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Kim TP, Enger SA. Characterizing the voxel-based approaches in radioembolization dosimetry with reDoseMC. Med Phys 2024; 51:4007-4027. [PMID: 38703394 DOI: 10.1002/mp.17054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 02/15/2024] [Accepted: 02/20/2024] [Indexed: 05/06/2024] Open
Abstract
BACKGROUND Yttrium-90 (90 Y $^{90}{\rm {Y}}$ ) represents the primary radioisotope used in radioembolization procedures, while holmium-166 (166 Ho $^{166}{\rm {Ho}}$ ) is hypothesized to serve as a viable substitute for90 Y $^{90}{\rm {Y}}$ due to its comparable therapeutic potential and improved quantitative imaging. Voxel-based dosimetry for these radioisotopes relies on activity images obtained through PET or SPECT and dosimetry methods, including the voxel S-value (VSV) and the local deposition method (LDM). However, the evaluation of the accuracy of absorbed dose calculations has been limited by the use of non-ideal reference standards and investigations restricted to the liver. The objective of this study was to expand upon these dosimetry characterizations by investigating the impact of image resolutions, voxel sizes, target volumes, and tissue materials on the accuracy of90 Y $^{90}{\rm {Y}}$ and166 Ho $^{166}{\rm {Ho}}$ dosimetry techniques. METHODS A specialized radiopharmaceutical dosimetry software called reDoseMC was developed using the Geant4 Monte Carlo toolkit and validated by benchmarking the generated90 Y $^{90}{\rm {Y}}$ kernels with published data. The decay spectra of both90 Y $^{90}{\rm {Y}}$ and166 Ho $^{166}{\rm {Ho}}$ were also compared. Multiple VSV kernels were generated for the liver, lungs, soft tissue, and bone for isotropic voxel sizes of 1 mm, 2 mm, and 4 mm. Three theoretical phantom setups were created with 20 or 40 mm activity and mass density inserts for the same three voxel sizes. To replicate the limited spatial resolutions present in PET and SPECT images, image resolutions were modeled using a 3D Gaussian kernel with a Full Width at Half Maximum (FWHM) ranging from 0 to 16 mm and with no added noise. The VSV and LDM dosimetry methods were evaluated by characterizing their respective kernels and analyzing their absorbed dose estimates calculated on theoretical phantoms. The ground truth for these estimations was calculated using reDoseMC. RESULTS The decay spectra obtained through reDoseMC showed less than a 1% difference when compared to previously published experimental data for energies below 1.9 MeV in the case of90 Y $^{90}{\rm {Y}}$ and less than 1% for energies below 1.5 MeV for166 Ho $^{166}{\rm {Ho}}$ . Additionally, the validation kernels for90 Y $^{90}{\rm {Y}}$ VSV exhibited results similar to those found in published Monte Carlo codes, with source dose depositions having less than a 3% error margin. Resolution thresholds (FWHM thresh s ${\rm {FWHM}}_\mathrm{thresh}{\rm {s}}$ ), defined as resolutions that resulted in similar dose estimates between the LDM and VSV methods, were observed for90 Y $^{90}{\rm {Y}}$ . They were 1.5 mm for bone, 2.5 mm for soft tissue and liver, and 8.5 mm for lungs. For166 Ho $^{166}{\rm {Ho}}$ , the accuracy of absorbed dose deposition was found to be dependent on the contributions of absorbed dose from photons. Volume errors due to variations in voxel size impacted the final dose estimates. Larger target volumes yielded more accurate mean doses than smaller volumes. For both radioisotopes, the radial dose profiles for the VSV and LDM approximated but never matched the reference standard. CONCLUSIONS reDoseMC was developed and validated for radiopharmaceutical dosimetry. The accuracy of voxel-based dosimetry was found to vary widely with changes in image resolutions, voxel sizes, chosen target volumes, and tissue material; hence, the standardization of dosimetry protocols was found to be of great importance for comparable dosimetry analysis.
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Affiliation(s)
- Taehyung Peter Kim
- Medical Physics Unit, Department of Oncology, McGill University, Montreal, Québec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada
| | - Shirin A Enger
- Medical Physics Unit, Department of Oncology, McGill University, Montreal, Québec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada
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Gustafsson J, Taprogge J. Future trends for patient-specific dosimetry methodology in molecular radiotherapy. Phys Med 2023; 115:103165. [PMID: 37880071 DOI: 10.1016/j.ejmp.2023.103165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 10/03/2023] [Accepted: 10/17/2023] [Indexed: 10/27/2023] Open
Abstract
Molecular radiotherapy is rapidly expanding, and new radiotherapeutics are emerging. The majority of treatments is still performed using empirical fixed activities and not tailored for individual patients. Molecular radiotherapy dosimetry is often seen as a promising candidate that would allow personalisation of treatments as outcome should ultimately depend on the absorbed doses delivered and not the activities administered. The field of molecular radiotherapy dosimetry has made considerable progress towards the feasibility of routine clinical dosimetry with reasonably accurate absorbed-dose estimates for a range of molecular radiotherapy dosimetry applications. A range of challenges remain with respect to the accurate quantification, assessment of time-integrated activity and absorbed dose estimation. In this review, we summarise a range of technological and methodological advancements, mainly focussed on beta-emitting molecular radiotherapeutics, that aim to improve molecular radiotherapy dosimetry to achieve accurate, reproducible, and streamlined dosimetry. We describe how these new technologies can potentially improve the often time-consuming considered process of dosimetry and provide suggestions as to what further developments might be required.
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Affiliation(s)
| | - Jan Taprogge
- National Radiotherapy Trials Quality Assurance (RTTQA) Group, Joint Department of Physics, Royal Marsden NHSFT, Downs Road, Sutton SM2 5PT, United Kingdom; The Institute of Cancer Research, 123 Old Brompton Road, London SW7 3RP, United Kingdom
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Gustafsson J, Ljungberg M, Alm Carlsson G, Larsson E, Warfvinge CF, Asp P, Sjögreen Gleisner K. Averaging of absorbed doses: How matter matters. Med Phys 2023; 50:6600-6613. [PMID: 37272586 DOI: 10.1002/mp.16528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 04/05/2023] [Accepted: 05/10/2023] [Indexed: 06/06/2023] Open
Abstract
BACKGROUND Dosimetry in radionuclide therapy often requires the calculation of average absorbed doses within and between spatial regions, for example, for voxel-based dosimetry methods, for paired organs, or across multiple tumors. Formation of such averages can be made in different ways, starting from different definitions. PURPOSE The aim of this study is to formally specify different averaging strategies for absorbed doses, and to compare their results when applied to absorbed dose distributions that are non-uniform within and between regions. METHODS For averaging within regions, two definitions of the average absorbed dose are considered: the simple average over the region (the region average) and the average when weighting by the mass density (density-weighted region average). The latter is shown to follow from the definition of mean absorbed dose according to the ICRU, and to be consistent with the MIRD formalism. For averaging between different spatial regions, three definitions follow: the volume-weighted, the mass-weighted, and the unweighted average. With respect to characterizing non-uniformity, the different average definitions lead to the use of dose-volume histograms (DVHs) (region average), dose-mass histograms (DMHs) (density-weighted region average), and unweighted histograms (unweighted average). Average absorbed doses are calculated for three worked examples, starting from the different definitions. The first, schematic, example concerns the calculation of the average absorbed dose between two regions with different volumes or mass densities. The second, stylized, example concerns voxel-based dosimetry, for which the average absorbed-dose rate within a region is calculated. The geometries studied include three 177 Lu-filled voxelized spheres, where the sphere masses are held constant while the material compositions, densities, and volumes are varied. For comparison, the mean absorbed-dose rates obtained using unit-density sphere S-values are also included. The third example concerns SPECT/CT-based tumor dosimetry for five patients undergoing therapy with 177 Lu-PSMA and six patients undergoing therapy with 177 Lu-DOTA-TATE, for which the average absorbed-dose rates across multiple tumors are calculated. For the second and third examples, analyses also include representations by histograms. RESULTS Example 1 shows that the average absorbed doses, calculated using different definitions, can differ considerably if the masses and absorbed doses for two regions are markedly different. From example 2 it is seen that the density-weighted region average is stable under different activity and density distributions and is also in line with results using S-values. In contrast, the region average varies as function of the activity distribution. In example 3, the absorbed dose rates for individual tumors differ by (1.1 ± 4.3)% and (-0.1 ± 0.4)% with maximum deviations of +34.4% and -1.4% for 177 Lu-PSMA and 177 Lu-DOTA-TATE, respectively, when calculated as region averages or density-weighted region averages, with largest deviations obtained when the density is non-uniform. The average absorbed doses calculated across all tumors are similar when comparing mass-weighted and volume-weighted averages but these differ substantially from unweighted averages. CONCLUSION Different strategies for averaging of absorbed doses within and between regions can lead to substantially different absorbed-dose estimates. At reporting of radionuclide therapy dosimetry, it is important to specify the averaging strategy applied.
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Affiliation(s)
| | | | - Gudrun Alm Carlsson
- Department of Radiation Physics, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Erik Larsson
- Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Carl Fredrik Warfvinge
- Division of Oncology and Pathology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Pernilla Asp
- Division of Oncology and Pathology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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Staanum PF. Tumor dosimetry using 177Lu: influence of background activity, measurement method and reconstruction algorithm. EJNMMI Phys 2023; 10:39. [PMID: 37341930 DOI: 10.1186/s40658-023-00561-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/13/2023] [Indexed: 06/22/2023] Open
Abstract
BACKGROUND Image-based tumor dosimetry after radionuclide therapy, using the isotope 177Lu, finds application e.g., for tumor-to-organ dose comparison and for dose response evaluation. When the tumor extent is not much larger than the image resolution, and when 177Lu is found in nearby organs or other tumors, an accurate determination of tumor dose is particularly challenging. Here a quantitative evaluation of three different methods for determining the 177Lu activity concentration in a phantom is performed, and the dependence on a variety of parameters is described. The phantom (NEMA IEC body phantom) has spheres of different size in a background volume, and sphere-to-background 177Lu activity concentration ratios of infinity, 9.5, 5.0 and 2.7 are applied. The methods are simple to implement and well-known from the literature. They are based on (1) a large VOI encompassing the whole sphere, without background activity and with volume information from other sources, (2) a small VOI located in the sphere center, and (3) a VOI consisting of voxels with voxel value above a certain percentage of the maximum voxel value. RESULTS The determined activity concentration varies significantly with sphere size, sphere-to-background ratio, SPECT reconstruction method and method for determining the concentration. Based on the phantom study, criteria are identified under which the activity concentration can be determined with a maximal error of 40% even in the presence of background activity. CONCLUSIONS Tumor dosimetry is feasible in the presence of background activity using the above-mentioned methods, provided appropriate SPECT reconstructions are applied and tumors are selected for dosimetry analysis according to the following criteria for the three methods: (1) solitary tumor with diameter > 15 mm, (2) tumor diameter > 30 mm and tumor-to-background ratio > 2, and (3) tumor diameter > 30 mm and tumor-to-background ratio > 3.
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Affiliation(s)
- Peter Frøhlich Staanum
- Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, 8200, Aarhus N, Denmark.
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Mínguez Gabiña P, Monserrat Fuertes T, Jauregui I, Del Amo C, Rodeño Ortiz de Zarate E, Gustafsson J. Activity recovery for differently shaped objects in quantitative SPECT. Phys Med Biol 2023; 68:125012. [PMID: 37236207 DOI: 10.1088/1361-6560/acd982] [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: 01/29/2023] [Accepted: 05/26/2023] [Indexed: 05/28/2023]
Abstract
Objective.The aim was to theoretically and experimentally investigate recovery in SPECT images with objects of different shapes. Furthermore, the accuracy of volume estimation by thresholding was studied for those shapes.Approach.Nine spheres, nine oblate spheroids, and nine prolate spheroids phantom inserts were used, of which the six smaller spheres were part of the NEMA IEC body phantom and the rest of the inserts were 3D-printed. The inserts were filled with99mTc and177Lu. When filled with99mTc, SPECT images were acquired in a Siemens Symbia Intevo Bold gamma camera and when filled with177Lu in a General Electric NM/CT 870 DR gamma camera. The signal rate per activity (SRPA) was determined for all inserts and represented as a function of the volume-to-surface ratio and of the volume-equivalent radius using VOIs defined according to the sphere dimensions and VOIs defined using thresholding. Experimental values were compared with theoretical curves obtained analytically (spheres) or numerically (spheroids), starting from the convolution of a source distribution with a point-spread function. Validation of the activity estimation strategy was performed using four 3D-printed ellipsoids. Lastly, the threshold values necessary to determine the volume of each insert were obtained.Main results.Results showed that SRPA values for the oblate spheroids diverted from the other inserts, when SRPA were represented as a function of the volume-equivalent radius. However, SRPA values for all inserts followed a similar behaviour when represented as a function of the volume-to-surface ratio. Results for ellipsoids were in agreement with those results. For the three types of inserts the volume could be accurately estimated using a threshold method for volumes larger than 25 ml.Significance.Determination of SRPA independently of lesion or organ shape should decrease uncertainties in estimated activities and thereby, in the long term, be beneficial to patient care.
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Affiliation(s)
- Pablo Mínguez Gabiña
- Department of Medical Physics and Radiation Protection, Gurutzeta-Cruces University Hospital/ Biocruces Bizkaia Health Research Institute, Plaza Cruces s/n, E-48903 Barakaldo, Spain
- Faculty of Engineering, Department of Applied Physics, UPV/EHU, Bilbao, Spain
| | - Teresa Monserrat Fuertes
- Department of Medical Physics and Radiation Protection, Central University Hospital of Asturias, Oviedo, Spain
- Faculty of Medicine and Nursing, Department of Surgery, Radiology and Physical Medicine, UPV/EHU, Bilbao, Spain
| | - Inés Jauregui
- 3D Printing and Bioprinting Laboratory, Biocruces Bizkaia Health Research Institute, Plaza Cruces s/n, E-48903 Barakaldo, Spain
| | - Cristina Del Amo
- 3D Printing and Bioprinting Laboratory, Biocruces Bizkaia Health Research Institute, Plaza Cruces s/n, E-48903 Barakaldo, Spain
| | - Emilia Rodeño Ortiz de Zarate
- Department of Nuclear Medicine, Gurutzeta-Cruces University Hospital/ Biocruces Bizkaia Health Research Institute, Plaza Cruces s/n, E-48903 Barakaldo, Spain
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Adam DP, Hammer C, Malyshev JZ, Culberson WS, Bradshaw TJ, Grudzinski JJ, Harari PM, Bednarz BP. Creation of waterproof, TLD probes for dose measurements to validate image-based radiopharmaceutical therapy dosimetry workflow. Biomed Phys Eng Express 2023; 9:10.1088/2057-1976/accf22. [PMID: 37084718 PMCID: PMC11186108 DOI: 10.1088/2057-1976/accf22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 04/21/2023] [Indexed: 04/23/2023]
Abstract
Voxel-level dosimetry based on nuclear medicine images offers patient-specific personalization of radiopharmaceutical therapy (RPT) treatments. Clinical evidence is emerging demonstrating improvements in treatment precision in patients when voxel-level dosimetry is used compared to MIRD. Voxel-level dosimetry requires absolute quantification of activity concentrations in the patient, but images from SPECT/CT scanners are not quantitative and require calibration using nuclear medicine phantoms. While phantom studies can validate a scanner's ability to recover activity concentrations, these studies provide only a surrogate for the true metric of interest: absorbed doses. Measurements using thermoluminescent dosimeters (TLDs) are a versatile and accurate method of measuring absorbed dose. In this work, a TLD probe was manufactured that can fit into currently available nuclear medicine phantoms for the measurement of absorbed dose of RPT agents. Next, 748 MBq of I-131 was administered to a 16 ml hollow source sphere placed in a 6.4 L Jaszczak phantom in addition to six TLD probes, each holding 4 TLD-100 1 × 1 × 1 mm TLD-100 (LiF:Mg,Ti) microcubes. The phantom then underwent a SPECT/CT scan in accordance with a standard SPECT/CT imaging protocol for I-131. The SPECT/CT images were then input into a Monte Carlo based RPT dosimetry platform named RAPID and a three dimensional dose distribution in the phantom was estimated. Additionally, a GEANT4 benchmarking scenario (denoted 'idealized') was created using a stylized representation of the phantom. There was good agreement for all six probes, the differences between measurement and RAPID ranged between -5.5% and 0.9%. The difference between the measured and the idealized GEANT4 scenario was calculated and ranged from -4.3% and -20.5%. This work demonstrates good agreement between TLD measurements and RAPID. In addition, it introduces a novel TLD probe that can be easily introduced into clinical nuclear medicine workflows to provide QA of image-based dosimetry for RPT treatments.
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Affiliation(s)
- David P Adam
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705, United States of America
| | - Clifford Hammer
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705, United States of America
| | - Julia Ziege Malyshev
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705, United States of America
| | - Wesley S Culberson
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705, United States of America
| | - Tyler J Bradshaw
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, 53705, United States of America
| | - Joseph J Grudzinski
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, 53705, United States of America
| | - Paul M Harari
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI, 53705, United States of America
| | - Bryan P Bednarz
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705, United States of America
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Chakraborty K, Mondal J, An JM, Park J, Lee YK. Advances in Radionuclides and Radiolabelled Peptides for Cancer Therapeutics. Pharmaceutics 2023; 15:pharmaceutics15030971. [PMID: 36986832 PMCID: PMC10054444 DOI: 10.3390/pharmaceutics15030971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/13/2023] [Accepted: 03/15/2023] [Indexed: 03/19/2023] Open
Abstract
Radiopharmaceutical therapy, which can detect and treat tumours simultaneously, was introduced more than 80 years ago, and it has changed medical strategies with respect to cancer. Many radioactive radionuclides have been developed, and functional, molecularly modified radiolabelled peptides have been used to produce biomolecules and therapeutics that are vastly utilised in the field of radio medicine. Since the 1990s, they have smoothly transitioned into clinical application, and as of today, a wide variety of radiolabelled radionuclide derivatives have been examined and evaluated in various studies. Advanced technologies, such as conjugation of functional peptides or incorporation of radionuclides into chelating ligands, have been developed for advanced radiopharmaceutical cancer therapy. New radiolabelled conjugates for targeted radiotherapy have been designed to deliver radiation directly to cancer cells with improved specificity and minimal damage to the surrounding normal tissue. The development of new theragnostic radionuclides, which can be used for both imaging and therapy purposes, allows for more precise targeting and monitoring of the treatment response. The increased use of peptide receptor radionuclide therapy (PRRT) is also important in the targeting of specific receptors which are overexpressed in cancer cells. In this review, we provide insights into the development of radionuclides and functional radiolabelled peptides, give a brief background, and describe their transition into clinical application.
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Affiliation(s)
- Kushal Chakraborty
- Department of IT and Energy Convergence (BK21 FOUR), Korea National University of Transportation, Chungju 27469, Republic of Korea
| | - Jagannath Mondal
- Department of Green Bio Engineering, Graduate School, Korea National University of Transportation, Chungju 27469, Republic of Korea
- 4D Convergence Technology Institute, Korea National University of Transportation, Jeungpyeong 27909, Republic of Korea
| | - Jeong Man An
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul 04763, Republic of Korea
| | - Jooho Park
- Department of Applied Life Science, Graduate School, BK21 Program, Konkuk University, Chungju 27478, Republic of Korea
- Research Institute for Biomedical & Health Science, Konkuk University, Chungju 27478, Republic of Korea
- Correspondence: (J.P.); (Y.-K.L.); Tel.: +82-43-841-5224 (Y.-K.L.)
| | - Yong-Kyu Lee
- Department of Green Bio Engineering, Graduate School, Korea National University of Transportation, Chungju 27469, Republic of Korea
- 4D Convergence Technology Institute, Korea National University of Transportation, Jeungpyeong 27909, Republic of Korea
- Correspondence: (J.P.); (Y.-K.L.); Tel.: +82-43-841-5224 (Y.-K.L.)
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Stenvall A, Gustafsson J, Larsson E, Roth D, Sundlöv A, Jönsson L, Hindorf C, Ohlsson T, Sjögreen Gleisner K. Relationships between uptake of [ 68Ga]Ga-DOTA-TATE and absorbed dose in [ 177Lu]Lu-DOTA-TATE therapy. EJNMMI Res 2022; 12:75. [PMID: 36534192 PMCID: PMC9763525 DOI: 10.1186/s13550-022-00947-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Somatostatin receptor 68Ga PET imaging is standard for evaluation of a patient's suitability for 177Lu peptide receptor radionuclide therapy of neuroendocrine tumours (NETs). The 68Ga PET serves to ensure sufficient somatostatin receptor expression, commonly evaluated qualitatively. The aim of this study is to investigate the quantitative relationships between uptake in 68Ga PET and absorbed doses in 177Lu therapy. METHOD Eighteen patients underwent [68Ga]Ga-DOTA-TATE PET imaging within 20 weeks prior to their first cycle of [177Lu]Lu-DOTA-TATE. Absorbed doses for therapy were estimated for tumours, kidney, spleen, and normal liver parenchyma using a hybrid SPECT/CT-planar method. Gallium-68 activity concentrations were retrieved from PET images and also used to calculate SUVs and normalized SUVs, using blood and tissue for normalization. The 68Ga activity concentrations per injected activity, SUVs, and normalized SUVs were compared with 177Lu activity concentrations 1 d post-injection and 177Lu absorbed doses. For tumours, for which there was a variable number per patient, both inter- and intra-patient correlations were analysed. Furthermore, the prediction of 177Lu tumour absorbed doses based on a combination of tumour-specific 68Ga activity concentrations and group-based estimates of the effective half-lives for grade 1 and 2 NETs was explored. RESULTS For normal organs, only spleen showed a significant correlation between the 68Ga activity concentration and 177Lu absorbed dose (r = 0.6). For tumours, significant, but moderate, correlations were obtained, with respect to both inter-patient (r = 0.7) and intra-patient (r = 0.45) analyses. The correlations to absorbed doses did not improve when using 68Ga SUVs or normalized SUVs. The relationship between activity uptakes for 68Ga PET and 177Lu SPECT was stronger, with correlation coefficients r = 0.8 for both inter- and intra-patient analyses. The 177Lu absorbed dose to tumour could be predicted from the 68Ga activity concentrations with a 95% coverage interval of - 65% to 248%. CONCLUSIONS On a group level, a high uptake of [68Ga]Ga-DOTA-TATE is associated with high absorbed doses at 177Lu-DOTA-TATE therapy, but the relationship has a limited potential with respect to individual absorbed dose planning. Using SUV or SUV normalized to reference tissues do not improve correlations compared with using activity concentration per injected activity.
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Affiliation(s)
- Anna Stenvall
- grid.4514.40000 0001 0930 2361Medical Radiation Physics, Lund, Lund University, Lund, Sweden ,grid.411843.b0000 0004 0623 9987Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Johan Gustafsson
- grid.4514.40000 0001 0930 2361Medical Radiation Physics, Lund, Lund University, Lund, Sweden
| | - Erik Larsson
- grid.411843.b0000 0004 0623 9987Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Daniel Roth
- grid.4514.40000 0001 0930 2361Medical Radiation Physics, Lund, Lund University, Lund, Sweden
| | - Anna Sundlöv
- grid.4514.40000 0001 0930 2361Division of Oncology, Department of Clinical Sciences, Lund, Lund University, Lund, Sweden
| | - Lena Jönsson
- grid.4514.40000 0001 0930 2361Medical Radiation Physics, Lund, Lund University, Lund, Sweden ,grid.411843.b0000 0004 0623 9987Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Cecilia Hindorf
- grid.4514.40000 0001 0930 2361Medical Radiation Physics, Lund, Lund University, Lund, Sweden ,grid.24381.3c0000 0000 9241 5705Department of Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Tomas Ohlsson
- grid.411843.b0000 0004 0623 9987Radiation Physics, Skåne University Hospital, Lund, Sweden
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Ramonaheng K, van Staden JA, du Raan H. Accuracy of two dosimetry software programs for 177Lu radiopharmaceutical therapy using voxel-based patient-specific phantoms. Heliyon 2022; 8:e09830. [PMID: 35865988 PMCID: PMC9293745 DOI: 10.1016/j.heliyon.2022.e09830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 02/18/2022] [Accepted: 06/24/2022] [Indexed: 12/01/2022] Open
Abstract
Purpose Virtual dosimetry using voxel-based patient-specific phantoms and Monte Carlo (MC) simulations offer the advantage of having a gold standard against which absorbed doses may be benchmarked to establish the dosimetry accuracy. Furthermore, these reference values assist in investigating the accuracy of the absorbed dose methodologies from different software programs. Therefore, this study aimed to compare the accuracy of the absorbed doses computed using LundADose and OLINDA/EXM 1.0. Methods The accuracy was based on 177Lu-DOTATATE distributions of three voxel-based phantoms. SPECT projection images were simulated for 1, 24, 96, and 168 h post-administration and reconstructed with LundADose using 3D OS-EM reconstruction. Mono-exponential curves were fitted to the bio-kinetic data for the kidneys, liver, spleen, and tumours resulting in SPECT time-integrated activity (SPECT-TIA). The SPECT-TIA were used to compute mean absorbed doses using LundADose (LND-DSPECT) and OLINDA (OLINDA-DSPECT) for the organs. Pre-defined true activity images, were used to obtain TRUE-TIA and, together with full MC simulations, computed the true doses (MC-DTrue). The dosimetry accuracy was assessed by comparing LND-DSPECT and OLINDA-DSPECT to MC-DTrue. Results Overall, the results presented an overestimation of the mean absorbed dose by LND-DSPECT compared to the MC-DTrue with a dosimetry accuracy ≤6.6%. This was attributed to spill-out activity from the reconstructed LND-DSPECT, resulting in a higher dose contribution than the MC-DTrue. There was a general underestimation (<8.1%) of OLINDA-DSPECT compared to MC-DTrue attributed to the geometrical difference in shape between the voxel-based phantoms and the OLINDA models. Furthermore, OLINDA-DSPECT considers self-doses while MC-DTrue reflects self-doses plus cross-doses. Conclusion The better than 10% accuracy suggests that the mean dose values obtained with LND-DSPECT and OLINDA-DSPECT approximate the true values. The mean absorbed doses of the two software programs, and the gold standard were comparable. This work shall be of use for optimising 177Lu dosimetry for clinical applications.
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Affiliation(s)
- Keamogetswe Ramonaheng
- Department of Medical Physics, Faculty of Health Sciences, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Johannes A van Staden
- Department of Medical Physics, Faculty of Health Sciences, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Hanlie du Raan
- Department of Medical Physics, Faculty of Health Sciences, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
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Adam DP, Grudzinski J, Bormett I, Cox BL, Marsh IR, Bradshaw TJ, Harari PM, Bednarz B. Validation of Monte Carlo 131 I radiopharmaceutical dosimetry workflow using a 3D printed anthropomorphic head and neck phantom. Med Phys 2022; 49:5491-5503. [PMID: 35607296 PMCID: PMC9388595 DOI: 10.1002/mp.15699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 04/11/2022] [Accepted: 04/14/2022] [Indexed: 11/11/2022] Open
Abstract
Purpose Approximately 50% of head and neck cancer (HNC) patients will experience loco‐regional disease recurrence following initial courses of therapy. Retreatment with external beam radiotherapy (EBRT) is technically challenging and may be associated with a significant risk of irreversible damage to normal tissues. Radiopharmaceutical therapy (RPT) is a potential method to treat recurrent HNC in conjunction with EBRT. Phantoms are used to calibrate and add quantification to nuclear medicine images, and anthropomorphic phantoms can account for both the geometrical and material composition of the head and neck. In this study, we present the creation of an anthropomorphic, head and neck, nuclear medicine phantom, and its characterization for the validation of a Monte Carlo, SPECT image‐based, 131I RPT dosimetry workflow. Methods 3D‐printing techniques were used to create the anthropomorphic phantom from a patient CT dataset. Three 131I SPECT/CT imaging studies were performed using a homogeneous, Jaszczak, and an anthropomorphic phantom to quantify the SPECT images using a GE Optima NM/CT 640 with a high energy general purpose collimator. The impact of collimator detector response (CDR) modeling and volume‐based partial volume corrections (PVCs) upon the absorbed dose was calculated using an image‐based, Geant4 Monte Carlo RPT dosimetry workflow and compared against a ground truth scenario. Finally, uncertainties were quantified in accordance with recent EANM guidelines. Results The 3D‐printed anthropomorphic phantom was an accurate re‐creation of patient anatomy including bone. The extrapolated Jaszczak recovery coefficients were greater than that of the 3D‐printed insert (∼22.8 ml) for both the CDR and non‐CDR cases (with CDR: 0.536 vs. 0.493, non‐CDR: 0.445 vs. 0.426, respectively). Utilizing Jaszczak phantom PVCs, the absorbed dose was underpredicted by 0.7% and 4.9% without and with CDR, respectively. Utilizing anthropomorphic phantom recovery coefficient overpredicted the absorbed dose by 3% both with and without CDR. All dosimetry scenarios that incorporated PVC were within the calculated uncertainty of the activity. The uncertainties in the cumulative activity ranged from 23.6% to 106.4% for Jaszczak spheres ranging in volume from 0.5 to 16 ml. Conclusion The accuracy of Monte Carlo‐based dosimetry for 131I RPT in HNC was validated with an anthropomorphic phantom. In this study, it was found that Jaszczak‐based PVCs were sufficient. Future applications of the phantom could involve 3D printing and characterizing patient‐specific volumes for more personalized RPT dosimetry estimates.
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Affiliation(s)
- David P Adam
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705
| | - Joseph Grudzinski
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, 53705
| | - Ian Bormett
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI, 53705
| | - Benjamin L Cox
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI, 53705
| | - Ian R Marsh
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705
| | - Tyler J Bradshaw
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, 53705
| | - Paul M Harari
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI, 53705
| | - Bryan Bednarz
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705
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11
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EANM dosimetry committee recommendations for dosimetry of 177Lu-labelled somatostatin-receptor- and PSMA-targeting ligands. Eur J Nucl Med Mol Imaging 2022; 49:1778-1809. [PMID: 35284969 PMCID: PMC9015994 DOI: 10.1007/s00259-022-05727-7] [Citation(s) in RCA: 79] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 02/13/2022] [Indexed: 12/25/2022]
Abstract
The purpose of the EANM Dosimetry Committee is to provide recommendations and guidance to scientists and clinicians on patient-specific dosimetry. Radiopharmaceuticals labelled with lutetium-177 (177Lu) are increasingly used for therapeutic applications, in particular for the treatment of metastatic neuroendocrine tumours using ligands for somatostatin receptors and prostate adenocarcinoma with small-molecule PSMA-targeting ligands. This paper provides an overview of reported dosimetry data for these therapies and summarises current knowledge about radiation-induced side effects on normal tissues and dose-effect relationships for tumours. Dosimetry methods and data are summarised for kidneys, bone marrow, salivary glands, lacrimal glands, pituitary glands, tumours, and the skin in case of radiopharmaceutical extravasation. Where applicable, taking into account the present status of the field and recent evidence in the literature, guidance is provided. The purpose of these recommendations is to encourage the practice of patient-specific dosimetry in therapy with 177Lu-labelled compounds. The proposed methods should be within the scope of centres offering therapy with 177Lu-labelled ligands for somatostatin receptors or small-molecule PSMA.
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12
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Danieli R, Milano A, Gallo S, Veronese I, Lascialfari A, Indovina L, Botta F, Ferrari M, Cicchetti A, Raspanti D, Cremonesi M. Personalized Dosimetry in Targeted Radiation Therapy: A Look to Methods, Tools and Critical Aspects. J Pers Med 2022; 12:205. [PMID: 35207693 PMCID: PMC8874397 DOI: 10.3390/jpm12020205] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/13/2022] [Accepted: 01/14/2022] [Indexed: 12/10/2022] Open
Abstract
Targeted radiation therapy (TRT) is a strategy increasingly adopted for the treatment of different types of cancer. The urge for optimization, as stated by the European Council Directive (2013/59/EURATOM), requires the implementation of a personalized dosimetric approach, similar to what already happens in external beam radiation therapy (EBRT). The purpose of this paper is to provide a thorough introduction to the field of personalized dosimetry in TRT, explaining its rationale in the context of optimization and describing the currently available methodologies. After listing the main therapies currently employed, the clinical workflow for the absorbed dose calculation is described, based on works of the most experienced authors in the literature and recent guidelines. Moreover, the widespread software packages for internal dosimetry are presented and critical aspects discussed. Overall, a selection of the most important and recent articles about this topic is provided.
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Affiliation(s)
- Rachele Danieli
- Dipartimento di Fisica, Università degli Studi di Pavia, Via Bassi 6, 27100 Pavia, Italy;
| | - Alessia Milano
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168 Roma, Italy;
- Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Roma, Italy
| | - Salvatore Gallo
- Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy; (S.G.); (I.V.)
- INFN Sezione di Milano, Via Celoria 16, 20133 Milano, Italy
| | - Ivan Veronese
- Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy; (S.G.); (I.V.)
- INFN Sezione di Milano, Via Celoria 16, 20133 Milano, Italy
| | - Alessandro Lascialfari
- INFN-Pavia Unit, Department of Physics, University of Pavia, Via Bassi 6, 27100 Pavia, Italy;
| | - Luca Indovina
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168 Roma, Italy;
| | - Francesca Botta
- Medical Physics Unit, European Institute of Oncology IRCCS, Via Giuseppe Ripamonti 435, 20141 Milano, Italy; (F.B.); (M.F.)
| | - Mahila Ferrari
- Medical Physics Unit, European Institute of Oncology IRCCS, Via Giuseppe Ripamonti 435, 20141 Milano, Italy; (F.B.); (M.F.)
| | - Alessandro Cicchetti
- Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Giacomo Venezian, 1, 20133 Milano, Italy;
| | - Davide Raspanti
- Temasinergie S.p.A., Via Marcello Malpighi 120, 48018 Faenza, Italy;
| | - Marta Cremonesi
- Radiation Research Unit, European Institute of Oncology IRCCS, Via Giuseppe Ripamonti 435, 20141 Milano, Italy;
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Amato E, Gnesin S, Cicone F, Auditore L. Fundamentals of internal radiation dosimetry. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00142-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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14
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Chiesa C, Sjogreen-Gleisner K, Walrand S, Strigari L, Flux G, Gear J, Stokke C, Gabina PM, Bernhardt P, Konijnenberg M. EANM dosimetry committee series on standard operational procedures: a unified methodology for 99mTc-MAA pre- and 90Y peri-therapy dosimetry in liver radioembolization with 90Y microspheres. EJNMMI Phys 2021; 8:77. [PMID: 34767102 PMCID: PMC8589932 DOI: 10.1186/s40658-021-00394-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 06/21/2021] [Indexed: 11/27/2022] Open
Abstract
The aim of this standard operational procedure is to standardize the methodology employed for the evaluation of pre- and post-treatment absorbed dose calculations in 90Y microsphere liver radioembolization. Basic assumptions include the permanent trapping of microspheres, the local energy deposition method for voxel dosimetry, and the patient-relative calibration method for activity quantification.The identity of 99mTc albumin macro-aggregates (MAA) and 90Y microsphere biodistribution is also assumed. The large observed discrepancies in some patients between 99mTc-MAA predictions and actual 90Y microsphere distributions for lesions is discussed. Absorbed dose predictions to whole non-tumoural liver are considered more reliable and the basic predictors of toxicity. Treatment planning based on mean absorbed dose delivered to the whole non-tumoural liver is advised, except in super-selective treatments.Given the potential mismatch between MAA simulation and actual therapy, absorbed doses should be calculated both pre- and post-therapy. Distinct evaluation between target tumours and non-tumoural tissue, including lungs in cases of lung shunt, are vital for proper optimization of therapy. Dosimetry should be performed first according to a mean absorbed dose approach, with an optional, but important, voxel level evaluation. Fully corrected 99mTc-MAA Single Photon Emission Computed Tomography (SPECT)/computed tomography (CT) and 90Y TOF PET/CT are regarded as optimal acquisition methodologies, but, for institutes where SPECT/CT is not available, non-attenuation corrected 99mTc-MAA SPECT may be used. This offers better planning quality than non dosimetric methods such as Body Surface Area (BSA) or mono-compartmental dosimetry. Quantitative 90Y bremsstrahlung SPECT can be used if dedicated correction methods are available.The proposed methodology is feasible with standard camera software and a spreadsheet. Available commercial or free software can help facilitate the process and improve calculation time.
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Affiliation(s)
- Carlo Chiesa
- Nuclear Medicine Unit, Foundation IRCCS Istituto Nazionale Tumori, Milan, Italy
| | | | - Stephan Walrand
- Nuclear Medicine, Molecular Imaging, Radiotherapy and Oncology Unit (MIRO), IECR, Université Catholique de Louvain, Brussels, Belgium
| | - Lidia Strigari
- Medical Physics Division, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Glenn Flux
- Joint Department of Physics, Royal Marsden Hospital & Institute of Cancer Research, Sutton, UK
| | - Jonathan Gear
- Joint Department of Physics, Royal Marsden Hospital & Institute of Cancer Research, Sutton, UK
| | - Caroline Stokke
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
| | - Pablo Minguez Gabina
- Department of Medical Physics and Radiation Protection, Gurutzeta/Cruces University Hospital, Barakaldo, Spain
| | - Peter Bernhardt
- Department of Radiation Physics, Institute of Clinical Science, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Mark Konijnenberg
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands.
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15
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Kim SP, Juneau D, Cohalan C, Enger SA. Standardizing SPECT/CT dosimetry following radioembolization with yttrium-90 microspheres. EJNMMI Phys 2021; 8:71. [PMID: 34716850 PMCID: PMC8557238 DOI: 10.1186/s40658-021-00413-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 09/10/2021] [Indexed: 12/19/2022] Open
Abstract
Background Multiple post-treatment dosimetry methods are currently under investigation for Yttrium-90 (\documentclass[12pt]{minimal}
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\begin{document}$$^{90}\hbox {Y}$$\end{document}90Y) radioembolization. Within each methodology, a variety of dosimetric inputs exists that affect the final dose estimates. Understanding their effects is essential to facilitating proper dose analysis and crucial in the eventual standardization of radioembolization dosimetry. The purpose of this study is to investigate the dose differences due to different self-calibrations and mass density assignments in the non-compartmental and local deposition methods. A practical mean correction method was introduced that permits dosimetry in images where the quality is compromised by patient motion and partial volume effects. Methods Twenty-one patients underwent \documentclass[12pt]{minimal}
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\begin{document}$$^{90}\hbox {Y}$$\end{document}90Y radioembolization and were imaged with SPECT/CT. Five different self-calibrations (FOV, Body, OAR, Liverlung, and Liver) were implemented and dosimetrically compared. The non-compartmental and local deposition method were used to perform dosimetry based on either nominal- or CT calibration-based mass densities. A mean correction method was derived assuming homogeneous densities. Cumulative dose volume histograms, linear regressions, boxplots, and Bland Altman plots were utilized for analysis. Results Up to 270% weighted dose difference was found between self-calibrations with mean dose differences up to 50 Gy in the liver and 23 Gy in the lungs. Between the local deposition and non-compartmental methods, the liver and lung had dose differences within 0.71 Gy and 20 Gy, respectively. The local deposition method’s nominal and CT calibration-based mass density implementations dosimetric metrics were within 1.4% in the liver and 24% in the lungs. The mean lung doses calculated with the CT method were shown to be inflated. The mean correction method demonstrated that the corrected mean doses were greater by up to \documentclass[12pt]{minimal}
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\begin{document}$$\sim 5$$\end{document}∼5 Gy in the liver and lower by up to \documentclass[12pt]{minimal}
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\begin{document}$$\sim 12$$\end{document}∼12 Gy in the lungs. Conclusions The OAR calibration may be utilized as a potentially more accurate and precise self-calibration. The non-compartmental method was found more comparable to the local deposition method in organs that were more homogeneous in mass densities. Due to the potential for inflated lung mean doses, the non-compartmental and local deposition method implemented with nominal mass densities is recommended for more consistent dosimetric results. If patient motion and partial volume effects are present in the liver, our practical correction method will calculate more representative doses in images suboptimal for dosimetry.
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Affiliation(s)
- S Peter Kim
- Medical Physics Unit, McGill University, Montreal, Canada. .,Biological and Biomedical Engineering, McGill University, Montreal, Canada.
| | - Daniel Juneau
- Department of Medical Imaging, Centre Hospitalier de l'Université de Montréal, Montreal, Canada
| | - Claire Cohalan
- Department of Physics and Biomedical Engineering, Centre Hospitalier de l'Université de Montréal, Montreal, Canada
| | - Shirin A Enger
- Medical Physics Unit, McGill University, Montreal, Canada.,Biological and Biomedical Engineering, McGill University, Montreal, Canada.,Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Canada
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16
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Asl RG, Sabbaghi R, Ahangari HT, Hejazi P, Foroutan M. Prediction of Absorbed Dose to Normal Organs with Endocrine Tumors for I-131 by use of 99mTC Single Photon Emission Computed Tomography/Computed Tomography and Geant4 Application for Tomographic Emission Simulation. Indian J Nucl Med 2021; 36:273-281. [PMID: 34658551 PMCID: PMC8481846 DOI: 10.4103/ijnm.ijnm_6_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 04/30/2021] [Accepted: 05/07/2021] [Indexed: 11/04/2022] Open
Abstract
Introduction: This study aimed to predict the dose absorbed by normal organs with neuroendocrine tumors for 131I using single photon emission computed tomography/computed tomography (SPECT/CT) images and Geant4 application for tomographic emission (GATE) simulation. Materials and Methods: Four to 5 whole-body planar scan series, along with one SPECT/CT image, were taken from four patients following 99mTc-hynic-Tyr3-octreotide radiotracer injection. After image quantification, the residence time of each organ was calculated using the image analysis and the activity time curves. The energy deposit and dose conversion (S-value) were extracted from the GATE simulation for the target organs of each patient. Using the residence times and S-values, the mean absorbed dose for the target organs of each patient was calculated and compared with the data obtained from the standard method. Results: Very close agreement was obtained between the S-value of the self–organ irradiation. The mean percentage difference between the two methods (i.e. GATE and Medical Internal Radiation Dose [MIRD]) was 1.8%, while a weak agreement was observed for cross-organ irradiation. The percentage difference between the total absorbed doses by the organs was 2%. The percentage difference between the absorbed doses obtained for tumors and three considered normal organs estimated by the GATE method was slightly higher than the MIRD method (about 11% on average for tumors). Conclusion: Regardless of the small difference between the obtained results for the organs and absorbed doses of the tumors in the present study, patient-specific dosimetry by the GATE methods is useful and essential for therapeutic radionuclides such as 131I due to high cross-dose effects, especially for young adult patients, to ensure the radiation safety and increase the effectiveness of the treatment.
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Affiliation(s)
- Rohollah Ghahraman Asl
- Department of Medical Physics and Radiation Sciences, Faculty of Paramedicine, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | - Rezvan Sabbaghi
- Department of Medical Physics, Faculty of medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Hadi Taleshi Ahangari
- Department of Medical Physics, Faculty of medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Payman Hejazi
- Department of Medical Physics, Faculty of medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Majid Foroutan
- Endocrinologist, Department of Internal Medicine, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
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Park H, Paganetti H, Schuemann J, Jia X, Min CH. Monte Carlo methods for device simulations in radiation therapy. Phys Med Biol 2021; 66:10.1088/1361-6560/ac1d1f. [PMID: 34384063 PMCID: PMC8996747 DOI: 10.1088/1361-6560/ac1d1f] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 08/12/2021] [Indexed: 11/12/2022]
Abstract
Monte Carlo (MC) simulations play an important role in radiotherapy, especially as a method to evaluate physical properties that are either impossible or difficult to measure. For example, MC simulations (MCSs) are used to aid in the design of radiotherapy devices or to understand their properties. The aim of this article is to review the MC method for device simulations in radiation therapy. After a brief history of the MC method and popular codes in medical physics, we review applications of the MC method to model treatment heads for neutral and charged particle radiation therapy as well as specific in-room devices for imaging and therapy purposes. We conclude by discussing the impact that MCSs had in this field and the role of MC in future device design.
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Affiliation(s)
- Hyojun Park
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Republic of Korea
| | - Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Xun Jia
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX 75235, United States of America
| | - Chul Hee Min
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Republic of Korea
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Monserrat Fuertes T, González García F, Peinado Montes M, Domínguez Grande M, Martín Fernández N, Gómez de Iturriaga Piña A, Mínguez Gabiña P. Description of the methodology for dosimetric quantification in treatments with 177Lu-DOTATATE. Rev Esp Med Nucl Imagen Mol 2021. [DOI: 10.1016/j.remnie.2021.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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19
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Monserrat Fuertes T, González García FM, Peinado Montes MÁ, Domínguez Grande ML, Martín Fernández N, Gómez de Iturriaga Piña A, Mínguez Gabiña P. Description of the methodology for dosimetric quantification in treatments with 177Lu-DOTATATE. Rev Esp Med Nucl Imagen Mol 2021; 40:167-178. [PMID: 33811003 DOI: 10.1016/j.remn.2021.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/22/2021] [Accepted: 02/24/2021] [Indexed: 11/28/2022]
Abstract
Implementation of dosimetry calculations in the daily practice of Nuclear Medicine Departments is, at this time, a controversial issue, partly due to the lack of a standardized methodology that is accepted by all interested parties (patients, nuclear medicine physicians and medical physicists). However, since the publication of RD 601/2019 there is a legal obligation to implement it, despite the fact that it is a complex and high resource consumption procedure. The aim of this article is to review the theoretical bases of in vivo dosimetry in treatments with 177Lu-DOTATATE. The exposed methodology is the one proposed by the MIRD Committee (Medical Internal Radiation Dose) of the SNMMI (Society of Nuclear Medicine & Molecular Imaging). According to this method, the absorbed dose is obtained as the product of 2factors: the time-integrated activity of the radiopharmaceutical present in a source region and a geometrical factor S. This approach, which a priori seems simple, in practice requires several SPECT/CT acquisitions, several measurements of the whole body activity and taking several blood samples, as well as hours of image processing and computation. The systematic implementation of these calculations, in all the patients we treat, will allow us to obtain homogeneous data to correlate the absorbed doses in the lesions with the biological effect of the treatment. The final purpose of the dosimetry calculations is to be able to maximize the therapeutic effect in the lesions, controlling the radiotoxicity in the organs at risk.
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Affiliation(s)
- T Monserrat Fuertes
- Servicio de Radiofísica y Protección Radiológica, Hospital Universitario Central de Asturias, Oviedo, Asturias, España; Departamento de Cirugía, Radiología y Medicina Física, UPV/EHU, Leioa, Bizkaia, España.
| | - F M González García
- Servicio de Medicina Nuclear, Hospital Universitario Central de Asturias, Oviedo, Asturias, España
| | - M Á Peinado Montes
- Servicio de Radiofísica y Protección Radiológica, Hospital Universitario Central de Asturias, Oviedo, Asturias, España
| | - M L Domínguez Grande
- Servicio de Medicina Nuclear, Hospital Universitario Central de Asturias, Oviedo, Asturias, España
| | - N Martín Fernández
- Servicio de Medicina Nuclear, Hospital Universitario Central de Asturias, Oviedo, Asturias, España
| | - A Gómez de Iturriaga Piña
- Departamento de Cirugía, Radiología y Medicina Física, UPV/EHU, Leioa, Bizkaia, España; Servicio de Oncología Radioterápica, Hospital Universitario Gurutzeta-Cruces/Instituto de Investigación Sanitaria BioCruces, Barakaldo, Bizkaia, España
| | - P Mínguez Gabiña
- Unidad de Protección Radiológica y Radiofísica, Hospital Universitario Gurutzeta-Cruces/Instituto de Investigación Sanitaria BioCruces, Barakaldo, Bizkaia, España
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20
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Bordes J, Incerti S, Mora-Ramirez E, Tranel J, Rossi C, Bezombes C, Bordenave J, Bardiès M, Brown R, Bordage MC. Monte Carlo dosimetry of a realistic multicellular model of follicular lymphoma in a context of radioimmunotherapy. Med Phys 2020; 47:5222-5234. [PMID: 32623743 DOI: 10.1002/mp.14370] [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: 12/05/2019] [Revised: 04/20/2020] [Accepted: 06/15/2020] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Small-scale dosimetry studies generally consider an artificial environment where the tumors are spherical and the radionuclides are homogeneously biodistributed. However, tumor shapes are irregular and radiopharmaceutical biodistributions are heterogeneous, impacting the energy deposition in targeted radionuclide therapy. To bring realism, we developed a dosimetric methodology based on a three-dimensional in vitro model of follicular lymphoma incubated with rituximab, an anti-CD20 monoclonal antibody used in the treatment of non-Hodgkin lymphomas, which might be combined with a radionuclide. The effects of the realistic geometry and biodistribution on the absorbed dose were highlighted by comparison with literature data. Additionally, to illustrate the possibilities of this methodology, the effect of different radionuclides on the absorbed dose distribution delivered to the in vitro tumor were compared. METHODS The starting point was a model named multicellular aggregates of lymphoma cells (MALC). Three MALCs of different dimensions and their rituximab biodistribution were considered. Geometry, antibody location and concentration were extracted from selective plane illumination microscopy. Assuming antibody radiolabeling with Auger electron (125 I and 111 In) and β- particle emitters (177 Lu, 131 I and 90 Y), we simulated energy deposition in MALCs using two Monte Carlo codes: Geant4-DNA with "CPA100" physics models for Auger electron emitters and Geant4 with "Livermore" physics models for β- particle emitters. RESULTS MALCs had ellipsoid-like shapes with major radii, r, of ~0.25, ~0.5 and ~1.3 mm. Rituximab was concentrated in the periphery of the MALCs. The absorbed doses delivered by 177 Lu, 131 I and 90 Y in MALCs were compared with literature data for spheres with two types of homogeneous biodistributions (on the surface or throughout the volume). Compared to the MALCs, the mean absorbed doses delivered in spheres with surface biodistributions were between 18% and 38% lower, while with volume biodistribution they were between 15% and 29% higher. Regarding the radionuclides comparison, the relationship between MALC dimensions, rituximab biodistribution and energy released per decay impacted the absorbed doses. Despite releasing less energy, 125 I delivered a greater absorbed dose per decay than 111 In in the r ~ 0.25 mm MALC (6.78·10-2 vs 6.26·10-2 µGy·Bq-1 ·s-1 ). Similarly, the absorbed doses per decay in the r ~ 0.5 mm MALC for 177 Lu (2.41·10-2 µGy·Bq-1 ·s-1 ) and 131 I (2.46·10-2 µGy·Bq-1 ·s-1 ) are higher than for 90 Y (1.98·10-2 µGy·Bq-1 ·s-1 ). Furthermore, radionuclides releasing more energy per decay delivered absorbed dose more uniformly through the MALCs. Finally, when considering the radiopharmaceutical effective half-life, due to the biological half-life of rituximab being best matched by the physical half-life of 177 Lu and 131 I compared to 90 Y, the first two radionuclides delivered higher absorbed doses. CONCLUSION In the simulated configurations, β- emitters delivered higher and more uniform absorbed dose than Auger electron emitters. When considering radiopharmaceutical half-lives, 177 Lu and 131 I delivered absorbed doses higher than 90 Y. In view of real irradiation of MALCs, such a work may be useful to select suited radionuclides and to help explain the biological effects.
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Affiliation(s)
- Julien Bordes
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Sébastien Incerti
- Université de Bordeaux, CENBG, UMR 5797, Gradignan, F-33170, France.,CNRS, IN2P3, CENBG, UMR 5797, Gradignan, F-33170, France
| | - Erick Mora-Ramirez
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,Escuela de Física, CICANUM, Universidad de Costa Rica, San José, 11501-2060, Costa Rica
| | - Jonathan Tranel
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Cédric Rossi
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,CHU Dijon, Hématologie Clinique, Hôpital François Mitterand, Dijon, 21000, France
| | - Christine Bezombes
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Julie Bordenave
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Manuel Bardiès
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Richard Brown
- Institute of Nuclear Medicine, University College London, 235 Euston Road, London, NW1 2BU, UK
| | - Marie-Claude Bordage
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
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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: 9] [Impact Index Per Article: 2.3] [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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Noori-Asl M. Investigation of Different Factors Affecting the Quality of SPECT Images: A Simulation Study. J Med Phys 2020; 45:44-51. [PMID: 32355434 PMCID: PMC7185706 DOI: 10.4103/jmp.jmp_88_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/10/2019] [Accepted: 12/16/2019] [Indexed: 11/15/2022] Open
Abstract
Background: Monte Carlo (MC) simulation codes are used extensively for modeling the nuclear medicine imaging systems, such as single photon emission computed tomography (SPECT) and positron emission tomography (PET). By using these codes, it is possible to set different imaging parameters and do various studies in the field of nuclear medicine imaging. Aims and Objectives: The aim of this study is to investigate the effective factors in improvement of the SPECT image quality by using MC simulation. Materials and Methods: In this study, we used the SIMIND MC simulation code and Jaszczak phantom containing six spheres with different diameters placed into a water-filled cylindrical phantom for consideration of the effects of different factors on quality of the images obtained from Tc-99m SPECT imaging system. The assessment criteria used to investigate these factors included image contrast, signal-to-noise ratio (SNR) and relative noise of the background (RNB). Results: The results of this study show that the right choice of the arc of rotation, the image matrix size, the number of angular views, type of the collimators, and also filters used in the image reconstruction affect the quality of SPECT images. Also, we show that use of scatter correction methods can improve the image quality. Conclusion: The MC simulation is a suitable tool for investigation of different factors affecting the quality of SPECT images, essentially in the studies based on the energy spectrum, such as the evaluation of the scatter correction methods.
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Affiliation(s)
- Mahsa Noori-Asl
- Department of Physics, Faculty of Science, University of Mohaghegh Ardabili, Ardabil, Iran
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23
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Gosewisch A, Ilhan H, Tattenberg S, Mairani A, Parodi K, Brosch J, Kaiser L, Gildehaus FJ, Todica A, Ziegler S, Bartenstein P, Böning G. 3D Monte Carlo bone marrow dosimetry for Lu-177-PSMA therapy with guidance of non-invasive 3D localization of active bone marrow via Tc-99m-anti-granulocyte antibody SPECT/CT. EJNMMI Res 2019; 9:76. [PMID: 31414241 PMCID: PMC6694348 DOI: 10.1186/s13550-019-0548-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/30/2019] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The bone marrow (BM) is a main risk organ during Lu-177-PSMA ligand therapy of metastasized castration-resistant prostate cancer (mCRPC) patients. So far, BM dosimetry relies on S values, which are pre-computed for reference anatomies, simplified activity distributions, and a physiological BM distribution. However, mCRPC patients may show a considerable bone lesion load, which leads to a heterogeneous and patient-specific activity accumulation close to BM-bearing sites. Furthermore, the patient-specific BM distribution might be significantly altered in the presence of bone lesions. The aim was to perform BM absorbed dose calculations through Monte Carlo (MC) simulations and to investigate the potential value of image-based BM localization. This study is based on 11 Lu-177-PSMA-617 therapy cycles of 10 patients (10 first cycles), who obtained a pre-therapeutic Ga-68-PSMA-11 PET/CT; quantitative Lu-177 SPECT acquisitions of the abdomen 24 (+CT), 48, and 72 h p.i.; and a Lu-177 whole-body planar acquisition at 24 h post-therapy. Patient-specific 3D volumes of interest were segmented from the Ga-68-PSMA-11 PET/CT, filled with activity information from the Lu-177 data, and imported into the FLUKA MC code together with the patient CT. MC simulations of the BM absorbed dose were performed assuming a physiological BM distribution according to the ICRP 110 reference male (MC1) or a displacement of active BM from the direct location of bone lesions (MC2). Results were compared with those from S values (SMIRD). BM absorbed doses were correlated with the decrease of lymphocytes, total white blood cells, hemoglobin level, and platelets. For two patients, an additional pre-therapeutic Tc-99m-anti-granulocyte antibody SPECT/CT was performed for BM localization. RESULTS Median BM absorbed doses were 130, 37, and 11 mGy/GBq for MC1, MC2, and SMIRD, respectively. Significant strong correlation with the decrease of platelet counts was found, with highest correlation for MC2 (MC1: r = - 0.63, p = 0.04; MC2: r = - 0.71, p = 0.01; SMIRD: r = - 0.62, p = 0.04). For both investigated patients, BM localization via Tc-99m-anti-granulocyte antibody SPECT/CT indicated a displacement of active BM from the direct location of lesions similar to model MC2 and led to a reduction in the BM absorbed dose of 40 and 41% compared to MC1. CONCLUSION Higher BM absorbed doses were observed for MC-based models; however, for MC2, all absorbed doses were still below 2 Gy. MC1 resulted in critical values for some patients, but is suspected to yield strongly exaggerated absorbed doses by neglecting bone marrow displacement. Image-based BM localization might be beneficial, and future studies are recommended to support an improvement for the prediction of hematoxicities.
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Affiliation(s)
- Astrid Gosewisch
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Harun Ilhan
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Sebastian Tattenberg
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Andrea Mairani
- Heidelberg Ion Beam Therapy Center, University Hospital Heidelberg, Heidelberg, Germany
| | - Katia Parodi
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Garching b. München, Germany
| | - Julia Brosch
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Lena Kaiser
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Franz Josef Gildehaus
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Andrei Todica
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Sibylle Ziegler
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Guido Böning
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
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Jafargholi Rangraz E, Coudyzer W, Maleux G, Baete K, Deroose CM, Nuyts J. Multi-modal image analysis for semi-automatic segmentation of the total liver and liver arterial perfusion territories for radioembolization. EJNMMI Res 2019; 9:19. [PMID: 30788640 PMCID: PMC6382918 DOI: 10.1186/s13550-019-0485-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 01/29/2019] [Indexed: 12/15/2022] Open
Abstract
Purpose We have developed a multi-modal imaging approach for SIRT, combining 99mTc-MAA SPECT/CT and/or 90Y PET, 18F-FDG PET/CT, and contrast-enhanced CBCT for voxel-based dosimetry, as a tool for treatment planning and verification. For radiation dose prediction calculations, a segmentation of the total liver volume and of the liver perfusion territories is required. Method In this paper, we proposed a procedure for multi-modal image analysis to assist SIRT treatment planning. The pre-treatment 18F-FDG PET/CT, 99mTc-MAA SPECT/CT, and contrast-enhanced CBCT images were registered to a common space using an initial rigid, followed by a deformable registration. The registration was scored by an expert using Likert scores. The total liver was segmented semi-automatically based on the PET/CT and SPECT/CT images, and the liver perfusion territories were determined based on the CBCT images. The segmentations of the liver and liver lobes were compared to the manual segmentations by an expert on a CT image. Result Our methodology showed that multi-modal image analysis can be used for determination of the liver and perfusion territories using CBCT in SIRT using all pre-treatment studies. The results for image registration showed acceptable alignment with limited impact on dosimetry. The image registration performs well according to the expert reviewer (scored as perfect or with little misalignment in 94% of the cases). The semi-automatic liver segmentation agreed well with manual liver segmentation (dice coefficient of 0.92 and an average Hausdorff distance of 3.04 mm). The results showed disagreement between lobe segmentation using CBCT images compared to lobe segmentation based on CT images (average Hausdorff distance of 14.18 mm), with a high impact on the dosimetry (differences up to 9 Gy for right and 21 Gy for the left liver lobe). Conclusion This methodology can be used for pre-treatment dosimetry and for SIRT planning including the determination of the activity that should be administered to achieve the therapeutical goal. The inclusion of perfusion CBCT enables perfusion-based definition of the liver lobes, which was shown to be markedly different from the anatomical definition in some of the patients.
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Affiliation(s)
| | - Walter Coudyzer
- Radiology Section, Department of imaging and pathology, UZ Leuven, Leuven, Belgium
| | - Geert Maleux
- Radiology Section, Department of imaging and pathology, UZ & KU Leuven, Leuven, Belgium
| | - Kristof Baete
- Nuclear Medicine, Department of imaging and pathology, UZ & KU Leuven, Leuven, Belgium
| | - Christophe M Deroose
- Nuclear Medicine, Department of imaging and pathology, UZ & KU Leuven, Leuven, Belgium
| | - Johan Nuyts
- Nuclear Medicine, Department of imaging and pathology, UZ & KU Leuven, Leuven, Belgium
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25
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Violet J, Jackson P, Ferdinandus J, Sandhu S, Akhurst T, Iravani A, Kong G, Kumar AR, Thang SP, Eu P, Scalzo M, Murphy D, Williams S, Hicks RJ, Hofman MS. Dosimetry of 177Lu-PSMA-617 in Metastatic Castration-Resistant Prostate Cancer: Correlations Between Pretherapeutic Imaging and Whole-Body Tumor Dosimetry with Treatment Outcomes. J Nucl Med 2018; 60:517-523. [PMID: 30291192 DOI: 10.2967/jnumed.118.219352] [Citation(s) in RCA: 271] [Impact Index Per Article: 45.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 09/17/2018] [Indexed: 01/15/2023] Open
Abstract
177Lu-prostate-specific membrane antigen (PSMA)-617 enables targeted delivery of β-particle radiation to prostate cancer. We determined its radiation dosimetry and relationships to pretherapeutic imaging and outcomes. Methods: Thirty patients with prostate cancer receiving 177Lu-PSMA-617 within a prospective clinical trial (ACTRN12615000912583) were studied. Screening 68Ga-PSMA-11 PET/CT demonstrated high PSMA expression in all patients. After therapy, patients underwent quantitative SPECT/CT at 4, 24, and 96 h. Pharmacokinetic uptake and clearance at a voxel level were calculated and translated into absorbed dose using voxel S values. Volumes of interest were drawn on normal tissues and tumor to assess radiation dose, and a whole-body tumor dose was defined. Correlations between PSMA PET/CT parameters, dosimetry, and biochemical and therapeutic response were analyzed to identify relationships between absorbed dose, tumor burden, and patient physiology. Results: Mean absorbed dose to kidneys, submandibular and parotid glands, liver, spleen, and bone marrow was 0.39, 0.44, 0.58, 0.1, 0.06, and 0.11 Gy/MBq, respectively. Median whole-body tumor-absorbed dose was 11.55 Gy and correlated with prostate-specific antigen (PSA) response at 12 wk. A median dose of 14.1 Gy was observed in patients achieving a PSA decline of at least 50%, versus 9.6 Gy for those achieving a PSA decline of less than 50% (P < 0.01). Of 11 patients receiving a tumor dose of less than 10 Gy, only one achieved a PSA response of at least 50%. On screening PSMA PET, whole-body tumor SUVmean correlated with mean absorbed dose (r = 0.62), and SUVmax of the parotids correlated with absorbed dose (r = 0.67). There was an inverse correlation between tumor volume and mean dose to the parotids (r = -0.41) and kidneys (r = -0.43). The mean parotid dose was also reduced with increasing body mass (r = -0.41) and body surface area (r = -0.37). Conclusion: 177Lu-PSMA-617 delivers high absorbed doses to tumor, with a significant correlation between whole-body tumor dose and PSA response. Patients receiving less than 10 Gy were unlikely to achieve a fall in PSA of at least 50%. Significant correlations between aspects of screening 68Ga-PET/CT and tumor and normal tissue dose were observed, providing a rationale for patient-specific dosing. Reduced salivary and kidney doses were observed in patients with a higher tumor burden. The parotid dose also reduced with increasing body mass and body surface area.
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Affiliation(s)
- John Violet
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Price Jackson
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia.,Department of Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Justin Ferdinandus
- Department of Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Shahneen Sandhu
- Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Tim Akhurst
- Department of Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Amir Iravani
- Department of Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Grace Kong
- Department of Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Aravind Ravi Kumar
- Department of Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Sue Ping Thang
- Department of Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Peter Eu
- Department of Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Mark Scalzo
- Department of Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Declan Murphy
- Department of Uro-Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia; and.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
| | - Scott Williams
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
| | - Rodney J Hicks
- Department of Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
| | - Michael S Hofman
- Department of Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
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Roth D, Gustafsson J, Sundlöv A, Sjögreen Gleisner K. A method for tumor dosimetry based on hybrid planar-SPECT/CT images and semiautomatic segmentation. Med Phys 2018; 45:5004-5018. [PMID: 30199102 DOI: 10.1002/mp.13178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 06/17/2018] [Accepted: 08/14/2018] [Indexed: 01/01/2023] Open
Abstract
PURPOSE A hybrid planar-SPECT/CT method for tumor dosimetry in 177 Lu-DOTATATE therapy, applicable to datasets consisting of multiple conjugate-view images and one SPECT/CT, is developed and evaluated. METHODS The imaging protocol includes conjugate-view imaging at 1, 24, 96, and 168 h post infusion (p.i.) and a SPECT/CT acquisition 24 h p.i. The dosimetry method uses the planar images to estimate the shape of the time-activity concentration curve, which is then rescaled to absolute units using the SPECT-derived activity concentration. The resulting time-integrated activity concentration coefficient (TIACC) is used to calculate the tumor-absorbed dose. Semiautomatic segmentation techniques are applied for tumor delineation in both planar and SPECT images, where the planar image segmentation is accomplished using an active-rays-based technique. The selection of tumors is done by visual inspection of planar and SPECT images and applying a set of criteria concerning the tumor visibility and possible interference from superimposed activity uptakes in the planar images. Five different strategies for determining values from planar regions of interest (ROIs), based on entire or partial ROIs, and with and without background correction, are evaluated. Evaluation is performed against a SPECT/CT-based method on data from six patients where sequential conjugate-view and SPECT/CT imaging have been performed in parallel and against ground truths in Monte Carlo simulated images. The patient data are also used to evaluate the interoperator variability and to assess the validity of the developed criteria for tumor selection. RESULTS For patient images, the hybrid method produces TIACCs that are on average 6% below those of the SPECT/CT only method, with standard deviations for the relative TIACC differences of 8%-11%. Simulations show that the hybrid and SPECT-based methods estimate the TIACCs to within approximately 10% for tumors larger than around 10 ml, while for smaller tumors, all methods underestimate the TIACCs due to underestimations of the activity concentrations in the SPECT images. The planar image segmentation has a low operator dependence, with a median Dice similarity coefficient of 0.97 between operators. The adopted criteria for tumor selection manage to discriminate the tumors for which the absorbed-dose deviations between the hybrid and SPECT methods are the highest. CONCLUSIONS The hybrid method is found suitable for studies of tumor-absorbed doses in radionuclide therapy, provided that selection criteria regarding the visibility and overlapping activities in the planar images are applied.
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Affiliation(s)
- Daniel Roth
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Johan Gustafsson
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Anna Sundlöv
- Division of Oncology and Pathology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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Huizing DMV, de Wit-van der Veen BJ, Verheij M, Stokkel MPM. Dosimetry methods and clinical applications in peptide receptor radionuclide therapy for neuroendocrine tumours: a literature review. EJNMMI Res 2018; 8:89. [PMID: 30159614 PMCID: PMC6115319 DOI: 10.1186/s13550-018-0443-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/21/2018] [Indexed: 12/25/2022] Open
Abstract
Background The main challenge for systemic radiation therapy using radiopharmaceuticals (SRT) is to optimise the dose delivered to the tumour, while minimising normal tissue irradiation. Dosimetry could help to increase therapy response and decrease toxicity after SRT by individual treatment planning. Peptide receptor radionuclide therapy (PRRT) is an accepted SRT treatment option for irresectable and metastatic neuroendocrine tumours (NET). However, dosimetry in PRRT is not routinely performed, mainly due to the lack of evidence in literature and clinical implementation difficulties. The goal of this review is to provide insight in dosimetry methods and requirements and to present an overview of clinical aspects of dosimetry in PRRT for NET. Methods A PubMed query including the search criteria dosimetry, radiation dose, peptide receptor radionuclide therapy, and radionuclide therapy was performed. Articles were selected based on title and abstract, and description of dosimetric approach. Results A total of 288 original articles were included. The most important dosimetry methods, their main advantages and limitations, and implications in the clinical setting are discussed. An overview of dosimetry in clinical studies regarding PRRT treatment for NET is provided. Conclusion Clinical dosimetry in PRRT is feasible and can result in improved treatment outcomes. Current clinical dosimetry studies focus on safety and apply non-voxel-based dosimetry methods. Personalised treatment using sophisticated dosimetry methods to assess tumour and normal tissue uptake in clinical trials is the next step towards routine dosimetry in PRRT for NET. Electronic supplementary material The online version of this article (10.1186/s13550-018-0443-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daphne Merel Valerie Huizing
- Department of Nuclear Medicine, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | | | - Marcel Verheij
- Department of Radiation Oncology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
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Gosewisch A, Delker A, Tattenberg S, Ilhan H, Todica A, Brosch J, Vomacka L, Brunegraf A, Gildehaus FJ, Ziegler S, Bartenstein P, Böning G. Patient-specific image-based bone marrow dosimetry in Lu-177-[DOTA 0,Tyr 3]-Octreotate and Lu-177-DKFZ-PSMA-617 therapy: investigation of a new hybrid image approach. EJNMMI Res 2018; 8:76. [PMID: 30076556 PMCID: PMC6081875 DOI: 10.1186/s13550-018-0427-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 07/16/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The bone marrow (BM) is a main organ at risk in Lu-177-PSMA-617 therapy of prostate cancer and Lu-177-Octreotate therapy of neuroendocrine tumours. BM dosimetry is challenging and time-consuming, as different sequential quantitative measurements must be combined. The BM absorbed dose from the remainder of the body (ROB) can be determined from sequential whole-body planar (WB-P) imaging, while quantitative Lu-177-SPECT allows for more robust tumour and organ absorbed doses. The aim was to investigate a time-efficient and patient-friendly hybrid protocol (HP) for the ROB absorbed dose to the BM. It combines three abdominal quantitative SPECT (QSPECT) scans with a single WB-P acquisition and was compared with a reference protocol (RP) using sequential WB-P in combination with sequential QSPECT images. We investigated five patients receiving 7.4 GBq Lu-177-Octreotate and five patients treated with 3.7 GBq Lu-177-PSMA-617. Each patient had WB-P and abdominal SPECT acquisitions 24 (+ CT), 48, and 72 h post-injection. Blood samples were drawn 30 min, 80 min, 24 h, 48 h, and 72 h post-injection. BM absorbed doses from the ROB were estimated from sequential WB-P images (RP), via a mono-exponential fit and mass-scaled organ-level S values. For the HP, a mono-exponential fit on the QSPECT data was scaled with the activity of one WB-P image acquired either 24, 48, or 72 h post-injection (HP24, HP48, HP72). Total BM absorbed doses were determined as a sum of ROB, blood, major organ, and tumour contributions. RESULTS Compared with the RP and for Lu-177-Octreotate therapy, median differences of the total BM absorbed doses were 13% (9-17%), 8% (4-15%), and 1% (0-5%) for the HP24, HP48, and HP72, respectively. For Lu-177-PSMA-617 therapy, total BM absorbed doses deviated 10% (2-20%), 3% (0-6%), and 2% (0-6%). CONCLUSION For both Lu-177-Octreotate and Lu-177-PSMA-617 therapy, BM dosimetry via sequential QSPECT imaging and a single WB-P acquisition is feasible, if this WB-P image is acquired at a late time point (48 or 72 h post-injection). The reliability of the HP can be well accepted considering the uncertainties of quantitative Lu-177 imaging and BM dosimetry using standardised organ-level S values.
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Affiliation(s)
- Astrid Gosewisch
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Andreas Delker
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Sebastian Tattenberg
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Harun Ilhan
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Andrei Todica
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Julia Brosch
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Lena Vomacka
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Anika Brunegraf
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Franz Josef Gildehaus
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Sibylle Ziegler
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Guido Böning
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377 Munich, Germany
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Sundlöv A, Gustafsson J, Brolin G, Mortensen N, Hermann R, Bernhardt P, Svensson J, Ljungberg M, Tennvall J, Sjögreen Gleisner K. Feasibility of simplifying renal dosimetry in 177Lu peptide receptor radionuclide therapy. EJNMMI Phys 2018; 5:12. [PMID: 29974391 PMCID: PMC6031553 DOI: 10.1186/s40658-018-0210-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Accepted: 03/21/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Recently, 177Lu-dotatate therapy for neuroendocrine tumours has received regulatory approval. Dosimetry can be used to optimize treatment on an individual basis, but there is no international consensus as to how it should be done. The aim of this study is to determine a feasible and accurate dosimetry method to guide individualized peptide receptor radionuclide therapy (PRRT) for patients with neuroendocrine tumours. As part of a clinical trial on 177Lu-dotatate therapy, renal dosimetry was performed for all patients in each treatment cycle, using a hybrid planar-SPECT/CT method. In the present study, we use the image data acquired from 22 patients and 119 cycles and define a set of alternative treatment planning strategies, each representing a simplification in terms of image acquisition and dosimetric calculations. The results from the simplified strategies are compared to the results from the protocol-prescribed hybrid planar-SPECT/CT-based method by analysing differences both in per-cycle and total cumulative absorbed dose (AD) analyses. RESULTS In general, the SPECT-based methods gave results that were largely consistent with the protocol-specified hybrid method, both in the per-cycle and cumulative AD analyses. Notably, performing one SPECT/CT per cycle at 96 h yielded ADs that were very similar to the protocol method. The methods using planar dosimetry resulted in larger variations, as expected, while giving 4 cycles to all patients resulted in the largest inter-individual differences in cumulative AD. CONCLUSIONS Performing one SPECT/CT at 96 h in every treatment cycle gives sufficiently reliable dosimetric results to base individualized treatment planning on, with a reasonable demand on resources.
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Affiliation(s)
- Anna Sundlöv
- Oncology and Pathology, Department of Clinical Sciences Lund, Skåne University Hospital, Lund University, Lund, Sweden.
- Department of Oncology, Skåne University Hospital, SE-221 85, Lund, Sweden.
| | - Johan Gustafsson
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Gustav Brolin
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Nadja Mortensen
- Oncology and Pathology, Department of Clinical Sciences Lund, Skåne University Hospital, Lund University, Lund, Sweden
| | - Rebecca Hermann
- Department of Radiation Physics, University of Gothenburg, Gothenburg, Sweden
| | - Peter Bernhardt
- Department of Radiation Physics, University of Gothenburg, Gothenburg, Sweden
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Johanna Svensson
- Department of Oncology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Michael Ljungberg
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Jan Tennvall
- Oncology and Pathology, Department of Clinical Sciences Lund, Skåne University Hospital, Lund University, Lund, Sweden
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Sandström M, Garske-Román U, Johansson S, Granberg D, Sundin A, Freedman N. Kidney dosimetry during 177Lu-DOTATATE therapy in patients with neuroendocrine tumors: aspects on calculation and tolerance. Acta Oncol 2018; 57:516-521. [PMID: 28920501 DOI: 10.1080/0284186x.2017.1378431] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Fractionated therapy with 177Lu-DOTATATE has been reported to be an effective treatment for patients with metastasized neuroendocrine tumors. To optimize the treatment, absorbed doses to risk organs are calculated for the individual patient. For each organ, absorbed dose due to activity in the organ itself (self-dose) and that originating from other organs (cross-dose) are calculated from serial measurements to obtain the activity distribution following treatment. The main aim of the present work were to calculate the cross-dose contribution to the total absorbed kidney dose. METHODS Five hundred patients with neuroendocrine tumors undergoing therapy with 177Lu-DOTATATE were included. Scintigraphic planar whole body images and single photon emission computed tomography/computed tomography (SPECT/CT) over the abdomen were acquired at 1, 4 and 7 days after treatment. Kidney self-dose was calculated based on radioactivity distribution obtained from SPECT/CT. Cross-dose to kidneys was estimated using organ-based analysis of planar whole body images and cross-fire dose factors from Olinda/EXM 1.1. RESULTS Cross-dose to kidneys in the majority of patients were less than 2% and almost all cross-doses were less than 10%. Cross-dose exceeded 10% only in rare cases of patients with high tumor burden and low absorbed doses to kidneys. CONCLUSIONS The absorbed dose from 177Lu-octreotate to solid organs due to cross-fire is generally low and can usually be neglected.
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Affiliation(s)
- Mattias Sandström
- Department of Surgical Sciences, Section of Nuclear Medicine and PET, Uppsala University, Uppsala, Sweden
- Department of Immunology, Genetics and Pathology, Section of Medical Physics, Uppsala University, Uppsala, Sweden
| | - Ulrike Garske-Román
- Department of Surgical Sciences, Section of Nuclear Medicine and PET, Uppsala University, Uppsala, Sweden
| | - Silvia Johansson
- Department of Immunology, Section of Oncology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Dan Granberg
- Department of Medical Sciences, Division of Endocrine Oncology, Uppsala University Hospital, Uppsala, Sweden
| | - Anders Sundin
- Department of Surgical Sciences, Section of Nuclear Medicine and PET, Uppsala University, Uppsala, Sweden
| | - Nanette Freedman
- Department of Medical Biophysics and Nuclear Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
- Department of Imaging, Institute of Nuclear Medicine, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
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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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Mikalsen LTG, Arnesen MR, Bogsrud TV, Dale E, Stokke C. Combining radioiodine and external beam radiation therapy: the potential of integrated treatment planning for differentiated thyroid cancer. Acta Oncol 2017; 56:894-897. [PMID: 28464741 DOI: 10.1080/0284186x.2017.1286384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
| | | | | | - Einar Dale
- Department of Oncology, Oslo University Hospital, Oslo, Norway
| | - Caroline Stokke
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
- Department of Life Sciences and Health, Oslo and Akershus University College of Applied Science, Oslo, Norway
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Pacilio M, Ferrari M, Chiesa C, Lorenzon L, Mira M, Botta F, Becci D, Torres LA, Coca Perez M, Vergara Gil A, Basile C, Ljungberg M, Pani R, Cremonesi M. Impact of SPECT corrections on 3D-dosimetry for liver transarterial radioembolization using the patient relative calibration methodology. Med Phys 2017; 43:4053. [PMID: 27370124 DOI: 10.1118/1.4953203] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
PURPOSE Many centers aim to plan liver transarterial radioembolization (TARE) with dosimetry, even without CT-based attenuation correction (AC), or with unoptimized scatter correction (SC) methods. This work investigates the impact of presence vs absence of such corrections, and limited spatial resolution, on 3D dosimetry for TARE. METHODS Three voxelized phantoms were derived from CT images of real patients with different body sizes. Simulations of (99m)Tc-SPECT projections were performed with the SIMIND code, assuming three activity distributions in the liver: uniform, inside a "liver's segment," or distributing multiple uptaking nodules ("nonuniform liver"), with a tumoral liver/healthy parenchyma ratio of 5:1. Projection data were reconstructed by a commercial workstation, with OSEM protocol not specifically optimized for dosimetry (spatial resolution of 12.6 mm), with/without SC (optimized, or with parameters predefined by the manufacturer; dual energy window), and with/without AC. Activity in voxels was calculated by a relative calibration, assuming identical microspheres and (99m)Tc-SPECT counts spatial distribution. 3D dose distributions were calculated by convolution with (90)Y voxel S-values, assuming permanent trapping of microspheres. Cumulative dose-volume histograms in lesions and healthy parenchyma from different reconstructions were compared with those obtained from the reference biodistribution (the "gold standard," GS), assessing differences for D95%, D70%, and D50% (i.e., minimum value of the absorbed dose to a percentage of the irradiated volume). γ tool analysis with tolerance of 3%/13 mm was used to evaluate the agreement between GS and simulated cases. The influence of deep-breathing was studied, blurring the reference biodistributions with a 3D anisotropic gaussian kernel, and performing the simulations once again. RESULTS Differences of the dosimetric indicators were noticeable in some cases, always negative for lesions and distributed around zero for parenchyma. Application of AC and SC reduced systematically the differences for lesions by 5%-14% for a liver segment, and by 7%-12% for a nonuniform liver. For parenchyma, the data trend was less clear, but the overall range of variability passed from -10%/40% for a liver segment, and -10%/20% for a nonuniform liver, to -13%/6% in both cases. Applying AC, SC with preset parameters gave similar results to optimized SC, as confirmed by γ tool analysis. Moreover, γ analysis confirmed that solely AC and SC are not sufficient to obtain accurate 3D dose distribution. With breathing, the accuracy worsened severely for all dosimetric indicators, above all for lesions: with AC and optimized SC, -38%/-13% in liver's segment, -61%/-40% in the nonuniform liver. For parenchyma, D50% resulted always less sensitive to breathing and sub-optimal correction methods (difference overall range: -7%/13%). CONCLUSIONS Reconstruction protocol optimization, AC, SC, PVE and respiratory motion corrections should be implemented to obtain the best possible dosimetric accuracy. On the other side, thanks to the relative calibration, D50% inaccuracy for the healthy parenchyma from absence of AC was less than expected, while the optimization of SC was scarcely influent. The relative calibration therefore allows to perform TARE planning, basing on D50% for the healthy parenchyma, even without AC or with suboptimal corrections, rather than rely on nondosimetric methods.
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Affiliation(s)
- Massimiliano Pacilio
- Department of Medical Physics, Azienda Ospedaliera San Camillo Forlanini, Rome 00152, Italy
| | - Mahila Ferrari
- Department of Medical Physics, Istituto Europeo di Oncologia, Milan 20141, Italy
| | - Carlo Chiesa
- Department of Nuclear Medicine, Istituto Nazionale Tumori IRCCS Foundation, Milan 20133, Italy
| | - Leda Lorenzon
- Postgraduate School of Medical Physics, "Sapienza" University of Rome, Rome 00185, Italy
| | - Marta Mira
- Post graduate Health Physics School, University of Milan, Milan 20122, Italy
| | - Francesca Botta
- Department of Medical Physics, Istituto Europeo di Oncologia, Milan 20141, Italy
| | - Domenico Becci
- Postgraduate School of Medical Physics, "Sapienza" University of Rome, Rome 00185, Italy
| | - Leonel Alberto Torres
- Department of Nuclear Medicine, Clinical Research Division of the Center of Isotopes (DIC-CENTIS), Havana 11100, Cuba
| | - Marco Coca Perez
- Department of PET-CT and Nuclear Medicine, Imaging Center Medscan-Concepciòn, Concepciòn 4070061, Chile
| | - Alex Vergara Gil
- Department of Nuclear Medicine, Clinical Research Division of the Center of Isotopes (DIC-CENTIS), Havana 11100, Cuba
| | - Chiara Basile
- Department of Medical Physics, Azienda Ospedaliera San Camillo Forlanini, Rome 00152, Italy
| | - Michael Ljungberg
- Department of Medical Radiation Physics, University of Lund, Lund 22100, Sweden
| | - Roberto Pani
- Department of Medico-surgical Sciences and Biotecnologies, "Sapienza" University of Rome, Rome 00185, Italy
| | - Marta Cremonesi
- Department of Medical Physics, Istituto Europeo di Oncologia, Milan 20141, Italy
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Gustafsson J, Sundlöv A, Sjögreen Gleisner K. SPECT image segmentation for estimation of tumour volume and activity concentration in 177Lu-DOTATATE radionuclide therapy. EJNMMI Res 2017; 7:18. [PMID: 28233160 PMCID: PMC5323339 DOI: 10.1186/s13550-017-0262-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 01/31/2017] [Indexed: 11/23/2022] Open
Abstract
Background Dosimetry in radionuclide therapy has the potential to allow for a treatment tailored to the individual patient. One therapeutic radiopharmaceutical where patient-specific dosimetry is feasible is 177Lu-DOTATATE, used for the treatment of neuroendocrine tumours. The emission of gamma photons by 177Lu allows for imaging with SPECT (single photon emission computed tomography). One important step for dosimetry using this imaging technique is the SPECT image segmentation, which needs to be robust and accurate for the estimated quantities to be reliable. This work investigates different methods for automatic tumour delineation in 177Lu-DOTATATE SPECT images. Three segmentation methods are considered: a fixed 42% threshold (FT), the Otsu method (OM) and a method based on Fourier surfaces (FS). Effects of including resolution compensation in the iterative SPECT image reconstruction are also studied. Evaluation is performed based on Monte Carlo-simulated SPECT images from 24 h and 336 h post injection (p.i.), for determination of the volume, activity concentration and dice similarity coefficient. In addition, patient data are used to investigate the correspondence of tumour volumes when delineated in SPECT or morphological CT or MR images. Patient data are also used to examine the sensitivity to the operator-dependent initialization. Results For simulated images from 24 h p.i. reconstructed without resolution compensation, a volume and activity-concentration root-mean-square error below 15% is typically obtained for tumours above approximately 10 cm3 when using OM or FS, while FT performs considerably worse. When including resolution compensation, the tumour volume becomes underestimated and the activity concentration overestimated. The FS method appears to be robust to noise, as seen for the 336 h images. The differences between the tumour volumes estimated from the SPECT images and the volumes estimated from morphological images are generally larger than the discrepancies seen for the simulated data sets. Conclusions Segmentation results are encouraging for future dosimetry of tumours with volumes above approximately 10 cm3. Using resolution compensation in the reconstruction may have a negative effect on volume estimation.
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Affiliation(s)
- Johan Gustafsson
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden.
| | - Anna Sundlöv
- Department of Oncology and Pathology, Clinical Sciences Lund, Lund University, Lund, Sweden.,Department of Oncology, Skåne University Hospital, Lund, Sweden
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Lysak Y, Dyomin V, Klimanov V, Narkevich B, Romodanov V. Approach to radionuclide therapy dosimetry planning. NUCLEAR ENERGY AND TECHNOLOGY 2016. [DOI: 10.1016/j.nucet.2016.11.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Gallio E, Richetta E, Finessi M, Stasi M, Pellerito RE, Bisi G, Ropolo R. Calculation of tumour and normal tissue biological effective dose in 90 Y liver radioembolization with different dosimetric methods. Phys Med 2016; 32:1738-1744. [DOI: 10.1016/j.ejmp.2016.10.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 10/27/2016] [Accepted: 10/28/2016] [Indexed: 01/25/2023] Open
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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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Momennezhad M, Nasseri S, Zakavi SR, Parach AA, Ghorbani M, Asl RG. A 3D Monte Carlo Method for Estimation of Patient-specific Internal Organs Absorbed Dose for (99m)Tc-hynic-Tyr(3)-octreotide Imaging. World J Nucl Med 2016; 15:114-23. [PMID: 27134562 PMCID: PMC4809152 DOI: 10.4103/1450-1147.174700] [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] [Indexed: 12/03/2022] Open
Abstract
Single-photon emission computed tomography (SPECT)-based tracers are easily available and more widely used than positron emission tomography (PET)-based tracers, and SPECT imaging still remains the most prevalent nuclear medicine imaging modality worldwide. The aim of this study is to implement an image-based Monte Carlo method for patient-specific three-dimensional (3D) absorbed dose calculation in patients after injection of 99mTc-hydrazinonicotinamide (hynic)-Tyr3-octreotide as a SPECT radiotracer. 99mTc patient-specific S values and the absorbed doses were calculated with GATE code for each source-target organ pair in four patients who were imaged for suspected neuroendocrine tumors. Each patient underwent multiple whole-body planar scans as well as SPECT imaging over a period of 1-24 h after intravenous injection of 99mhynic-Tyr3-octreotide. The patient-specific S values calculated by GATE Monte Carlo code and the corresponding S values obtained by MIRDOSE program differed within 4.3% on an average for self-irradiation, and differed within 69.6% on an average for cross-irradiation. However, the agreement between total organ doses calculated by GATE code and MIRDOSE program for all patients was reasonably well (percentage difference was about 4.6% on an average). Normal and tumor absorbed doses calculated with GATE were slightly higher than those calculated with MIRDOSE program. The average ratio of GATE absorbed doses to MIRDOSE was 1.07 ± 0.11 (ranging from 0.94 to 1.36). According to the results, it is proposed that when cross-organ irradiation is dominant, a comprehensive approach such as GATE Monte Carlo dosimetry be used since it provides more reliable dosimetric results.
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Affiliation(s)
- Mehdi Momennezhad
- Department of Medical Physics, Faculty of Medicine, University of Medical Sciences, Mashhad, Iran
| | - Shahrokh Nasseri
- Department of Medical Physics, Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Seyed Rasoul Zakavi
- Department of Nuclear Medicine, Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Asghar Parach
- Department of Medical Physics, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mahdi Ghorbani
- Department of Medical Physics, Faculty of Medicine, University of Medical Sciences, Mashhad, Iran
| | - Ruhollah Ghahraman Asl
- Department of Medical Physics, Faculty of Medicine, University of Medical Sciences, Mashhad, Iran
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Ahlstedt J, Tran TA, Strand SE, Gram M, Åkerström B. Human Anti-Oxidation Protein A1M--A Potential Kidney Protection Agent in Peptide Receptor Radionuclide Therapy. Int J Mol Sci 2015; 16:30309-20. [PMID: 26694383 PMCID: PMC4691176 DOI: 10.3390/ijms161226234] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 11/28/2015] [Accepted: 12/11/2015] [Indexed: 11/16/2022] Open
Abstract
Peptide receptor radionuclide therapy (PRRT) has been in clinical use for 15 years to treat metastatic neuroendocrine tumors. PRRT is limited by reabsorption and retention of the administered radiolabeled somatostatin analogues in the proximal tubule. Consequently, it is essential to develop and employ methods to protect the kidneys during PRRT. Today, infusion of positively charged amino acids is the standard method of kidney protection. Other methods, such as administration of amifostine, are still under evaluation and show promising results. α1-microglobulin (A1M) is a reductase and radical scavenging protein ubiquitously present in plasma and extravascular tissue. Human A1M has antioxidation properties and has been shown to prevent radiation-induced in vitro cell damage and protect non-irradiated surrounding cells. It has recently been shown in mice that exogenously infused A1M and the somatostatin analogue octreotide are co-localized in proximal tubules of the kidney after intravenous infusion. In this review we describe the current situation of kidney protection during PRRT, discuss the necessity and implications of more precise dosimetry and present A1M as a new, potential candidate for renal protection during PRRT and related targeted radionuclide therapies.
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Affiliation(s)
- Jonas Ahlstedt
- Section for Infection Medicine, Department of Clinical Sciences in Lund, Lund University, Lund 221 84, Sweden.
| | - Thuy A Tran
- Lund University Bioimaging Center, Lund University, Lund 221 84, Sweden.
| | - Sven-Erik Strand
- Section of Medical Radiation Physics, Department of Clinical Sciences in Lund, Lund University, Lund 221 84, Sweden.
| | - Magnus Gram
- Section for Infection Medicine, Department of Clinical Sciences in Lund, Lund University, Lund 221 84, Sweden.
| | - Bo Åkerström
- Section for Infection Medicine, Department of Clinical Sciences in Lund, Lund University, Lund 221 84, Sweden.
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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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Sandström M, Ilan E, Karlberg A, Johansson S, Freedman N, Garske-Román U. Method dependence, observer variability and kidney volumes in radiation dosimetry of (177)Lu-DOTATATE therapy in patients with neuroendocrine tumours. EJNMMI Phys 2015; 2:24. [PMID: 26501825 PMCID: PMC4883125 DOI: 10.1186/s40658-015-0127-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 09/24/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Radionuclide therapy can be individualized by performing dosimetry. To determine absorbed organ doses in (177)Lu-DOTATATE therapy, three methods based on activity concentrations are currently in use: the small volume of interest (sVOI) method, and two methods based on large VOIs either on anatomical CT (aVOI) or on thresholds on functional images (tVOI). The main aim of the present work was to validate the sVOI in comparison to the other two methods regarding agreement and time efficiency. Secondary aims were to investigate inter-observer variability for the sVOI and the change of functional organ volumes following therapy. METHODS Thirty patients diagnosed with neuroendocrine tumours undergoing therapy with (177)Lu-DOTATATE were included. Each patient underwent three SPECT/CT scans at 1, 4 and 7 days after the treatment. Three independent observers calculated absorbed doses to the right and left kidney and the spleen using sVOI and one observer used aVOI. For tVOI, the absorbed doses were calculated based on automatically drawn isocontours around the organs at different thresholds (42, 50, 60 and 70 %). The inter-observer difference between the calculated absorbed doses for sVOI was calculated, and the differences between the three methods were computed. Ratios of organ volumes acquired at days 1, 4 and 7 versus the volume at day 1 were calculated for the tVOI method. RESULTS The differences in results of the absorbed dose calculations using all the sVOI and tVOI were small (<5 %). Absorbed dose calculations using aVOI differed slightly more from these results but were still below 10 %. The differences between the three dose calculation methods varied between <5 and 10 %. The organ volumes derived from the tVOI were independent of time for the spleen while they decreased with time for the kidneys. The fastest analysis was performed with the sVOI method. CONCLUSIONS All three dose calculation methods rendered comparable results with small inter-observer differences for sVOI. Unlike the spleen, the functional volume of the kidneys decreased over time during therapy, which suggests that the absorbed dose calculation for the kidneys on activity concentrations should be performed for each time point. The sVOI is the preferred method for calculating absorbed doses in solid organs.
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Affiliation(s)
- Mattias Sandström
- Section of Nuclear Medicine and PET, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden. .,Section of Medical Physics, Department of Immunology, Genetics and Pathology, Uppsala University, 751 85, Uppsala, Sweden.
| | - Ezgi Ilan
- Section of Nuclear Medicine and PET, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.,Section of Medical Physics, Department of Immunology, Genetics and Pathology, Uppsala University, 751 85, Uppsala, Sweden
| | - Anna Karlberg
- Section of Medical Physics, Department of Immunology, Genetics and Pathology, Uppsala University, 751 85, Uppsala, Sweden
| | - Silvia Johansson
- Section of Oncology, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Nanette Freedman
- Medical Biophysics and Nuclear Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ulrike Garske-Román
- Section of Nuclear Medicine and PET, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
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Gustafsson J, Brolin G, Cox M, Ljungberg M, Johansson L, Gleisner KS. Uncertainty propagation for SPECT/CT-based renal dosimetry in177Lu peptide receptor radionuclide therapy. Phys Med Biol 2015; 60:8329-46. [DOI: 10.1088/0031-9155/60/21/8329] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Hippeläinen E, Tenhunen M, Sohlberg A. Fast voxel-level dosimetry for (177)Lu labelled peptide treatments. Phys Med Biol 2015; 60:6685-700. [PMID: 26270032 DOI: 10.1088/0031-9155/60/17/6685] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In peptide receptor radionuclide therapy (PRRT), voxel-level radiation absorbed dose calculations can be performed using several different methods. Each method has it strengths and weaknesses; however, Monte Carlo (MC) simulation is presently considered the most accurate method at providing absorbed dose distributions. Unfortunately MC simulation is time-consuming and often impractical to carry out in a clinical practice. In this work, a fast semi-Monte Carlo (sMC) absorbed dose calculation method for (177)Lu PRRT dosimetry is presented. The sMC method is based on a local electron absorption assumption and fast photon MC simulations. The sMC method is compared against full MC simulation code built on PENELOPE (vxlPen) using digital phantoms to assess the accuracy of these assumptions.Due to the local electron absorption assumption of sMC, the potential errors in cross-fire dose from electrons and photons emitted by (177)Lu were first evaluated using an ellipsoidal kidney model by comparing vxlPen and sMC. The photon cross-fire dose from background to kidney and kidney to background with varying kidney-to-background activity concentration ratios were calculated. In addition, kidney to kidney photon and electron cross-dose with different kidney to kidney distances were studied. Second, extended cardiac-torso (XCAT) phantoms were created with liver lesions and with realistic activity distributions and tissue densities. The XCAT phantoms were used to simulate SPECT projections and 3D activity distribution images were reconstructed using an OSEM algorithm. Image-based dose rate distributions were calculated using vxlPen and sMC. Total doses and dose rate volume histograms (DrVH) produced by the two methods were compared.The photon cross-fire dose from the kidney increased the background's absorbed dose by 5% or more up to 5.8 cm distance with 20 : 1 kidney to background activity concentration ratio. On the other hand, the photon cross-fire dose from the background to the kidney volume was negligible. The vxlPen results showed that the cross fire dose between two similar kidney volumes relative to the source kidney's self-dose were 0.5% and 0.02% for photon and electrons, respectively, when source and target kidneys were modelled next to each other. The photon cross-dose decreased as function of distance, and electron doses were zero at distances larger than 4 mm. The difference between sMC and vxlPen kidney total doses in the XCAT phantom study was -0.4% while the electron dose DrVHs were identical between the methods. There was a systematic 5% difference in photon doses in soft tissue between the codes due to different simulations parameters. However, the photons produced only 4% of the kidney's total dose, thus the difference was not considered significant for total dose calculations.The comparison studies show that the absorbed doses calculated using the sMC differ only slightly from dedicated MC simulator results, while the dose estimates can be obtained in a fraction of the dedicated simulator's calculation time. Results imply that there is no need for electron MC simulation for (177)Lu absorption calculations with current SPECT systems. However, the photon cross-fire dose should be taken into account in healthy tissues, which have a relatively low uptake especially in cases where there are high uptake volumes are nearby.
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Affiliation(s)
- E Hippeläinen
- Clinical Research Institute HUCH Ltd, Helsinki, Finland. Department of Physics, University of Helsinki, PO Box 64, FI-00014, Helsinki, Finland. Helsinki University Central Hospital, Hus Medical Imaging Center, POB 340, FI-00029, Helsinki, Finland
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Brolin G, Gustafsson J, Ljungberg M, Gleisner KS. Pharmacokinetic digital phantoms for accuracy assessment of image-based dosimetry in (177)Lu-DOTATATE peptide receptor radionuclide therapy. Phys Med Biol 2015. [PMID: 26215085 DOI: 10.1088/0031-9155/60/15/6131] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Patient-specific image-based dosimetry is considered to be a useful tool to limit toxicity associated with peptide receptor radionuclide therapy (PRRT). To facilitate the establishment and reliability of absorbed-dose response relationships, it is essential to assess the accuracy of dosimetry in clinically realistic scenarios. To this end, we developed pharmacokinetic digital phantoms corresponding to patients treated with (177)Lu-DOTATATE. Three individual voxel phantoms from the XCAT population were generated and assigned a dynamic activity distribution based on a compartment model for (177)Lu-DOTATATE, designed specifically for this purpose. The compartment model was fitted to time-activity data from 10 patients, primarily acquired using quantitative scintillation camera imaging. S values for all phantom source-target combinations were calculated based on Monte-Carlo simulations. Combining the S values and time-activity curves, reference values of the absorbed dose to the phantom kidneys, liver, spleen, tumours and whole-body were calculated. The phantoms were used in a virtual dosimetry study, using Monte-Carlo simulated gamma-camera images and conventional methods for absorbed-dose calculations. The characteristics of the SPECT and WB planar images were found to well represent those of real patient images, capturing the difficulties present in image-based dosimetry. The phantoms are expected to be useful for further studies and optimisation of clinical dosimetry in (177)Lu PRRT.
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Affiliation(s)
- Gustav Brolin
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Sweden
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Pacilio M, Amato E, Lanconelli N, Basile C, Torres LA, Botta F, Ferrari M, Diaz NC, Perez MC, Fernández M, Lassmann M, Gil AV, Cremonesi M. Differences in 3D dose distributions due to calculation method of voxel S-values and the influence of image blurring in SPECT. Phys Med Biol 2015; 60:1945-64. [DOI: 10.1088/0031-9155/60/5/1945] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Kost SD, Dewaraja YK, Abramson RG, Stabin MG. VIDA: a voxel-based dosimetry method for targeted radionuclide therapy using Geant4. Cancer Biother Radiopharm 2015; 30:16-26. [PMID: 25594357 PMCID: PMC4322792 DOI: 10.1089/cbr.2014.1713] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We have developed the Voxel-Based Internal Dosimetry Application (VIDA) to provide patient-specific dosimetry in targeted radionuclide therapy performing Monte Carlo simulations of radiation transport with the Geant4 toolkit. The code generates voxel-level dose rate maps using anatomical and physiological data taken from individual patients. Voxel level dose rate curves are then fit and integrated to yield a spatial map of radiation absorbed dose. In this article, we present validation studies using established dosimetry results, including self-dose factors (DFs) from the OLINDA/EXM program for uniform activity in unit density spheres and organ self- and cross-organ DFs in the Radiation Dose Assessment Resource (RADAR) reference adult phantom. The comparison with reference data demonstrated agreement within 5% for self-DFs to spheres and reference phantom source organs for four common radionuclides used in targeted therapy ((131)I, (90)Y, (111)In, (177)Lu). Agreement within 9% was achieved for cross-organ DFs. We also present dose estimates to normal tissues and tumors from studies of two non-Hodgkin Lymphoma patients treated by (131)I radioimmunotherapy, with comparison to results generated independently with another dosimetry code. A relative difference of 12% or less was found between methods for mean absorbed tumor doses accounting for tumor regression.
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Affiliation(s)
- Susan D. Kost
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee
| | - Yuni K. Dewaraja
- Department of Radiology, University of Michigan, Ann Arbor, Michigan
| | - Richard G. Abramson
- Department of Radiology/Radiological Science, Vanderbilt University, Nashville, Tennessee
| | - Michael G. Stabin
- Department of Radiology/Radiological Science, Vanderbilt University, Nashville, Tennessee
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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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Jackson PA, Beauregard JM, Hofman MS, Kron T, Hogg A, Hicks RJ. An automated voxelized dosimetry tool for radionuclide therapy based on serial quantitative SPECT/CT imaging. Med Phys 2014; 40:112503. [PMID: 24320462 DOI: 10.1118/1.4824318] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
PURPOSE To create an accurate map of the distribution of radiation dose deposition in healthy and target tissues during radionuclide therapy. METHODS Serial quantitative SPECT∕CT images were acquired at 4, 24, and 72 h for 28 (177)Lu-octreotate peptide receptor radionuclide therapy (PRRT) administrations in 17 patients with advanced neuroendocrine tumors. Deformable image registration was combined with an in-house programming algorithm to interpolate pharmacokinetic uptake and clearance at a voxel level. The resultant cumulated activity image series are comprised of values representing the total number of decays within each voxel's volume. For PRRT, cumulated activity was translated to absorbed dose based on Monte Carlo-determined voxel S-values at a combination of long and short ranges. These dosimetric image sets were compared for mean radiation absorbed dose to at-risk organs using a conventional MIRD protocol (OLINDA 1.1). RESULTS Absorbed dose values to solid organs (liver, kidneys, and spleen) were within 10% using both techniques. Dose estimates to marrow were greater using the voxelized protocol, attributed to the software incorporating crossfire effect from nearby tumor volumes. CONCLUSIONS The technique presented offers an efficient, automated tool for PRRT dosimetry based on serial post-therapy imaging. Following retrospective analysis, this method of high-resolution dosimetry may allow physicians to prescribe activity based on required dose to tumor volume or radiation limits to healthy tissue in individual patients.
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Affiliation(s)
- Price A Jackson
- Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne 3002, Australia
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Jamdade AS, John A. Technetium-99m bone scan and panoramic radiography in detection of bone invasion by oral carcinoma. J Clin Diagn Res 2014; 8:ZC49-53. [PMID: 24995244 DOI: 10.7860/jcdr/2014/8429.4378] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 04/20/2014] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The correct extension of cancer in the bone usually remains undetected on static imaging which may lead to inadequate or over excision. The conventional radiography as well as other anatomical imaging modalities like computed tomography, magnetic resonance imaging often fails to detect functional changes in the bone. However, bone scinitigraphy is highly sensitive in detecting earlier changes in the bone but lack anatomical definition. The purpose of the study was to evaluate the accuracy of combining technetium-99m bone scan and panoramic radiography (Tc scan/PR) over using single diagnostic modality in detection of jaw bone invasion by oral carcinomas. The accuracy of these imaging modalities either alone or in combination were determined by comparing with the histopathological findings. MATERIALS AND METHODS Twenty patients with biopsy-proven oral malignant tumors were randomly selected from Oral Medicine and Radiology department over a period of two years. All patients were investigated preoperatively by Tc scan and PR. Lewis - Jones's designed diagnostic criterion was applied on Tc scan/PR to evaluate bone involvement by cancer. To test the accuracy of Tc scan, PR and Tc scan/PR, their results were compared with the histopathological findings of resected specimen. RESULTS Hybrid Tc scan/PR had higher specificity, accuracy and positive predictive value (83.3%, 94.7%, 92.8%) than Tc scan alone (50%, 84.2%, 81.2%) and higher sensitivity and negative predictive value (100%, 100%) than PR (69.2%, 55.5%). CONCLUSION Combination of Tc scan and PR was more accurate in detecting jaw bone invasion by oral squamous cell carcinoma than Tc scan and PR alone.
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Affiliation(s)
- Anshuman Suresh Jamdade
- Professor, Department of Oral Medicine and Radiology, Mahatma Gandhi Dental College & Hospital , Jaipur, India
| | - Ani John
- EX-Professor and Head, Department of Oral Medicine and Radiology, Government Dental College & Hospital , Mumbai, India
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