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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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Kappadath SC, Henry EC, Lopez BP, Mahvash A. Quantitative evaluation of 90Y-PET/CT and 90Y-SPECT/CT-based dosimetry following Yttrium-90 radioembolization. Med Phys 2024. [PMID: 38781554 DOI: 10.1002/mp.17175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 05/02/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Following yttrium-90 radioembolization (90Y-RE), 90Y-PET/CT and 90Y-SPECT/CT imaging provide the means to calculate the voxelized absorbed dose distribution. Given the widespread use of the two imaging modalities and lack of well-established standardized dosimetry protocols for 90Y-RE, there is a clinical need to systematically investigate and evaluate differences in the performance of voxel-based dosimetry between 90Y-PET/CT and 90Y-SPECT/CT. PURPOSE To quantitatively analyze and compare 90Y-PET/CT and 90Y-SPECT/CT-based dosimetry following 90Y-RE. METHODS 90Y-PET/CT and 90Y-SPECT/CT imaging was acquired for 35 patients following 90Y-RE with TheraSphere for the treatment of unresectable hepatocellular carcinoma. Dosimetry was performed using the local deposition method with known activity and the mean dose (Dmean) was calculated for perfused liver volumes (PV), tumors (T), and perfused normal livers (NL). Additionally, the absorbed dose to x% of the volume (Dx, x ∈ $ \in $ [5%, 10%, …, 90%, 95%]) and the volume receiving y Gy (Vy, y ∈ $ \in $ [10 Gy, 20 Gy, …, 190 Gy, 200 Gy]) were calculated for T and NL, respectively. Dose metrics were compared using linear regression, Bland-Altman analysis, and statistical testing. RESULTS Both 90Y-SPECT/CT and 90Y-PET/CT-based tumor Dmean were strongly correlated (R2 ≥ 0.90) with Dx, excluding metrics on the extrema. Intra-modality comparisons of various Dx and Vy metrics yielded statistically significant differences (ANOVA, p < 0.001) for both90Y-PET/CT and 90Y-SPECT/CT. Based on statistical testing, only Dx metrics separated by greater than 20%-30% coverage, and only Vy metrics separated by greater than 40-70 Gy, reported significant differences. For PV, there was a strong correlation (R2 ≥ 0.99) between Dmean derived separately from 90Y-PET/CT and 90Y-SPECT/CT imaging. The strength of the correlation was slightly reduced for T and NL with R2 = 0.91 and R2 = 0.95, respectively. For PV, the mean bias ± standard error (SE) and 95% limits of agreement (LOA) between Dmean from the two modalities was effectively zero with -0.8 ± 0.4% (± 2.5%). For T and NL, the mean bias ± SE (± LOA) was -14.5 ± 3.7% (± 24%) and 9.4 ± 4.7% (± 27%), respectively. CONCLUSION The strong correlation between Dmean and Dx suggests information from multiple dose metrics (e.g., D70 and Dmean) is largely redundant when establishing dose-response relationships in 90Y-RE. Dmean is highly correlated between 90Y-PET/CT and 90Y-SPECT/CT-based dosimetry, for all liver VOIs. Relative to 90Y-SPECT/CT, 90Y-PET/CT, on average, yielded higher Dmean to tumors (14%) and lower Dmean to perfused normal livers (9%). Absorbed dose differences for perfused liver volumes between 90Y-SPECT/CT and 90Y-PET/CT were negligible.
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Affiliation(s)
| | - Eric Courtney Henry
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Benjamin P Lopez
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Armeen Mahvash
- Department of Interventional Radiology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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Henry EC, Mahvash A, Lopez BP, Kappadath SC. A comparison of methods for in vivo activity and absorbed dose quantification with PET/CT following yttrium-90 radioembolization. Med Phys 2024. [PMID: 38772046 DOI: 10.1002/mp.17174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 05/02/2024] [Accepted: 05/07/2024] [Indexed: 05/23/2024] Open
Abstract
BACKGROUND Yttrium-90 (90Y) positron emission tomography (PET)/computed tomography (CT) imaging is increasingly being used to perform tumor (T) and normal liver (NL) voxel dosimetry after 90Y-radioembolization (90Y-RE). Yet, the accuracy of in vivo 90Y-PET/CT imaging, subject to motion blur and co-registration inaccuracies, and 90Y-PET/CT dose quantification, subject to availability of different voxel dosimetry algorithms, are not well understood. PURPOSE The purpose of this study was to investigate the accuracy of 90Y-PET/CT-based activity estimates following 90Y-RE and characterize differences between 90Y-PET/CT-based voxel dosimetry algorithms. METHODS Thirty-five patients underwent 90Y-PET/CT imaging after 90Y-RE with TheraSphere. The net administered 90Y activity (Aadmin) was determined using a dose calibrator and pre- and post-procedure exposure rate measurements. The summation of image-based activity (Aimage) was extracted from perfused volume (PV) and 3D-isotropically 2-cm expanded PV contour (PV+2 cm). Absorbed doses were calculated using voxel S-value (VSV), local deposition method (LDM), and LDM with known activity (LDMKA) dosimetry algorithms. Linear regression and Bland-Altman analysis quantified the relationship between Aimage and Aadmin and between mean dose estimates (DLDM, DVSV, DLDM-KA) for PV, T, and perfused NL volumes. RESULTS While Aadmin and Aimage in PV were highly correlated (R2 > 0.95), the mean bias ± standard error (SE) and (95% limits of agreement, LOA) was significantly non-zero with -22.7 ± 4.7% (± 28.4%). In PV+2 cm, the mean bias ± SE (± LOA) decreased to 1.3 ± 3.4% (± 18.0%) consistent with zero mean error. DLDM and DVSV were highly correlated (R2 > 0.99) for all volumes of interest (VOIs) and the mean bias ± SE (± LOA) was 2.2 ± 0.2% (± 1.0%), 0.7 ± 0.4% (± 2.8%), and 3.2 ± 0.5% (± 2.8%) for PV, T, and NL, respectively. DLDM-KA and DVSV were correlated with R2 = 0.86, 0.80, and 0.86 for PV, T, and NL, respectively. The mean bias ± SE (± LOA) between DLDM-KA and DVSV was significantly non-zero with -19.6 ± 5.1% (± 31.0%), -20.8 ± 4.4% (± 29.0%), and -18.1 ± 5.3% (± 31.1%) for PV, T, and NL, respectively. CONCLUSIONS The summation of Aimage in PV was underestimated relative to Aadmin. Only by accounting for respiratory motion, limited spatial resolution, and PET/CT co-registration errors through VOI expansion was Aimage, on average, equal to Aadmin. The differences between DLDM and DVSV were not clinically relevant, though DLDM-KA was approximately 20% greater than DVSV. Given the high quantitative accuracy of dose calibrators and challenges associated with accurate 90Y-PET/CT quantification, LDMKA is the preferred algorithm for accurate 90Y-PET/CT-based dosimetry following 90Y-RE.
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Affiliation(s)
- Eric Courtney Henry
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Armeen Mahvash
- Department of Interventional Radiology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Benjamin P Lopez
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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Busse NC, Al‐Ghazi MSAL, Abi‐Jaoudeh N, Alvarez D, Ayan AS, Chen E, Chuong MD, Dezarn WA, Enger SA, Graves SA, Hobbs RF, Jafari ME, Kim SP, Maughan NM, Polemi AM, Stickel JR. AAPM Medical Physics Practice Guideline 14.a: Yttrium-90 microsphere radioembolization. J Appl Clin Med Phys 2024; 25:e14157. [PMID: 37820316 PMCID: PMC10860558 DOI: 10.1002/acm2.14157] [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: 04/13/2023] [Revised: 06/19/2023] [Accepted: 08/25/2023] [Indexed: 10/13/2023] Open
Abstract
Radioembolization using Yttrium-90 (90 Y) microspheres is widely used to treat primary and metastatic liver tumors. The present work provides minimum practice guidelines for establishing and supporting such a program. Medical physicists play a key role in patient and staff safety during these procedures. Products currently available are identified and their properties and suppliers summarized. Appropriateness for use is the domain of the treating physician. Patient work up starts with pre-treatment imaging. First, a mapping study using Technetium-99m (Tc-99m ) is carried out to quantify the lung shunt fraction (LSF) and to characterize the vascular supply of the liver. An MRI, CT, or a PET-CT scan is used to obtain information on the tumor burden. The tumor volume, LSF, tumor histology, and other pertinent patient characteristics are used to decide the type and quantity of 90 Y to be ordered. On the day of treatment, the appropriate dose is assayed using a dose calibrator with a calibration traceable to a national standard. In the treatment suite, the care team led by an interventional radiologist delivers the dose using real-time image guidance. The treatment suite is posted as a radioactive area during the procedure and staff wear radiation dosimeters. The treatment room, patient, and staff are surveyed post-procedure. The dose delivered to the patient is determined from the ratio of pre-treatment and residual waste exposure rate measurements. Establishing such a treatment modality is a major undertaking requiring an institutional radioactive materials license amendment complying with appropriate federal and state radiation regulations and appropriate staff training commensurate with their respective role and function in the planning and delivery of the procedure. Training, documentation, and areas for potential failure modes are identified and guidance is provided to ameliorate them.
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Affiliation(s)
| | | | - Nadine Abi‐Jaoudeh
- Department of Radiological SciencesUniversity of CaliforniaIrvineCaliforniaUSA
| | - Diane Alvarez
- Baptist HospitalMiami Cancer InstituteMiamiFloridaUSA
| | - Ahmet S. Ayan
- Department of Radiation OncologyOhio State UniversityColumbusOhioUSA
| | - Erli Chen
- Department of Radiation OncologyCheshire Medical CenterKeeneNew HampshireUSA
| | - Michael D. Chuong
- Department of Radiation OncologyMiami Cancer InstituteMiamiFloridaUSA
| | - William A. Dezarn
- Department of Radiation OncologyWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | | | | | - Robert F. Hobbs
- Department of Radiation OncologyJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Mary Ellen Jafari
- Diagnostic Physics, Atlantic Health SystemMorristown Medical CenterMorristownNew JerseyUSA
| | - S. Peter Kim
- Medical Physics UnitMcGill UniversityMontrealCanada
| | - Nichole M. Maughan
- Department of Radiation OncologyWashington University in St. LouisSaint LouisMissouriUSA
| | - Andrew M. Polemi
- Department of RadiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
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Linder PM, Lan W, Trautwein NF, Brosch-Lenz J, von Beschwitz S, Kupferschläger J, Reischl G, Grözinger G, Dittmann H, la Fougère C, Schmidt FP. Optimization of Y-90 Radioembolization Imaging for Post-Treatment Dosimetry on a Long Axial Field-of-View PET/CT Scanner. Diagnostics (Basel) 2023; 13:3418. [PMID: 37998554 PMCID: PMC10670048 DOI: 10.3390/diagnostics13223418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/07/2023] [Accepted: 11/07/2023] [Indexed: 11/25/2023] Open
Abstract
BACKGROUND PET imaging after yttrium-90 (Y-90) radioembolization is challenging because of the low positron fraction of Y-90 (32 × 10-6). The resulting low number of events can be compensated by the high sensitivity of long axial field-of-view (LAFOV) PET/CT scanners. Nevertheless, the reduced event statistics require optimization of the imaging protocol to achieve high image quality (IQ) and quantification accuracy sufficient for post-treatment dosimetry. METHODS Two phantoms (NEMA IEC and AbdoMan phantoms, mimicking human liver) filled with Y-90 and a 4:1 sphere (tumor)-to-background ratio were scanned for 24 h with the Biograph Vision Quadra (Siemens Healthineers). Eight patients were scanned after Y-90 radioembolization (1.3-4.7 GBq) using the optimized protocol (obtained by phantom studies). The IQ, contrast recovery coefficients (CRCs) and noise were evaluated for their limited and full acceptance angles, different rebinned scan durations, numbers of iterations and post-reconstruction filters. The s-value-based absorbed doses were calculated to assess their suitability for dosimetry. RESULTS The phantom studies demonstrate that two iterations, five subsets and a 4 mm Gaussian filter provide a reasonable compromise between a high CRC and low noise. For a 20 min scan duration, an adequate CRC of 56% (vs. 24 h: 62%, 20 mm sphere) was obtained, and the noise was reduced by a factor of 1.4, from 40% to 29%, using the full acceptance angle. The patient scan results were consistent with those from the phantom studies, and the impacts on the absorbed doses were negligible for all of the studied parameter sets, as the maximum percentage difference was -3.89%. CONCLUSIONS With 2i5s, a 4 mm filter and a scan duration of 20 min, IQ and quantification accuracy that are suitable for post-treatment dosimetry of Y-90 radioembolization can be achieved.
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Affiliation(s)
- Pia M. Linder
- Department of Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, 72076 Tuebingen, Germany; (P.M.L.); (W.L.); (S.v.B.); (C.l.F.); (H.D.)
| | - Wenhong Lan
- Department of Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, 72076 Tuebingen, Germany; (P.M.L.); (W.L.); (S.v.B.); (C.l.F.); (H.D.)
| | - Nils F. Trautwein
- Department of Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, 72076 Tuebingen, Germany; (P.M.L.); (W.L.); (S.v.B.); (C.l.F.); (H.D.)
| | - Julia Brosch-Lenz
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technical University Munich, 81675 Munich, Germany
| | - Sebastian von Beschwitz
- Department of Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, 72076 Tuebingen, Germany; (P.M.L.); (W.L.); (S.v.B.); (C.l.F.); (H.D.)
| | - Jürgen Kupferschläger
- Department of Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, 72076 Tuebingen, Germany; (P.M.L.); (W.L.); (S.v.B.); (C.l.F.); (H.D.)
| | - Gerald Reischl
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard-Karls University Tuebingen, 72074 Tuebingen, Germany;
- Cluster of Excellence iFIT (EXC 2180) “Image Guided and Functionally Instructed Tumor Therapies”, University of Tuebingen, 72074 Tuebingen, Germany
| | - Gerd Grözinger
- Department for Diagnostic and Interventional Radiology, University Hospital Tuebingen, 72076 Tuebingen, Germany;
| | - Helmut Dittmann
- Department of Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, 72076 Tuebingen, Germany; (P.M.L.); (W.L.); (S.v.B.); (C.l.F.); (H.D.)
| | - Christian la Fougère
- Department of Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, 72076 Tuebingen, Germany; (P.M.L.); (W.L.); (S.v.B.); (C.l.F.); (H.D.)
- Cluster of Excellence iFIT (EXC 2180) “Image Guided and Functionally Instructed Tumor Therapies”, University of Tuebingen, 72074 Tuebingen, Germany
| | - Fabian P. Schmidt
- Department of Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, 72076 Tuebingen, Germany; (P.M.L.); (W.L.); (S.v.B.); (C.l.F.); (H.D.)
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard-Karls University Tuebingen, 72074 Tuebingen, Germany;
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Pham TP, Presles B, Popoff R, Alberini JL, Vrigneaud JM. Pre-treatment dosimetry in 90Y-SIRT: Is it possible to optimise SPECT reconstruction parameters and calculation methods for accurate dosimetry? Phys Med 2023; 115:103145. [PMID: 37852020 DOI: 10.1016/j.ejmp.2023.103145] [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: 10/01/2022] [Revised: 06/03/2023] [Accepted: 09/21/2023] [Indexed: 10/20/2023] Open
Abstract
PURPOSE The aim of this study was (a) to optimise the99mTc-SPECT reconstruction parameters for the pre-treatment dosimetry of90Y-selective internal radiation therapy (SIRT) and (b) to compare the accuracy of clinical dosimetry methods with full Monte-Carlo dosimetry (fMCD) performed with Gate. METHODS To optimise the reconstruction parameters, two hundred reconstructions with different parameters were performed on a NEMA phantom, varying the number of iterations, subsets, and post-filtering. The accuracy of the dosimetric methods was then investigated using an anthropomorphic phantom. Absorbed dose maps were generated using (1) the Partition Model (PM), (2) the Dose Voxel Kernel (DVK) convolution, and (3) the Local Deposition Method (LDM) with known activity restricted to the whole phantom (WP) or to the liver and lungs (LL). The dose to the lungs was calculated using the "multiple DVK" and "multiple LDM" methods. RESULTS Optimal OSEM reconstruction parameters were found to depend on object size and dosimetric criterion chosen (Dmean or DVH-derived metric). The Dmean of all three dosimetric methods was close (≤ 10%) to the Dmean of fMCD simulations when considering large segmented volumes (whole liver, normal liver). In contrast, the Dmean to the small volume (∅=31) was systemically underestimated (12%-25%). For lungs, the "multiple DVK" and "multiple LDM" methods yielded a Dmean within 20% for the WP method and within 10% for the LL method. CONCLUSIONS All three methods showed a substantial degradation of the dose-volume histograms (DVHs) compared to fMCD simulations. The DVK and LDM methods performed almost equally well, with the "multiple DVK" method being more accurate in the lungs.
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Affiliation(s)
- Tien-Phong Pham
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) - UMR CNRS 6302, University of Burgundy, Dijon, France; Department of Nuclear Medicine, Georges-François Leclerc Cancer Centre, Dijon, France.
| | - Benoit Presles
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) - UMR CNRS 6302, University of Burgundy, Dijon, France
| | - Romain Popoff
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) - UMR CNRS 6302, University of Burgundy, Dijon, France; Department of Nuclear Medicine, Georges-François Leclerc Cancer Centre, Dijon, France
| | - Jean-Louis Alberini
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) - UMR CNRS 6302, University of Burgundy, Dijon, France; Department of Nuclear Medicine, Georges-François Leclerc Cancer Centre, Dijon, France
| | - Jean-Marc Vrigneaud
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) - UMR CNRS 6302, University of Burgundy, Dijon, France; Department of Nuclear Medicine, Georges-François Leclerc Cancer Centre, Dijon, France.
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Phantom-based evaluation of yttrium-90 datasets using biograph vision quadra. Eur J Nucl Med Mol Imaging 2023; 50:1168-1182. [PMID: 36504278 PMCID: PMC9931793 DOI: 10.1007/s00259-022-06074-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 12/04/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE The image quality characteristics of two NEMA phantoms with yttrium-90 (90Y) were evaluated on a long axial field-of-view (AFOV) PET/CT. The purpose was to identify the optimized reconstruction setup for the imaging of patients with hepatocellular carcinoma after 90Y radioembolization. METHODS Two NEMA phantoms were used, where one had a 1:10 sphere to background activity concentration ratio and the second had cold background. Reconstruction parameters used are as follows: iterations 2 to 8, Gaussian filter 2- to 6-mm full-width-at-half-maximum, reconstruction matrices 440 × 440 and 220 × 220, high sensitivity (HS), and ultra-high sensitivity (UHS) modes. 50-, 40-, 30-, 20-, 10-, and 5-min acquisitions were reconstructed. The measurements included recovery coefficients (RC), signal-to-noise ratio (SNR), background variability, and lung error which measures the residual error in the corrections. Patient data were reconstructed with 20-, 10-, 5-, and 1-min time frames and evaluated in terms of SNR. RESULTS The RC for the hot phantom was 0.36, 0.45, 0.53, 0.63, 0.68, and 0.84 for the spheres with diameters of 10, 13, 17, 22, 28, and 37 mm, respectively, for UHS 2 iterations, a 220 × 220 matrix, and 50-min acquisition. The RC values did not differ with acquisition times down to 20 min. The SNR was the highest for 2 iterations, measured 11.7, 16.6, 17.6, 19.4, 21.9, and 27.7 while the background variability was the lowest (27.59, 27.08, 27.36, 26.44, 30.11, and 33.51%). The lung error was 18%. For the patient dataset, the SNR was 19%, 20%, 24%, and 31% higher for 2 iterations compared to 4 iterations for 20-, 10-, 5-, and 1-min time frames, respectively. CONCLUSIONS This study evaluates the NEMA image quality of a long AFOV PET/CT scanner with 90Y. It provides high RC for the smallest sphere compared to other standard AFOV scanners at shorter scan times. The maximum patient SNR was for 2 iterations, 20 min, while 5 min delivers images with acceptable SNR.
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Sharma NK, Kappadath SC, Chuong M, Folkert M, Gibbs P, Jabbour SK, Jeyarajah DR, Kennedy A, Liu D, Meyer JE, Mikell J, Patel RS, Yang G, Mourtada F. The American Brachytherapy Society consensus statement for permanent implant brachytherapy using Yttrium-90 microsphere radioembolization for liver tumors. Brachytherapy 2022; 21:569-591. [PMID: 35599080 PMCID: PMC10868645 DOI: 10.1016/j.brachy.2022.04.004] [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: 12/20/2021] [Revised: 03/25/2022] [Accepted: 04/14/2022] [Indexed: 11/02/2022]
Abstract
PURPOSE To develop a multidisciplinary consensus for high quality multidisciplinary implementation of brachytherapy using Yttrium-90 (90Y) microspheres transarterial radioembolization (90Y TARE) for primary and metastatic cancers in the liver. METHODS AND MATERIALS Members of the American Brachytherapy Society (ABS) and colleagues with multidisciplinary expertise in liver tumor therapy formulated guidelines for 90Y TARE for unresectable primary liver malignancies and unresectable metastatic cancer to the liver. The consensus is provided on the most recent literature and clinical experience. RESULTS The ABS strongly recommends the use of 90Y microsphere brachytherapy for the definitive/palliative treatment of unresectable liver cancer when recommended by the multidisciplinary team. A quality management program must be implemented at the start of 90Y TARE program development and follow-up data should be tracked for efficacy and toxicity. Patient-specific dosimetry optimized for treatment intent is recommended when conducting 90Y TARE. Implementation in patients on systemic therapy should account for factors that may enhance treatment related toxicity without delaying treatment inappropriately. Further management and salvage therapy options including retreatment with 90Y TARE should be carefully considered. CONCLUSIONS ABS consensus for implementing a safe 90Y TARE program for liver cancer in the multidisciplinary setting is presented. It builds on previous guidelines to include recommendations for appropriate implementation based on current literature and practices in experienced centers. Practitioners and cooperative groups are encouraged to use this document as a guide to formulate their clinical practices and to adopt the most recent dose reporting policies that are critical for a unified outcome analysis of future effectiveness studies.
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Affiliation(s)
- Navesh K Sharma
- Department of Radiation Oncology, Penn State Hershey School of Medicine, Hershey, PA
| | - S Cheenu Kappadath
- Department of Imaging Physics, UT MD Anderson Cancer Center, Houston, TX
| | - Michael Chuong
- Department of Radiation Oncology, Miami Cancer Institute, Miami, FL
| | - Michael Folkert
- Northwell Health Cancer Institute, Radiation Medicine at the Center for Advanced Medicine, New Hyde Park, NY
| | - Peter Gibbs
- Personalised Oncology Division, Walter and Eliza Hall Institute, Melbourne, Victoria, Australia
| | - Salma K Jabbour
- Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ
| | | | | | - David Liu
- Vancouver General Hospital, Vancouver, British Columbia, Canada
| | | | | | - Rahul S Patel
- Icahn School of Medicine at Mount Sinai, New York, NY
| | - Gary Yang
- Loma Linda University, Loma Linda, CA
| | - Firas Mourtada
- Helen F. Graham Cancer Center & Research Institute, Christiana Care Health System, Newark, DE; Department of Radiation Oncology, Sidney Kimmel Cancer Center at Thomas Jefferson University, Philadelphia, PA.
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Costa G, Spencer B, Omidvari N, Foster C, Rusnak M, Hunt H, Caudle DT, Pillai RT, Vu CT, Roncali E. Radioembolization Dosimetry with Total-Body 90Y PET. J Nucl Med 2022; 63:1101-1107. [PMID: 34795015 PMCID: PMC9258581 DOI: 10.2967/jnumed.121.263145] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/08/2021] [Indexed: 01/26/2023] Open
Abstract
Transarterial radioembolization (TARE) is a locoregional radiopharmaceutical therapy based on the delivery of radioactive 90Y microspheres to liver tumors. The importance of personalized dosimetry to make TARE safer and more effective has been demonstrated in recent clinical studies, stressing the need for quantification of the dose-response relationship to ultimately optimize the administered activity before treatment and image it after treatment. 90Y dosimetric studies are challenging because of the lack of accurate and precise methods but are best realized with PET combined with Monte Carlo simulations and other image modalities to calculate a segmental dose distribution. The aim of this study was to assess the suitability of imaging 90Y PET patients with the total-body PET/CT uEXPLORER and to investigate possible improvements in TARE 90Y PET-based dosimetry. The uEXPLORER is the first commercially available ultra-high-resolution (171 cps/kBq) total-body digital PET/CT device with a 194-cm axial PET field of view that enables the whole body to be scanned at a single bed position. Methods: Two PET/CT scanners were evaluated in this study: the Biograph mCT and the total-body uEXPLORER. Images of a National Electrical Manufacturers Association (NEMA) image-quality phantom and 2 patients were reconstructed using our standard clinical oncology protocol. A late portal phase contrast-enhanced CT scan was used to contour the liver segments and create corresponding volumes of interest. To calculate the absorbed dose, Monte Carlo simulations were performed using Geant4 Application for Tomographic Emission (GATE). The absorbed dose and dose-volume histograms were calculated for all 6 spheres (diameters ranging from 10 to 37 mm) of the NEMA phantom, the liver segments, and the entire liver. Differences between the phantom doses and an analytic ground truth were quantified through the root mean squared error. Results: The uEXPLORER showed a higher signal-to-noise ratio at 10- and 13-mm diameters, consistent with its high spatial resolution and system sensitivity. The total liver-absorbed dose showed excellent agreement between the uEXPLORER and the mCT for both patients, with differences lower than 0.2%. Larger differences of up to 60% were observed when comparing the liver segment doses. All dose-volume histograms were in good agreement, with narrower tails for the uEXPLORER in all segments, indicating lower image noise. Conclusion: This patient study is compelling for the use of total-body 90Y PET for liver dosimetry. The uEXPLORER scanner showed a better signal-to-noise ratio than mCT, especially in lower-count regions of interest, which is expected to improve dose quantification and tumor dosimetry.
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Affiliation(s)
- Gustavo Costa
- Department of Biomedical Engineering, University of California–Davis, Davis, California; and
| | - Benjamin Spencer
- Department of Biomedical Engineering, University of California–Davis, Davis, California; and
| | - Negar Omidvari
- Department of Biomedical Engineering, University of California–Davis, Davis, California; and
| | - Cameron Foster
- Department of Radiology, University of California–Davis, Davis, California
| | - Michael Rusnak
- Department of Radiology, University of California–Davis, Davis, California
| | - Heather Hunt
- Department of Radiology, University of California–Davis, Davis, California
| | - Denise T. Caudle
- Department of Radiology, University of California–Davis, Davis, California
| | - Rex T. Pillai
- Department of Radiology, University of California–Davis, Davis, California
| | - Catherine Tram Vu
- Department of Radiology, University of California–Davis, Davis, California
| | - Emilie Roncali
- Department of Biomedical Engineering, University of California–Davis, Davis, California; and,Department of Radiology, University of California–Davis, Davis, California
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10
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Millardet M, Moussaoui S, Idier J, Mateus D, Conti M, Bailly C, Stute S, Carlier T. A Multiobjective Comparative Analysis of Reconstruction Algorithms in the Context of Low-Statistics 90Y-PET Imaging. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2022. [DOI: 10.1109/trpms.2021.3126951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Mael Millardet
- LS2N, CNRS UMR 6004, École centrale de Nantes, Nantes, France
| | - Said Moussaoui
- LS2N, CNRS UMR 6004, École centrale de Nantes, Nantes, France
| | - Jerome Idier
- LS2N, CNRS UMR 6004, École centrale de Nantes, Nantes, France
| | - Diana Mateus
- LS2N, CNRS UMR 6004, École centrale de Nantes, Nantes, France
| | - Maurizio Conti
- Physics Research Group, Siemens Medical Solution USA Inc., Knoxville, TN, USA
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Guerrero M, Yao W, Lin M, Becker S, Molitoris J, Vedam S, Yi B. Validation of a commercial software dose calculation for Y-90 microspheres. Brachytherapy 2022; 21:561-566. [DOI: 10.1016/j.brachy.2022.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 03/24/2022] [Accepted: 03/26/2022] [Indexed: 11/26/2022]
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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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Hesse M, d'Abadie P, Lhommel R, Jamar F, Walrand S. Yttrium-90 TOF-PET-Based EUD Predicts Response Post Liver Radioembolizations Using Recommended Manufacturer FDG Reconstruction Parameters. Front Oncol 2021; 11:592529. [PMID: 34676157 PMCID: PMC8523947 DOI: 10.3389/fonc.2021.592529] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 09/07/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose Explaining why 90Y TOF-PET based equivalent uniform dose (EUD) using recommended manufacturer FDG reconstruction parameters has been shown to predict response. Methods The hot rods insert of a Jaszczak deluxe phantom was partially filled with a 2.65 GBq 90Y - 300ml DTPA water solution resulting in a 100 Gy mean absorbed dose in the 6 sectors. A two bed 20min/position acquisition was performed on a 550ps- and on a 320ps- TOF-PET/CT and reconstructed with recommended manufacturer FDG reconstruction parameters, without and with additional filtering. The whole procedure was repeated on both PET after adding 300ml of water (50Gy setup). The phantom was acquired again after decay by a factor of 10 (5Gy setup), but with 200min per bed position. For comparison, the phantom was also acquired with 18F activity corresponding to a clinical FDG whole body acquisition. Results The 100Gy-setup provided a hot rod sectors image almost as good as the 18F phantom. However, despite acquisition time compensation, the 5Gy-setup provides much lower quality imaging. TOF-PET based sectors EUDs for the three large rod sectors agreed with the actual EUDs computed with a radiosensitivity of 0.021Gy-1 well in the range observed in external beam radiotherapy (EBRT), i.e. 0.01-0.04Gy-1. This agreement explains the reunification of the dose-response relationships of the glass and resin spheres in HCC using the TOF-PET based EUD. Additional filtering reduced the EUDs agreement quality. Conclusions Recommended manufacturer FDG reconstruction parameters are suitable in TOF-PET post 90Y liver radioembolization for accurate tumour EUD computation. The present results rule out the use of low specific activity phantom studies to optimize reconstruction parameters.
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Affiliation(s)
- Michel Hesse
- Nuclear Medicine, Cliniques universitaires Saint-Luc, Brussels, Belgium
| | - Philipe d'Abadie
- Nuclear Medicine, Cliniques universitaires Saint-Luc, Brussels, Belgium
| | - Renaud Lhommel
- Nuclear Medicine, Cliniques universitaires Saint-Luc, Brussels, Belgium
| | - Francois Jamar
- Nuclear Medicine, Cliniques universitaires Saint-Luc, Brussels, Belgium
| | - Stephan Walrand
- Nuclear Medicine, Cliniques universitaires Saint-Luc, Brussels, Belgium
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Labour J, Boissard P, Baudier T, Khayi F, Kryza D, Durebex PV, Martino SPD, Mognetti T, Sarrut D, Badel JN. Yttrium-90 quantitative phantom study using digital photon counting PET. EJNMMI Phys 2021; 8:56. [PMID: 34318383 PMCID: PMC8316557 DOI: 10.1186/s40658-021-00402-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 06/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND PET imaging of 90Y-microsphere distribution following radioembolisation is challenging due to the count-starved statistics from the low branching ratio of e+/e- pair production during 90Y decay. PET systems using silicon photo-multipliers have shown better 90Y image quality compared to conventional photo-multiplier tubes. The main goal of the present study was to evaluate reconstruction parameters for different phantom configurations and varying listmode acquisition lengths to improve quantitative accuracy in 90Y dosimetry, using digital photon counting PET/CT. METHODS Quantitative PET and dosimetry accuracy were evaluated using two uniform cylindrical phantoms specific for PET calibration validation. A third body phantom with a 9:1 hot sphere-to-background ratio was scanned at different activity concentrations of 90Y. Reconstructions were performed using OSEM algorithm with varying parameters. Time-of-flight and point-spread function modellings were included in all reconstructions. Absorbed dose calculations were carried out using voxel S-values convolution and were compared to reference Monte Carlo simulations. Dose-volume histograms and root-mean-square deviations were used to evaluate reconstruction parameter sets. Using listmode data, phantom and patient datasets were rebinned into various lengths of time to assess the influence of count statistics on the calculation of absorbed dose. Comparisons between the local energy deposition method and the absorbed dose calculations were performed. RESULTS Using a 2-mm full width at half maximum post-reconstruction Gaussian filter, the dosimetric accuracy was found to be similar to that found with no filter applied but also reduced noise. Larger filter sizes should not be used. An acquisition length of more than 10 min/bed reduces image noise but has no significant impact in the quantification of phantom or patient data for the digital photon counting PET. 3 iterations with 10 subsets were found suitable for large spheres whereas 1 iteration with 30 subsets could improve dosimetry for smaller spheres. CONCLUSION The best choice of the combination of iterations and subsets depends on the size of the spheres. However, one should be careful on this choice, depending on the imaging conditions and setup. This study can be useful in this choice for future studies for more accurate 90Y post-dosimetry using a digital photon counting PET/CT.
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Affiliation(s)
- Joey Labour
- CREATIS; CNRS UMR 5220; INSERM U 1044; Université de Lyon; INSA-Lyon; Université Lyon 1, Lyon, France
- Centre de lutte contre le cancer Léon Bérard, Lyon, France
| | | | - Thomas Baudier
- CREATIS; CNRS UMR 5220; INSERM U 1044; Université de Lyon; INSA-Lyon; Université Lyon 1, Lyon, France
- Centre de lutte contre le cancer Léon Bérard, Lyon, France
| | - Fouzi Khayi
- Centre de lutte contre le cancer Léon Bérard, Lyon, France
| | - David Kryza
- Centre de lutte contre le cancer Léon Bérard, Lyon, France
- Hospices Civils de Lyon; Université de Lyon; Université Claude Bernard Lyon 1; LAGEPP UMR 5007 CNRS, Lyon, France
| | | | | | | | - David Sarrut
- CREATIS; CNRS UMR 5220; INSERM U 1044; Université de Lyon; INSA-Lyon; Université Lyon 1, Lyon, France
- Centre de lutte contre le cancer Léon Bérard, Lyon, France
| | - Jean-Noël Badel
- CREATIS; CNRS UMR 5220; INSERM U 1044; Université de Lyon; INSA-Lyon; Université Lyon 1, Lyon, France
- Centre de lutte contre le cancer Léon Bérard, Lyon, France
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15
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Hou X, Ma H, Esquinas PL, Uribe C, Tolhurst S, Bénard F, Liu D, Rahmim A, Celler A. Impact of image reconstruction method on dose distributions derived from 90Y PET images: phantom and liver radioembolization patient studies. Phys Med Biol 2020; 65:215022. [PMID: 33245057 DOI: 10.1088/1361-6560/aba8b5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PET images acquired after liver 90Y radioembolization therapies are typically very noisy, which significantly challenges both visualization and quantification of activity distributions. To improve their noise characteristics, regularized iterative reconstruction algorithms such as block sequential regularized expectation maximization (Q.Clear for GE Healthcare, USA) have been proposed. In this study, we aimed to investigate the effects which different reconstruction algorithms may have on patient images, with reconstruction parameters initially narrowed down using phantom studies. Moreover, we evaluated the impact of these reconstruction methods on voxel-based dose distribution in phantom and patient studies (lesions and healthy livers). The International Electrotechnical Commission (IEC)/NEMA phantom, containing six spheres, was filled with 90Y and imaged using a GE Discovery 690 PET/CT scanner with time-of-flight enabled. The images were reconstructed using Q.Clear (with β parameter ranging from 0 to 8000) and ordered subsets expectation maximization. The image quality and quantification accuracy were evaluated by computing the hot ([Formula: see text]) and cold ([Formula: see text]) contrast recovery coefficients, background variability (BV) and activity bias. Next, dose distributions and dose volume histograms were generated using MIM® software's SurePlan LiverY90 toolbox. Subsequently, parameters optimized in these phantom studies were applied to five patient datasets. Dose parameters, such as Dmax, Dmean, D70, and V100Gy, were estimated, and their variability for different reconstruction methods was investigated. Based on phantom studies, the β parameter values optimized for image quality and quantification accuracy were 2500 and 300, respectively. When all investigated reconstructions were applied to patient studies, Dmean, D50, D70, and V100Gy showed coefficients of variation below 8%; whereas the variability of Dmax was up to 30% for both phantom and patient images. Although β = 300-1000 would provide accurate activity quantification for a region of interest, when considering activity/dose voxelized distribution, higher β value (e.g. 4000-5000) would provide the greatest accuracy for dose distributions. In this 90Y radioembolization PET/CT study, the β parameter in regularized iterative (Q.Clear) reconstruction was investigated for image quality, accurate quantification and dose distributions based on phantom experiments and then applied to patient studies. Our results indicate that more accurate dose distribution can be achieved from smoother PET images, reconstructed with larger β values than those yielding the best activity quantifications but noisy images. Most importantly, these results suggest that quantitative measures, which are commonly used in clinics, such as SUVmax or SUVpeak( equivalent of Dmax), should not be employed for 90Y PET images, since their values would highly depend on the image reconstruction.
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Affiliation(s)
- Xinchi Hou
- Department of Radiology, University of British Columbia, Vancouver, Canada
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Chun SY, Nguyen MP, Phan TQ, Kim H, Fessler JA, Dewaraja YK. Algorithms and Analyses for Joint Spectral Image Reconstruction in Y-90 Bremsstrahlung SPECT. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:1369-1379. [PMID: 31647425 PMCID: PMC7263381 DOI: 10.1109/tmi.2019.2949068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Quantitative yttrium-90 (Y-90) SPECT imaging is challenging due to the nature of Y-90, an almost pure beta emitter that is associated with a continuous spectrum of bremsstrahlung photons that have a relatively low yield. This paper proposes joint spectral reconstruction (JSR), a novel bremsstrahlung SPECT reconstruction method that uses multiple narrow acquisition windows with accurate multi-band forward modeling to cover a wide range of the energy spectrum. Theoretical analyses using Fisher information and Monte-Carlo (MC) simulation with a digital phantom show that the proposed JSR model with multiple acquisition windows has better performance in terms of covariance (precision) than previous methods using multi-band forward modeling with a single acquisition window, or using a single-band forward modeling with a single acquisition window. We also propose an energy-window subset (ES) algorithm for JSR to achieve fast empirical convergence and maximum-likelihood based initialization for all reconstruction methods to improve quantification accuracy in early iterations. For both MC simulation with a digital phantom and experimental study with a physical multi-sphere phantom, our proposed JSR-ES, a fast algorithm for JSR with ES, yielded higher recovery coefficients (RCs) on hot spheres over all iterations and sphere sizes than all the other evaluated methods, due to fast empirical convergence. In experimental study, for the smallest hot sphere (diameter 1.6cm), at the 20th iteration the increase in RCs with JSR-ES was 66 and 31% compared with single wide and narrow band forward models, respectively. JSR-ES also yielded lower residual count error (RCE) on a cold sphere over all iterations than other methods for MC simulation with known scatter, but led to greater RCE compared with single narrow band forward model at higher iterations for experimental study when using estimated scatter.
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17
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Siman W, Mawlawi OR, Mourtada F, Kappadath SC. Systematic and random errors of PET‐based
90
Y 3D dose quantification. Med Phys 2020; 47:2441-2449. [DOI: 10.1002/mp.14117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 01/21/2020] [Accepted: 02/26/2020] [Indexed: 11/10/2022] Open
Affiliation(s)
- W. Siman
- Department of Radiology The University of Colorado School of Medicine Denver CO USA
| | - O. R. Mawlawi
- Department of Imaging Physics The University of Texas MD Anderson Cancer Center Houston TX USA
- The University of Texas Graduate School of Biomedical Sciences at Houston Houston TX USA
| | | | - S. C. Kappadath
- Department of Imaging Physics The University of Texas MD Anderson Cancer Center Houston TX USA
- The University of Texas Graduate School of Biomedical Sciences at Houston Houston TX USA
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