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Yonekura Y, Mattsson S, Flux G, Bolch WE, Dauer LT, Fisher DR, Lassmann M, Palm S, Hosono M, Doruff M, Divgi C, Zanzonico P. ICRP Publication 140: Radiological Protection in Therapy with Radiopharmaceuticals. Ann ICRP 2019; 48:5-95. [PMID: 31565950 DOI: 10.1177/0146645319838665] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Radiopharmaceuticals are increasingly used for the treatment of various cancers with novel radionuclides, compounds, tracer molecules, and administration techniques. The goal of radiation therapy, including therapy with radiopharmaceuticals, is to optimise the relationship between tumour control probability and potential complications in normal organs and tissues. Essential to this optimisation is the ability to quantify the radiation doses delivered to both tumours and normal tissues. This publication provides an overview of therapeutic procedures and a framework for calculating radiation doses for various treatment approaches. In radiopharmaceutical therapy, the absorbed dose to an organ or tissue is governed by radiopharmaceutical uptake, retention in and clearance from the various organs and tissues of the body, together with radionuclide physical half-life. Biokinetic parameters are determined by direct measurements made using techniques that vary in complexity. For treatment planning, absorbed dose calculations are usually performed prior to therapy using a trace-labelled diagnostic administration, or retrospective dosimetry may be performed on the basis of the activity already administered following each therapeutic administration. Uncertainty analyses provide additional information about sources of bias and random variation and their magnitudes; these analyses show the reliability and quality of absorbed dose calculations. Effective dose can provide an approximate measure of lifetime risk of detriment attributable to the stochastic effects of radiation exposure, principally cancer, but effective dose does not predict future cancer incidence for an individual and does not apply to short-term deterministic effects associated with radiopharmaceutical therapy. Accident prevention in radiation therapy should be an integral part of the design of facilities, equipment, and administration procedures. Minimisation of staff exposures includes consideration of equipment design, proper shielding and handling of sources, and personal protective equipment and tools, as well as education and training to promote awareness and engagement in radiological protection. The decision to hold or release a patient after radiopharmaceutical therapy should account for potential radiation dose to members of the public and carers that may result from residual radioactivity in the patient. In these situations, specific radiological protection guidance should be provided to patients and carers.
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Kafrouni M, Allimant C, Fourcade M, Vauclin S, Guiu B, Mariano-Goulart D, Ben Bouallègue F. Analysis of differences between 99mTc-MAA SPECT- and 90Y-microsphere PET-based dosimetry for hepatocellular carcinoma selective internal radiation therapy. EJNMMI Res 2019; 9:62. [PMID: 31332585 PMCID: PMC6646451 DOI: 10.1186/s13550-019-0533-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 07/12/2019] [Indexed: 12/15/2022] Open
Abstract
Background The aim of this study was to compare predictive and post-treatment dosimetry and analyze the differences, investigating factors related to activity preparation and delivery, imaging modality used, and interventional radiology. Methods Twenty-three HCC patients treated by selective internal radiation therapy with 90Y glass microspheres were included in this study. Predictive and post-treatment dosimetry were calculated at the voxel level based on 99mTc-MAA SPECT/CT and 90Y-microsphere PET/CT respectively. Dose distribution was analyzed through mean dose, metrics extracted from dose-volume histograms, and Dice similarity coefficients applied on isodoses. Reproducibility of the radiological gesture and its influence on dose deviation was evaluated. Results 90Y delivered activity was lower than expected in 67% (16/24) of the cases mainly due to the residual activity. A mean deviation of − 6 ± 11% was observed between the delivered activity and the 90Y PET’s FOV activity. In addition, a substantial difference of − 20 ± 8% was measured on 90Y PET images between the activity in the liver and in the whole FOV. After normalization, 99mTc-MAA SPECT dosimetry was highly correlated and concordant with 90Y-microsphere PET dosimetry for all dose metrics evaluated (ρ = 0.87, ρc = 0.86, P = 3.10−8 and ρ = 0.91, ρc = 0.90, P = 7.10−10 for tumor and normal liver mean dose respectively for example). Besides, mean tumor dose deviation was lower when the catheter position was identical than when it differed (16 Gy vs. 37 Gy, P = 0.007). Concordance between predictive and post-treatment dosimetry, evaluated with Dice similarity coefficients applied on isodoses, significantly correlated with the distance of the catheter position from artery bifurcation (P = 0.04, 0.0004, and 0.05, for 50 Gy, 100 Gy, and 150 Gy isodoses respectively). Conclusions Discrepancies between planned activity and activity measured on 90Y PET images were observed and seemed to be mainly related to clinical hazards and equipment issues. Predictive vs. post-treatment comparison of relative dose distributions between tumor and normal liver showed a good correlation and no significant difference highlighting the predictive value of 99mTc MAA SPECT/CT-based dosimetry. Besides, the reproducibility of catheter tip position appears critical in the agreement between predictive and actual dose distribution.
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Affiliation(s)
- Marilyne Kafrouni
- Department of Nuclear Medicine, Montpellier University Hospital, Montpellier, France. .,PhyMedExp, Montpellier University, INSERM, CNRS, Montpellier, France. .,DOSIsoft SA, Cachan, France.
| | - Carole Allimant
- Department of Radiology, Montpellier University Hospital, Montpellier, France
| | - Marjolaine Fourcade
- Department of Nuclear Medicine, Montpellier University Hospital, Montpellier, France
| | | | - Boris Guiu
- PhyMedExp, Montpellier University, INSERM, CNRS, Montpellier, France.,Department of Radiology, Montpellier University Hospital, Montpellier, France
| | - Denis Mariano-Goulart
- Department of Nuclear Medicine, Montpellier University Hospital, Montpellier, France.,PhyMedExp, Montpellier University, INSERM, CNRS, Montpellier, France
| | - Fayçal Ben Bouallègue
- Department of Nuclear Medicine, Montpellier University Hospital, Montpellier, France.,PhyMedExp, Montpellier University, INSERM, CNRS, Montpellier, France
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Alsultan AA, Smits MLJ, Barentsz MW, Braat AJAT, Lam MGEH. The value of yttrium-90 PET/CT after hepatic radioembolization: a pictorial essay. Clin Transl Imaging 2019. [DOI: 10.1007/s40336-019-00335-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Dewaraja YK, Devasia T, Kaza RK, Mikell JK, Owen D, Roberson PL, Schipper MJ. Prediction of Tumor Control in 90Y Radioembolization by Logit Models with PET/CT-Based Dose Metrics. J Nucl Med 2019; 61:104-111. [PMID: 31147404 DOI: 10.2967/jnumed.119.226472] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 05/23/2019] [Indexed: 12/17/2022] Open
Abstract
The aim of this work was to develop models for tumor control probability (TCP) in radioembolization with 90Y PET/CT-derived radiobiologic dose metrics. Methods: Patients with primary liver cancer or liver metastases who underwent radioembolization with glass microspheres were imaged with 90Y PET/CT for voxel-level dosimetry to determine lesion absorbed dose (AD) metrics, biological effective dose (BED) metrics, equivalent uniform dose, and equivalent uniform BED for 28 treatments (89 lesions). The lesion dose-shrinkage correlation was assessed on the basis of RECIST and, when available, modified RECIST (mRECIST) at first follow-up. For a subset with mRECIST, logit regression TCP models were fit via maximum likelihood to relate lesion-level binary response to the dose metrics. As an exploratory analysis, the nontumoral liver dose-toxicity relationship was also evaluated. Results: Lesion dose-shrinkage analysis showed that there were no significant differences between model parameters for primary and metastatic subgroups and that correlation coefficients were superior with mRECIST. Therefore, subsequent TCP analysis was performed for the combined group using mRECIST only. The overall lesion-level mRECIST response rate was 57%. The AD and BED metrics yielding 50% TCP were 292 and 441 Gy, respectively. All dose metrics considered for TCP modeling, including mean AD, were significantly associated with the probability of response, with high areas under the curve (0.87-0.90, P < 0.0001) and high sensitivity (>0.75) and specificity (>0.83) calculated using a threshold corresponding to 50% TCP. Because nonuniform AD deposition by microspheres cannot be determined by PET at a microscopic scale, radiosensitivity values extracted here by fitting models to clinical response data were substantially lower than reported for in vitro cell cultures or for external-beam radiotherapy clinical studies. There was no correlation between nontumoral liver AD and toxicity measures. Conclusion: Despite the heterogeneous patient cohort, logistic regression TCP models showed a strong association between various dose metrics and the probability of response. The performance of mean AD was comparable to that of radiobiologic dose metrics that involve more complex calculations. These results demonstrate the importance of considering TCP in treatment planning for radioembolization.
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Affiliation(s)
- Yuni K Dewaraja
- Department of Radiology, University of Michigan, Ann Arbor, Michigan
| | - Theresa Devasia
- Department of Biostatistics, University of Michigan, Ann Arbor, Michigan; and
| | - Ravi K Kaza
- Department of Radiology, University of Michigan, Ann Arbor, Michigan
| | - Justin K Mikell
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Dawn Owen
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Peter L Roberson
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Matthew J Schipper
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
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Scott NP, McGowan DR. Optimising quantitative 90Y PET imaging: an investigation into the effects of scan length and Bayesian penalised likelihood reconstruction. EJNMMI Res 2019; 9:40. [PMID: 31076913 PMCID: PMC6510762 DOI: 10.1186/s13550-019-0512-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 04/23/2019] [Indexed: 01/03/2023] Open
Abstract
Background Positron emission tomography (PET) imaging of 90Y following selective internal radiation therapy (SIRT) is possible, but image quality is poor, and therefore, accurate quantification and dosimetry are challenging. This study aimed to quantitatively optimise 90Y PET imaging using a new Bayesian penalised likelihood (BPL) reconstruction algorithm (Q.Clear, GE Healthcare). The length of time per bed was also investigated to study its impact on quantification accuracy. Methods A NEMA IQ phantom with an 8:1 sphere-to-background ratio was scanned overnight on a GE Discovery 710 PET/CT scanner. Datasets were rebinned into varying lengths of time (5–60 min); the 15-min rebins were reconstructed using BPL reconstruction with a range of noise penalisation weighting factors (beta values). The metrics of contrast recovery (CR), background variability (BV), and recovered activity percentage (RAP) were calculated in order to identify the optimum beta value. Reconstructions were then carried out on the rest of the timing datasets using the optimised beta value; the same metrics were used to assess the quantification accuracy of the reconstructed images. Results A beta value of 1000 produced the highest CR and RAP (76% and 73%, 37 mm sphere) without overly accentuating the noise (BV) in the image. There was no statistically significant increase (p < 0.05) in either the CR or RAP for scan times of > 15 min. For the 5-min acquisitions, there was a statistically significant decrease in RAP (28 mm sphere, p < 0.01) when compared to the 15-min acquisition. Conclusion Our results indicate that an acquisition length of 15 min and beta value of 1000 (when using Q.Clear reconstruction) are optimum for quantitative 90Y PET imaging. Increasing the acquisition time to more than 15 min reduces the image noise but has no significant impact on image quantification. Electronic supplementary material The online version of this article (10.1186/s13550-019-0512-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nathaniel P Scott
- Radiation Physics and Protection, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Old Road, Oxford, OX37LE, UK. .,Department of Oncology, University of Oxford, Old Road Campus Research Building, Oxford, UK.
| | - Daniel R McGowan
- Radiation Physics and Protection, Churchill Hospital, Oxford University Hospitals NHS Foundation Trust, Old Road, Oxford, OX37LE, UK.,Department of Oncology, University of Oxford, Old Road Campus Research Building, Oxford, UK
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Mikell JK, Majdalany BS, Owen D, Paradis KC, Dewaraja YK. Assessing Spatial Concordance Between Theranostic Pairs Using Phantom and Patient-Specific Acceptance Criteria: Application to 99mTc-MAA SPECT/ 90Y-Microsphere PET. Int J Radiat Oncol Biol Phys 2019; 104:1133-1140. [PMID: 31022511 DOI: 10.1016/j.ijrobp.2019.04.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/30/2019] [Accepted: 04/11/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE Predictive 3-dimensional dosimetry requires spatial concordance between diagnostic and therapeutic activity distributions. We assess similarity between theranostic pairs (99mTc-macroaggregated albumin [MAA] single photon emission computed tomography [SPECT] and 90Y microsphere positron emission tomography [PET]) in patients using criteria that account for spatial resolution differences and misregistration. METHODS AND MATERIALS Phantom-based acceptance criteria were determined using a liver phantom filled with 99mTc and 90YCl3 and scanned with SPECT/computed tomography [CT] and PET/CT, respectively. Gaussian blurring was applied to PET to match 99mTc phantom scan image quality. After rigid registration between SPECT/CT and PET/CT, perturbations up to ±3 voxels were applied to determine the similarity metric (SM) sensitivity. 99mTc-MAA SPECT/CT and 90Y microsphere PET/CT image pairs/patients (n = 23) were processed analogously. SMs calculated included the Pearson correlation coefficient (ρr), Lin's concordance correlation coefficient (ρc), Spearman's rank correlation coefficient (ρs), the mean squared difference, and the Dice similarity coefficient (DSC). Patient-specific acceptance criteria were determined by evaluating the SMs of the blurred PET compared with itself misregistered. RESULTS After transforming PET to SPECT resolution, high similarity was found in phantom, with ρc, ρr, ρs > 0.98 ± 0.01, a mean squared difference of (4.1 ± 0.3) × 10-4 and DSC > 0.85 ± 0.01 for investigated thresholds (5%, 30%, and 50%). SMs for patients varied from poor to good. A small percentage (13%-30%) of patient scans were acceptable using phantom-based acceptance criteria. The percentage increased slightly (17%-35%) using patient-specific acceptance criteria. DSC for most patients were substantially lower (average 0.95 vs 0.61 for 5% threshold) than phantom values. CONCLUSIONS At best, 35% of patients had an SM within the acceptance criteria established to account for imaging-related effects impacting spatial concordance between 99mTc-MAA SPECT and 90Y PET. Additional clinical factors should be evaluated in the future. The procedure of accounting for image-related effects when assessing spatial concordance can be applied to other theranostic pairs.
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Affiliation(s)
- Justin K Mikell
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.
| | - Bill S Majdalany
- Department of Radiology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Dawn Owen
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Kelly C Paradis
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Yuni K Dewaraja
- Department of Radiology, University of Michigan Medical School, Ann Arbor, Michigan
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Maughan NM, Garcia-Ramirez J, Arpidone M, Swallen A, Laforest R, Goddu SM, Parikh PJ, Zoberi JE. Validation of post-treatment PET-based dosimetry software for hepatic radioembolization of Yttrium-90 microspheres. Med Phys 2019; 46:2394-2402. [PMID: 30742714 DOI: 10.1002/mp.13444] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 01/27/2019] [Accepted: 01/28/2019] [Indexed: 01/06/2023] Open
Abstract
PURPOSE Yttrium-90 (90 Y) microsphere radioembolization enables selective internal radiotherapy for hepatic malignancies. Currently, there is no standard postdelivery imaging and dosimetry of the microsphere distribution to verify treatment. Recent studies have reported utilizing the small positron yield of 90 Y (32 ppm) with positron emission tomography (PET) to perform treatment verification and dosimetry analysis. In this study, we validated a commercial dosimetry software, MIM SurePlan™ LiverY90 (MIM Software Inc., Cleveland, OH), for clinical use. METHODS A MATLAB-based algorithm for 90 Y PET-based dosimetry was developed in-house and validated for the purpose of commissioning the commercial software. The algorithm is based on voxel S values and dosimetry formalism reported in MIRD Pamphlet 17. We validated the in-house algorithm to establish it as the ground truth by comparing results from a digital point phantom and a digital uniform cylinder to manual calculations. Once we validated our in-house MATLAB-based algorithm, we used it to perform acceptance testing and commissioning of the commercial dosimetry software, MIM SurePlan, which uses the same dosimetry formalism. A 0.4 cm/5% gamma test was performed on PET-derived dose maps from each algorithm of uniform digital and nonuniform physical phantoms filled with 90 Y chloride solution. Average dose (Davg ) and minimum dose to 70% (D70 ) of a given volume of interest (VOI) were compared for the digital phantom, the physical phantom, and five patient cases (27 tumor VOIs), representing different clinical scenarios. RESULTS The gamma-pass rates were 97.26% and 97.66% for the digital and physical phantoms, respectively. The differences between Davg and D70 were 0.076% and 0.10% for the digital phantom, respectively, and <5.2% for various VOIs in the physical phantom. In the clinical cases, 96.3% of the VOIs had a difference <5% for Davg , and 88.9% of the VOIs had a difference <5% for D70 . CONCLUSIONS Dose calculation results from MIM SurePlan were found to be in good agreement with our in-house algorithm. This indicates that MIM SurePlan performs as it should and, hence, can be deemed accepted and commissioned for clinical use for post-implant PET-based dosimetry of 90 Y radioembolization.
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Affiliation(s)
- Nichole M Maughan
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Jose Garcia-Ramirez
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | | | | | - Richard Laforest
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - S Murty Goddu
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Parag J Parikh
- Department of Radiation Oncology, Henry Ford Hospital, Detroit, MI, 48202, USA
| | - Jacqueline E Zoberi
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, 63110, USA
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Reinders MTM, Smits MLJ, van Roekel C, Braat AJAT. Holmium-166 Microsphere Radioembolization of Hepatic Malignancies. Semin Nucl Med 2019; 49:237-243. [PMID: 30954190 DOI: 10.1053/j.semnuclmed.2019.01.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Holmium microspheres have recently become available in the European market as the third type of microspheres for radioembolization of unresectable liver malignancies. Holmium microspheres come with a dedicated administration system, and since these microspheres contain holmium-166 (166Ho) instead of yttrium-90, unique dosing and imaging possibilities have become available as well. In addition, a scout dose of 166Ho microspheres (Conformité Européenne mark is now granted and not pending anymore) can be used instead of 99mTc-macroaggragated albumin during the preparatory angiography procedure. So far, two prospective phase I and phase II clinical studies have been performed on 166Ho radioembolization in a population of liver metastases from mixed origins. These studies showed that a mean whole-liver dose of 60 Gy is safe and induces tumor response. Ongoing trials investigate the effect of 166Ho radioembolization in patients with neuroendocrine tumor metastases, hepatocellular carcinoma, and colorectal cancer metastases. Data derived from these studies will be used to refine the dosing schedule of 60 Gy to the whole liver and determine the optimal level of activity for each patient. This paper discusses several basics and provides an overview of relevant dosing aspects, technical aspects of performing holmium radioembolization, as well as a summary of completed and ongoing clinical studies and the upcoming developments regarding these microspheres.
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Vega JCDL, Esquinas PL, Rodríguez-Rodríguez C, Bokharaei M, Moskalev I, Liu D, Saatchi K, Häfeli UO. Radioembolization of Hepatocellular Carcinoma with Built-In Dosimetry: First in vivo Results with Uniformly-Sized, Biodegradable Microspheres Labeled with 188Re. Theranostics 2019; 9:868-883. [PMID: 30809314 PMCID: PMC6376476 DOI: 10.7150/thno.29381] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 01/02/2019] [Indexed: 12/28/2022] Open
Abstract
A common form of treatment for patients with hepatocellular carcinoma (HCC) is transarterial radioembolization (TARE) with non-degradable glass or resin microspheres (MS) labeled with 90Y (90Y-MS). To further simplify the dosimetry calculations in the clinical setting, to have more control over the particle size and to change the permanent embolization to a temporary one, we developed uniformly-sized, biodegradable 188Re-labeled MS (188Re-MS) as a new and easily imageable TARE agent. Methods: MS made of poly(L-lactic acid) were produced in a flow focusing microchip. The MS were labeled with 188Re using a customized kit. An orthotopic HCC animal model was developed in male Sprague Dawley rats by injecting N1-S1 cells directly into the liver using ultrasound guidance. A suspension of 188Re-MS was administered via hepatic intra-arterial catheterization 2 weeks post-inoculation of the N1-S1 cells. The rats were imaged by SPECT 1, 24, 48, and 72 h post-radioembolization. Results: The spherical 188Re-MS had a diameter of 41.8 ± 6.0 µm (CV = 14.5%). The site and the depth of the injection of N1-S1 cells were controlled by visualization of the liver in sonograms. Single 0.5 g tumors were grown in all rats. 188Re-MS accumulated in the liver with no deposition in the lungs. 188Re decays to stable 188Os by emission of β¯ particles with similar energy to those emitted by 90Y while simultaneously emitting γ photons, which were imaged directly by single photon computed tomography (SPECT). Using Monte Carlo methods, the dose to the tumors was calculated to be 3-6 times larger than to the healthy liver tissue. Conclusions:188Re-MS have the potential to become the next generation of β¯-emitting MS for TARE. Future work revolves around the investigation of the therapeutic potential of 188Re-MS in a large-scale, long-term preclinical study as well as the evaluation of the clinical outcomes of using 188Re-MS with different sizes, from 20 to 50 µm.
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Price E, Robinson AP, Cullen DM, Tipping J, Calvert N, Hamilton D, Oldfield C, Page E, Pietras B, Smith A. Improving molecular radiotherapy dosimetry using anthropomorphic calibration. Phys Med 2019; 58:40-46. [PMID: 30824148 DOI: 10.1016/j.ejmp.2019.01.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 12/10/2018] [Accepted: 01/17/2019] [Indexed: 11/17/2022] Open
Abstract
The optimised delivery of Molecular Radiotherapy requires individualised calculation of absorbed dose to both targeted lesions and neighbouring healthy tissue. To achieve this, accurate quantification of the activity distribution in the patient by external detection is vital. METHODS This work extends specific anatomy-related calibration to true organ shapes. A set of patient-specific 3D printed organ inserts based on a diagnostic CT scan was produced, comprising the liver, spleen and both kidneys. The inserts were used to calculate patient-specific calibration factors for 177Lu. These calibration factors were compared with previously reported calibration factors for corresponding organ models based on the Cristy and Eckerman phantom series and for a comparably sized sphere. Monte Carlo calculations of the patient-specific radiation dose were performed for comparison with current clinical dosimetry methods for these data. RESULTS Patient-specific calibration factors are shown to be dependent on the volume, shape and position of the organ containing activity with a corresponding impact on the calculation of the dose to the patient. The impact of organ morphology on calculated dose is reduced when the dominant contributor to dose is beta particles. This is due to the small range of beta particles in tissue. Overestimations of recovered activity and hence dose of up to 135% are observed. CONCLUSION For accurate quantification to be performed calibration factors accounting for organ size, shape and position must be used. Such quantification is vital if accurate, patient-specific dosimetry is to be achieved.
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Affiliation(s)
- Emlyn Price
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom; Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom.
| | - Andrew P Robinson
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom; National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, United Kingdom
| | - David M Cullen
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Jill Tipping
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom
| | - Nick Calvert
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom
| | - David Hamilton
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom
| | - Christopher Oldfield
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Emma Page
- Christie Medical Physics and Engineering (CMPE), The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom; Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Ben Pietras
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Andrew Smith
- Schuster Laboratory, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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van der Velden S, Dietze MMA, Viergever MA, de Jong HWAM. Fast technetium-99m liver SPECT for evaluation of the pretreatment procedure for radioembolization dosimetry. Med Phys 2019; 46:345-355. [PMID: 30347130 PMCID: PMC7379506 DOI: 10.1002/mp.13253] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 01/08/2023] Open
Abstract
PURPOSE The efficiency of radioembolization procedures could be greatly enhanced if results of the 99m Tc-MAA pretreatment procedure were immediately available in the interventional suite, enabling 1-day procedures as a result of direct estimation of the hepatic radiation dose and lung shunt fraction. This would, however, require a relatively fast, but still quantitative, SPECT procedure, which might be achieved with acquisition protocols using nonuniform durations of the projection images. METHODS SPECT liver images of the 150-MBq 99m Tc-MAA pretreatment procedure were simulated for eight different lesion locations and two different lesion sizes using the digital XCAT phantom for both single- and dual-head scanning geometries with respective total acquisition times of 1, 2, 5, 10, and 30 min. Three nonuniform projection-time acquisition protocols ("half-circle SPECT (HCS)," "nonuniform SPECT (NUS) I," and "NUS II") for fast quantitative SPECT of the liver were designed and compared with the standard uniform projection-time protocol. Images were evaluated in terms of contrast-to-noise ratio (CNR), activity recovery coefficient (ARC), tumor/non-tumor (T/N) activity concentration ratio, and lung shunt fraction (LSF) estimation. In addition, image quality was verified with a physical phantom experiment, reconstructed with both clinical and Monte Carlo-based reconstruction software. RESULTS Simulations showed no substantial change in image quality and dosimetry by usage of a nonuniform projection-time acquisition protocol. Upon shortening acquisition times, CNR dropped, but ARC, T/N ratio, and LSF estimates were stable across all simulated acquisition times. Results of the physical phantom were in agreement with those of the simulations. CONCLUSION Both uniform and nonuniform projection-time acquisition liver SPECT protocols yield accurate dosimetric metrics for radioembolization treatment planning in the interventional suite within 10 min, without compromising image quality. Consequently, fast quantitative SPECT of the liver in the interventional suite is feasible.
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Affiliation(s)
- Sandra van der Velden
- Radiology and Nuclear MedicineUniversity Medical Center UtrechtP.O. Box 855003508 GAUtrechtNetherlands
- Image Sciences InstituteUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtNetherlands
| | - Martijn M. A. Dietze
- Radiology and Nuclear MedicineUniversity Medical Center UtrechtP.O. Box 855003508 GAUtrechtNetherlands
- Image Sciences InstituteUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtNetherlands
| | - Max A. Viergever
- Image Sciences InstituteUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtNetherlands
| | - Hugo W. A. M. de Jong
- Radiology and Nuclear MedicineUniversity Medical Center UtrechtP.O. Box 855003508 GAUtrechtNetherlands
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d'Abadie P, Hesse M, Jamar F, Lhommel R, Walrand S. 90Y TOF-PET based EUD reunifies patient survival prediction in resin and glass microspheres radioembolization of HCC tumours. Phys Med Biol 2018; 63:245010. [PMID: 30524029 DOI: 10.1088/1361-6560/aaf205] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Clinical studies reported a twofold ratio between the efficacies per Gy of resin versus glass spheres. Our aim is to investigate whether this difference could result from the different degrees of heterogeneity in sphere distribution between the two medical devices. The 90Y TOF-PET based equivalent uniform doses (EUD) was used for this purpose. 58 consecutive HCC radioembolizations were retrospectively analyzed. Absorbed doses D and Jones-Hoban EUD in lesions were computed. Radioembolization efficacy was assessed using Kaplan-Meier survival curves. In order to match together the glass and resin spheres survival curves using a 40 Gy-threshold, an efficacy factor of 0.73 and 0.36 has to be applied on their absorbed dose, respectively. Using EUD, a nice matching between glass and resin survival curves was obtained with a better separation of the responding and not responding survival curves. The results clearly support the fact that the activity heterogeneity observed in 90Y TOF-PET post radioembolization does not only result from statistical noise, but also reflects the actual heterogeneity of the spheres distribution. Use of EUD reunifies the efficacy of the two medical devices.
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Affiliation(s)
- P d'Abadie
- Nuclear Medicine, Saint-Luc Hospital, Brussels, Belgium
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65
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Esquinas PL, Shinto A, Kamaleshwaran KK, Joseph J, Celler A. Biodistribution, pharmacokinetics, and organ-level dosimetry for 188Re-AHDD-Lipiodol radioembolization based on quantitative post-treatment SPECT/CT scans. EJNMMI Phys 2018; 5:30. [PMID: 30523435 PMCID: PMC6283804 DOI: 10.1186/s40658-018-0227-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 08/08/2018] [Indexed: 12/25/2022] Open
Abstract
Background Rhenium-188-labelled-Lipiodol radioembolization is a safe and cost-effective treatment for primary liver cancer. In order to determine correlations between treatment doses and patient response to therapy, accurate patient-specific dosimetry is required. Up to date, the reported dosimetry of 188Re-Lipiodol has been based on whole-body (WB) planar imaging only, which has limited quantitative accuracy. The aim of the present study is to determine the in vivo pharmacokinetics, bio-distribution, and organ-level dosimetry of 188Re-AHDD-Lipiodol radioembolization using a combination of post-treatment planar and quantitative SPECT/CT images. Furthermore, based on the analysis of the pharmacokinetic data, a practical and relatively simple imaging and dosimetry method that could be implemented in clinics for 188Re-AHDD-Lipiodol radioembolization is proposed. Thirteen patients with histologically proven hepatocellular carcinoma underwent 188Re-AHDD-Lipiodol radioembolization. A series of 2–3 WB planar images and one SPECT/CT scan were acquired over 48 h after the treatment. The time-integrated activity coefficients (TIACs, also known as residence-times) and absorbed doses of tumors and organs at risk (OARs) were determined using a hybrid WB/SPECT imaging method. Results Whole-body imaging showed that 188Re-AHDD-Lipiodol accumulated mostly in the tumor and liver tissue but a non-negligible amount of the pharmaceutical was also observed in the stomach, lungs, salivary glands, spleen, kidneys, and urinary bladder. On average, the measured effective half-life of 188Re-AHDD-Lipiodol was 12.5 ± 1.9 h in tumor. The effective half-life in the liver and lungs (the two organs at risk) was 12.6 ± 1.7 h and 12.0 ± 1.9 h, respectively. The presence of 188Re in other organs was probably due to the chemical separation and subsequent release of the free radionuclide from Lipiodol. The average doses per injected activity in the tumor, liver, and lungs were 23.5 ± 40.8 mGy/MBq, 2.12 ± 1.78 mGy/MBq, and 0.11 ± 0.05 mGy/MBq, respectively. The proposed imaging and dosimetry method, consisting of a single SPECT/CT for activity determination followed by 188Re-AHDD-Lipiodol clearance with the liver effective half-life of 12.6 h, resulted in TIACs estimates (and hence, doses) mostly within ± 20% from the reference TIACs (estimated using three WB images and one SPECT/CT). Conclusions The large inter-patient variability of the absorbed doses in tumors and normal tissue in 188Re-HDD-Lipiodol radioembolization patients emphasizes the importance of patient-specific dosimetry calculations based on quantitative post-treatment SPECT/CT imaging. Electronic supplementary material The online version of this article (10.1186/s40658-018-0227-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pedro L Esquinas
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada. .,Medical Imaging Research Group, Vancouver, British Columbia, Canada.
| | - Ajit Shinto
- Department of Nuclear Medicine, Kovai Medical Center and Hospital, Coimbatore, Tamil Nadu, India
| | | | - Jephy Joseph
- Department of Nuclear Medicine, Kovai Medical Center and Hospital, Coimbatore, Tamil Nadu, India
| | - Anna Celler
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada.,Medical Imaging Research Group, Vancouver, British Columbia, Canada
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66
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Siman W, Mikell JK, Mawlawi OR, Mourtada F, Kappadath SC. Dose volume histogram-based optimization of image reconstruction parameters for quantitative 90 Y-PET imaging. Med Phys 2018; 46:229-237. [PMID: 30375655 DOI: 10.1002/mp.13269] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 10/21/2018] [Accepted: 10/22/2018] [Indexed: 12/20/2022] Open
Abstract
PURPOSE 90 Y-microsphere radioembolization or selective internal radiation therapy is increasingly being used as a treatment option for tumors that are not candidates for surgery and external beam radiation therapy. Recently, volumetric 90 Y-dosimetry techniques have been implemented to explore tumor dose-response on the basis of 3D 90 Y-activity distribution from PET imaging. Despite being a theranostic study, the optimization of quantitative 90 Y-PET image reconstruction still uses the mean activity concentration recovery coefficient (RC) as the objective function, which is more relevant to diagnostic and detection tasks than is to dosimetry. The aim of this study was to optimize 90 Y-PET image reconstruction by minimizing errors in volumetric dosimetry via the dose volume histogram (DVH). We propose a joint optimization of the number of equivalent iterations (the product of the iterations and subsets) and the postreconstruction filtration (FWHM) to improve the accuracy of voxel-level 90 Y dosimetry. METHODS A modified NEMA IEC phantom was used to emulate clinically relevant 90 Y-PET imaging conditions through various combinations of acquisition durations, activity concentrations, sphere-to-background ratios, and sphere diameters. PET data were acquired in list mode for 300 min in a single-bed position; we then rebinned the list mode PET data to 60, 45, 30, 15, and 5 min per bed, with 10 different realizations. Errors in the DVH were calculated as root mean square errors (RMSE) of the differences in the image-based DVH and the expected DVH. The new optimization approach was tested in a phantom study, and the results were compared with the more commonly used objective function of the mean activity concentration RC. RESULTS In a wide range of clinically relevant imaging conditions, using 36 equivalent iterations with a 5.2-mm filtration resulted in decreased systematic errors in volumetric 90 Y dosimetry, quantified as image-based DVH, in 90 Y-PET images reconstructed using the ordered subset expectation maximization (OSEM) iterative reconstruction algorithm with time of flight (TOF) and point spread function (PSF) modeling. Our proposed objective function of minimizing errors in DVH, which allows for joint optimization of 90 Y-PET iterations and filtration for volumetric quantification of the 90 Y dose, was shown to be superior to conventional RC-based optimization approaches for image-based absorbed dose quantification. CONCLUSION Our proposed objective function of minimizing errors in DVH, which allows for joint optimization of iterations and filtration to reduce errors in the PET-based volumetric quantification 90 Y dose, is relevant to dosimetry in therapy procedures. The proposed optimization method using DVH as the objective function could be applied to any imaging modality used to assess voxel-level quantitative information.
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Affiliation(s)
- Wendy Siman
- Department of Radiology, The University of Tennessee Medical Center, Knoxville, TN, USA.,The University of Tennessee Graduate School of Medicine, Knoxville, TN, USA
| | - Justin K Mikell
- Department of Radiation Oncology, University of Michigan Hospital and Health Systems, Ann Arbor, MI, USA
| | - Osama 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 Cheenu 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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Bastiaannet R, Kappadath SC, Kunnen B, Braat AJAT, Lam MGEH, de Jong HWAM. The physics of radioembolization. EJNMMI Phys 2018; 5:22. [PMID: 30386924 PMCID: PMC6212377 DOI: 10.1186/s40658-018-0221-z] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 06/19/2018] [Indexed: 12/11/2022] Open
Abstract
Radioembolization is an established treatment for chemoresistant and unresectable liver cancers. Currently, treatment planning is often based on semi-empirical methods, which yield acceptable toxicity profiles and have enabled the large-scale application in a palliative setting. However, recently, five large randomized controlled trials using resin microspheres failed to demonstrate a significant improvement in either progression-free survival or overall survival in both hepatocellular carcinoma and metastatic colorectal cancer. One reason for this might be that the activity prescription methods used in these studies are suboptimal for many patients.In this review, the current dosimetric methods and their caveats are evaluated. Furthermore, the current state-of-the-art of image-guided dosimetry and advanced radiobiological modeling is reviewed from a physics' perspective. The current literature is explored for the observation of robust dose-response relationships followed by an overview of recent advancements in quantitative image reconstruction in relation to image-guided dosimetry.This review is concluded with a discussion on areas where further research is necessary in order to arrive at a personalized treatment method that provides optimal tumor control and is clinically feasible.
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Affiliation(s)
- Remco Bastiaannet
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Room E01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - S. Cheenu Kappadath
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, 1155 Pressler St, Unit 1352, Houston, TX 77030 USA
| | - Britt Kunnen
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Room E01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Arthur J. A. T. Braat
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Room E01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Marnix G. E. H. Lam
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Room E01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Hugo W. A. M. de Jong
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Room E01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
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68
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Kappadath SC, Mikell J, Balagopal A, Baladandayuthapani V, Kaseb A, Mahvash A. Hepatocellular Carcinoma Tumor Dose Response After 90Y-radioembolization With Glass Microspheres Using 90Y-SPECT/CT-Based Voxel Dosimetry. Int J Radiat Oncol Biol Phys 2018; 102:451-461. [DOI: 10.1016/j.ijrobp.2018.05.062] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 05/16/2018] [Accepted: 05/22/2018] [Indexed: 12/17/2022]
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69
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Kunnen B, van der Velden S, Bastiaannet R, Lam MGEH, Viergever MA, de Jong HWAM. Radioembolization lung shunt estimation based on a 90
Y pretreatment procedure: A phantom study. Med Phys 2018; 45:4744-4753. [DOI: 10.1002/mp.13168] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 08/20/2018] [Accepted: 08/28/2018] [Indexed: 12/15/2022] Open
Affiliation(s)
- Britt Kunnen
- Radiology and Nuclear Medicine; UMC Utrecht; P.O. Box 85500 3508 GA Utrecht The Netherlands
- Image Sciences Institute; UMC Utrecht; University Utrecht; Heidelberglaan 100 3584 CX Utrecht The Netherlands
| | - Sandra van der Velden
- Radiology and Nuclear Medicine; UMC Utrecht; P.O. Box 85500 3508 GA Utrecht The Netherlands
- Image Sciences Institute; UMC Utrecht; University Utrecht; Heidelberglaan 100 3584 CX Utrecht The Netherlands
| | - Remco Bastiaannet
- Radiology and Nuclear Medicine; UMC Utrecht; P.O. Box 85500 3508 GA Utrecht The Netherlands
- Image Sciences Institute; UMC Utrecht; University Utrecht; Heidelberglaan 100 3584 CX Utrecht The Netherlands
| | - Marnix G. E. H. Lam
- Radiology and Nuclear Medicine; UMC Utrecht; P.O. Box 85500 3508 GA Utrecht The Netherlands
| | - Max A. Viergever
- Image Sciences Institute; UMC Utrecht; University Utrecht; Heidelberglaan 100 3584 CX Utrecht The Netherlands
| | - Hugo W. A. M. de Jong
- Radiology and Nuclear Medicine; UMC Utrecht; P.O. Box 85500 3508 GA Utrecht The Netherlands
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70
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Knešaurek K, Tuli A, Kim E, Heiba S, Kostakoglu L. Comparison of PET/CT and PET/MR imaging and dosimetry of yttrium-90 ( 90Y) in patients with unresectable hepatic tumors who have received intra-arterial radioembolization therapy with 90Y microspheres. EJNMMI Phys 2018; 5:23. [PMID: 30159638 PMCID: PMC6115317 DOI: 10.1186/s40658-018-0222-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 07/27/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The aim of our study was to compare 90Y dosimetry obtained from PET/MRI versus PET/CT post-therapy imaging among patients with primary or metastatic hepatic tumors. First, a water-filled Jaszczak phantom containing fillable sphere with 90Y-chloride was acquired on both the PET/CT and PET/MRI systems, in order to check the cross-calibration of the modalities. Following selective internal radiation therapy (SIRT) with 90Y microspheres, 32 patients were imaged on a PET/CT system, immediately followed by a PET/MRI study. Reconstructed images were transferred to a common platform and used to calculate 90Y dosimetry. A Passing-Bablok regression scatter diagram and the Bland and Altman method were used to analyze the difference between the dosimetry values. RESULTS The phantom study showed that both modalities were calibrated with less than 1% error. The mean liver doses for the 32 subjects calculated from PET/CT and PET/MRI were 51.6 ± 24.7 Gy and 46.5 ± 22.7 Gy, respectively, with a mean difference of 5.1 ± 5.0 Gy. The repeatability coefficient was 9.0 (18.5% of the mean). The Spearman rank correlation coefficient was very high, ρ = 0.97. Although the maximum dose to the liver can be significantly different (up to 40%), mean liver doses from each modalities were relatively close, with a difference of 18.5% or less. CONCLUSIONS The two main contributors to the difference in 90Y dosimetry calculations using PET/CT versus PET/MRI can be attributed to the differences in regions of interest (ROIs) and differences attributed to attenuation correction. Due to the superior soft-tissue contrast of MRI, liver contours are usually better seen than in CT images. However, PET/CT provides better quantification of PET images, due to better attenuation correction. In spite of these differences, our results demonstrate that the dosimetry values obtained from PET/MRI and PET/CT in post-therapy 90Y studies were similar.
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Affiliation(s)
- Karin Knešaurek
- Division of Nuclear Medicine, Department of Radiology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1141, New York, NY, 10029, USA.
| | - Abbas Tuli
- Division of Nuclear Medicine, Department of Radiology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1141, New York, NY, 10029, USA
| | - Edward Kim
- Division of Interventional Radiology, Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Sherif Heiba
- Division of Nuclear Medicine, Department of Radiology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1141, New York, NY, 10029, USA
| | - Lale Kostakoglu
- Division of Nuclear Medicine, Department of Radiology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1141, New York, NY, 10029, USA
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71
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Levillain H, Duran Derijckere I, Marin G, Guiot T, Vouche M, Reynaert N, Hendlisz A, Vanderlinden B, Flamen P. 90Y-PET/CT-based dosimetry after selective internal radiation therapy predicts outcome in patients with liver metastases from colorectal cancer. EJNMMI Res 2018; 8:60. [PMID: 30006851 PMCID: PMC6045565 DOI: 10.1186/s13550-018-0419-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 06/27/2018] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND The aim of this work was to confirm that post-selective internal radiation therapy (SIRT) 90Y-PET/CT-based dosimetry correlates with lesion metabolic response and to determine its correlation with overall survival (OS) in liver-only metastases from colorectal cancer (mCRC) patients treated with SIRT. Twenty-four mCRC patients underwent pre/post-SIRT FDG-PET/CT and post-SIRT 90Y-PET/CT. Lesions delineated on pre/post-SIRT FDG-PET/CT were classified as non-metabolic responders (total lesion glycolysis (TLG)-decrease < 15%) and high-metabolic responders (TLG-decrease ≥ 50%). Lesion delineations were projected on the anatomically registered 90Y-PET/CT. Voxel-based 3D dosimetrywas performed on the 90Y-PET/CT and lesions' mean absorbed dose (Dmean) was measured. The coefficient of correlation between Dmean and TLG-decrease was calculated. The ability of lesion Dmean to predict non-metabolic response and high-metabolic response was tested and two cutoff values (Dmean-under-treated and Dmean-well-treated) were determined using ROC analysis. Patients were dichotomised in the "treated" group (all the lesions received a Dmean > Dmean-under-treated) and in the "under-treated" group (at least one lesion received a Dmean < Dmean-under-treated). Kaplan-Meier product limit method was used to describe OS curves. RESULTS Fifty-seven evaluable mCRC lesions were included. The coefficient of correlation between Dmean and TLG-decrease was 0.82. Two lesion Dmean cutoffs of 39 Gy (sensitivity 80%, specificity 95%, predictive-positive-value 86% and negative-predictive-value 92%) and 60 Gy (sensitivity 70%, specificity 95%, predictive positive-value 96% and negative-predictive-value 63%) were defined to predict non-metabolic response and high-metabolic response respectively. Patients with all lesions Dmean> 39 Gy had a significantly longer OS (13 months) than patients with at least one lesion Dmean < 39 Gy (OS = 5 months) (p = 0.012;hazard-ratio, 2.6 (95% CI 0.98-7.00)). CONCLUSIONS In chemorefractory mCRC patients treated with SIRT, lesion Dmean determined on post-SIRT 90Y-PET/CT correlates with metabolic response and higher lesion Dmean is associated with prolonged OS.
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Affiliation(s)
- Hugo Levillain
- Department of Nuclear Medicine, Jules Bordet Institute, Université Libre de Bruxelles, Rue Héger-Bordet 1, B-1000, Brussels, Belgium.
| | - Ivan Duran Derijckere
- Department of Nuclear Medicine, Jules Bordet Institute, Université Libre de Bruxelles, Rue Héger-Bordet 1, B-1000, Brussels, Belgium
| | - Gwennaëlle Marin
- Department of Medical Physics, Jules Bordet Institute, Université Libre de Bruxelles, Rue Héger-Bordet 1, B-1000, Brussels, Belgium
| | - Thomas Guiot
- Department of Nuclear Medicine, Jules Bordet Institute, Université Libre de Bruxelles, Rue Héger-Bordet 1, B-1000, Brussels, Belgium
| | - Michaël Vouche
- Department of Radiology, Hôpital St-Pierre, Jules Bordet Institute, Université Libre de Bruxelles, Rue Héger-Bordet 1, B-1000, Brussels, Belgium
| | - Nick Reynaert
- Department of Medical Physics, Jules Bordet Institute, Université Libre de Bruxelles, Rue Héger-Bordet 1, B-1000, Brussels, Belgium
| | - Alain Hendlisz
- Department of Digestive Oncology, Jules Bordet Institute, Université Libre de Bruxelles, Rue Héger-Bordet 1, B-1000, Brussels, Belgium
| | - Bruno Vanderlinden
- Department of Medical Physics, Jules Bordet Institute, Université Libre de Bruxelles, Rue Héger-Bordet 1, B-1000, Brussels, Belgium
| | - Patrick Flamen
- Department of Nuclear Medicine, Jules Bordet Institute, Université Libre de Bruxelles, Rue Héger-Bordet 1, B-1000, Brussels, Belgium
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Lassmann M, Eberlein U. The Relevance of Dosimetry in Precision Medicine. J Nucl Med 2018; 59:1494-1499. [PMID: 30002109 DOI: 10.2967/jnumed.117.206649] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/29/2018] [Indexed: 11/16/2022] Open
Abstract
The aim of this review is to provide an overview of the most recent technologic developments in state-of-the-art equipment and tools for dosimetry in radionuclide therapies. This includes, but is not restricted to, calibration methods for imaging systems. In addition, a summary of new developments that consider the influence of small-scale dosimetry and of biologic effects on radionuclide therapies is given. Finally, the current limitations of patient-specific dosimetry such as bone-marrow dosimetry or dosimetry of α-emitters are discussed.
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Affiliation(s)
- Michael Lassmann
- Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Würzburg, Würzburg, Germany
| | - Uta Eberlein
- Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Würzburg, Würzburg, Germany
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73
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Allred JD, Niedbala J, Mikell JK, Owen D, Frey KA, Dewaraja YK. The value of 99mTc-MAA SPECT/CT for lung shunt estimation in 90Y radioembolization: a phantom and patient study. EJNMMI Res 2018; 8:50. [PMID: 29904808 PMCID: PMC6003896 DOI: 10.1186/s13550-018-0402-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 05/31/2018] [Indexed: 12/17/2022] Open
Abstract
Background A major toxicity concern in radioembolization therapy of hepatic malignancies is radiation-induced pneumonitis and sclerosis due to hepatopulmonary shunting of 90Y microspheres. Currently, 99mTc macroaggregated albumin (99mTc-MAA) imaging is used to estimate the lung shunt fraction (LSF) prior to treatment. The aim of this study was to evaluate the accuracy/precision of LSF estimated from 99mTc planar and SPECT/CT phantom imaging, and within this context, to compare the corresponding LSF and lung-absorbed dose values from 99mTc-MAA patient studies. Additionally, LSFs from pre- and post-therapy imaging were compared. Results A liver/lung torso phantom filled with 99mTc to achieve three lung shunt values was scanned by planar and SPECT/CT imaging with repeat acquisitions to assess accuracy and precision. To facilitate processing of patient data, a workflow that relies on SPECT and CT-based auto-contouring to define liver and lung volumes for the LSF calculation was implemented. Planar imaging-based LSF estimates for 40 patients, obtained from their medical records, were retrospectively compared with SPECT/CT imaging-based calculations with attenuation and scatter correction. Additionally, in a subset of 20 patients, the pre-therapy estimates were compared with 90Y PET/CT-based measurements. In the phantom study, improved accuracy in LSF estimation was achieved using SPECT/CT with attenuation and scatter correction (within 13% of the true value) compared with planar imaging (up to 44% overestimation). The results in patients showed a similar trend with planar imaging significantly overestimating LSF compared to SPECT/CT. There was no correlation between lung shunt estimates and the delay between 99mTc-MAA administration and scanning, but off-target extra hepatic uptake tended to be more likely in patients with a longer delay. The mean lung absorbed dose predictions for the 28 patients who underwent therapy was 9.3 Gy (range 1.3–29.4) for planar imaging and 3.2 Gy (range 0.4–13.4) for SPECT/CT. For the patients with post-therapy imaging, the mean LSF from 90Y PET/CT was 1.0%, (range 0.3–2.8). This value was not significantly different from the mean LSF estimate from 99mTc-MAA SPECT/CT (mean 1.0%, range 0.4–1.6; p = 0.968), but was significantly lower than the mean LSF estimate based on planar imaging (mean 4.1%, range 1.2–15.0; p = 0.0002). Conclusions The improved accuracy demonstrated by the phantom study, agreement with 90Y PET/CT in patient studies, and the practicality of using auto-contouring for liver/lung definition suggests that 99mTc-MAA SPECT/CT with scatter and attenuation corrections should be used for lung shunt estimation prior to radioembolization.
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Affiliation(s)
- Jonathan D Allred
- Radiotherapy Physics, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Jeremy Niedbala
- Department of Radiology, University of Michigan, 1301 Catherine, 2276 Med Sci I/SPC 5610, Ann Arbor, MI, 48109, USA
| | - Justin K Mikell
- Department of Radiation Oncology, University of Michigan, Ann Arbor, USA
| | - Dawn Owen
- Department of Radiation Oncology, University of Michigan, Ann Arbor, USA
| | - Kirk A Frey
- Department of Radiology, University of Michigan, 1301 Catherine, 2276 Med Sci I/SPC 5610, Ann Arbor, MI, 48109, USA
| | - Yuni K Dewaraja
- Department of Radiology, University of Michigan, 1301 Catherine, 2276 Med Sci I/SPC 5610, Ann Arbor, MI, 48109, USA.
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Ho CL, Chen S, Cheung SK, Leung YL, Cheng KC, Wong KN, Wong YH, Leung TWT. Radioembolization with 90Y glass microspheres for hepatocellular carcinoma: significance of pretreatment 11C-acetate and 18F-FDG PET/CT and posttreatment 90Y PET/CT in individualized dose prescription. Eur J Nucl Med Mol Imaging 2018; 45:2110-2121. [DOI: 10.1007/s00259-018-4064-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/27/2018] [Indexed: 10/14/2022]
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75
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Chan KT, Alessio AM, Johnson GE, Vaidya S, Kwan SW, Monsky W, Wilson AE, Lewis DH, Padia SA. Prospective Trial Using Internal Pair-Production Positron Emission Tomography to Establish the Yttrium-90 Radioembolization Dose Required for Response of Hepatocellular Carcinoma. Int J Radiat Oncol Biol Phys 2018; 101:358-365. [DOI: 10.1016/j.ijrobp.2018.01.116] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 01/08/2018] [Accepted: 01/22/2018] [Indexed: 12/16/2022]
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van Nierop BJ, Prince JF, van Rooij R, van den Bosch MA, Lam MG, de Jong HW. Accuracy of SPECT/CT-based lung dose calculation for Holmium-166 hepatic radioembolization before OSEM convergence. Med Phys 2018; 45:3871-3879. [PMID: 29858506 PMCID: PMC6099428 DOI: 10.1002/mp.13024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 04/26/2018] [Accepted: 05/14/2018] [Indexed: 11/06/2022] Open
Abstract
PURPOSE In intra-arterial hepatic radioembolization using Holmium-166 (166 Ho) microspheres, a predicted lung-absorbed dose of more than 30 Gy is a contraindication for therapy. Therefore, scout imaging by means of quantitative SPECT of the lungs after a low-dose pretreatment session is essential. Earlier we showed the superiority of Monte Carlo-based iterative SPECT reconstructions over conventional reconstructions due to its quantitative nature, required for dosimetry, at the cost of substantial computation times. In clinical routine, however, the limited available time between scout imaging and therapy constrains its application. To reduce computation times, we investigated the minimum number of iterations required to guarantee a clinical acceptable accuracy in lung dose estimation using patient and phantom data. METHODS 166 Ho scout SPECT data (range: 222-283 MBq) were used from 10 patients. SPECT images were Monte Carlo-based OSEM reconstructed (effective iterations: 240). Additionally, the 4D XCAT anthropomorphic phantom was used to mimic studies with an injected scout activity of 250 MBq and with varying lung-absorbed doses ranging from 0.9 to 225 Gy for a therapeutic dosage of 15 GBq. These studies were reconstructed in the same way as the patient data, and were also reconstructed using a clinically available, standard OSEM algorithm for comparison. Lung-absorbed dose was determined using VOI analysis as a function of iterations. RESULTS The estimated lung-absorbed dose in nine patients ranged upon MC-based OSEM convergence from 0 to 0.26 Gy for a therapeutic dosage. One patient had an estimated lung absorbed-dose for a therapeutic dosage of 20.3 Gy upon MC-based OSEM convergence, or 18.4 Gy after 40 iterations (-9%). The phantom data showed that the lung-absorbed dose upon OSEM convergence was underestimated by 15% as compared to the actual simulated lung dose, and the dose after 40 iterations was underestimated by 9% as compared to the dose upon convergence. Both underestimations were irrespective of the magnitude of the lung-absorbed dose (0.9 to 225 Gy) and thus can be easily corrected for. The quantitative accuracy of the MC-based OSEM reconstructions (40 iterations, before convergence) outperformed the clinical OSEM reconstruction while estimating the lung dose. CONCLUSIONS The number of effective iterations necessary for quantitative estimation of the lung dose using MC-based OSEM can be reduced from 240 to 40. The resulting sixfold reduction in calculation time enables processing of the scout images before therapy administration.
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Affiliation(s)
- Bastiaan J. van Nierop
- Department of Radiology and Nuclear MedicineUniversity Medical Centre UtrechtP.O. Box 85500UtrechtGA3508The Netherlands
| | - Jip F. Prince
- Department of Radiology and Nuclear MedicineUniversity Medical Centre UtrechtP.O. Box 85500UtrechtGA3508The Netherlands
| | - Rob van Rooij
- Department of Radiology and Nuclear MedicineUniversity Medical Centre UtrechtP.O. Box 85500UtrechtGA3508The Netherlands
| | - Maurice A.A.J. van den Bosch
- Department of Radiology and Nuclear MedicineUniversity Medical Centre UtrechtP.O. Box 85500UtrechtGA3508The Netherlands
| | - Marnix G.E.H. Lam
- Department of Radiology and Nuclear MedicineUniversity Medical Centre UtrechtP.O. Box 85500UtrechtGA3508The Netherlands
| | - Hugo W.A.M. de Jong
- Department of Radiology and Nuclear MedicineUniversity Medical Centre UtrechtP.O. Box 85500UtrechtGA3508The Netherlands
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77
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Maughan NM, Eldib M, Faul D, Conti M, Elschot M, Knešaurek K, Leek F, Townsend D, DiFilippo FP, Jackson K, Nekolla SG, Lukas M, Tapner M, Parikh PJ, Laforest R. Multi institutional quantitative phantom study of yttrium-90 PET in PET/MRI: the MR-QUEST study. EJNMMI Phys 2018; 5:7. [PMID: 29616365 PMCID: PMC5882483 DOI: 10.1186/s40658-018-0206-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/16/2018] [Indexed: 12/22/2022] Open
Abstract
Background Yttrium-90 (90Y) radioembolization involves the intra-arterial delivery of radioactive microspheres to treat hepatic malignancies. Though this therapy involves careful pre-treatment planning and imaging, little is known about the precise location of the microspheres once they are administered. Recently, there has been growing interest post-radioembolization imaging using positron-emission tomography (PET) for quantitative dosimetry and identifying lesions that may benefit from additional salvage therapy. In this study, we aim to measure the inter-center variability of 90Y PET measurements as measured on PET/MRI in preparation for a multi-institutional prospective phase I/II clinical trial. Eight institutions participated in this study and followed a standardized phantom filling and imaging protocol. The NEMA NU2-2012 body phantom was filled with 3 GBq of 90Y chloride solution. The phantom was imaged for 30 min in listmode on a Siemens Biograph mMR non-TOF PET/MRI scanner at five time points across 10 days (0.3–3.0 GBq). Raw PET data were sent to a central site for image reconstruction and data analysis. Images were reconstructed with optimal parameters determined from a previous study. Volumes of interest (VOIs) matching the known sphere diameters were drawn on the vendor-provided attenuation map and propagated to the PET images. Recovery coefficients (RCs) and coefficient of variation of the RCs (COV) were calculated from these VOIs for each sphere size and activity level. Results Mean RCs ranged from 14.5 to 75.4%, with the lowest mean RC coming from the smallest sphere (10 mm) on the last day of imaging (0.16 MBq/ml) and the highest mean RC coming from the largest sphere (37 mm) on the first day of imaging (2.16 MBq/ml). The smaller spheres tended to exhibit higher COVs. In contrast, the larger spheres tended to exhibit lower COVs. COVs from the 37 mm sphere were < 25.3% in all scans. For scans with ≥ 0.60 MBq/ml, COVs were ≤ 25% in spheres ≥ 22 mm. However, for all other spheres sizes and activity levels, COVs were usually > 25%. Conclusions Post-radioembolization dosimetry of lesions or other VOIs ≥ 22 mm in diameter can be consistently obtained (< 25% variability) at a multi-institutional level using PET/MRI for any clinically significant activity for 90Y radioembolization.
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Affiliation(s)
- Nichole M Maughan
- Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, MO, 63110, USA
| | - Mootaz Eldib
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave, New York, NY, 10029, USA.,Department of Biomedical Engineering, City College of New York, 160 Convent Ave, New York, NY, 10031, USA
| | - David Faul
- Siemens Healthineers, Siemens Medical Solutions USA, Inc., 40 Liberty Boulevard, Malvern, PA, 19355-9998, USA
| | - Maurizio Conti
- Molecular Imaging, Siemens Healthineers, 810 Innovation Dr, Knoxville, TN, 37932, USA
| | - Mattijs Elschot
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, NTNU, Norwegian University of Science and Technology, Postboks 8905, 7491, Trondheim, Norway
| | - Karin Knešaurek
- Department of Radiology, Icahn School of Medicine at Mt. Sinai, One G. Levy Pl., Box 1141, New York, NY, 10029, USA
| | - Francesca Leek
- Agency for Science Technology and Research, National University of Singapore Clinical Imaging Research Centre, 14 Medical Drive, #B1-01, Singapore, 117599, Singapore
| | - David Townsend
- Agency for Science Technology and Research, National University of Singapore Clinical Imaging Research Centre, 14 Medical Drive, #B1-01, Singapore, 117599, Singapore
| | - Frank P DiFilippo
- Department of Nuclear Medicine, Cleveland Clinic, Mail Code Jb3, 9500 Euclid Ave, Cleveland, OH, 44195, USA
| | | | - Stephan G Nekolla
- Klinik und Poliklinik für Nuklearmedizin, TU München, Strasse 22, 81675, Munich, Germany
| | - Mathias Lukas
- Department of Nuclear Medicine, Charité-Universitätsmedizin Berlin, Charitépl. 1, 10117, Berlin, Germany.,Siemens Healthcare GmbH, Berlin, Germany
| | - Michael Tapner
- Sirtex Medical Ltd, Level 33, 101 Miller St, North Sydney, NSW, 2060, Australia.,ABX-CRO Advanced Pharmaceutical Services, 1 Begonia Road, Normanhurst, NSW, 2076, Australia
| | - Parag J Parikh
- Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, MO, 63110, USA.
| | - Richard Laforest
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway, Campus Box 8225, St. Louis, MO, 63110, USA
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78
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Filippi L, Schillaci O, Cianni R, Bagni O. Yttrium-90 resin microspheres and their use in the treatment of intrahepatic cholangiocarcinoma. Future Oncol 2018; 14:809-818. [DOI: 10.2217/fon-2017-0443] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Intrahepatic cholangiocarcinoma (ICC) is a severe and rapidly progressive hepatic tumor. Surgery is often impracticable due to locally advanced presentation. On the other hand, chemotherapy has demonstrated only limited effectiveness. For these reasons, liver-directed therapies have been successfully applied for treating ICC. In particular, radioembolization with Yttrium-90 (90Y)-labeled spheres has been reported to be a promising therapeutic approach for this neoplasia. Two commercial forms of 90Y-labeled spheres are available: glass (TheraSphere®) and resin (SIR-Spheres®) microspheres. The aim of the present paper is to review the existing literature on the use of the resin microspheres for the treatment of unresectable and chemorefractory ICC, focusing on the methodology, clinical applications and side effects.
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Affiliation(s)
- Luca Filippi
- Nuclear Medicine Unit, “Santa Maria Goretti” Hospital, Latina, Italy
| | - Orazio Schillaci
- Department of Biomedicine & Prevention, University Tor Vergata, Rome, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - Roberto Cianni
- Interventional Radiology Unit, “San Camillo Hospital”, Rome, Italy
| | - Oreste Bagni
- Nuclear Medicine Unit, “Santa Maria Goretti” Hospital, Latina, Italy
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79
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Walrand S, Hesse M, Jamar F, Lhommel R. The origin and reduction of spurious extrahepatic counts observed in 90Y non-TOF PET imaging post radioembolization. Phys Med Biol 2018. [PMID: 29513273 DOI: 10.1088/1361-6560/aab4e9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Our literature survey revealed a physical effect unknown to the nuclear medicine community, i.e. internal bremsstrahlung emission, and also the existence of long energy resolution tails in crystal scintillation. None of these effects has ever been modelled in PET Monte Carlo (MC) simulations. This study investigates whether these two effects could be at the origin of two unexplained observations in 90Y imaging by PET: the increasing tails in the radial profile of true coincidences, and the presence of spurious extrahepatic counts post radioembolization in non-TOF PET and their absence in TOF PET. These spurious extrahepatic counts hamper the microsphere delivery check in liver radioembolization. An acquisition of a 32P vial was performed on a GSO PET system. This is the ideal setup to study the impact of bremsstrahlung x-rays on the true coincidence rate when no positron emission and no crystal radioactivity are present. A MC simulation of the acquisition was performed using Gate-Geant4. MC simulations of non-TOF PET and TOF-PET imaging of a synthetic 90Y human liver radioembolization phantom were also performed. Internal bremsstrahlung and long energy resolution tails inclusion in MC simulations quantitatively predict the increasing tails in the radial profile. In addition, internal bremsstrahlung explains the discrepancy previously observed in bremsstrahlung SPECT between the measure of the 90Y bremsstrahlung spectrum and its simulation with Gate-Geant4. However the spurious extrahepatic counts in non-TOF PET mainly result from the failure of conventional random correction methods in such low count rate studies and poor robustness versus emission-transmission inconsistency. A novel proposed random correction method succeeds in cleaning the spurious extrahepatic counts in non-TOF PET. Two physical effects not considered up to now in nuclear medicine were identified to be at the origin of the unusual 90Y true coincidences radial profile. TOF reconstruction removing of the spurious extrahepatic counts was theoretically explained by a better robustness against emission-transmission inconsistency. A novel random correction method was proposed to overcome the issue in non-TOF PET. Further studies are needed to assess the novel random correction method robustness.
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80
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Lim H, Dewaraja YK, Fessler JA. A PET reconstruction formulation that enforces non-negativity in projection space for bias reduction in Y-90 imaging. Phys Med Biol 2018; 63:035042. [PMID: 29327692 PMCID: PMC5854483 DOI: 10.1088/1361-6560/aaa71b] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Most existing PET image reconstruction methods impose a nonnegativity constraint in the image domain that is natural physically, but can lead to biased reconstructions. This bias is particularly problematic for Y-90 PET because of the low probability positron production and high random coincidence fraction. This paper investigates a new PET reconstruction formulation that enforces nonnegativity of the projections instead of the voxel values. This formulation allows some negative voxel values, thereby potentially reducing bias. Unlike the previously reported NEG-ML approach that modifies the Poisson log-likelihood to allow negative values, the new formulation retains the classical Poisson statistical model. To relax the non-negativity constraint embedded in the standard methods for PET reconstruction, we used an alternating direction method of multipliers (ADMM). Because choice of ADMM parameters can greatly influence convergence rate, we applied an automatic parameter selection method to improve the convergence speed. We investigated the methods using lung to liver slices of XCAT phantom. We simulated low true coincidence count-rates with high random fractions corresponding to the typical values from patient imaging in Y-90 microsphere radioembolization. We compared our new methods with standard reconstruction algorithms and NEG-ML and a regularized version thereof. Both our new method and NEG-ML allow more accurate quantification in all volumes of interest while yielding lower noise than the standard method. The performance of NEG-ML can degrade when its user-defined parameter is tuned poorly, while the proposed algorithm is robust to any count level without requiring parameter tuning.
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Affiliation(s)
- Hongki Lim
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, United States of America. Department of Radiology, University of Michigan, Ann Arbor, MI 48109, United States of America
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81
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Ausland L, Revheim ME, Skretting A, Stokke C. Respiratory motion during 90Yttrium PET contributes to underestimation of tumor dose and overestimation of normal liver tissue dose. Acta Radiol 2018; 59:132-139. [PMID: 28509566 DOI: 10.1177/0284185117710052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Background Yttrium-90 dosimetry after radioembolization is reliant on accurate quantitative imaging of the microsphere deposition. Previous studies have focused on the correction of geometrical resolution effects. Purpose To uncover additional effects of respiratory motion. Material and Methods Mathematical models describing spherical tumors were formed and two blurring effects, limited geometrical resolution and respiratory motion, were simulated. The virtual images were used as basis for dose volume histogram estimations by convolving the radioactivity representations with a dose point kernel. Results For respiratory motion only, the largest errors were found for the smallest tumors and/or tumors with heterogeneous distribution of yttrium-90 microspheres. The deviations in max dose and dose to 25% and 50% of the tumor volume were estimated at 20-40%, 10-30%, and 0-30%, respectively. Additional blurring from geometrical resolution increased the errors to 55-75%, 50-60%, and 25-60%, respectively. Conclusion Respiratory motion contributes to underestimation of tumor dose and overestimation of normal tissue dose.
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Affiliation(s)
- Line Ausland
- 1 Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
| | - Mona-Elisabeth Revheim
- 2 Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.,3 Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Arne Skretting
- 1 Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
| | - Caroline Stokke
- 1 Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway.,4 Oslo and Akershus University College of Applied Science, Oslo, Norway
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82
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D'Arienzo M, Pimpinella M, Capogni M, De Coste V, Filippi L, Spezi E, Patterson N, Mariotti F, Ferrari P, Chiaramida P, Tapner M, Fischer A, Paulus T, Pani R, Iaccarino G, D'Andrea M, Strigari L, Bagni O. Phantom validation of quantitative Y-90 PET/CT-based dosimetry in liver radioembolization. EJNMMI Res 2017; 7:94. [PMID: 29185067 PMCID: PMC5705539 DOI: 10.1186/s13550-017-0341-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 10/29/2017] [Indexed: 12/20/2022] Open
Abstract
Background PET/CT has recently been shown to be a viable alternative to traditional post-infusion imaging methods providing good quality images of 90Y-laden microspheres after selective internal radiation therapy (SIRT). In the present paper, first we assessed the quantitative accuracy of 90Y-PET using an anthropomorphic phantom provided with lungs, liver, spine, and a cylindrical homemade lesion located into the hepatic compartment. Then, we explored the accuracy of different computational approaches on dose calculation, including (I) direct Monte Carlo radiation transport using Raydose, (II) Kernel convolution using Philips Stratos, (III) local deposition algorithm, (IV) Monte Carlo technique (MCNP) considering a uniform activity distribution, and (V) MIRD (Medical Internal Radiation Dose) analytical approach. Finally, calculated absorbed doses were compared with those obtained performing measurements with LiF:Mg,Cu,P TLD chips in a liquid environment. Results Our results indicate that despite 90Y-PET being likely to provide high-resolution images, the 90Y low branch ratio, along with other image-degrading factors, may produce non-uniform activity maps, even in the presence of uniform activity. A systematic underestimation of the recovered activity, both for the tumor insert and for the liver background, was found. This is particularly true if no partial volume correction is applied through recovery coefficients. All dose algorithms performed well, the worst case scenario providing an agreement between absorbed dose evaluations within 20%. Average absorbed doses determined with the local deposition method are in excellent agreement with those obtained using the MIRD and the kernel-convolution dose calculation approach. Finally, absorbed dose assessed with MC codes are in good agreement with those obtained using TLD in liquid solution, thus confirming the soundness of both calculation approaches. This is especially true for Raydose, which provided an absorbed dose value within 3% of the measured dose, well within the stated uncertainties. Conclusions Patient-specific dosimetry is possible even in a scenario with low true coincidences and high random fraction, as in 90Y–PET imaging, granted that accurate absolute PET calibration is performed and acquisition times are sufficiently long. Despite Monte Carlo calculations seeming to outperform all dose estimation algorithms, our data provide a strong argument for encouraging the use of the local deposition algorithm for routine 90Y dosimetry based on PET/CT imaging, due to its simplicity of implementation.
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Affiliation(s)
- Marco D'Arienzo
- ENEA, Italian National Institute of Ionizing Radiation Metrology, Via Anguillarese 301, 00123, Rome, Italy. .,Department of Anatomical, Histological, Forensic Medicine and Orthopedic Sciences, Sapienza University, Rome, Italy.
| | - Maria Pimpinella
- ENEA, Italian National Institute of Ionizing Radiation Metrology, Via Anguillarese 301, 00123, Rome, Italy
| | - Marco Capogni
- ENEA, Italian National Institute of Ionizing Radiation Metrology, Via Anguillarese 301, 00123, Rome, Italy
| | - Vanessa De Coste
- ENEA, Italian National Institute of Ionizing Radiation Metrology, Via Anguillarese 301, 00123, Rome, Italy
| | - Luca Filippi
- Nuclear Medicine Department, Santa Maria Goretti Hospital, Latina, Italy
| | - Emiliano Spezi
- School of Engineering, Cardiff University, Cardiff, CF24 3AA, United Kingdom.,Department of Medical Physics, Velindre Cancer Centre, Cardiff, UK
| | - Nick Patterson
- Department of Medical Physics, Velindre Cancer Centre, Cardiff, UK
| | - Francesca Mariotti
- ENEA, Radiation Protection Institute, Bologna Via Martiri di Monte Sole 4, 40129, Bologna, Italy
| | - Paolo Ferrari
- ENEA, Radiation Protection Institute, Bologna Via Martiri di Monte Sole 4, 40129, Bologna, Italy
| | | | | | - Alexander Fischer
- Philips Technologie GmbH Innovative Technologies, Research Laboratories Pauwelsstr, 17, 52074, Aachen, Germany
| | - Timo Paulus
- Philips Technologie GmbH Innovative Technologies, Research Laboratories Pauwelsstr, 17, 52074, Aachen, Germany
| | - Roberto Pani
- Depertment of Medico-surgical Sciences and Biotecnologies, Sapienza University of Rome, Rome, Italy
| | - Giuseppe Iaccarino
- Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144, Rome, Italy
| | - Marco D'Andrea
- Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144, Rome, Italy
| | - Lidia Strigari
- Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144, Rome, Italy
| | - Oreste Bagni
- Nuclear Medicine Department, Santa Maria Goretti Hospital, Latina, Italy
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83
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Stokke C, Gabiña PM, Solný P, Cicone F, Sandström M, Gleisner KS, Chiesa C, Spezi E, Paphiti M, Konijnenberg M, Aldridge M, Tipping J, Wissmeyer M, Brans B, Bacher K, Kobe C, Flux G. Dosimetry-based treatment planning for molecular radiotherapy: a summary of the 2017 report from the Internal Dosimetry Task Force. EJNMMI Phys 2017; 4:27. [PMID: 29164483 PMCID: PMC5698234 DOI: 10.1186/s40658-017-0194-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 11/06/2017] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND The European directive on basic safety standards (Council directive 2013/59 Euratom) mandates dosimetry-based treatment planning for radiopharmaceutical therapies. The directive comes into operation February 2018, and the aim of a report produced by the Internal Dosimetry Task Force of the European Association of Nuclear Medicine is to address this aspect of the directive. A summary of the report is presented. RESULTS A brief review of five of the most common therapy procedures is included in the current text, focused on the potential to perform patient-specific dosimetry. In the full report, 11 different therapeutic procedures are included, allowing additional considerations of effectiveness, references to specific literature on quantitative imaging and dosimetry, and existing evidence for absorbed dose-effect correlations for each treatment. Individualized treatment planning with tracer diagnostics and verification of the absorbed doses delivered following therapy is found to be scientifically feasible for almost all procedures investigated, using quantitative imaging and/or external monitoring. Translation of this directive into clinical practice will have significant implications for resource requirements. CONCLUSIONS Molecular radiotherapy is undergoing a significant expansion, and the groundwork for dosimetry-based treatment planning is already in place. The mandated individualization is likely to improve the effectiveness of the treatments, although must be adequately resourced.
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Affiliation(s)
- Caroline Stokke
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway.
| | - Pablo Minguez Gabiña
- Department of Medical Physics and Radiation Protection, Gurutzeta/Cruces University Hospital, Barakaldo, Spain
| | - Pavel Solný
- Department of Dosimetry and Application of Ionizing Radiation, Czech Technical University in Prague, Prague, Czech Republic
| | - Francesco Cicone
- Nuclear Medicine, Sant'Andrea Hospital, Department of Surgical and Medical Sciences and Translational Medicine, Sapienza University of Rome, Rome, Italy
| | - Mattias Sandström
- Section of Nuclear Medicine and PET, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | | | - Carlo Chiesa
- Nuclear Medicine Division, Foundation IRCCS istituto nazionale Tumori, Milan, Italy
| | | | - Maria Paphiti
- Department of Medical Physics, Pammakaristos Hospital, Athens, Greece
| | - Mark Konijnenberg
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Matt Aldridge
- Nuclear Medicine/Radiotherapy Physics, UCL Institute of Nuclear Medicine and UCL Hospitals NHS Foundation Trust, London, UK
| | - Jill Tipping
- The Christie NHS Foundation Trust, Nuclear Medicine, Manchester, UK
| | - Michael Wissmeyer
- Department of Nuclear Medicine, University Hospital of Geneva, Geneva, Switzerland
| | - Boudewijn Brans
- Department of Nuclear Medicine and PET Center, University Hospital, Ghent, Belgium
| | - Klaus Bacher
- Department of Basic Medical Sciences, Division of Medical Physics, Ghent University, Ghent, Belgium
| | - Carsten Kobe
- Department for Nuclear Medicine, University Hospital of Cologne, Cologne, Germany
| | - Glenn Flux
- Joint Department of Physics, Royal Marsden Hospital and Institute of Cancer Research, Sutton, UK
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84
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Low-dose 90Y PET/CT imaging optimized for lesion detectability and quantitative accuracy. Nucl Med Commun 2017; 38:985-997. [DOI: 10.1097/mnm.0000000000000742] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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85
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Dewaraja YK, Chun SY, Srinivasa RN, Kaza RK, Cuneo KC, Majdalany BS, Novelli PM, Ljungberg M, Fessler JA. Improved quantitative 90 Y bremsstrahlung SPECT/CT reconstruction with Monte Carlo scatter modeling. Med Phys 2017; 44:6364-6376. [PMID: 28940483 DOI: 10.1002/mp.12597] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 01/07/2023] Open
Abstract
PURPOSE In 90 Y microsphere radioembolization (RE), accurate post-therapy imaging-based dosimetry is important for establishing absorbed dose versus outcome relationships for developing future treatment planning strategies. Additionally, accurately assessing microsphere distributions is important because of concerns for unexpected activity deposition outside the liver. Quantitative 90 Y imaging by either SPECT or PET is challenging. In 90 Y SPECT model based methods are necessary for scatter correction because energy window-based methods are not feasible with the continuous bremsstrahlung energy spectrum. The objective of this work was to implement and evaluate a scatter estimation method for accurate 90 Y bremsstrahlung SPECT/CT imaging. METHODS Since a fully Monte Carlo (MC) approach to 90 Y SPECT reconstruction is computationally very demanding, in the present study the scatter estimate generated by a MC simulator was combined with an analytical projector in the 3D OS-EM reconstruction model. A single window (105 to 195-keV) was used for both the acquisition and the projector modeling. A liver/lung torso phantom with intrahepatic lesions and low-uptake extrahepatic objects was imaged to evaluate SPECT/CT reconstruction without and with scatter correction. Clinical application was demonstrated by applying the reconstruction approach to five patients treated with RE to determine lesion and normal liver activity concentrations using a (liver) relative calibration. RESULTS There was convergence of the scatter estimate after just two updates, greatly reducing computational requirements. In the phantom study, compared with reconstruction without scatter correction, with MC scatter modeling there was substantial improvement in activity recovery in intrahepatic lesions (from > 55% to > 86%), normal liver (from 113% to 104%), and lungs (from 227% to 104%) with only a small degradation in noise (13% vs. 17%). Similarly, with scatter modeling contrast improved substantially both visually and in terms of a detectability index, which was especially relevant for the low uptake extrahepatic objects. The trends observed for the phantom were also seen in the patient studies where lesion activity concentrations and lesion-to-liver concentration ratios were lower for SPECT without scatter correction compared with reconstruction with just two MC scatter updates: in eleven lesions the mean uptake was 4.9 vs. 7.1 MBq/mL (P = 0.0547), the mean normal liver uptake was 1.6 vs. 1.5 MBq/mL (P = 0.056) and the mean lesion-to-liver uptake ratio was 2.7 vs. 4.3 (P = 0.0402) for reconstruction without and with scatter correction respectively. CONCLUSIONS Quantitative accuracy of 90 Y bremsstrahlung imaging can be substantially improved with MC scatter modeling without significant degradation in image noise or intensive computational requirements.
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Affiliation(s)
- Yuni K Dewaraja
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Se Young Chun
- School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology, Ulsan, Korea
| | - Ravi N Srinivasa
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Ravi K Kaza
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kyle C Cuneo
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Bill S Majdalany
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Paula M Novelli
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael Ljungberg
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Jeffrey A Fessler
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
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86
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van der Vos CS, Koopman D, Rijnsdorp S, Arends AJ, Boellaard R, van Dalen JA, Lubberink M, Willemsen ATM, Visser EP. Quantification, improvement, and harmonization of small lesion detection with state-of-the-art PET. Eur J Nucl Med Mol Imaging 2017; 44:4-16. [PMID: 28687866 PMCID: PMC5541089 DOI: 10.1007/s00259-017-3727-z] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 05/09/2017] [Indexed: 01/09/2023]
Abstract
In recent years, there have been multiple advances in positron emission tomography/computed tomography (PET/CT) that improve cancer imaging. The present generation of PET/CT scanners introduces new hardware, software, and acquisition methods. This review describes these new developments, which include time-of-flight (TOF), point-spread-function (PSF), maximum-a-posteriori (MAP) based reconstruction, smaller voxels, respiratory gating, metal artefact reduction, and administration of quadratic weight-dependent 18F-fluorodeoxyglucose (FDG) activity. Also, hardware developments such as continuous bed motion (CBM), (digital) solid-state photodetectors and combined PET and magnetic resonance (MR) systems are explained. These novel techniques have a significant impact on cancer imaging, as they result in better image quality, improved small lesion detectability, and more accurate quantification of radiopharmaceutical uptake. This influences cancer diagnosis and staging, as well as therapy response monitoring and radiotherapy planning. Finally, the possible impact of these developments on the European Association of Nuclear Medicine (EANM) guidelines and EANM Research Ltd. (EARL) accreditation for FDG-PET/CT tumor imaging is discussed.
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Affiliation(s)
- Charlotte S van der Vos
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
- MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Daniëlle Koopman
- MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
- Department of Nuclear Medicine, Isala Hospital, Zwolle, The Netherlands
| | - Sjoerd Rijnsdorp
- Department of Medical Physics, Catharina Hospital, Eindhoven, The Netherlands
| | - Albert J Arends
- Department of Medical Physics, Catharina Hospital, Eindhoven, The Netherlands
| | - Ronald Boellaard
- Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Jorn A van Dalen
- Department of Nuclear Medicine, Isala Hospital, Zwolle, The Netherlands
- Department of Medical Physics, Isala, Zwolle, The Netherlands
| | - Mark Lubberink
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
- Department of Medical Physics, Uppsala University Hospital, Uppsala, Sweden
| | - Antoon T M Willemsen
- Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Eric P Visser
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands.
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87
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Optimisation of reconstruction, volumetry and dosimetry for 99mTc-SPECT and 90Y-PET images: Towards reliable dose-volume histograms for selective internal radiation therapy with 90Y-microspheres. Phys Med 2017; 39:147-155. [PMID: 28687192 DOI: 10.1016/j.ejmp.2017.06.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 05/19/2017] [Accepted: 06/24/2017] [Indexed: 01/10/2023] Open
Abstract
PURPOSE In Selective Internal Radiation Therapy (SIRT), 99mTc-MAA SPECT images are commonly used to predict microspheres distribution but recent works used 90Y-microspheres PET images. Nevertheless, evaluation of the predictive power of 99mTc-MAA has been hampered by the lack of reliable comparisons between 99mTc-SPECT and 90Y-PET images. Our aim was to determine the "in situ" optimisation procedure in order to reliably compare 99mTc-SPECT and 90Y-PET images and achieve optimal personal dosimetry. METHODS We acquired 99mTc-SPECT/CT and 90Y-PET/CT images of NEMA and Jaszczak phantoms. We found the best reconstruction parameters for quantification and for volume estimations. We determined adaptive threshold curves on the volumetric reconstruction. We copied the optimised volumes on the quantitative reconstruction, named here the "cross volumes" technique. Finally, we compared 99mTc-SPECT and 90Y-PET Dose Volume Histograms. RESULTS Our "in situ" optimisation procedure decreased errors on volumes and quantification (from -44.2% and -15.8% to -3.4% and -3.28%, respectively, for the 26.5mL PET phantom sphere). Moreover, 99mTc-SPECT and 90Y-PET DVHs were equivalent only after the optimisation procedure (difference in mean dose <5% for the three biggest spheres). CONCLUSIONS This work showed that a preliminary "in situ" phantom study was necessary to optimise volumes and quantification of 99mTc-SPECT and 90Y-PET images and allowed to achieve a reliable comparison between patient treatment planning and post implant dosimetry, notably by the use of the "cross volumes" technique. Methodology developed in this work will enable robust evaluations of the predictive power of 99mTc-SPECT, as well as dose-response relationship and side effects in SIRT treatments.
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88
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The conflict between treatment optimization and registration of radiopharmaceuticals with fixed activity posology in oncological nuclear medicine therapy. Eur J Nucl Med Mol Imaging 2017; 44:1783-1786. [DOI: 10.1007/s00259-017-3707-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 04/16/2017] [Indexed: 10/19/2022]
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89
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Willowson KP, Hayes AR, Chan DLH, Tapner M, Bernard EJ, Maher R, Pavlakis N, Clarke SJ, Bailey DL. Clinical and imaging-based prognostic factors in radioembolisation of liver metastases from colorectal cancer: a retrospective exploratory analysis. EJNMMI Res 2017; 7:46. [PMID: 28536968 PMCID: PMC5442040 DOI: 10.1186/s13550-017-0292-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 05/12/2017] [Indexed: 02/07/2023] Open
Abstract
Background The aim of this study was to investigate the relationship between absorbed dose and response of colorectal cancer liver metastases treated with [90Y]-resin microspheres and to explore possible clinical and imaging derived prognostic factors. Methods FDG PET/CT was used to measure response of individual lesions to a measured absorbed dose, derived from post-treatment 90Y PET imaging. Predicted dose was also derived from planning [99mTc]-MAA SPECT data. Peak standardised uptake value and total lesion glycolysis (TLG) were explored as response measures, and compared to dose metrics including average dose (Davg), biologically effective dose, minimum dose to 70% of lesion volume and volume receiving at least 50 Gy. Prognostic factors examined included baseline TLG, RAS mutation status, FDG heterogeneity and dose heterogeneity. In an exploratory analysis, response and clinico-pathological variables were evaluated and compared to overall survival. Results Sixty-three lesions were analysed from 22 patients. Poor agreement was seen between predicted and measured dose values. TLG was a superior measure of response, and all dose metrics were significant prognostic factors, with a Davg of ~50 Gy derived as the critical threshold for a significant response (>50% reduction in TLG). No significant correlation was found between baseline TLG or RAS mutation status and response. Measured dose heterogeneity was a significant prognostic factor and when combined with Davg had a positive predictive value for response >80%. In the exploratory analysis for prognostic factors of survival, low hepatic tumour burden and mean reduction in TLG >65% were independently associated with improved overall survival. Conclusions Lesions receiving an average dose greater than 50 Gy are likely to have a significant response. For lesions receiving less than 50 Gy, dose heterogeneity is a significant prognostic factor. Lesions receiving an average dose less than 20 Gy are unlikely to respond. A reduction in TLG may be associated with improved overall survival. Electronic supplementary material The online version of this article (doi:10.1186/s13550-017-0292-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kathy P Willowson
- Institute of Medical Physics, School of Physics, University of Sydney, Camperdown, NSW, Australia.
| | - Aimee R Hayes
- Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, NSW, Australia.,Department of Medical Oncology, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - David L H Chan
- Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, NSW, Australia.,Department of Medical Oncology, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Michael Tapner
- Research and Development, Sirtex Medical Limited, North Sydney, Australia
| | - Elizabeth J Bernard
- Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, NSW, Australia.,Sydney Medical School, University of Sydney, Camperdown, NSW, Australia
| | - Richard Maher
- Department of Radiology, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Nick Pavlakis
- Department of Medical Oncology, Royal North Shore Hospital, St Leonards, NSW, Australia.,Sydney Medical School, University of Sydney, Camperdown, NSW, Australia
| | - Stephen J Clarke
- Department of Medical Oncology, Royal North Shore Hospital, St Leonards, NSW, Australia.,Sydney Medical School, University of Sydney, Camperdown, NSW, Australia
| | - Dale L Bailey
- Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, NSW, Australia.,Faculty of Health Sciences, University of Sydney, Camperdown, NSW, Australia
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90
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Beijst C, de Keizer B, Lam MGEH, Janssens GO, Tytgat GAM, de Jong HWAM. A phantom study: Should 124 I-mIBG PET/CT replace 123 I-mIBG SPECT/CT? Med Phys 2017; 44:1624-1631. [PMID: 28273347 DOI: 10.1002/mp.12202] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 02/24/2017] [Accepted: 02/28/2017] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The isotope 123 I is commonly labeled with meta-iodobenzylguanidine (mIBG) for imaging of neuroendocrine tumors, such as pheochromocytomas and neuroblastomas. 123 I-mIBG SPECT/CT imaging is performed for staging, follow-up and selection of patients for treatment with 131 I mIBG. As an alternative to 123 I, 124 I-mIBG PET/CT may be used, potentially taking advantage of the superior PET image quality. The purpose of this study was to investigate whether 124 I PET/CT improves image quality as compared with 123 I SPECT/CT for equal patient effective radiation dose (in mSv). METHODS Phantom measurements were performed using the NEMA-2007 image quality phantom. SPECT and PET reconstruction settings were used with and without time-of-flight (TOF) and point-spread-function (PSF) modeling. As a measure of image quality, the contrast-to-noise ratio (CNR) was calculated. The ratio of the 123 I to 124 I activity concentration was determined at which the contrast-to-noise ratio was equal for both modalities. This metric was defined as the contrast equivalent activity ratio (CEAR). RESULTS CEARs of 47.7, 25.6, 23.1, 14.6, 10.0, and 9.1 were obtained for a TOF and PSF modeled 124 I reconstruction method and an attenuation and scatter-corrected 123 I reconstruction method for sphere sizes of 10 to 37 mm, respectively. As the effective radiation dose of 124 I-mIBG is higher than of 123 I-mIBG (in mSv/MBq), an equal effective dose corresponds to a CEAR of 5 to 10. Therefore, CEARs higher than 5 to 10 indicate that 124 I PET/CT outperforms 123 I SPECT/CT in the sense of image quality for equal patient effective radiation dose. CONCLUSION The CEAR is much larger than a factor of 5 to 10 (needed for equal patient effective radiation dose) for most of the reconstruction methods and sphere sizes. Therefore, 124 I-mIBG PET/CT is expected to improve image quality and/or may be used to reduce effective patient dose as compared with 123 I-mIBG SPECT/CT.
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Affiliation(s)
- Casper Beijst
- Department of Radiology and Nuclear Medicine, UMC Utrecht, Utrecht, The Netherlands.,Image Sciences Institute, UMC Utrecht, Utrecht, The Netherlands
| | - Bart de Keizer
- Department of Radiology and Nuclear Medicine, UMC Utrecht, Utrecht, The Netherlands
| | - Marnix G E H Lam
- Department of Radiology and Nuclear Medicine, UMC Utrecht, Utrecht, The Netherlands
| | - Geert O Janssens
- Department of Radiation Oncology, UMC Utrecht, Utrecht, The Netherlands
| | | | - Hugo W A M de Jong
- Department of Radiology and Nuclear Medicine, UMC Utrecht, Utrecht, The Netherlands
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91
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Conti M, Eriksson L, Rothfuss H, Sjoeholm T, Townsend D, Rosenqvist G, Carlier T. Characterization of176Lu background in LSO-based PET scanners. Phys Med Biol 2017; 62:3700-3711. [DOI: 10.1088/1361-6560/aa68ca] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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92
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Siman W, Mikell JK, Kappadath SC. Practical reconstruction protocol for quantitative (90)Y bremsstrahlung SPECT/CT. Med Phys 2017; 43:5093. [PMID: 27587040 DOI: 10.1118/1.4960629] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
PURPOSE To develop a practical background compensation (BC) technique to improve quantitative (90)Y-bremsstrahlung single-photon emission computed tomography (SPECT)/computed tomography (CT) using a commercially available imaging system. METHODS All images were acquired using medium-energy collimation in six energy windows (EWs), ranging from 70 to 410 keV. The EWs were determined based on the signal-to-background ratio in planar images of an acrylic phantom of different thicknesses (2-16 cm) positioned below a (90)Y source and set at different distances (15-35 cm) from a gamma camera. The authors adapted the widely used EW-based scatter-correction technique by modeling the BC as scaled images. The BC EW was determined empirically in SPECT/CT studies using an IEC phantom based on the sphere activity recovery and residual activity in the cold lung insert. The scaling factor was calculated from 20 clinical planar (90)Y images. Reconstruction parameters were optimized in the same SPECT images for improved image quantification and contrast. A count-to-activity calibration factor was calculated from 30 clinical (90)Y images. RESULTS The authors found that the most appropriate imaging EW range was 90-125 keV. BC was modeled as 0.53× images in the EW of 310-410 keV. The background-compensated clinical images had higher image contrast than uncompensated images. The maximum deviation of their SPECT calibration in clinical studies was lowest (<10%) for SPECT with attenuation correction (AC) and SPECT with AC + BC. Using the proposed SPECT-with-AC + BC reconstruction protocol, the authors found that the recovery coefficient of a 37-mm sphere (in a 10-mm volume of interest) increased from 39% to 90% and that the residual activity in the lung insert decreased from 44% to 14% over that of SPECT images with AC alone. CONCLUSIONS The proposed EW-based BC model was developed for (90)Y bremsstrahlung imaging. SPECT with AC + BC gave improved lesion detectability and activity quantification compared to SPECT with AC only. The proposed methodology can readily be used to tailor (90)Y SPECT/CT acquisition and reconstruction protocols with different SPECT/CT systems for quantification and improved image quality in clinical settings.
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Affiliation(s)
- W Siman
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030
| | - J K Mikell
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030
| | - S C Kappadath
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030
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93
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Yue J, Mauxion T, Reyes DK, Lodge MA, Hobbs RF, Rong X, Dong Y, Herman JM, Wahl RL, Geschwind JFH, Frey EC. Comparison of quantitative Y-90 SPECT and non-time-of-flight PET imaging in post-therapy radioembolization of liver cancer. Med Phys 2017; 43:5779. [PMID: 27782730 DOI: 10.1118/1.4962472] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Radioembolization with yttrium-90 microspheres may be optimized with patient-specific pretherapy treatment planning. Dose verification and validation of treatment planning methods require quantitative imaging of the post-therapy distribution of yttrium-90 (Y-90). Methods for quantitative imaging of Y-90 using both bremsstrahlung SPECT and PET have previously been described. The purpose of this study was to compare the two modalities quantitatively in humans. METHODS Calibration correction factors for both quantitative Y-90 bremsstrahlung SPECT and a non-time-of-flight PET system without compensation for prompt coincidences were developed by imaging three phantoms. The consistency of these calibration correction factors for the different phantoms was evaluated. Post-therapy images from both modalities were obtained from 15 patients with hepatocellular carcinoma who underwent hepatic radioembolization using Y-90 glass microspheres. Quantitative SPECT and PET images were rigidly registered and the total liver activities and activity distributions estimated for each modality were compared. The activity distributions were compared using profiles, voxel-by-voxel correlation and Bland-Altman analyses, and activity-volume histograms. RESULTS The mean ± standard deviation of difference in the total activity in the liver between the two modalities was 0% ± 9% (range -21%-18%). Voxel-by-voxel comparisons showed a good agreement in regions corresponding roughly to treated tumor and treated normal liver; the agreement was poorer in regions with low or no expected activity, where PET appeared to overestimate the activity. The correlation coefficients between intrahepatic voxel pairs for the two modalities ranged from 0.86 to 0.94. Cumulative activity volume histograms were in good agreement. CONCLUSIONS These data indicate that, with appropriate reconstruction methods and measured calibration correction factors, either Y-90 SPECT/CT or Y-90 PET/CT can be used for quantitative post-therapy monitoring of Y-90 activity distribution following hepatic radioembolization.
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Affiliation(s)
- Jianting Yue
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland 21287
| | - Thibault Mauxion
- Biocompatibles UK Ltd, A BTG Group Company, Camberley, GU15 3YL, United Kingdom
| | - Diane K Reyes
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland 21287
| | - Martin A Lodge
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland 21287
| | - Robert F Hobbs
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland 21287 and Department of Radiation Oncology, Johns Hopkins University, Baltimore, Maryland 21287
| | - Xing Rong
- Siemens Medical Solutions USA Inc., Hoffman Estates, Illinois 60192
| | - Yinfeng Dong
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland 21287
| | - Joseph M Herman
- Department of Radiation Oncology, Johns Hopkins University, Baltimore, Maryland 21287
| | - Richard L Wahl
- Department of Diagnostic Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri 06310
| | | | - Eric C Frey
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland 21287
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94
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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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95
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Strydhorst J, Carlier T, Dieudonné A, Conti M, Buvat I. A gate evaluation of the sources of error in quantitative 90 Y PET. Med Phys 2017; 43:5320-5329. [PMID: 28105711 DOI: 10.1118/1.4961747] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 07/28/2016] [Accepted: 08/13/2016] [Indexed: 01/08/2023] Open
Abstract
PURPOSE Accurate reconstruction of the dose delivered by 90 Y microspheres using a postembolization PET scan would permit the establishment of more accurate dose-response relationships for treatment of hepatocellular carcinoma with 90 Y. However, the quality of the PET data obtained is compromised by several factors, including poor count statistics and a very high random fraction. This work uses Monte Carlo simulations to investigate what impact factors other than low count statistics have on the quantification of90 Y PET. METHODS PET acquisitions of two phantoms-a NEMA PET phantom and the NEMA IEC PET body phantom-containing either 90 Y or 18 F were simulated using gate. Simulated projections were created with subsets of the simulation data allowing the contributions of random, scatter, and LSO background to be independently evaluated. The simulated projections were reconstructed using the commercial software for the simulated scanner, and the quantitative accuracy of the reconstruction and the contrast recovery of the reconstructed images were evaluated. RESULTS The quantitative accuracy of the 90 Y reconstructions were not strongly influenced by the high random fraction present in the projection data, and the activity concentration was recovered to within 5% of the known value. The contrast recovery measured for simulated 90 Y data was slightly poorer than that for simulated 18 F data with similar count statistics. However, the degradation was not strongly linked to any particular factor. Using a more restricted energy range to reduce the random fraction in the projections had no significant effect. CONCLUSIONS Simulations of 90 Y PET confirm that quantitative 90 Y is achievable with the same approach as that used for 18 F, and that there is likely very little margin for improvement by attempting to model aspects unique to 90 Y, such as the much higher random fraction or the presence of bremsstrahlung in the singles data.
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Affiliation(s)
- Jared Strydhorst
- IMIV, U1023 Inserm/CEA/Université Paris-Sud and ERL 9218 CNRS, Université Paris-Saclay, CEA/SHFJ, Orsay 91401, France
| | - Thomas Carlier
- Department of Nuclear Medicine, Centre Hospitalier Universitaire de Nantes and CRCNA, Inserm U892, Nantes 44000, France
| | - Arnaud Dieudonné
- Department of Nuclear Medicine, Hôpital Beaujon, HUPNVS, APHP and Inserm U1149, Clichy 92110, France
| | - Maurizio Conti
- Siemens Healthcare Molecular Imaging, Knoxville, Tennessee, 37932
| | - Irène Buvat
- IMIV, U1023 Inserm/CEA/Université Paris-Sud and ERL 9218 CNRS, Université Paris-Saclay, CEA/SHFJ, Orsay 91401, France
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96
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van der Velden S, Beijst C, Viergever MA, de Jong HWAM. Simultaneous fluoroscopic and nuclear imaging: impact of collimator choice on nuclear image quality. Med Phys 2017; 44:249-261. [PMID: 28044322 DOI: 10.1002/mp.12010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 11/04/2016] [Accepted: 11/04/2016] [Indexed: 11/10/2022] Open
Abstract
PURPOSE X-ray-guided oncological interventions could benefit from the availability of simultaneously acquired nuclear images during the procedure. To this end, a real-time, hybrid fluoroscopic and nuclear imaging device, consisting of an X-ray c-arm combined with gamma imaging capability, is currently being developed (Beijst C, Elschot M, Viergever MA, de Jong HW. Radiol. 2015;278:232-238). The setup comprises four gamma cameras placed adjacent to the X-ray tube. The four camera views are used to reconstruct an intermediate three-dimensional image, which is subsequently converted to a virtual nuclear projection image that overlaps with the X-ray image. The purpose of the present simulation study is to evaluate the impact of gamma camera collimator choice (parallel hole versus pinhole) on the quality of the virtual nuclear image. METHODS Simulation studies were performed with a digital image quality phantom including realistic noise and resolution effects, with a dynamic frame acquisition time of 1 s and a total activity of 150 MBq. Projections were simulated for 3, 5, and 7 mm pinholes and for three parallel hole collimators (low-energy all-purpose (LEAP), low-energy high-resolution (LEHR) and low-energy ultra-high-resolution (LEUHR)). Intermediate reconstruction was performed with maximum likelihood expectation-maximization (MLEM) with point spread function (PSF) modeling. In the virtual projection derived therefrom, contrast, noise level, and detectability were determined and compared with the ideal projection, that is, as if a gamma camera were located at the position of the X-ray detector. Furthermore, image deformations and spatial resolution were quantified. Additionally, simultaneous fluoroscopic and nuclear images of a sphere phantom were acquired with a physical prototype system and compared with the simulations. RESULTS For small hot spots, contrast is comparable for all simulated collimators. Noise levels are, however, 3 to 8 times higher in pinhole geometries than in parallel hole geometries. This results in higher contrast-to-noise ratios for parallel hole geometries. Smaller spheres can thus be detected with parallel hole collimators than with pinhole collimators (17 mm vs 28 mm). Pinhole geometries show larger image deformations than parallel hole geometries. Spatial resolution varied between 1.25 cm for the 3 mm pinhole and 4 cm for the LEAP collimator. The simulation method was successfully validated by the experiments with the physical prototype. CONCLUSION A real-time hybrid fluoroscopic and nuclear imaging device is currently being developed. Image quality of nuclear images obtained with different collimators was compared in terms of contrast, noise, and detectability. Parallel hole collimators showed lower noise and better detectability than pinhole collimators.
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Affiliation(s)
- Sandra van der Velden
- Radiology and Nuclear Medicine, UMC Utrecht, 85500, 3508 GA, Utrecht, Netherlands.,Image Sciences Institute, UMC Utrecht, 85500, 3508 GA, Utrecht, Netherlands
| | - Casper Beijst
- Radiology and Nuclear Medicine, UMC Utrecht, 85500, 3508 GA, Utrecht, Netherlands.,Image Sciences Institute, UMC Utrecht, 85500, 3508 GA, Utrecht, Netherlands
| | - Max A Viergever
- Image Sciences Institute, UMC Utrecht, 85500, 3508 GA, Utrecht, Netherlands
| | - Hugo W A M de Jong
- Radiology and Nuclear Medicine, UMC Utrecht, 85500, 3508 GA, Utrecht, Netherlands
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97
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Kendi AT, Moncayo VM, Nye JA, Galt JR, Halkar R, Schuster DM. Radionuclide Therapies in Molecular Imaging and Precision Medicine. PET Clin 2017; 12:93-103. [DOI: 10.1016/j.cpet.2016.08.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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98
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Siman W, Mawlawi OR, Mikell JK, Mourtada F, Kappadath SC. Effects of image noise, respiratory motion, and motion compensation on 3D activity quantification in count-limited PET images. Phys Med Biol 2016; 62:448-464. [DOI: 10.1088/1361-6560/aa5088] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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99
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Gear JI, Cummings C, Craig AJ, Divoli A, Long CDC, Tapner M, Flux GD. Abdo-Man: a 3D-printed anthropomorphic phantom for validating quantitative SIRT. EJNMMI Phys 2016; 3:17. [PMID: 27495914 PMCID: PMC4975728 DOI: 10.1186/s40658-016-0151-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 07/26/2016] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The use of selective internal radiation therapy (SIRT) is rapidly increasing, and the need for quantification and dosimetry is becoming more widespread to facilitate treatment planning and verification. The aim of this project was to develop an anthropomorphic phantom that can be used as a validation tool for post-SIRT imaging and its application to dosimetry. METHOD The phantom design was based on anatomical data obtained from a T1-weighted volume-interpolated breath-hold examination (VIBE) on a Siemens Aera 1.5 T MRI scanner. The liver, lungs and abdominal trunk were segmented using the Hermes image processing workstation. Organ volumes were then uploaded to the Delft Visualization and Image processing Development Environment for smoothing and surface rendering. Triangular meshes defining the iso-surfaces were saved as stereo lithography (STL) files and imported into the Autodesk® Meshmixer software. Organ volumes were subtracted from the abdomen and a removable base designed to allow access to the liver cavity. Connection points for placing lesion inserts and filling holes were also included. The phantom was manufactured using a Stratasys Connex3 PolyJet 3D printer. The printer uses stereolithography technology combined with ink jet printing. Print material is a solid acrylic plastic, with similar properties to polymethylmethacrylate (PMMA). RESULTS Measured Hounsfield units and calculated attenuation coefficients of the material were shown to also be similar to PMMA. Total print time for the phantom was approximately 5 days. Initial scans of the phantom have been performed with Y-90 bremsstrahlung SPECT/CT, Y-90 PET/CT and Tc-99m SPECT/CT. The CT component of these images compared well with the original anatomical reference, and measurements of volume agreed to within 9 %. Quantitative analysis of the phantom was performed using all three imaging techniques. Lesion and normal liver absorbed doses were calculated from the quantitative images in three dimensions using the local deposition method. CONCLUSIONS 3D printing is a flexible and cost-efficient technology for manufacture of anthropomorphic phantom. Application of such phantoms will enable quantitative imaging and dosimetry methodologies to be evaluated, which with optimisation could help improve outcome for patients.
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Affiliation(s)
- Jonathan I Gear
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey, UK.
| | - Craig Cummings
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey, UK
| | - Allison J Craig
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey, UK
| | - Antigoni Divoli
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey, UK
| | - Clive D C Long
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey, UK
| | - Michael Tapner
- Research and Development, Sirtex, North Sydney, Australia
| | - Glenn D Flux
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey, UK
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100
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Pasciak AS, Lin A, Georgiades C, Findeiss LK, Kauffman S, Bradley YC. Computational simulation of the predicted dosimetric impact of adjuvant yttrium-90 PET/CT-guided percutaneous ablation following radioembolization. EJNMMI Res 2016; 6:89. [PMID: 27957721 PMCID: PMC5153383 DOI: 10.1186/s13550-016-0244-1] [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: 10/26/2016] [Accepted: 11/29/2016] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND 90Y PET/CT post-radioembolization imaging has demonstrated that the distribution of 90Y in a tumor can be non-uniform. Using computational modeling, we predicted the dosimetric impact of post-treatment 90Y PET/CT-guided percutaneous ablation of the portions of a tumor receiving the lowest absorbed dose. A cohort of fourteen patients with non-resectable liver cancer previously treated using 90Y radioembolization were included in this retrospective study. Each patient exhibited potentially under-treated areas of tumor following treatment based on quantitative 90Y PET/CT. 90Y PET/CT was used to guide electrode placement for simulated adjuvant radiofrequency ablation in areas of tumor receiving the lowest dose. The finite element method was used to solve Penne's bioheat transport equation, coupled with the Arrhenius thermal cell-death model to determine 3D thermal ablation zones. Tumor and unablated tumor absorbed-dose metrics (average dose, D50, D70, D90, V100) following ablation were compared, where D70 is the minimum dose to 70% of tumor and V100 is the fractional tumor volume receiving more than 100 Gy. RESULTS Compared to radioembolization alone, 90Y radioembolization with adjuvant ablation was associated with predicted increases in all tumor dose metrics evaluated. The mean average absorbed dose increased by 11.2 ± 6.9 Gy. Increases in D50, D70, and D90 were 11.0 ± 6.9 Gy, 13.3 ± 10.9 Gy, and 11.8 ± 10.8 Gy, respectively. The mean increase in V100 was 7.2 ± 4.2%. All changes were statistically significant (P < 0.01). A negative correlation between pre-ablation tumor volume and D50, average dose, and V100 was identified (ρ < - 0.5, P < 0.05) suggesting that adjuvant radiofrequency ablation may be less beneficial to patients with large tumor burdens. CONCLUSIONS This study has demonstrated that adjuvant 90Y PET/CT-guided radiofrequency ablation may improve tumor absorbed-dose metrics. These data may justify a prospective clinical trial to further evaluate this hybrid approach.
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Affiliation(s)
- Alexander S Pasciak
- Department of Radiology, University of Tennessee Graduate School of Medicine, Knoxville, TN, USA.
- School of Medicine, The Johns Hopkins Hospital, 733 N Broadway, Baltimore, MD, 21205, USA.
| | - Abigail Lin
- School of Medicine, The Johns Hopkins Hospital, 733 N Broadway, Baltimore, MD, 21205, USA
| | | | - Laura K Findeiss
- Department of Radiology, University of Tennessee Graduate School of Medicine, Knoxville, TN, USA
| | | | - Yong C Bradley
- Department of Radiology, University of Tennessee Graduate School of Medicine, Knoxville, TN, USA
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