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Griffiths GL, Vasquez C, Escorcia F, Clanton J, Lindenberg L, Mena E, Choyke PL. Translating a radiolabeled imaging agent to the clinic. Adv Drug Deliv Rev 2022; 181:114086. [PMID: 34942275 PMCID: PMC8889912 DOI: 10.1016/j.addr.2021.114086] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 11/30/2021] [Accepted: 12/16/2021] [Indexed: 02/03/2023]
Abstract
Molecular Imaging is entering the most fruitful, exciting period in its history with many new agents under development, and several reaching the clinic in recent years. While it is unusual for just one laboratory to take an agent from initial discovery through to full clinical approval the steps along the way are important to understand for all interested participants even if one is not involved in the entire process. Here, we provide an overview of these processes beginning at discovery and preclinical validation of a new molecular imaging agent and using as an exemplar a low molecular weight disease-specific targeted positron emission tomography (PET) agent. Compared to standard drug development requirements, molecular imaging agents may benefit from a regulatory standpoint from their low mass administered doses, they nonetheless still need to go through a series of well-defined steps before they can be considered for Phase 1 human testing. After outlining the discovery and preclinical validation approaches, we will also discuss the nuances of Phase 1, Phase 2 and Phase 3 studies that may culminate in an FDA general use approval. Finally, some post-approval aspects of novel molecular imaging agents are considered.
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Affiliation(s)
- Gary L. Griffiths
- Clinical Research Directorate, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD
| | - Crystal Vasquez
- Molecular Imaging Branch, National Cancer Institute, Bethesda, MD
| | - Freddy Escorcia
- Molecular Imaging Branch, National Cancer Institute, Bethesda, MD
| | | | - Liza Lindenberg
- Molecular Imaging Branch, National Cancer Institute, Bethesda, MD
| | - Esther Mena
- Molecular Imaging Branch, National Cancer Institute, Bethesda, MD
| | - Peter L. Choyke
- Molecular Imaging Branch, National Cancer Institute, Bethesda, MD
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2
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Alfuraih AA, Alzimami K, Ma AK. Investigation of 18F and 89Zr Isotopes Self-Absorption and Dose Rate Parameters for PET Imaging. Dose Response 2021; 19:15593258211028467. [PMID: 34290574 PMCID: PMC8274111 DOI: 10.1177/15593258211028467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/16/2021] [Accepted: 06/09/2021] [Indexed: 11/15/2022] Open
Abstract
This work concerns study of self-absorption factor (SAF) and dose rate constants of zirconium-89 (89Zr) for the purpose of radiation protection in positron emission tomography (PET) and to compare them with those of 18F-deoxyglucose (18F-FDG). We analyzed the emitted energy spectra by 18F and 89Zr through anthropomorphic phantom and calculated the absorbed energy using Monte Carlo method. The dose rate constants for both radionuclides were estimated with 2 different fluence-to-effective dose conversion coefficients. Our estimated SAF value of 0.65 for 18F agreed with the recommendation of the American Association of Physicists in Medicine (AAPM). The SAF for 89Zr was in the range of 0.61-0.66 depending on the biodistribution. Using the fluence-to-effective dose conversion coefficients recommended jointly by the American National Standards Institute and the American Nuclear Society (ANSI/ANS), the dose rate at 1 m from the patient for 18F was 0.143 μSv·MBq-1·hr-1, which is consistent with the AAPM recommendation, while that for 89Zr was 0.154 μSv·MBq-1·hr-1. With the conversion coefficients currently recommended by the International Committee on Radiological Protection (ICRP), the dose rate estimates were lowered by 2.8% and 2.6% for 89Zr and 18F, respectively. Also, we observed that the AAPM derived dose is an overestimation near the patient, compared to our simulations, which can be explained by the biodistribution nature and the assumption of the point source. Thus, we proposed new radiation protection factors for 89Zr radionuclide.
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Affiliation(s)
- Abdulrahman A. Alfuraih
- Department of Radiological Sciences, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
| | - Khalid Alzimami
- Department of Radiological Sciences, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
| | - Andy K. Ma
- School of Medicine, Royal College of Surgeons in Ireland-Bahrain, Adliya, Bahrain
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Hermansen JS, Fonslet J, Søndergaard LR. Technical Note: DoseMapper: A validated GUI-based exact numerical modeling method of shielding in PET/CT facilities. Med Phys 2017; 44:6053-6060. [DOI: 10.1002/mp.12536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 08/16/2017] [Accepted: 08/16/2017] [Indexed: 11/11/2022] Open
Affiliation(s)
- Jonas S. Hermansen
- Department of Clinical Physiology and Nuclear Medicine; Herlev University Hospital; Herlev Denmark
| | - Jesper Fonslet
- Department of Clinical Physiology and Nuclear Medicine; Herlev University Hospital; Herlev Denmark
| | - Lasse R. Søndergaard
- Department of Clinical Physiology and Nuclear Medicine; Hvidovre Hospital; Hvidovre Denmark
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Tulik P, Kowalska M, Golnik N, Budzynska A, Dziuk M. MEASUREMENTS OF THE IONISING RADIATION LEVEL AT A NUCLEAR MEDICINE FACILITY PERFORMING PET/CT EXAMINATIONS. RADIATION PROTECTION DOSIMETRY 2017; 174:501-509. [PMID: 27542812 DOI: 10.1093/rpd/ncw228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 07/06/2016] [Indexed: 06/06/2023]
Abstract
This paper presents the results of radiation level measurements at workplaces in a nuclear medicine facility performing PET/CT examinations. This study meticulously determines the staff radiation exposure in a PET/CT facility by tracking the path of patient movement. The measurements of the instantaneous radiation exposure were performed using an electronic radiometer with a proportional counter that was equipped with the option of recording the results on line. The measurements allowed for visualisation of the staff's instantaneous exposure caused by a patient walking through the department after the administration of 18F-FDG. An estimation of low doses associated with each working step and the exposure during a routine day in the department was possible. The measurements were completed by determining the average radiation level using highly sensitive thermoluminescent detectors.
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Affiliation(s)
- P Tulik
- Institute of Metrology and Biomedical Engineering, Faculty of Mechatronics, Warsaw University of Technology, Warsaw, Poland
- Present address: Andrzeja Boboli 8, 02-525 Warsaw, Poland
| | - M Kowalska
- The Institute of Radioelectronics, Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw, Poland
| | - N Golnik
- Institute of Metrology and Biomedical Engineering, Faculty of Mechatronics, Warsaw University of Technology, Warsaw, Poland
| | - A Budzynska
- Affidea MASOVIA PET-CT CENTER, Warsaw, Poland
| | - M Dziuk
- Affidea MASOVIA PET-CT CENTER, Warsaw, Poland
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5
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Nagamine S, Fujibuchi T, Umezu Y, Himuro K, Awamoto S, Tsutsui Y, Nakamura Y. Estimation of ambient dose equivalent distribution in the 18F-FDG administration room using Monte Carlo simulation. Radiol Phys Technol 2016; 10:121-128. [PMID: 27531215 DOI: 10.1007/s12194-016-0371-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 07/30/2016] [Accepted: 08/02/2016] [Indexed: 11/28/2022]
Abstract
In this study, we estimated the ambient dose equivalent rate (hereafter "dose rate") in the fluoro-2-deoxy-D-glucose (FDG) administration room in our hospital using Monte Carlo simulations, and examined the appropriate medical-personnel locations and a shielding method to reduce the dose rate during FDG injection using a lead glass shield. The line source was assumed to be the FDG feed tube and the patient a cube source. The dose rate distribution was calculated with a composite source that combines the line and cube sources. The dose rate distribution was also calculated when a lead glass shield was placed in the rear section of the lead-acrylic shield. The dose rate behind the automatic administration device decreased by 87 % with respect to that behind the lead-acrylic shield. Upon positioning a 2.8-cm-thick lead glass shield, the dose rate behind the lead-acrylic shield decreased by 67 %.
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Affiliation(s)
- Shuji Nagamine
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
| | - Toshioh Fujibuchi
- Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yoshiyuki Umezu
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Kazuhiko Himuro
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Shinichi Awamoto
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yuji Tsutsui
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yasuhiko Nakamura
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
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Perez ME, Verde JM, Montes C, Ramos JA, García S, Hernandez J. Optimization of radiation doses received by personnel in PET uptake rooms. HEALTH PHYSICS 2014; 107:S198-S201. [PMID: 25272030 DOI: 10.1097/hp.0000000000000178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Reduction of dose to exposed personnel during positron emission tomography (PET) installation usually relies on physical shielding. While the major contribution of shielding is unquestioned, it is usually the only method applied. Other methods of reduction, such as working procedure optimization, the position of the furniture, and rooms are usually disregarded in these installations. This paper presents a design and work optimization procedure used in a particular institution. The influence on the dose received by personnel due to the positioning of injection chairs, injection room configuration, and working procedures is studied. Using this optimization strategy, it is possible to reduce the technician dose due to patients by a factor of 0.59. Injection room design is much more important for optimizing the received dose than is work-flow management. The influence of the order of patient entrance on received dose was the aspect that produced the smallest variation in received doses. It is recommended that the optimization be carried out for the installation proposed in the design phase, when no additional cost is required, because the position of the doors of the injection rooms depends on the where the injection chairs are situated.
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Affiliation(s)
- Maria E Perez
- *University Hospital of Salamanca, Medical Physics Department, Paseo de San Vicente, 58-182, Salamanca, Spain
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Lo Meo S, Cicoria G, Campanella F, Mattozzi M, Panebianco AS, Marengo M. Radiation dose around a PET scanner installation: comparison of Monte Carlo simulations, analytical calculations and experimental results. Phys Med 2014; 30:448-53. [PMID: 24440536 DOI: 10.1016/j.ejmp.2013.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 12/19/2013] [Accepted: 12/20/2013] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Monte Carlo study of radiation transmission around areas surrounding a PET room. METHODS An extended population of patients administered with (18)F-FDG for PET-CT investigations was studied, collecting air kerma rate and gamma ray spectra measurements at a reference distance. An MC model of the diagnostic room was developed, including the scanner and walls with variable material and thickness. MC simulations were carried out with the widely used code GEANT4. RESULTS The model was validated by comparing simulated radiation dose values and gamma ray spectra produced by a volumetric source with experimental measurements; ambient doses in the surrounding areas were assessed for different combinations of wall materials and shielding and compared with analytical calculations, based on the AAPM Report 108. In the range 1.5-3.0 times of the product between the linear attenuation coefficient and thickness of an absorber (μ x), it was observed that the effectiveness of different combinations of shielding is roughly equivalent. An extensive tabulation of results is given in the text. CONCLUSIONS The validation tests performed showed a satisfactory agreement between the simulated and expected results. The simulated dose rates incident on, and transmitted by the walls in our model of PET scanner room, are generally in good agreement with analytical estimates performed using the AAPM Publication No. 108 method. This provides an independent confirmation of AAPM's approach. Even in this specific field of application, GEANT4 proved to be a relevant and accurate tool for dosimetry estimates, shielding evaluation and for general radiation protection use.
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Affiliation(s)
- S Lo Meo
- ENEA, Via Martiri di Monte Sole 4, I-40129 Bologna, Italy.
| | - G Cicoria
- Medical Physics Department, Malpighi - S. Orsola University Hospital, Via Massarenti 9, I-40138 Bologna, Italy
| | - F Campanella
- Ionizing Radiation Laboratory, National Institution for Insurance against Accidents at Work (INAIL), Via Fontana Candida 1, I-00040 Monte Porzio Catone, Rome, Italy
| | - M Mattozzi
- Ionizing Radiation Laboratory, National Institution for Insurance against Accidents at Work (INAIL), Via Fontana Candida 1, I-00040 Monte Porzio Catone, Rome, Italy
| | - A S Panebianco
- Ionizing Radiation Laboratory, National Institution for Insurance against Accidents at Work (INAIL), Via Fontana Candida 1, I-00040 Monte Porzio Catone, Rome, Italy
| | - M Marengo
- Medical Physics Department, Malpighi - S. Orsola University Hospital, Via Massarenti 9, I-40138 Bologna, Italy
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Alzimami KS, Ma AK. Effective dose to staff members in a positron emission tomography/CT facility using zirconium-89. Br J Radiol 2013; 86:20130318. [PMID: 23934963 DOI: 10.1259/bjr.20130318] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE Positron emission tomography (PET) using zirconium-89 ((89)Zr) is complicated by its complex decay scheme. In this study, we quantified the effective dose from (89)Zr and compared it with fluorine-18 fludeoxyglucose ((18)F-FDG). METHODS Effective dose distribution in a PET/CT facility in Riyadh was calculated by Monte Carlo simulations using MCNPX. The positron bremsstrahlung, the annihilation photons, the delayed gammas from (89)Zr and those emissions from (18)F-FDG were modelled in the simulations but low-energy characteristic X-rays were ignored. RESULTS On the basis of injected activity, the dose from (89)Zr was higher than that of (18)F-FDG. However, the dose per scan from (89)Zr became less than that from (18)F-FDG near the patient, owing to the difference in injected activities. In the corridor and control rooms, the (89)Zr dose was much higher than (18)F-FDG, owing to the difference in attenuation by the shielding materials. CONCLUSION The presence of the high-energy photons from (89)Zr-labelled immuno-PET radiopharmaceuticals causes a significantly higher effective dose than (18)F-FDG to the staff outside the patient room. Conversely, despite the low administered activity of (89)Zr, it gives rise to a comparable or even lower dose than (18)F-FDG to the staff near the patient. This interesting result raises apparently contradictory implications in the radiation protection considerations of a PET/CT facility. ADVANCES IN KNOWLEDGE To the best of our knowledge, radiation exposure to staff and public in the PET/CT unit using (89)Zr has not been investigated. The ultimate output of this study will lead to the optimal design of the facility for routine use of (89)Zr.
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Affiliation(s)
- K S Alzimami
- Department of Radiological Sciences, King Saud University, Riyadh, Saudi Arabia.
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Quinn B, Holahan B, Aime J, Humm J, St Germain J, Dauer LT. Measured dose rate constant from oncology patients administered 18F for positron emission tomography. Med Phys 2012; 39:6071-9. [PMID: 23039646 DOI: 10.1118/1.4749966] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Patient exposure rate measurements verify published patient dose rate data and characterize dose rates near 2-18-fluorodeoxyglucose ((18)F-FDG) patients. A specific dose rate constant based on patient exposure rate measurements is a convenient quantity that can be applied to the desired distance, injection activity, and time postinjection to obtain an accurate calculation of cumulative external radiation dose. This study reports exposure rates measured at various locations near positron emission tomography (PET) (18)F-FDG patients prior to PET scanning. These measurements are normalized for the amount of administered activity, measurement distance, and time postinjection and are compared with other published data. METHODS Exposure rates were measured using a calibrated ionization chamber at various body locations from 152 adult oncology patients postvoid after a mean uptake time of 76 min following injection with a mean activity of 490 MBq (18)F-FDG. Data were obtained at nine measurement locations for each patient: three near the head, four near the chest, and two near the feet. RESULTS On contact with, 30 cm superior to and 30 cm lateral to the head, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.482 (0.511), 0.135 (0.155), and 0.193 (0.223) μSv∕MBq h, respectively. On contact with, 30 cm anterior to, 30 cm lateral to and 1 m anterior to the chest, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.623 (0.709), 0.254 (0.283), 0.190 (0.218), and 0.067 (0.081) μSv∕MBq h respectively. 30 cm inferior and 30 cm lateral to the feet, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.024 (0.022) and 0.039 (0.044) μSv∕MBq h, respectively. CONCLUSIONS The measurements for this study support the use of 0.092 μSv m(2)∕MBq h as a reasonable representation of the dose rate anterior from the chest of patients immediately following injection. This value can then be reliably scaled to the desired time and distance for planning and staff dose evaluation purposes. At distances closer than 1 m, a distance-specific dose rate constant of 0.367 μSv∕MBq h at 30 cm is recommended for accurate calculations. An accurate patient-specific dose rate constant that accounts for patient-specific variables (e.g., distribution and attenuation) will allow an accurate evaluation of the dose rate from a patient injected with an isotope rather than simply utilizing a physical constant.
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Affiliation(s)
- Brian Quinn
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
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Pasciak AS, Jones AK. PShield: An exact three-dimensional numerical solution for determining optimal shielding designs for PET/CT facilities. Med Phys 2012; 39:3060-9. [DOI: 10.1118/1.4711758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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