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Pastrana Orejuela CO, de Assis Coelho F, Oliveira SM, Souza SAL, Vasconcellos de Sá L, Xavier da Silva A, Torres Berdeguez MB. SPECT performance evaluation on image of Yttrium 90 - Bremsstrahlung using Monte Carlo simulation. Appl Radiat Isot 2020; 168:109456. [PMID: 33321371 DOI: 10.1016/j.apradiso.2020.109456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 09/16/2020] [Accepted: 09/30/2020] [Indexed: 11/15/2022]
Abstract
Yttrium-90 (90Y) is one of the most widely used radionuclides in Nuclear Medicine practice. However, characteristic energy of this beta emitter constitutes a difficulty for dose planning using SPECT imaging. This work aimed to study bremsstrahlung X-rays effects produced by 90Y beta particles during SPECT image acquisition using Monte Carlo code MCNPX. Several simulations were carried out to evaluate different aspects that could affect SPECT image quality, such as: collimator type, source-collimator distance and composition of each interacting material. Two configurations of 90Y sources were simulated: a point source in several spheres of different materials (soft tissue, water, articular cartilage, and bone) and dimensions with radius ranging from 1 to 20 mm; and a uniformly distributed source in a Lucite cylindrical phantom filled with water. It was evaluated the bremsstrahlung photon emission generated inside different materials; for this was considered the number photons that passing through every different sphere's surface for each radii and material. In case of cylindrical phantom filled with water, in order to obtain the energy deposited over NaI (Tl) crystal detector; there was considered Median Energy General Purpose (MEGP) and Low Energy High Resolution (LEHR) collimators. Moreover, using TMESH routine available in the MCNPX Monte Carlo code, energy distribution images according to the collimator type and the source-collimator distance were obtained. The simulation was validated by comparing with the spectral distribution of the 90Y bremsstrahlung X-rays obtained experimentally from an acrylic cylindrical phantom. Results corroborated the importance of Monte Carlo simulation method to evaluate a performance of SPECT image acquisition with 90Y. The best resolution was obtained with MEGP collimator independent of source-collimator distance.
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Affiliation(s)
| | - Francisco de Assis Coelho
- Department of Nuclear Medicine, Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Susie Medeiros Oliveira
- Department of Nuclear Medicine, Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Sergio A L Souza
- Department of Nuclear Medicine, Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Lidia Vasconcellos de Sá
- Institute of Radiation Protection and Dosimetry, Brazilian Nuclear Energy Commission, Rio de Janeiro, RJ, Brazil.
| | - Ademir Xavier da Silva
- Department of Nuclear Engineering, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Mirta B Torres Berdeguez
- Department of Nuclear Engineering, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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Hou X, Ma H, Esquinas PL, Uribe C, Tolhurst S, Bénard F, Liu D, Rahmim A, Celler A. Impact of image reconstruction method on dose distributions derived from 90Y PET images: phantom and liver radioembolization patient studies. Phys Med Biol 2020; 65:215022. [PMID: 33245057 DOI: 10.1088/1361-6560/aba8b5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PET images acquired after liver 90Y radioembolization therapies are typically very noisy, which significantly challenges both visualization and quantification of activity distributions. To improve their noise characteristics, regularized iterative reconstruction algorithms such as block sequential regularized expectation maximization (Q.Clear for GE Healthcare, USA) have been proposed. In this study, we aimed to investigate the effects which different reconstruction algorithms may have on patient images, with reconstruction parameters initially narrowed down using phantom studies. Moreover, we evaluated the impact of these reconstruction methods on voxel-based dose distribution in phantom and patient studies (lesions and healthy livers). The International Electrotechnical Commission (IEC)/NEMA phantom, containing six spheres, was filled with 90Y and imaged using a GE Discovery 690 PET/CT scanner with time-of-flight enabled. The images were reconstructed using Q.Clear (with β parameter ranging from 0 to 8000) and ordered subsets expectation maximization. The image quality and quantification accuracy were evaluated by computing the hot ([Formula: see text]) and cold ([Formula: see text]) contrast recovery coefficients, background variability (BV) and activity bias. Next, dose distributions and dose volume histograms were generated using MIM® software's SurePlan LiverY90 toolbox. Subsequently, parameters optimized in these phantom studies were applied to five patient datasets. Dose parameters, such as Dmax, Dmean, D70, and V100Gy, were estimated, and their variability for different reconstruction methods was investigated. Based on phantom studies, the β parameter values optimized for image quality and quantification accuracy were 2500 and 300, respectively. When all investigated reconstructions were applied to patient studies, Dmean, D50, D70, and V100Gy showed coefficients of variation below 8%; whereas the variability of Dmax was up to 30% for both phantom and patient images. Although β = 300-1000 would provide accurate activity quantification for a region of interest, when considering activity/dose voxelized distribution, higher β value (e.g. 4000-5000) would provide the greatest accuracy for dose distributions. In this 90Y radioembolization PET/CT study, the β parameter in regularized iterative (Q.Clear) reconstruction was investigated for image quality, accurate quantification and dose distributions based on phantom experiments and then applied to patient studies. Our results indicate that more accurate dose distribution can be achieved from smoother PET images, reconstructed with larger β values than those yielding the best activity quantifications but noisy images. Most importantly, these results suggest that quantitative measures, which are commonly used in clinics, such as SUVmax or SUVpeak( equivalent of Dmax), should not be employed for 90Y PET images, since their values would highly depend on the image reconstruction.
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Affiliation(s)
- Xinchi Hou
- Department of Radiology, University of British Columbia, Vancouver, Canada
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İnce C, Karadeniz Ö, Ertay T, Durak H. Collimator and energy window optimization for YTTRIUM-90 bremsstrahlung SPECT imaging. Appl Radiat Isot 2020; 167:109453. [PMID: 33039763 DOI: 10.1016/j.apradiso.2020.109453] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/01/2020] [Accepted: 09/25/2020] [Indexed: 10/23/2022]
Abstract
The optimal collimator and energy window for Yttrium-90 bremsstrahlung SPECT imaging was investigated in the study. Yttrium-90 images were acquired with a dual-head gamma camera, equipped with parallel hole collimators and 90Y vial for different energy windows ranging from 56 to 232 keV. Image quality parameters (sensitivity, %FOV, and S/B) were examined for the energy window and collimator combinations. It is concluded that the optimal SPECT imaging was achieved using FBP Method with a HEGP collimator and the energy window of 90-110 keV.
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Affiliation(s)
- Caner İnce
- Department of Medical Physics, Institute of Health Sciences, Dokuz Eylül University, 35340, İnciraltı, İzmir, Turkey
| | - Özlem Karadeniz
- Department of Medical Physics, Institute of Health Sciences, Dokuz Eylül University, 35340, İnciraltı, İzmir, Turkey; Department of Physics, Faculty of Sciences, Dokuz Eylül University, 35390, Tınaztepe, İzmir, Turkey.
| | - Türkan Ertay
- Department of Medical Physics, Institute of Health Sciences, Dokuz Eylül University, 35340, İnciraltı, İzmir, Turkey; Department of Nuclear Medicine, Faculty of Medicine, Dokuz Eylül University, 35340, İnciraltı, İzmir, Turkey
| | - Hatice Durak
- Department of Medical Physics, Institute of Health Sciences, Dokuz Eylül University, 35340, İnciraltı, İzmir, Turkey; Department of Nuclear Medicine, Faculty of Medicine, Dokuz Eylül University, 35340, İnciraltı, İzmir, Turkey
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Seo Y. Quantitative Imaging of Alpha-Emitting Therapeutic Radiopharmaceuticals. Nucl Med Mol Imaging 2019; 53:182-188. [PMID: 31231438 DOI: 10.1007/s13139-019-00589-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/02/2019] [Accepted: 02/07/2019] [Indexed: 11/24/2022] Open
Abstract
Targeted alpha therapy (TAT) is an active area of drug development as a highly specific and highly potent therapeutic modality that can be applied to many types of late-stage cancers. In order to properly evaluate its safety and efficacy, understanding biokinetics of alpha-emitting radiopharmaceuticals is essential. Quantitative imaging of alpha-emitting radiopharmaceuticals is often possible via imaging of gammas and positrons produced during complex decay chains of these radionuclides. Analysis of the complex decay chains for alpha-emitting radionuclides (Tb-149, At-211, Bi-212 (decayed from Pb-212), Bi-213, Ra-223, Ac-225, and Th-227) with relevance to imageable signals is attempted in this mini-review article. Gamma camera imaging, single-photon emission computed tomography, positron emission tomography, bremsstrahlung radiation imaging, Cerenkov luminescence imaging, and Compton cameras are briefly discussed as modalities for imaging alpha-emitting radiopharmaceuticals.
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Affiliation(s)
- Youngho Seo
- 1Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA USA
- 2Department of Radiation Oncology, University of California, San Francisco, CA USA
- 3Bakar Computational Health Sciences Institute, University of California, San Francisco, CA USA
- UC Berkeley - UCSF Bioengineering Graduate Program, Berkeley and San Francisco, CA USA
- 5Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA USA
- 6UCSF Physics Research Laboratory, 185 Berry Street, Suite 350, San Francisco, CA 94143-0946 USA
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Effects of collimator on imaging performance of Yttrium-90 Bremsstrahlung photons: Monte Carlo simulation. NUCLEAR ENGINEERING AND TECHNOLOGY 2019. [DOI: 10.1016/j.net.2018.11.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Nezami N, Kokabi N, Camacho JC, Schuster DM, Xing M, Kim HS. 90Y radioembolization dosimetry using a simple semi-quantitative method in intrahepatic cholangiocarcinoma: Glass versus resin microspheres. Nucl Med Biol 2018; 59:22-28. [PMID: 29448165 DOI: 10.1016/j.nucmedbio.2018.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/26/2017] [Accepted: 01/10/2018] [Indexed: 12/31/2022]
Abstract
INTRODUCTION There are two different types of 90Y Microspheres, glass and resin, in the market for 90Y radioembolization (90Y-RE). This study aimed to investigate the dose of radiation delivered through glass vs. resin-based 90Y-RE to intrahepatic cholangiocarcinoma (ICC). METHODS In this retrospective study, 10 patients with ICC underwent 90Y-RE, five underwent glass (Glass group) and other 5 resin (Resin group) microspheres. Technetium-99m macro-aggregated albumin (Tc-99m MAA) shunt study was performed two weeks before 90Y-RE. Within 2 h from 90Y-RE, Bremsstrahlung SPECT/CT was obtained. Regions of interest (ROIs) were segmented around the targeted tumor and the liver. Tumor and liver volumes, corresponding radioactive counts, and tumor to liver count ratio were calculated using MIM software and compared between Glass and Resin groups. RESULTS Mean hepatopulmonary shunt fraction was 7.1 vs. 6.2% for the Glass and Resin groups (p = 0.83), with no extrahepatic activity. There was no difference in the activity and tumor uptake of administered Tc-99m MAA between both groups (p = 0.71 and p = 0.63). Mean administered activity of 90Y in the Glass group was higher than the Resin group (73.2 ± 24.3 vs. 44.5 ± 18.2 mCi, p < 0.001). The tumor 90Y uptake was significantly higher in the Glass group compared to the Resin group (41.3% vs. 33.5%, p < 0.001), corresponding to the mean tumor dose of 205.7 ± 19.7 vs. 128.9 ± 10.6 Gy, respectively (p < 0.001). The tumor to normal liver parenchyma 90Y dose ratio was significantly higher in the Glass group compared to the Resin group, 4.9 ± 0.7 versus 2.4 ± 0.3 respectably (p < 0.001). CONCLUSIONS Both 90Y glass and resin-based microsphere 90Y-RE are feasible and safe in patients with ICC, while 90Y glass microsphere delivers higher dose of 90Y to the targeted tumors. ADVANCES IN KNOWLEDGE While both 90Y glass and resin-based microsphere yttrium-90 radioembolization are feasible and safe treatment options for in patients with intrahepatic cholangiocarcinoma, 90Y glass microsphere delivers higher dose of 90Y to the targeted tumors. IMPLICATIONS FOR PATIENT CARE Both of 90Y glass and resin-based microsphere can be safely and feasibly used for treatment of intrahepatic cholangiocarcinoma, difference in dose of 90Y delivered to the targeted tumors should be clinically considered while choosing the microsphere type.
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Affiliation(s)
- Nariman Nezami
- Division of Interventional Radiology, Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Nima Kokabi
- Division of Interventional Radiology, Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Juan C Camacho
- Department of Radiology, Medical University of South Caroline, Charleston, SC, USA
| | - David M Schuster
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Science, Emory University School of Medicine, Atlanta, GA, USA
| | - Minzhi Xing
- Division of Interventional Radiology, Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Hyun S Kim
- Division of Interventional Radiology, Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA; Yale Cancer Center, Yale School of Medicine, New Haven, CT, USA.
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Ciarrocchi E, Belcari N. Cerenkov luminescence imaging: physics principles and potential applications in biomedical sciences. EJNMMI Phys 2017; 4:14. [PMID: 28283990 PMCID: PMC5346099 DOI: 10.1186/s40658-017-0181-8] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 02/27/2017] [Indexed: 12/24/2022] Open
Abstract
Cerenkov luminescence imaging (CLI) is a novel imaging modality to study charged particles with optical methods by detecting the Cerenkov luminescence produced in tissue. This paper first describes the physical processes that govern the production and transport in tissue of Cerenkov luminescence. The detectors used for CLI and their most relevant specifications to optimize the acquisition of the Cerenkov signal are then presented, and CLI is compared with the other optical imaging modalities sharing the same data acquisition and processing methods. Finally, the scientific work related to CLI and the applications for which CLI has been proposed are reviewed. The paper ends with some considerations about further perspectives for this novel imaging modality.
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Affiliation(s)
- Esther Ciarrocchi
- Department of Physics "E. Fermi", University of Pisa, Pisa, Italy. .,INFN, section of Pisa, Pisa, Italy.
| | - Nicola Belcari
- Department of Physics "E. Fermi", University of Pisa, Pisa, Italy.,INFN, section of Pisa, Pisa, Italy
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Personalized Dosimetry for Radionuclide Therapy Using Molecular Imaging Tools. Biomedicines 2016; 4:biomedicines4040025. [PMID: 28536392 PMCID: PMC5344265 DOI: 10.3390/biomedicines4040025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 11/07/2016] [Accepted: 11/08/2016] [Indexed: 11/16/2022] Open
Abstract
For treatment of systemic malignancies, when external radiation therapy is not applicable, radionuclide therapy can be an alternative. In this form of therapy, radionuclides are administered to the patient, often in a form where the radionuclide is labelled to a molecule that plays the active part in the localization of the tumor. Since the aim is to impart lethal damage to tumor cells while maintaining possible side-effects to normal tissues at tolerable levels, a proper and accurate personalized dosimetry should be a pre-requisite. In radionuclide therapy, there is a need to measure the distribution of the radiopharmaceutical in vivo, as well as its re-distribution over time, in order estimate the total energy released in radioactive decays and subsequent charged-particle interactions, governing the absorbed dose to different organs and tumors. Measurements are usually performed by molecular imaging, more specifically planar and SPECT (Single-Photon Emission Computed Tomography) imaging, combined with CT. This review describes the different parts in the dosimetry chain of radionuclide therapy. Emphasis is given to molecular imaging tools and the requirements for determining absorbed doses from quantitative planar and SPECT images. As example solutions to the different problems that need to be addressed in such a dosimetric chain, we describe our tool, Lundadose, which is a set of methods that we have developed for personalized dosimetry.
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Analysis of the influence of 111In on 90Y-bremsstrahlung SPECT based on Monte Carlo simulation. Ann Nucl Med 2016; 30:675-681. [PMID: 27510893 DOI: 10.1007/s12149-016-1112-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 08/01/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVE 90Y-ibritumomab tiuxetan (Zevalin) which is used for the treatment of malignant lymphomas can be used for SPECT imaging based on bremsstrahlung from 90Y beta particles. However, gamma rays emitted by 111In, which is administered to evaluate the indication for the treatment, contaminate the 90Y bremsstrahlung images. Our objective is to investigate the influence of 111In on the 90Y SPECT images using Monte Carlo simulation. METHODS We used an in-house developed simulation code for the Monte Carlo simulation of electrons and photons (MCEP). Two hot spheres with diameters of 40 mm were put in an elliptical phantom. Both spheres ("sphere 1" and "sphere 2") were filled with 90Y and 111In mixed solutions. The activities of 90Y in sphere 1 and sphere 2 were 241 and 394 kBq/mL, respectively, and the ones of 111In were 8.14 and 13.3 kBq/mL, respectively. The background activity of 90Y was 38.6 kBq/mL, whereas that of 111In was 1.30 kBq/mL; moreover, the acquisition time was 30 min. Two energy windows were used: one is 90-190 keV included the 111In photopeak; the other is 90-160 keV. To evaluate the quality of the SPECT images, the contrast recovery coefficient (CRC) and the constant noise ratio (CNR) of the SPECT images were derived. RESULTS For the energy window between 90 and 160 keV, the 111In count was 74 % of the total. In that case, the CRC values were 30.1 and 30.7 % for "sphere 1" and "sphere 2", respectively, whereas the CNR values were 6.8 and 12.1, respectively. For the energy window between 90 and 190 keV, the 111In count reached 85 % of the total count. The CRC and CNR values were 38.6 and 40.0 % and 10.6 and 19.4, respectively. CONCLUSIONS Our simulation study revealed that the cross talk between 111In and 90Y in SPECT imaging is rather serious. Even for the energy window excluding the 111In photopeak, the count ratio of 90Y was less than 30 % of the total. However, the influence of 111In on 90Y-SPECT imaging cannot be ignored, and the count ratio because of 111In is important to estimate the density of 90Y.
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Ahmadzadehfar H, Muckle M, Sabet A, Wilhelm K, Kuhl C, Biermann K, Haslerud T, Biersack HJ, Ezziddin S. The significance of bremsstrahlung SPECT/CT after yttrium-90 radioembolization treatment in the prediction of extrahepatic side effects. Eur J Nucl Med Mol Imaging 2016; 39:309-15. [PMID: 21975832 DOI: 10.1007/s00259-011-1940-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 09/09/2011] [Indexed: 01/06/2023]
Abstract
Purpose Unwanted deposition of 90Y microspheres in organs other than the liver during radioembolization of liver tumours may cause severe side effects such as duodenal ulcer. The aim of this study was to evaluate the significance of posttherapy bremsstrahlung (BS) SPECT/CT images of the liver in comparison to planar and SPECT images in the prediction of radioembolization-induced extrahepatic side effects.Methods A total of 188 radioembolization procedures were performed in 123 patients (50 women, 73 men) over a 2-year period. Planar, whole-body and BS SPECT/CT imaging were performed 24 h after treatment as a part of therapy work-up.Any focally increased extrahepatic accumulation was evaluated as suspicious. Clinical follow-up and gastroduodenoscopy served as reference standards. The studies were reviewed to evaluate whether BS SPECT/CT imaging was of benefit.Results In the light of anatomic data obtained from SPECT/CT, apparent extrahepatic BS in 43% of planar and in 52% of SPECT images proved to be in the liver and hence false positive.The results of planar scintigraphy could not be analysed further since 12 images were not assessable due to high scatter artefacts. On the basis of the gastrointestinal (GI)complications and the results of gastroduodenoscopy, true positive,true-negative, false-positive and false-negative results of BS SPECT and SPECT/CT imaging in the prediction of GI ulcers were determined. The sensitivity, specificity, positive and negative predictive values and the accuracy of SPECT and SPECT/CT in the prediction of GI ulcers were 13%, 88%, 8%,92% and 82%, and 87%, 100%, 100%, 99% and 99%,respectively.Conclusion Despite the low quality of BS images, BSSPECT/CT can be used as a reliable method to confirm the safe distribution of 90Y microspheres and in the prediction of GI side effects.
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Uribe CF, Esquinas PL, Gonzalez M, Celler A. Characteristics of Bremsstrahlung emissions of (177)Lu, (188)Re, and (90)Y for SPECT/CT quantification in radionuclide therapy. Phys Med 2016; 32:691-700. [PMID: 27157626 DOI: 10.1016/j.ejmp.2016.04.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 04/27/2016] [Accepted: 04/28/2016] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Beta particles emitted by radioisotopes used in targeted radionuclide therapies (TRT) create Bremsstrahlung (BRS) which may affect SPECT quantification when imaging these isotopes. The purpose of the current study was to investigate the characteristics of Bremsstrahlung produced in tissue by three β-emitting radioisotopes used in TRT. METHODS Monte Carlo simulations of (177)Lu, (188)Re, and (90)Y sources placed in water filled cylinders were performed. BRS yields, mean energies and energy spectra for (a) all photons generated in the decays, (b) photons that were not absorbed and leave the cylinder, and (c) photons detected by the camera were analyzed. Next, the results of simulations were compared with those from experiments performed on a clinical SPECT camera using same acquisition conditions and phantom configurations as in simulations. RESULTS Simulations reproduced relatively well the shapes of the measured spectra, except for (90)Y which showed an overestimation in the low energy range. Detailed analysis of the results allowed us to suggest best collimators and imaging conditions for each of the investigated isotopes. Finally, our simulations confirmed that the BRS contribution to the energy spectra in quantitative imaging of (177)Lu and (188)Re could be ignored. CONCLUSIONS For (177)Lu and (188)Re, BRS contributes only marginally to the total spectra recorded by the camera. Our analysis shows that MELP and HE collimators are the best for imaging these two isotopes. For (90)Y, HE collimator should be used.
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Affiliation(s)
- Carlos F Uribe
- Medical Imaging Research Group, University of British Columbia, Vancouver, British Columbia, Canada; Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.
| | - Pedro L Esquinas
- Medical Imaging Research Group, University of British Columbia, Vancouver, British Columbia, Canada; Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - Marjorie Gonzalez
- Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada
| | - Anna Celler
- Medical Imaging Research Group, University of British Columbia, Vancouver, British Columbia, Canada
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Takahashi A, Himuro K, Yamashita Y, Komiya I, Baba S, Sasaki M. Monte Carlo simulation of PET and SPECT imaging of 90Y. Med Phys 2015; 42:1926-35. [PMID: 25832083 DOI: 10.1118/1.4915545] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Yittrium-90 ((90)Y) is traditionally thought of as a pure beta emitter, and is used in targeted radionuclide therapy, with imaging performed using bremsstrahlung single-photon emission computed tomography (SPECT). However, because (90)Y also emits positrons through internal pair production with a very small branching ratio, positron emission tomography (PET) imaging is also available. Because of the insufficient image quality of (90)Y bremsstrahlung SPECT, PET imaging has been suggested as an alternative. In this paper, the authors present the Monte Carlo-based simulation-reconstruction framework for (90)Y to comprehensively analyze the PET and SPECT imaging techniques and to quantitatively consider the disadvantages associated with them. METHODS Our PET and SPECT simulation modules were developed using Monte Carlo simulation of Electrons and Photons (MCEP), developed by Dr. S. Uehara. PET code (MCEP-PET) generates a sinogram, and reconstructs the tomography image using a time-of-flight ordered subset expectation maximization (TOF-OSEM) algorithm with attenuation compensation. To evaluate MCEP-PET, simulated results of (18)F PET imaging were compared with the experimental results. The results confirmed that MCEP-PET can simulate the experimental results very well. The SPECT code (MCEP-SPECT) models the collimator and NaI detector system, and generates the projection images and projection data. To save the computational time, the authors adopt the prerecorded (90)Y bremsstrahlung photon data calculated by MCEP. The projection data are also reconstructed using the OSEM algorithm. The authors simulated PET and SPECT images of a water phantom containing six hot spheres filled with different concentrations of (90)Y without background activity. The amount of activity was 163 MBq, with an acquisition time of 40 min. RESULTS The simulated (90)Y-PET image accurately simulated the experimental results. PET image is visually superior to SPECT image because of the low background noise. The simulation reveals that the detected photon number in SPECT is comparable to that of PET, but the large fraction (approximately 75%) of scattered and penetration photons contaminates SPECT image. The lower limit of (90)Y detection in SPECT image was approximately 200 kBq/ml, while that in PET image was approximately 100 kBq/ml. CONCLUSIONS By comparing the background noise level and the image concentration profile of both the techniques, PET image quality was determined to be superior to that of bremsstrahlung SPECT. The developed simulation codes will be very useful in the future investigations of PET and bremsstrahlung SPECT imaging of (90)Y.
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Affiliation(s)
- Akihiko Takahashi
- Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Kazuhiko Himuro
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yasuo Yamashita
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Isao Komiya
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Shingo Baba
- Department of Clinical Radiology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Masayuki Sasaki
- Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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Theranostic Imaging of Yttrium-90. BIOMED RESEARCH INTERNATIONAL 2015; 2015:481279. [PMID: 26106608 PMCID: PMC4464848 DOI: 10.1155/2015/481279] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Accepted: 04/22/2015] [Indexed: 01/07/2023]
Abstract
This paper overviews Yttrium-90 ((90)Y) as a theranostic and nuclear medicine imaging of (90)Y radioactivity with bremsstrahlung imaging and positron emission tomography. In addition, detection and optical imaging of (90)Y radioactivity using Cerenkov luminescence will also be reviewed. Methods and approaches for qualitative and quantitative (90)Y imaging will be briefly discussed. Although challenges remain for (90)Y imaging, continued clinical demand for predictive imaging response assessment and target/nontarget dosimetry will drive research and technical innovation to provide greater clinical utility of (90)Y as a theranostic agent.
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Abstract
Peptide receptor radionuclide therapy with (90)Y-peptides is generally well tolerated. Acute side effects are usually mild; some are related to the coadministration of amino acids and others to the radiopeptide itself. Chronic and permanent effects on target organs, particularly kidneys and bone marrow, are generally mild if necessary precautions are taken. The potential risk to kidney and red marrow limits the amount of radioactivity that may be administered. However, when tumor masses are irradiated with adequate doses, volume reduction may be observed. (90)Y-octreotide has been the most used radiopeptide in the first 8 to 10 years of experience.
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Affiliation(s)
- Lisa Bodei
- Division of Nuclear Medicine, European Institute of Oncology, via Ripamonti 435, 20141 Milan, Italy
| | - Marta Cremonesi
- Division of Medical Physics, European Institute of Oncology, via Ripamonti 435, 20141 Milan, Italy
| | - Giovanni Paganelli
- Division of Nuclear Medicine, European Institute of Oncology, via Ripamonti 435, 20141 Milan, Italy.
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Attarwala AA, Molina-Duran F, Büsing KA, Schönberg SO, Bailey DL, Willowson K, Glatting G. Quantitative and qualitative assessment of Yttrium-90 PET/CT imaging. PLoS One 2014; 9:e110401. [PMID: 25369020 PMCID: PMC4219690 DOI: 10.1371/journal.pone.0110401] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 09/22/2014] [Indexed: 11/24/2022] Open
Abstract
Yttrium-90 is known to have a low positron emission decay of 32 ppm that may allow for personalized dosimetry of liver cancer therapy with 90Y labeled microspheres. The aim of this work was to image and quantify 90Y so that accurate predictions of the absorbed dose can be made. The measurements were performed within the QUEST study (University of Sydney, and Sirtex Medical, Australia). A NEMA IEC body phantom containing 6 fillable spheres (10–37 mm ∅) was used to measure the 90Y distribution with a Biograph mCT PET/CT (Siemens, Erlangen, Germany) with time-of-flight (TOF) acquisition. A sphere to background ratio of 8∶1, with a total 90Y activity of 3 GBq was used. Measurements were performed for one week (0, 3, 5 and 7 d). he acquisition protocol consisted of 30 min-2 bed positions and 120 min-single bed position. mages were reconstructed with 3D ordered subset expectation maximization (OSEM) and point spread function (PSF) for iteration numbers of 1–12 with 21 (TOF) and 24 (non-TOF) subsets and CT based attenuation and scatter correction. Convergence of algorithms and activity recovery was assessed based on regions-of-interest (ROI) analysis of the background (100 voxels), spheres (4 voxels) and the central low density insert (25 voxels). For the largest sphere, the recovery coefficient (RC) values for the 30 min –2-bed position, 30 min-single bed and 120 min-single bed were 1.12±0.20, 1.14±0.13, 0.97±0.07 respectively. For the smaller diameter spheres, the PSF algorithm with TOF and single bed acquisition provided a comparatively better activity recovery. Quantification of Y-90 using Biograph mCT PET/CT is possible with a reasonable accuracy, the limitations being the size of the lesion and the activity concentration present. At this stage, based on our study, it seems advantageous to use different protocols depending on the size of the lesion.
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Affiliation(s)
- Ali Asgar Attarwala
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Flavia Molina-Duran
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Karen-Anett Büsing
- Institute of Clinical Radiology and Nuclear Medicine, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Stefan O. Schönberg
- Institute of Clinical Radiology and Nuclear Medicine, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Dale L. Bailey
- Department of Nuclear Medicine, Royal North Shore Hospital, Sydney, Australia
| | - Kathy Willowson
- Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia
| | - Gerhard Glatting
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- * E-mail:
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A simple method for estimating dose delivered to hepatocellular carcinoma after yttrium-90 glass-based radioembolization therapy: preliminary results of a proof of concept study. J Vasc Interv Radiol 2014; 25:277-87. [PMID: 24461133 DOI: 10.1016/j.jvir.2013.11.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 11/01/2013] [Accepted: 11/06/2013] [Indexed: 12/23/2022] Open
Abstract
PURPOSE To investigate a simple semiquantitative method to estimate yttrium-90 ((90)Y) dose delivered with radioembolization to infiltrative hepatocellular carcinoma (HCC). MATERIALS AND METHODS In a prospective study, patients with infiltrative HCC and portal vein thrombosis (PVT) underwent glass-based (90)Y radioembolization including technetium-99m macroaggregated albumin ((99m)Tc-MAA) hepatopulmonary shunt study before therapy and bremsstrahlung single photon emission computed tomography (SPECT)/computed tomography (CT) after (90)Y radioembolization. Baseline magnetic resonance imaging was coregistered with (99m)Tc-MAA and bremsstrahlung SPECT/CT imaging separately. Unit tumor activity ((90)Y radioactivity delivered to each cubic centimeter of tumor) was estimated based on a lobar infusion approach. Correlation between proportions of (99m)Tc-MAA and (90)Y delivered to the tumor was investigated. Survival analysis was performed using Kaplan-Meier estimations. RESULTS (90)Y therapy was administered in 18 consecutive patients (median age, 55.3 y; mean tumor volume, 588 cm(3)). Higher intratumoral (90)Y dose predicted prolonged survival, with 13.2-month median survival in patients with HCC and mean (90)Y dose of ≥ 100 Gy versus 4.6-month median survival for other patients (P < .001). Of administered (90)Y dose, 51.9% was delivered to the targeted tumors compared with 74.1% of (99m)Tc-MAA with linear correlation between biodistribution of (99m)Tc-MAA and (90)Y observed (Pearson r = 0.774, P < .001). CONCLUSIONS The findings in this study suggest that approximately 50% of administered (90)Y dose is taken up by targeted infiltrative HCC with PVT. Intratumoral (90)Y dose ≥ 100 Gy in unresectable infiltrative HCC via a lobar intraarterial approach is a positive prognostic factor for survival.
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Cremonesi M, Chiesa C, Strigari L, Ferrari M, Botta F, Guerriero F, De Cicco C, Bonomo G, Orsi F, Bodei L, Di Dia A, Grana CM, Orecchia R. Radioembolization of hepatic lesions from a radiobiology and dosimetric perspective. Front Oncol 2014; 4:210. [PMID: 25191640 PMCID: PMC4137387 DOI: 10.3389/fonc.2014.00210] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/23/2014] [Indexed: 12/18/2022] Open
Abstract
Radioembolization (RE) of liver cancer with 90Y-microspheres has been applied in the last two decades with notable responses and acceptable toxicity. Two types of microspheres are available, glass and resin, the main difference being the activity/sphere. Generally, administered activities are established by empirical methods and differ for the two types. Treatment planning based on dosimetry is a prerogative of few centers, but has notably gained interest, with evidence of predictive power of dosimetry on toxicity, lesion response, and overall survival (OS). Radiobiological correlations between absorbed doses and toxicity to organs at risk, and tumor response, have been obtained in many clinical studies. Dosimetry methods have evolved from the macroscopic approach at the organ level to voxel analysis, providing absorbed dose spatial distributions and dose–volume histograms (DVH). The well-known effects of the external beam radiation therapy (EBRT), such as the volume effect, underlying disease influence, cumulative damage in parallel organs, and different tolerability of re-treatment, have been observed also in RE, identifying in EBRT a foremost reference to compare with. The radiobiological models – normal tissue complication probability and tumor control probability – and/or the style (DVH concepts) used in EBRT are introduced in RE. Moreover, attention has been paid to the intrinsic different activity distribution of resin and glass spheres at the microscopic scale, with dosimetric and radiobiological consequences. Dedicated studies and mathematical models have developed this issue and explain some clinical evidences, e.g., the shift of dose to higher toxicity thresholds using glass as compared to resin spheres. This paper offers a comprehensive review of the literature incident to dosimetry and radiobiological issues in RE, with the aim to summarize the results and to identify the most useful methods and information that should accompany future studies.
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Affiliation(s)
| | | | - Lidia Strigari
- Istituto Nazionale dei Tumori Regina Elena , Rome , Italy
| | | | | | | | | | | | - Franco Orsi
- Istituto Europeo di Oncologia , Milan , Italy
| | - Lisa Bodei
- Istituto Europeo di Oncologia , Milan , Italy
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Technical Considerations of Phosphorous-32 Bremsstrahlung SPECT Imaging after Radioembolization of Hepatic Tumors: A Clinical Assessment with a Review of Imaging Parameters. Radiol Res Pract 2014; 2014:407158. [PMID: 24800073 PMCID: PMC3985385 DOI: 10.1155/2014/407158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/15/2014] [Accepted: 02/19/2014] [Indexed: 12/12/2022] Open
Abstract
Background. Bremsstrahlung (BS) imaging during radioembolization (RE) confirms the deposition of radiotracer in hepatic/extrahepatic tumors. The aim of this study is to demonstrate (32)P images and to optimize the imaging parameters. Materials and Methods. Thirty-nine patients with variable types of hepatic tumors, treated with the intra-arterial injection of (32)P, were included. All patients underwent BS SPECT imaging 24-72 h after tracer administration, using low energy high resolution (LEHR) (18 patients) or medium energy general purpose (MEGP) (21 patients) collimators. A grading scale from 1 to 4 was used to express the compatibility of the (32)P images with those obtained from CT/MRI. Results. Although the image quality obtained with the MEGP collimator was visually and quantitatively better than with the LEHR (76% concordance score versus 71%, resp.), there was no statistically significant difference between them. Conclusion. The MEGP collimator is the first choice for BS SPECT imaging. However, if the collimator change is time consuming (as in a busy center) or an MEGP collimator is not available, the LEHR collimator could be practical with acceptable images, especially in a SPECT study. In addition, BS imaging is a useful method to confirm the proper distribution of radiotherapeutic agents and has good correlation with anatomical findings.
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19
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Sihver W, Pietzsch J, Krause M, Baumann M, Steinbach J, Pietzsch HJ. Radiolabeled Cetuximab Conjugates for EGFR Targeted Cancer Diagnostics and Therapy. Pharmaceuticals (Basel) 2014; 7:311-38. [PMID: 24603603 PMCID: PMC3978494 DOI: 10.3390/ph7030311] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/11/2014] [Accepted: 02/21/2014] [Indexed: 01/09/2023] Open
Abstract
The epidermal growth factor receptor (EGFR) has evolved over years into a main molecular target for the treatment of different cancer entities. In this regard, the anti-EGFR antibody cetuximab has been approved alone or in combination with: (a) chemotherapy for treatment of colorectal and head and neck squamous cell carcinoma and (b) with external radiotherapy for treatment of head and neck squamous cell carcinoma. The conjugation of radionuclides to cetuximab in combination with the specific targeting properties of this antibody might increase its therapeutic efficiency. This review article gives an overview of the preclinical studies that have been performed with radiolabeled cetuximab for imaging and/or treatment of different tumor models. A particularly promising approach seems to be the treatment with therapeutic radionuclide-labeled cetuximab in combination with external radiotherapy. Present data support an important impact of the tumor micromilieu on treatment response that needs to be further validated in patients. Another important challenge is the reduction of nonspecific uptake of the radioactive substance in metabolic organs like liver and radiosensitive organs like bone marrow and kidneys. Overall, the integration of diagnosis, treatment and monitoring as a theranostic approach appears to be a promising strategy for improvement of individualized cancer treatment.
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Affiliation(s)
- Wiebke Sihver
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany.
| | - Jens Pietzsch
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany.
| | - Mechthild Krause
- Department of Radiation Oncology and OncoRay, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden 01307, Germany.
| | - Michael Baumann
- Department of Radiation Oncology and OncoRay, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden 01307, Germany.
| | - Jörg Steinbach
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany.
| | - Hans-Jürgen Pietzsch
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany.
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20
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Ahmadzadehfar H, Duan H, Haug AR, Walrand S, Hoffmann M. The role of SPECT/CT in radioembolization of liver tumours. Eur J Nucl Med Mol Imaging 2014; 41 Suppl 1:S115-24. [PMID: 24442600 DOI: 10.1007/s00259-013-2675-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 12/17/2013] [Indexed: 01/14/2023]
Abstract
Radioembolization (RE) with (90)Y microspheres is a promising catheter-based therapeutic option for patients with unresectable primary and metastatic liver tumours. Its rationale arises from the dual blood supply of liver tissue through the hepatic artery and the portal vein. Metastatic hepatic tumours measuring >3 mm derive 80 - 100 % of their blood supply from the arterial rather than the portal hepatic circulation. Typically, an angiographic evaluation combined with (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) scan precedes therapy to map the tumour feeding vessels as well as to avoid the inadvertent deposition of microspheres in organs other than the liver. Prior to administration of (99m)Tc-MAA, prophylactic coil embolization of the gastroduodenal artery is recommended to avoid extrahepatic deposition of the microspheres. SPECT/CT allows direct correlation of anatomic and functional information in patients with unresectable liver disease. SPECT/CT is recommended to assess intrahepatic distribution as well as extrahepatic gastrointestinal uptake in these patients. Pretherapeutic SPECT/CT is an important component of treatment planning including catheter positioning and dose finding. A post-therapy bremsstrahlung (BS) scan should follow RE to verify the distribution of the administered tracer. BS SPECT/CT imaging enables better localization and definition of intrahepatic and possible extrahepatic sphere distribution and to a certain degree allows posttreatment dosimetry. In this paper we address the usefulness and significance of SPECT/CT in therapy planning and therapy monitoring of RE.
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21
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Abstract
Personalized dosimetry in radionuclide therapy has gained much attention in recent years. This attention has also an impact on peptide receptor radionuclide therapy (PRRT). This article reviews the PET-based imaging techniques that can be used for pretherapeutic prediction of doses in PRRT. More specifically the usage of (86)Y, (90)Y, (68)Ga, and (44)Sc are discussed: their characteristics for PET acquisition, the available peptides for labeling, the specifics of the imaging protocols, and the experiences gained from phantom and clinical studies. These techniques are evaluated with regard to their usefulness for dosimetry predictions in PRRT, and future perspectives are discussed.
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22
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Gleisner KS, Ljungberg M. Patient-specific whole-body attenuation correction maps from a CT system for conjugate-view-based activity quantification: method development and evaluation. Cancer Biother Radiopharm 2013; 27:652-64. [PMID: 23210927 DOI: 10.1089/cbr.2011.1082] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
For activity quantification based on planar scintillation camera measurements, photon attenuation is an important factor that needs to be corrected for in a patient- and organ-specific manner. One possibility for obtaining attenuation correction maps is to use X-ray CT scout images. Since the intensity of scout images is in relative numbers, their image values need to be multiplied by a factor to become quantitative and thus useful for attenuation correction. The calibration factor can for our current imaging system be obtained from a scanner system file, but is generally not available. For this purpose, a method based on the patient weight has been developed. Results based on 79 patient scout images show that the calibration factor thus determined correlates well with values that, in this case, are independently specified by the system. The accuracy of attenuation correction factors (ACFs) derived from the scout-based attenuation correction maps is evaluated by comparison to ACFs derived from three-dimensional CT studies. For photon energies of 208, 245, and 364 keV, scout-based ACFs are on average 1.2% and 0.5% from the CT-derived values, using the system-based and the weight-based values of the scout-image calibration factor, respectively. The imprecision is somewhat higher for the weight-based method, due to variability in the delineation of the patient contour used as a part of this method. In conclusion, X-ray scouts are found useful for attenuation correction with a satisfactory accuracy obtained, both using the new, weight-based method, and using the previous, system-based method, for determining the required calibration factor.
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23
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Zaknun JJ, Bodei L, Mueller-Brand J, Pavel ME, Baum RP, Hörsch D, O’Dorisio MS, O’Dorisiol TM, Howe JR, Cremonesi M, Kwekkeboom DJ. The joint IAEA, EANM, and SNMMI practical guidance on peptide receptor radionuclide therapy (PRRNT) in neuroendocrine tumours. Eur J Nucl Med Mol Imaging 2013; 40:800-16. [PMID: 23389427 PMCID: PMC3622744 DOI: 10.1007/s00259-012-2330-6] [Citation(s) in RCA: 489] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Peptide receptor radionuclide therapy (PRRNT) is a molecularly targeted radiation therapy involving the systemic administration of a radiolabelled peptide designed to target with high affinity and specificity receptors overexpressed on tumours. PRRNT employing the radiotagged somatostatin receptor agonists (90)Y-DOTATOC ([(90)Y-DOTA(0),Tyr(3)]-octreotide) or (177)Lu-DOTATATE ([(177)Lu-DOTA(0),Tyr(3),Thr(8)]-octreotide or [(177)Lu-DOTA(0),Tyr(3)]-octreotate) have been successfully used for the past 15 years to target metastatic or inoperable neuroendocrine tumours expressing the somatostatin receptor subtype 2. Accumulated evidence from clinical experience indicates that these tumours can be subjected to a high absorbed dose which leads to partial or complete objective responses in up to 30 % of treated patients. Survival analyses indicate that patients presenting with high tumour receptor expression at study entry and receiving (177)Lu-DOTATATE or (90)Y-DOTATOC treatment show significantly higher objective responses, leading to longer survival and improved quality of life. Side effects of PRRNT are typically seen in the kidneys and bone marrow. These, however, are usually mild provided adequate protective measures are undertaken. Despite the large body of evidence regarding efficacy and clinical safety, PRRNT is still considered an investigational treatment and its implementation must comply with national legislation, and ethical guidelines concerning human therapeutic investigations. This guidance was formulated based on recent literature and leading experts' opinions. It covers the rationale, indications and contraindications for PRRNT, assessment of treatment response and patient follow-up. This document is aimed at guiding nuclear medicine specialists in selecting likely candidates to receive PRRNT and to deliver the treatment in a safe and effective manner. This document is largely based on the book published through a joint international effort under the auspices of the Nuclear Medicine Section of the International Atomic Energy Agency.
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Affiliation(s)
- John J. Zaknun
- Nuclear Medicine Section, Division of Human Health, International Atomic Energy Agency, IAEA, Vienna, Austria
- Zentralklinik Bad Berka, Center for Molecular Radiotherapy and Molecular Imaging, ENETS Center of Excellence, Bad Berka, Germany
| | - L. Bodei
- Division of Nuclear Medicine, European Institute of Oncology, Milan, Italy
| | - J. Mueller-Brand
- Klinik und Institut für Nuklearmedizin, Universitätsspital Basel, Basel, Switzerland
| | - M. E. Pavel
- Campus Virchow Klinikum, Klinik für Gastroenterologie, Hepatologie, Endokrinologie, Diabetes und Stoffwechsel-erkrankungen, Charité Universitaetsmedizin Berlin, Berlin, Germany
| | - R. P. Baum
- Zentralklinik Bad Berka, Department of Internal Medicine, Gastroenterology and Endocrinology, ENETS Center of Excellence, Bad Berka, Germany
| | - D. Hörsch
- Zentralklinik Bad Berka, Department of Internal Medicine, Gastroenterology and Endocrinology, ENETS Center of Excellence, Bad Berka, Germany
| | - M. S. O’Dorisio
- RJ and LA Carver College of Medicine, Department of Pediatrics, University of Iowa, Iowa City, IA USA
| | - T. M. O’Dorisiol
- RJ and LA Carver College of Medicine, Department of Internal Medicine, University of Iowa, Iowa City, IA USA
| | - J. R. Howe
- RJ and LA Carver College of Medicine, Department of Surgical Oncology, University of Iowa, Iowa City, IA USA
| | - M. Cremonesi
- Service of Health Physics, European Institute of Oncology, Milan, Italy
| | - D. J. Kwekkeboom
- Department of Nuclear Medicine, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
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Quantitative comparison of PET and Bremsstrahlung SPECT for imaging the in vivo yttrium-90 microsphere distribution after liver radioembolization. PLoS One 2013; 8:e55742. [PMID: 23405207 PMCID: PMC3566032 DOI: 10.1371/journal.pone.0055742] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 12/30/2012] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND After yttrium-90 ((90)Y) microsphere radioembolization (RE), evaluation of extrahepatic activity and liver dosimetry is typically performed on (90)Y Bremsstrahlung SPECT images. Since these images demonstrate a low quantitative accuracy, (90)Y PET has been suggested as an alternative. The aim of this study is to quantitatively compare SPECT and state-of-the-art PET on the ability to detect small accumulations of (90)Y and on the accuracy of liver dosimetry. METHODOLOGY/PRINCIPAL FINDINGS SPECT/CT and PET/CT phantom data were acquired using several acquisition and reconstruction protocols, including resolution recovery and Time-Of-Flight (TOF) PET. Image contrast and noise were compared using a torso-shaped phantom containing six hot spheres of various sizes. The ability to detect extra- and intrahepatic accumulations of activity was tested by quantitative evaluation of the visibility and unique detectability of the phantom hot spheres. Image-based dose estimates of the phantom were compared to the true dose. For clinical illustration, the SPECT and PET-based estimated liver dose distributions of five RE patients were compared. At equal noise level, PET showed higher contrast recovery coefficients than SPECT. The highest contrast recovery coefficients were obtained with TOF PET reconstruction including resolution recovery. All six spheres were consistently visible on SPECT and PET images, but PET was able to uniquely detect smaller spheres than SPECT. TOF PET-based estimates of the dose in the phantom spheres were more accurate than SPECT-based dose estimates, with underestimations ranging from 45% (10-mm sphere) to 11% (37-mm sphere) for PET, and 75% to 58% for SPECT, respectively. The differences between TOF PET and SPECT dose-estimates were supported by the patient data. CONCLUSIONS/SIGNIFICANCE In this study we quantitatively demonstrated that the image quality of state-of-the-art PET is superior over Bremsstrahlung SPECT for the assessment of the (90)Y microsphere distribution after radioembolization.
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Bodei L, Cremonesi M, Grana CM, Chinol M, Baio SM, Severi S, Paganelli G. Yttrium-labelled peptides for therapy of NET. Eur J Nucl Med Mol Imaging 2012; 39 Suppl 1:S93-102. [PMID: 22388625 DOI: 10.1007/s00259-011-2002-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Peptide receptor radionuclide therapy (PRRT) consists in the systemic administration of a synthetic peptide, labelled with a suitable beta-emitting radionuclide, able to irradiate tumours and their metastases via the internalization through a specific receptor, overexpressed on the cell membrane. After 15 years of experience, we can state that PRRT with (90)Y-labelled peptides is generally well tolerated. Acute side effects are usually mild, some of which are related to the co-administration of amino acids, such as nausea. Others are related to the radiopeptide, such as fatigue or the exacerbation of an endocrine syndrome, which rarely occurs in functioning tumours. Chronic and permanent effects on target organs, particularly the kidneys and the bone marrow, are generally mild if the necessary precautions are taken. Currently, the potential risk to kidney and red marrow limits the amount of radioactivity that may be administered. However, when tumour masses are irradiated with adequate doses, volume reduction may be observed. (90)Y-octreotide has been the most widely used radiopeptide in the first 8-10 years of experience. Unfortunately, all of the published results derive from different and inhomogeneous phase I/II studies. Hence, a direct comparison is virtually impossible to date. Nevertheless, even with these limitations, objective responses are registered in 10-34% of patients. The optimal timing of (90)Y-DOTATOC in the management of somatostatin receptor (SSTR)-positive tumours and the way in which it should be integrated with other treatments have yet to be defined, and prospective phase II/III trials comparing the efficacy and toxicity of different schemes of (90)Y-DOTATOC administration are still warranted.
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Affiliation(s)
- Lisa Bodei
- Division of Nuclear Medicine, European Institute of Oncology, Via Ripamonti 435, 20141 Milan, Italy
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26
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Claudio Traino A, Boni G, Mariani G. Radiodosimetric estimates for radioembolic therapy of liver tumors: challenges and opportunities. J Nucl Med 2012; 53:509-11. [PMID: 22410462 DOI: 10.2967/jnumed.111.100537] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- A Claudio Traino
- Division of Health Physics University Hospital of Pisa Pisa, Italy
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Feasibility of bremsstrahlung dosimetry for direct dose estimation in patients undergoing treatment with 90Y-ibritumomab tiuxetan. Eur J Nucl Med Mol Imaging 2012; 39:956-66. [DOI: 10.1007/s00259-011-2040-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 12/13/2011] [Indexed: 10/14/2022]
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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: 55] [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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Fung GSK, Segars WP, Gullberg GT, Tsui BMW. Development of a model of the coronary arterial tree for the 4D XCAT phantom. Phys Med Biol 2011; 56:5651-63. [PMID: 21828911 PMCID: PMC3169781 DOI: 10.1088/0031-9155/56/17/012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A detailed three-dimensional (3D) model of the coronary artery tree with cardiac motion has great potential for applications in a wide variety of medical imaging research areas. In this work, we first developed a computer-generated 3D model of the coronary arterial tree for the heart in the extended cardiac-torso (XCAT) phantom, thereby creating a realistic computer model of the human anatomy. The coronary arterial tree model was based on two datasets: (1) a gated cardiac dual-source computed tomography (CT) angiographic dataset obtained from a normal human subject and (2) statistical morphometric data of porcine hearts. The initial proximal segments of the vasculature and the anatomical details of the boundaries of the ventricles were defined by segmenting the CT data. An iterative rule-based generation method was developed and applied to extend the coronary arterial tree beyond the initial proximal segments. The algorithm was governed by three factors: (1) statistical morphometric measurements of the connectivity, lengths and diameters of the arterial segments; (2) avoidance forces from other vessel segments and the boundaries of the myocardium, and (3) optimality principles which minimize the drag force at the bifurcations of the generated tree. Using this algorithm, the 3D computational model of the largest six orders of the coronary arterial tree was generated, which spread across the myocardium of the left and right ventricles. The 3D coronary arterial tree model was then extended to 4D to simulate different cardiac phases by deforming the original 3D model according to the motion vector map of the 4D cardiac model of the XCAT phantom at the corresponding phases. As a result, a detailed and realistic 4D model of the coronary arterial tree was developed for the XCAT phantom by imposing constraints of anatomical and physiological characteristics of the coronary vasculature. This new 4D coronary artery tree model provides a unique simulation tool that can be used in the development and evaluation of instrumentation and methods for imaging normal and pathological hearts with myocardial perfusion defects.
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Affiliation(s)
- George S K Fung
- Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.
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Walrand S, Flux GD, Konijnenberg MW, Valkema R, Krenning EP, Lhommel R, Pauwels S, Jamar F. Dosimetry of yttrium-labelled radiopharmaceuticals for internal therapy: 86Y or 90Y imaging? Eur J Nucl Med Mol Imaging 2011; 38 Suppl 1:S57-68. [DOI: 10.1007/s00259-011-1771-7] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 02/22/2011] [Indexed: 12/31/2022]
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Minarik D, Sjögreen-Gleisner K, Linden O, Wingårdh K, Tennvall J, Strand SE, Ljungberg M. 90Y Bremsstrahlung Imaging for Absorbed-Dose Assessment in High-Dose Radioimmunotherapy. J Nucl Med 2010; 51:1974-8. [DOI: 10.2967/jnumed.110.079897] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Rault E, Staelens S, Van Holen R, De Beenhouwer J, Vandenberghe S. Fast simulation of yttrium-90 bremsstrahlung photons with GATE. Med Phys 2010; 37:2943-50. [PMID: 20632606 DOI: 10.1118/1.3431998] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Multiple investigators have recently reported the use of yttrium-90 (90Y) bremsstrahlung single photon emission computed tomography (SPECT) imaging for the dosimetry of targeted radionuclide therapies. Because Monte Carlo (MC) simulations are useful for studying SPECT imaging, this study investigates the MC simulation of 90Y bremsstrahlung photons in SPECT. To overcome the computationally expensive simulation of electrons, the authors propose a fast way to simulate the emission of 90Y bremsstrahlung photons based on prerecorded bremsstrahlung photon probability density functions (PDFs). METHODS The accuracy of bremsstrahlung photon simulation is evaluated in two steps. First, the validity of the fast bremsstrahlung photon generator is checked. To that end, fast and analog simulations of photons emitted from a 90Y point source in a water phantom are compared. The same setup is then used to verify the accuracy of the bremsstrahlung photon simulations, comparing the results obtained with PDFs generated from both simulated and measured data to measurements. In both cases, the energy spectra and point spread functions of the photons detected in a scintillation camera are used. RESULTS Results show that the fast simulation method is responsible for a 5% overestimation of the low-energy fluence (below 75 keV) of the bremsstrahlung photons detected using a scintillation camera. The spatial distribution of the detected photons is, however, accurately reproduced with the fast method and a computational acceleration of approximately 17-fold is achieved. When measured PDFs are used in the simulations, the simulated energy spectrum of photons emitted from a point source of 90Y in a water phantom and detected in a scintillation camera closely approximates the measured spectrum. The PSF of the photons imaged in the 50-300 keV energy window is also accurately estimated with a 12.4% underestimation of the full width at half maximum and 4.5% underestimation of the full width at tenth maximum. CONCLUSIONS Despite its limited accuracy, the fast bremsstrahlung photon generator is well suited for the simulation of bremsstrahlung photons emitted in large homogeneous organs, such as the liver, and detected in a scintillation camera. The computational acceleration makes it very useful for future investigations of 90Y bremsstrahlung SPECT imaging.
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Affiliation(s)
- Erwann Rault
- Department of Electronics and Information Systems, MEDISIP Ghent University-IBBT-IBiTech, De Pintelaan 185, Block B, B-9000 Ghent, Belgium.
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