusions Intratumorally administered 166HoAcAcMS has great potential as a new local treatment of renal tumors for surgically unfit patients. In addition to strong cancer control, it provides powerful multimodality imaging opportunities.
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Affiliation(s)
- Wouter Bult
- Imaging Division, Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
- Department of Hospital and Clinical Pharmacy, University Medical Center Groningen, Groningen, The Netherlands
| | - Stephanie G. C. Kroeze
- Department of Urology, University Medical Center Utrecht, Utrecht, The Netherlands
- Laboratory of Experimental Oncology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mattijs Elschot
- Imaging Division, Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Peter R. Seevinck
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Freek J. Beekman
- Milabs, Utrecht, The Netherlands
- Section Radiation Detection & Medical Imaging, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands
| | - Hugo W. A. M. de Jong
- Imaging Division, Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Donald R. A. Uges
- Department of Hospital and Clinical Pharmacy, University Medical Center Groningen, Groningen, The Netherlands
| | - Jos G. W. Kosterink
- Department of Hospital and Clinical Pharmacy, University Medical Center Groningen, Groningen, The Netherlands
| | - Peter R. Luijten
- Imaging Division, Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Wim E. Hennink
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
| | - Alfred D. van het Schip
- Imaging Division, Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - J. L. H. Ruud Bosch
- Department of Urology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - J. Frank W. Nijsen
- Imaging Division, Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
- * E-mail:
| | - Judith J. M. Jans
- Department of Urology, University Medical Center Utrecht, Utrecht, The Netherlands
- Laboratory of Experimental Oncology, University Medical Center Utrecht, Utrecht, The Netherlands
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Holmium-166 radioembolisation in patients with unresectable, chemorefractory liver metastases (HEPAR trial): a phase 1, dose-escalation study. Lancet Oncol 2012; 13:1025-34. [DOI: 10.1016/s1470-2045(12)70334-0] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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van de Maat GH, Seevinck PR, Elschot M, Smits MLJ, de Leeuw H, van Het Schip AD, Vente MAD, Zonnenberg BA, de Jong HWAM, Lam MGEH, Viergever MA, van den Bosch MAAJ, Nijsen JFW, Bakker CJG. MRI-based biodistribution assessment of holmium-166 poly(L-lactic acid) microspheres after radioembolisation. Eur Radiol 2012; 23:827-35. [PMID: 23014797 PMCID: PMC3563959 DOI: 10.1007/s00330-012-2648-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 07/20/2012] [Accepted: 08/15/2012] [Indexed: 12/16/2022]
Abstract
Objectives To demonstrate the feasibility of MRI-based assessment of the intrahepatic Ho-PLLA-MS biodistribution after radioembolisation in order to estimate the absorbed radiation dose. Methods Fifteen patients were treated with holmium-166 (166Ho) poly(L-lactic acid)-loaded microspheres (Ho-PLLA-MS, mean 484 mg; range 408–593 mg) in a phase I study. Multi-echo gradient-echo MR images were acquired from which R2* maps were constructed. The amount of Ho-PLLA-MS in the liver was determined by using the relaxivity r2* of the Ho-PLLA-MS and compared with the administered amount. Quantitative single photon emission computed tomography (SPECT) was used for comparison with MRI regarding the whole liver absorbed radiation dose. Results R2* maps visualised the deposition of Ho-PLLA-MS with great detail. The mean total amount of Ho-PLLA-MS detected in the liver based on MRI was 431 mg (range 236–666 mg) or 89 ± 19 % of the delivered amount (correlation coefficient r = 0.7; P < 0.01). A good correlation was found between the whole liver mean absorbed radiation dose as assessed by MRI and SPECT (correlation coefficient r = 0.927; P < 0.001). Conclusion MRI-based dosimetry for holmium-166 radioembolisation is feasible. Biodistribution is visualised with great detail and quantitative measurements are possible. Key Points • Radioembolisation is increasingly used for treating unresectable primary or metastatic liver tumours. • MRI-based intrahepatic microsphere biodistribution assessment is feasible after holmium-166 radioembolisation. • MRI enables quantification of holmium-166 microspheres in liver in a short imaging time. • MRI can estimate the whole liver absorbed radiation dose following holmium-166 radioembolisation.
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Affiliation(s)
- Gerrit H van de Maat
- Image Sciences Institute, University Medical Center Utrecht, Q S.459, PO Box 85500, 3508 GA Utrecht, The Netherlands.
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Bult W, Vente MAD, Vandermeulen E, Gielen I, Seevinck PR, Saunders J, van Het Schip AD, Bakker CJG, Krijger GC, Peremans K, Nijsen JFW. Microbrachytherapy using holmium-166 acetylacetonate microspheres: a pilot study in a spontaneous cancer animal model. Brachytherapy 2012; 12:171-7. [PMID: 22999975 DOI: 10.1016/j.brachy.2012.08.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 07/29/2011] [Accepted: 03/13/2012] [Indexed: 10/27/2022]
Abstract
PURPOSE Holmium-166 acetylacetonate microspheres ((166)Ho-AcAc-MS) are proposed as an intratumoral radioablation device. This article presents a pilot study in housecats with unresectable liver cancer. Feasibility and tolerability of intratumoral administrations of (166)Ho-AcAc-MS was investigated. METHODS AND MATERIALS Three cats with unresectable liver tumors of different histotype were included. One cat had hepatocellular carcinoma (HCC), one had cholangiocarcinoma (CC), and one had a malignant epithelial liver tumor (MELT) of unspecified histotype. (166)Ho-AcAc-MS were injected percutaneously under ultrasound guidance into the tumors. Followup consisted of physical examinations and hematologic and biochemical analyses. RESULTS (166)Ho-AcAc-MS were administered to three liver tumor-bearing cats. The treatment was well tolerated and the clinical condition, that is body weight, alertness, mobility, and coat condition of the animals improved markedly. Most biochemical and hematologic parameters normalized shortly after treatment. Life of all cats was extended and associated with a good quality of life. The HCC cat that received 33-Gy tumor-absorbed dose was euthanized 6 months after the first administration owing to disease progression. The MELT cat received 99-Gy tumor dose and was euthanized 3 months posttreatment owing to bacterial meningitis. The CC cat received 333Gy and succumbed 4 months after the first treatment owing to the formation of a pulmonary embolism. CONCLUSIONS Percutaneous intratumoral injection of radioactive (166)Ho-AcAc-MS is feasible in liver tumor-bearing cats. The findings of this pilot study indicate that (166)Ho-AcAc-MS may constitute safe brachytherapeutic microspheres and warrant studies to confirm the clinical utility of this novel brachytherapy device.
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Affiliation(s)
- Wouter Bult
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
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Shcherbinin S, Piwowarska-Bilska H, Celler A, Birkenfeld B. Quantitative SPECT/CT reconstruction for177Lu and177Lu/90Y targeted radionuclide therapies. Phys Med Biol 2012; 57:5733-47. [DOI: 10.1088/0031-9155/57/18/5733] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Magnetic Resonance Imaging-Based Radiation-Absorbed Dose Estimation of 166Ho Microspheres in Liver Radioembolization. Int J Radiat Oncol Biol Phys 2012; 83:e437-44. [DOI: 10.1016/j.ijrobp.2011.12.085] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 12/21/2011] [Accepted: 12/28/2011] [Indexed: 01/17/2023]
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Dewaraja YK, Frey EC, Sgouros G, Brill AB, Roberson P, Zanzonico PB, Ljungberg M. MIRD pamphlet No. 23: quantitative SPECT for patient-specific 3-dimensional dosimetry in internal radionuclide therapy. J Nucl Med 2012; 53:1310-25. [PMID: 22743252 DOI: 10.2967/jnumed.111.100123] [Citation(s) in RCA: 238] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In internal radionuclide therapy, a growing interest in voxel-level estimates of tissue-absorbed dose has been driven by the desire to report radiobiologic quantities that account for the biologic consequences of both spatial and temporal nonuniformities in these dose estimates. This report presents an overview of 3-dimensional SPECT methods and requirements for internal dosimetry at both regional and voxel levels. Combined SPECT/CT image-based methods are emphasized, because the CT-derived anatomic information allows one to address multiple technical factors that affect SPECT quantification while facilitating the patient-specific voxel-level dosimetry calculation itself. SPECT imaging and reconstruction techniques for quantification in radionuclide therapy are not necessarily the same as those designed to optimize diagnostic imaging quality. The current overview is intended as an introduction to an upcoming series of MIRD pamphlets with detailed radionuclide-specific recommendations intended to provide best-practice SPECT quantification-based guidance for radionuclide dosimetry.
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Affiliation(s)
- Yuni K Dewaraja
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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Elschot M, Nijsen JFW, Dam AJ, de Jong HWAM. Quantitative evaluation of scintillation camera imaging characteristics of isotopes used in liver radioembolization. PLoS One 2011; 6:e26174. [PMID: 22073149 PMCID: PMC3207835 DOI: 10.1371/journal.pone.0026174] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 09/21/2011] [Indexed: 02/07/2023] Open
Abstract
Background Scintillation camera imaging is used for treatment planning and post-treatment dosimetry in liver radioembolization (RE). In yttrium-90 (90Y) RE, scintigraphic images of technetium-99m (99mTc) are used for treatment planning, while 90Y Bremsstrahlung images are used for post-treatment dosimetry. In holmium-166 (166Ho) RE, scintigraphic images of 166Ho can be used for both treatment planning and post-treatment dosimetry. The aim of this study is to quantitatively evaluate and compare the imaging characteristics of these three isotopes, in order that imaging protocols can be optimized and RE studies with varying isotopes can be compared. Methodology/Principal Findings Phantom experiments were performed in line with NEMA guidelines to assess the spatial resolution, sensitivity, count rate linearity, and contrast recovery of 99mTc, 90Y and 166Ho. In addition, Monte Carlo simulations were performed to obtain detailed information about the history of detected photons. The results showed that the use of a broad energy window and the high-energy collimator gave optimal combination of sensitivity, spatial resolution, and primary photon fraction for 90Y Bremsstrahlung imaging, although differences with the medium-energy collimator were small. For 166Ho, the high-energy collimator also slightly outperformed the medium-energy collimator. In comparison with 99mTc, the image quality of both 90Y and 166Ho is degraded by a lower spatial resolution, a lower sensitivity, and larger scatter and collimator penetration fractions. Conclusions/Significance The quantitative evaluation of the scintillation camera characteristics presented in this study helps to optimize acquisition parameters and supports future analysis of clinical comparisons between RE studies.
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Affiliation(s)
- Mattijs Elschot
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.
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Norek M, Peters JA. MRI contrast agents based on dysprosium or holmium. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2011; 59:64-82. [PMID: 21600356 DOI: 10.1016/j.pnmrs.2010.08.002] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 08/31/2010] [Indexed: 05/30/2023]
Affiliation(s)
- Małgorzata Norek
- Biocatalysis and Organic Chemistry, Department of Biotechnology, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
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Goorden MC, van der Have F, Kreuger R, Beekman FJ. An efficient simulator for pinhole imaging of PET isotopes. Phys Med Biol 2011; 56:1617-34. [DOI: 10.1088/0031-9155/56/6/007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Gianolio E, Maciocco L, Imperio D, Giovenzana GB, Simonelli F, Abbas K, Bisi G, Aime S. Dual MRI-SPECT agent for pH-mapping. Chem Commun (Camb) 2011; 47:1539-41. [DOI: 10.1039/c0cc03554h] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Bult W, Varkevisser R, Soulimani F, Seevinck PR, de Leeuw H, Bakker CJG, Luijten PR, van het Schip AD, Hennink WE, Nijsen JFW. Holmium nanoparticles: preparation and in vitro characterization of a new device for radioablation of solid malignancies. Pharm Res 2010; 27:2205-12. [PMID: 20680667 PMCID: PMC2939345 DOI: 10.1007/s11095-010-0226-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Accepted: 07/19/2010] [Indexed: 12/02/2022]
Abstract
Purpose The present study introduces the preparation and in vitro characterization of a nanoparticle device comprising holmium acetylacetonate for radioablation of unresectable solid malignancies. Methods HoAcAc nanoparticles were prepared by dissolving holmium acetylacetonate in chloroform, followed by emulsification in an aqueous solution of a surfactant and evaporation of the solvent. The diameter, surface morphology, holmium content, and zeta potential were measured, and thermal behavior of the resulting particles was investigated. The stability of the particles was tested in HEPES buffer. The r2* relaxivity of protons and mass attenuation coefficient of the nanoparticles were determined. The particle diameter and surface morphology were studied after neutron activation. Results Spherical particles with a smooth surface and diameter of 78 ± 10 nm were obtained, and the particles were stable in buffer. Neutron irradiation did not damage the particles, and adequate amounts of activity were produced for nuclear imaging and radioablation of malignancies through intratumoral injections. Conclusions The present study demonstrates that HoAcAc nanoparticles were prepared using a solvent evaporation process. The particle diameter can easily be adapted and can be optimized for specific therapeutic applications and tumor types.
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Affiliation(s)
- Wouter Bult
- Department of Radiology and Nuclear Medicine, Imaging Division, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- Department of Pharmaceutics Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Sorbonnelaan 16, P.O. Box 80082, 3508 TB Utrecht, The Netherlands
| | - Rosanne Varkevisser
- Department of Radiology and Nuclear Medicine, Imaging Division, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- Present Address: Department of Medical Physiology, Division Heart and Lungs, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Fouad Soulimani
- Inorganic Chemistry and Catalysis Group, Department of Chemistry Faculty of Science, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands
| | - Peter R. Seevinck
- Imaging Sciences Institute, Imaging Division, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Hendrik de Leeuw
- Imaging Sciences Institute, Imaging Division, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Chris J. G. Bakker
- Imaging Sciences Institute, Imaging Division, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Peter R. Luijten
- Department of Radiology and Nuclear Medicine, Imaging Division, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Alfred D. van het Schip
- Department of Radiology and Nuclear Medicine, Imaging Division, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Wim E. Hennink
- Department of Pharmaceutics Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Sorbonnelaan 16, P.O. Box 80082, 3508 TB Utrecht, The Netherlands
| | - J. Frank W. Nijsen
- Department of Radiology and Nuclear Medicine, Imaging Division, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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Wu C, van der Have F, Vastenhouw B, Dierckx RAJO, Paans AMJ, Beekman FJ. Absolute quantitative total-body small-animal SPECT with focusing pinholes. Eur J Nucl Med Mol Imaging 2010; 37:2127-35. [PMID: 20577738 PMCID: PMC2948163 DOI: 10.1007/s00259-010-1519-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 06/03/2010] [Indexed: 11/02/2022]
Abstract
PURPOSE In pinhole SPECT, attenuation of the photon flux on trajectories between source and pinholes affects quantitative accuracy of reconstructed images. Previously we introduced iterative methods that compensate for image degrading effects of detector and pinhole blurring, pinhole sensitivity and scatter for multi-pinhole SPECT. The aim of this paper is (1) to investigate the accuracy of the Chang algorithm in rodents and (2) to present a practical Chang-based method using body outline contours obtained with optical cameras. METHODS Here we develop and experimentally validate a practical method for attenuation correction based on a Chang first-order method. This approach has the advantage that it is employed after, and therefore independently from, iterative reconstruction. Therefore, no new system matrix has to be calculated for each specific animal. Experiments with phantoms and animals were performed with a high-resolution focusing multi-pinhole SPECT system (U-SPECT-II, MILabs, The Netherlands). This SPECT system provides three additional optical camera images of the animal for each SPECT scan from which the animal contour can be estimated. RESULTS Phantom experiments demonstrated that an average quantification error of -18.7% was reduced to -1.7% when both window-based scatter correction and Chang correction based on the body outline from optical images were applied. Without scatter and attenuation correction, quantification errors in a sacrificed rat containing sources with known activity ranged from -23.6 to -9.3%. These errors were reduced to values between -6.3 and +4.3% (with an average magnitude of 2.1%) after applying scatter and Chang attenuation correction. CONCLUSION We conclude that the modified Chang correction based on body contour combined with window-based scatter correction is a practical method for obtaining small-animal SPECT images with high quantitative accuracy.
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Affiliation(s)
- Chao Wu
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Hanzeplein 1, RB, Groningen, The Netherlands.
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Smits MLJ, Nijsen JFW, van den Bosch MAAJ, Lam MGEH, Vente MAD, Huijbregts JE, van het Schip AD, Elschot M, Bult W, de Jong HWAM, Meulenhoff PCW, Zonnenberg BA. Holmium-166 radioembolization for the treatment of patients with liver metastases: design of the phase I HEPAR trial. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2010; 29:70. [PMID: 20550679 PMCID: PMC2903532 DOI: 10.1186/1756-9966-29-70] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Accepted: 06/15/2010] [Indexed: 12/14/2022]
Abstract
BACKGROUND Intra-arterial radioembolization with yttrium-90 microspheres ( 90Y-RE) is an increasingly used therapy for patients with unresectable liver malignancies. Over the last decade, radioactive holmium-166 poly(L-lactic acid) microspheres ( 166Ho-PLLA-MS) have been developed as a possible alternative to 90Y-RE. Next to high-energy beta-radiation, 166Ho also emits gamma-radiation, which allows for imaging by gamma scintigraphy. In addition, Ho is a highly paramagnetic element and can therefore be visualized by MRI. These imaging modalities are useful for assessment of the biodistribution, and allow dosimetry through quantitative analysis of the scintigraphic and MR images. Previous studies have demonstrated the safety of 166Ho-PLLA-MS radioembolization ( 166Ho-RE) in animals. The aim of this phase I trial is to assess the safety and toxicity profile of 166Ho-RE in patients with liver metastases. METHODS The HEPAR study (Holmium Embolization Particles for Arterial Radiotherapy) is a non-randomized, open label, safety study. We aim to include 15 to 24 patients with liver metastases of any origin, who have chemotherapy-refractory disease and who are not amenable to surgical resection. Prior to treatment, in addition to the standard technetium-99m labelled macroaggregated albumin ( 99mTc-MAA) dose, a low radioactive safety dose of 60-mg 166Ho-PLLA-MS will be administered. Patients are treated in 4 cohorts of 3-6 patients, according to a standard dose escalation protocol (20 Gy, 40 Gy, 60 Gy, and 80 Gy, respectively). The primary objective will be to establish the maximum tolerated radiation dose of 166Ho-PLLA-MS. Secondary objectives are to assess tumour response, biodistribution, performance status, quality of life, and to compare the 166Ho-PLLA-MS safety dose and the 99mTc-MAA dose distributions with respect to the ability to accurately predict microsphere distribution. DISCUSSION This will be the first clinical study on 166Ho-RE. Based on preclinical studies, it is expected that 166Ho-RE has a safety and toxicity profile comparable to that of 90Y-RE. The biochemical and radionuclide characteristics of 166Ho-PLLA-MS that enable accurate dosimetry calculations and biodistribution assessment may however improve the overall safety of the procedure.
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Affiliation(s)
- Maarten L J Smits
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Heidelberglaan 100, E01,132, 3584 CX Utrecht, The Netherlands
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Holmium-166 poly(L-lactic acid) microsphere radioembolisation of the liver: technical aspects studied in a large animal model. Eur Radiol 2009; 20:862-9. [PMID: 19789880 PMCID: PMC2835632 DOI: 10.1007/s00330-009-1613-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 08/13/2009] [Accepted: 08/20/2009] [Indexed: 01/14/2023]
Abstract
Objective To assess the accuracy of a scout dose of holmium-166 poly(L-lactic acid) microspheres (166Ho-PLLA-MS) in predicting the distribution of a treatment dose of 166Ho-PLLA-MS, using single photon emission tomography (SPECT). Methods A scout dose (60 mg) was injected into the hepatic artery of five pigs and SPECT acquired. Subsequently, a ‘treatment dose’ was administered (540 mg) and SPECT, computed tomography (CT) and magnetic resonance imaging (MRI) of the total dose performed. The two SPECT images of each animal were compared. To validate quantitative SPECT an ex vivo liver was instilled with 166Ho-PLLA-MS and SPECT acquired. The liver was cut into slices and planar images were acquired, which were registered to the SPECT image. Results Qualitatively, the scout dose and total dose images were similar, except in one animal because of catheter displacement. Quantitative analysis, feasible in two animals, tended to confirm this similarity (r2 = 0.34); in the other animal the relation was significantly better (r2 = 0.66). The relation between the SPECT and planar images acquired from the ex vivo liver was strong (r2 = 0.90). Conclusion In the porcine model a scout dose of 166Ho-PLLA-MS can accurately predict the biodistribution of a treatment dose. Quantitative 166Ho SPECT was validated for clinical application.
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Vente MAD, Nijsen JFW, de Roos R, van Steenbergen MJ, Kaaijk CNJ, Koster-Ammerlaan MJJ, de Leege PFA, Hennink WE, van Het Schip AD, Krijger GC. Neutron activation of holmium poly(L-lactic acid) microspheres for hepatic arterial radio-embolization: a validation study. Biomed Microdevices 2009; 11:763-72. [PMID: 19241172 PMCID: PMC2708336 DOI: 10.1007/s10544-009-9291-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Poly(L-lactic acid) microspheres loaded with holmium-166 acetylacetonate (166Ho-PLLA-MS) are a novel microdevice for intra-arterial radioembolization in patients with unresectable liver malignancies. The neutron activation in a nuclear reactor, in particular the gamma heating, damages the 166Ho-PLLA-MS. The degree of damage is dependent on the irradiation characteristics and irradiation time in a particular reactor facility. The aim of this study was to standardize and objectively validate the activation procedure in a particular reactor. The methods included light- and scanning electron microscopy (SEM), particle size analysis, differential scanning calorimetry, viscometry, thermal neutron flux measurements and energy deposition calculations. Seven hours-neutron irradiation results in sufficient specific activity of the 166Ho-PLLA-MS while structural integrity is preserved. Neutron flux measurements and energy deposition calculations are required in the screening of other nuclear reactors. For the evaluation of microsphere quality, light microscopy, SEM and particle size analysis are appropriate techniques.
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Affiliation(s)
- M A D Vente
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
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Shcherbinin S, Celler A, Belhocine T, Vanderwerf R, Driedger A. Accuracy of quantitative reconstructions in SPECT/CT imaging. Phys Med Biol 2008; 53:4595-604. [PMID: 18678930 DOI: 10.1088/0031-9155/53/17/009] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The goal of this study was to determine the quantitative accuracy of our OSEM-APDI reconstruction method based on SPECT/CT imaging for Tc-99m, In-111, I-123, and I-131 isotopes. Phantom studies were performed on a SPECT/low-dose multislice CT system (Infinia-Hawkeye-4 slice, GE Healthcare) using clinical acquisition protocols. Two radioactive sources were centrally and peripherally placed inside an anthropometric Thorax phantom filled with non-radioactive water. Corrections for attenuation, scatter, collimator blurring and collimator septal penetration were applied and their contribution to the overall accuracy of the reconstruction was evaluated. Reconstruction with the most comprehensive set of corrections resulted in activity estimation with error levels of 3-5% for all the isotopes.
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Affiliation(s)
- S Shcherbinin
- Department of Radiology, University of British Columbia, 366-828 West 10th Avenue, Vancouver BC, V5Z 1L8, Canada.
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Clinical effects of transcatheter hepatic arterial embolization with holmium-166 poly(L-lactic acid) microspheres in healthy pigs. Eur J Nucl Med Mol Imaging 2008; 35:1259-71. [PMID: 18330569 PMCID: PMC2440967 DOI: 10.1007/s00259-008-0747-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2007] [Accepted: 02/04/2008] [Indexed: 11/13/2022]
Abstract
Purpose The aim of this study is to evaluate the toxicity of holmium-166 poly(l-lactic acid) microspheres administered into the hepatic artery in pigs. Methods Healthy pigs (20–30 kg) were injected into the hepatic artery with holmium-165-loaded microspheres (165HoMS; n = 5) or with holmium-166-loaded microspheres (166HoMS; n = 13). The microspheres’ biodistribution was assessed by single-photon emission computed tomography and/or MRI. The animals were monitored clinically, biochemically, and (166HoMS group only) hematologically over a period of 1 month (165HoMS group) or over 1 or 2 months (166HoMS group). Finally, a pathological examination was undertaken. Results After microsphere administration, some animals exhibited a slightly diminished level of consciousness and a dip in appetite, both of which were transient. Four lethal adverse events occurred in the 166HoMS group due either to incorrect administration or comorbidity: inadvertent delivery of microspheres into the gastric wall (n = 2), preexisting gastric ulceration (n = 1), and endocarditis (n = 1). AST levels were transitorily elevated post-166HoMS administration. In the other blood parameters, no abnormalities were observed. Nuclear scans were acquired from all animals from the 166HoMS group, and MRI scans were performed if available. In pigs from the 166HoMS group, atrophy of one or more liver lobes was frequently observed. The actual radioactivity distribution was assessed through ex vivo 166mHo measurements. Conclusion It can be concluded that the toxicity profile of HoMS is low. In pigs, hepatic arterial embolization with 166HoMS in amounts corresponding with liver-absorbed doses of over 100 Gy, if correctly administered, is not associated with clinically relevant side effects. This result offers a good perspective for upcoming patient trials.
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Zielhuis SW, Seppenwoolde JH, Bakker CJG, Jahnz U, Zonnenberg BA, van het Schip AD, Hennink WE, Nijsen JFW. Characterization of holmium loaded alginate microspheres for multimodality imaging and therapeutic applications. J Biomed Mater Res A 2007; 82:892-8. [PMID: 17335019 DOI: 10.1002/jbm.a.31183] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In this paper the preparation and characterization of holmium-loaded alginate microspheres is described. The rapid development of medical imaging techniques offers new opportunities for the visualisation of (drug-loaded) microparticles. Therefore, suitable imaging agents have to be incorporated into these particles. For this reason, the element holmium was used in this study in order to utilize its unique imaging characteristics. The paramagnetic behaviour of this element allows visualisation with MRI and holmium can also be neutron-activated resulting in the emission of gamma-radiation, allowing visualisation with gamma cameras, and beta-radiation, suitable for therapeutic applications. Almost monodisperse alginate microspheres were obtained by JetCutter technology where alginate droplets of a uniform size were hardened in an aqueous holmium chloride solution. Ho(3+) binds via electrostatic interactions to the carboxylate groups of the alginate polymer and as a result alginate microspheres loaded with holmium were obtained. The microspheres had a mean size of 159 microm and a holmium loading of 1.3 +/- 0.1% (w/w) (corresponding with a holmium content based on dry alginate of 18.3 +/- 0.3% (w/w)). The binding capacity of the alginate polymer for Ho(3+) (expressed in molar amounts) is equal to that for Ca(2+), which is commonly used for the hardening of alginate. This indicates that Ho(3+) has the same binding affinity as Ca(2+). In line herewith, dynamic mechanical analyses demonstrated that alginate gels hardened with Ca(2+) or Ho(3+) had similar viscoelastic properties. The MRI relaxation properties of the microspheres were determined by a MRI phantom experiment, demonstrating a strong R(2)* effect of the particles. Alginate microspheres could also be labelled with radioactive holmium by adding holmium-166 to alginate microspheres, previously hardened with calcium (labelling efficiency 96%). The labelled microspheres had a high radiochemical stability (94% after 48 h incubation in human serum), allowing therapeutic applications for treatment of cancer. The potential in vivo application of the microspheres for a MR-guided renal embolization procedure was illustrated by selective administration of microspheres to the left kidney of a pig. Anatomic MR-imaging showed the presence of holmium-loaded microspheres in the kidney. In conclusion, this study demonstrates that the incorporation of holmium into alginate microspheres allows their visualisation with a gamma camera and MRI. Holmium-loaded alginate microspheres can be used therapeutically for embolization and, when radioactive, for local radiotherapy of tumours.
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Affiliation(s)
- S W Zielhuis
- Department of Nuclear Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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