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Dolovich MB. Radiolabeling Methods. J Aerosol Med Pulm Drug Deliv 2022; 35:227-236. [PMID: 35834639 DOI: 10.1089/jamp.2022.29067.md] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In vivo measurements of the deposition of an inhaled radiolabeled pharmaceutic have provided useful information related to the inhaler efficiency for depositing drug in the lung. A number of labeling techniques have been developed and applied to pharmaceutical aerosols delivered by pressurized metered-dose inhalers (pMDIs), dry powder inhalers (DPIs) and nebulizers; the choice of radiotracer depends on the type of imaging study being performed and the equipment used to image the lung. Preparation, validation and calibration of the radiolabeled pharmaceutical product is key to successful interpretation of the imaging study. When imaging a subject after inhalation of a radiolabeled formulation, it is the radioactivity that is detected and measured by the scanner; absolute amounts of deposited drug are inferred from the counts of radioactivity in the lung and other regions, based on the assumption that there is a 1:1 relationship between the two components-drug and radioactivity. This relationship holds true for direct-labeled PET products or for those formulations where a firm bond can be demonstrated between the drug and radiotracer for the time taken to acquire all the images. This chapter will discuss radiolabeling methods applied to therapeutic aerosols for the purpose of determining the deposition efficiency of these aerosols in the lung. The techniques apply to both in vivo studies in man and in animal models, and to some extent to in vitro models.
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Affiliation(s)
- Myrna B Dolovich
- McMaster University, Dept. Medicine, Firestone Research Aerosol Laboratory, St. Joseph's Hospital, Hamilton, Ontario, Canada
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Dotinga M, Vriens D, van Velden F, Heijmen L, Nagarajah J, Hicks R, Kapiteijn E, de Geus-Oei LF. Managing radioiodine refractory thyroid cancer: the role of dosimetry and redifferentiation on subsequent I-131 therapy. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF RADIOPHARMACEUTICAL CHEMISTRY AND BIOLOGY 2021; 64:250-264. [PMID: 32744039 DOI: 10.23736/s1824-4785.20.03264-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Poor responses to iodine-131 (I-131) therapy can relate to either low iodine uptake and retention in thyroid cancer cells or to increased radioresistance. Both mechanisms are currently termed radioactive iodine (RAI)-refractory (RAI-R) thyroid cancer but the first reflects unsuitability for I-131 therapy that can be evaluated in advance of treatment, whereas the other can only be identified post hoc. Management of both represents a considerable challenge in clinical practice as failure of I-131 therapy, the most effective treatment of metastatic thyroid cancer, is associated with a poor overall prognosis. The development of targeted therapies has shown substantial promise in the treatment of RAI-R thyroid cancer in progressive patients. Recent studies show that selective tyrosine kinase inhibitors (TKIs) targeting B-type rapidly accelerated fibrosarcoma kinase (BRAF) and mitogen-activated protein kinase (MEK) can be used as redifferentiation agents to re-induce RAI uptake, thereby (re)enabling I-131 therapy. The use of dosimetry prior- and post-TKI treatment can assist in quantifying RAI uptake and improve identification of patients that will benefit from I-131 therapy. It also potentially offers the prospect of calculating individualized therapeutic administered activities to enhance efficacy and limit toxicity. In this review, we present an overview of the regulation of RAI uptake and clinically investigated redifferentiation agents, both reimbursed and in experimental setting, that induce renewed RAI uptake. We describe the role of dosimetry in redifferentiation and subsequent I-131 therapy in RAI-R thyroid cancer, explain different dosimetry approaches and discuss limitations and considerations in the field.
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Affiliation(s)
- Maaike Dotinga
- Section of Nuclear Medicine, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands -
| | - Dennis Vriens
- Section of Nuclear Medicine, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Floris van Velden
- Section of Nuclear Medicine, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Linda Heijmen
- Section of Nuclear Medicine, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - James Nagarajah
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Nuclear Medicine, Technical University Munich, Munich, Germany
| | - Rodney Hicks
- Department of Molecular Imaging, Peter MacCallum Cancer Center, Melbourne, VIC, Australia
| | - Ellen Kapiteijn
- Department of Medical Oncology, Leiden University Medical Center, Leiden, the Netherlands
| | - Lioe-Fee de Geus-Oei
- Section of Nuclear Medicine, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.,Biomedical Photonic Imaging Group, University of Twente, Enschede, the Netherlands
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Toward Individualized Voxel-Level Dosimetry for Radiopharmaceutical Therapy. Int J Radiat Oncol Biol Phys 2021; 109:902-904. [PMID: 33610302 PMCID: PMC10081021 DOI: 10.1016/j.ijrobp.2020.08.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/03/2020] [Accepted: 08/06/2020] [Indexed: 11/21/2022]
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Mariani G, Tonacchera M, Grosso M, Orsolini F, Vitti P, Strauss HW. The Role of Nuclear Medicine in the Clinical Management of Benign Thyroid Disorders, Part 1: Hyperthyroidism. J Nucl Med 2020; 62:304-312. [PMID: 33008929 DOI: 10.2967/jnumed.120.243170] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 09/02/2020] [Indexed: 12/15/2022] Open
Abstract
Benign thyroid disorders, especially hyper- and hypothyroidism, are the most prevalent endocrine disorders. The most common etiologies of hyperthyroidism are autoimmune hyperthyroidism (Graves disease, GD), toxic multinodular goiter (TMNG), and toxic thyroid adenoma (TA). Less common etiologies include destructive thyroiditis (e.g., amiodarone-induced thyroid dysfunction) and factitious hyperthyroidism. GD is caused by autoantibodies against the thyroid-stimulating hormone (TSH) receptor. TMNG and TA are caused by a somatic activating gain-of-function mutation. Typical laboratory findings in patients with hyperthyroidism are low TSH, elevated free-thyroxine and free-triiodothyronine levels, and TSH-receptor autoantibodies in patients with GD. Ultrasound imaging is used to determine the size and vascularity of the thyroid gland and the location, size, number, and characteristics of thyroid nodules. Combined with lab tests, these features constitute the first-line diagnostic approach to distinguishing different forms of hyperthyroidism. Thyroid scintigraphy with either radioiodine or 99mTc-pertechnetate is useful to characterize different forms of hyperthyroidism and provides information for planning radioiodine therapy. There are specific scintigraphic patterns for GD, TMNG, TA, and destructive thyroiditis. Scintigraphy with 99mTc-sestamibi allows differentiation of type 1 from type 2 amiodarone-induced hyperthyroidism. The radioiodine uptake test provides information for planning radioiodine therapy of hyperthyroidism. Hyperthyroidism can be treated with oral antithyroid drugs, surgical thyroidectomy, or 131I-iodide. Radioiodine therapy is generally considered after failure of treatment with antithyroid drugs, or when surgery is contraindicated or refused by the patient. In patients with TA or TMNG, the goal of radioiodine therapy is to achieve euthyroid status. In GD, the goal of radioiodine therapy is to induce hypothyroidism, a status that is readily treatable with oral thyroid hormone replacement therapy. Dosimetric estimates based on the thyroid volume to be treated and on radioiodine uptake should guide selection of the 131I-activity to be administered. Early side effects of radioiodine therapy (typically mild pain in the thyroid) can be handled by nonsteroidal antiinflammatory drugs. Delayed side effects after radioiodine therapy for hyperthyroidism are hypothyroidism and a minimal risk of radiation-induced malignancies.
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Affiliation(s)
- Giuliano Mariani
- Department of Translational Research and Advanced Technologies in Medicine and Surgery, Regional Center of Nuclear Medicine, University of Pisa, Pisa, Italy
| | - Massimo Tonacchera
- Endocrinology Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Mariano Grosso
- Regional Center of Nuclear Medicine, University Hospital of Pisa, Pisa, Italy; and
| | - Francesca Orsolini
- Endocrinology Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Paolo Vitti
- Endocrinology Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - H William Strauss
- Molecular Imaging and Therapy Service, Memorial Sloan Kettering Cancer Center, New York, New York
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Dolovich MB, Bailey DL. Positron emission tomography (PET) for assessing aerosol deposition of orally inhaled drug products. J Aerosol Med Pulm Drug Deliv 2013; 25 Suppl 1:S52-71. [PMID: 23215847 DOI: 10.1089/jamp.2012.1su6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The topical distribution of inhaled therapies in the lung can be viewed using radionuclides and imaging. Positron emission tomography (PET) is a three-dimensional functional imaging technique providing quantitatively accurate localization of the quantity and distribution of an inhaled or injected PET radiotracer in the lung. A series of transaxial slices through the lungs are obtained, comparable to an X-ray computed tomography (CT) scan. Subsequent reformatting allows coronal and sagittal images of the distribution of radioactivity to be viewed. This article describes procedures for administering [(18)F]-fluorodeoxyglucose aerosol to human subjects for the purpose of determining dose and distribution following inhalation from an aerosol drug delivery device (ADDD). The advantages of using direct-labeled PET drugs in the ADDD are discussed with reference to the literature. The methods for designing the inhalation system, determining proper radiation shielding, calibration, and validation of administered radioactivity, scanner setup, and data handling procedures are described. Obtaining an X-ray CT or radionuclide transmission scan to provide accurate geometry of the lung and also correct for tissue attenuation of the PET radiotracer is discussed. Protocols for producing accurate images, including factors that need to be incorporated into the data calibration, are described, as well as a proposed standard method for partitioning the lung into regions of interest. Alternate methods are described for more detailed assessments. Radiation dosimetry/risk calculations for the procedures are appended, as well as a sample data collection form and spreadsheet for calculations. This article should provide guidance for those interested in using PET to determine quantity and distribution of inhaled therapeutics.
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Affiliation(s)
- Myrna B Dolovich
- Faculty of Health Sciences, Michael de Groote School of Medicine, McMaster University, Hamilton, Ontario, Canada.
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Lahooti A, Shanehsazzadeh S, Jalilian AR, Tavakoli MB. Assessment of effective absorbed dose of (111)In-DTPA-Buserelin in human on the basis of biodistribution rat data. RADIATION PROTECTION DOSIMETRY 2013; 154:1-8. [PMID: 22874898 DOI: 10.1093/rpd/ncs137] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In this study, the effective absorbed dose to human organs was estimated, following intra vascular administration of (111)In-DTPA-Buserelin using biodistribution data from rats. Rats were sacrificed at exact time intervals of 0.25, 0.5, 1, 2, 4 and 24 h post injections. The Medical Internal Radiation Dose formulation was applied to extrapolate from rats to humans and to project the absorbed radiation dose for various human organs. From rat data, it was estimated that a 185-MBq injection of (111)In-DTPA-Buserelin into the human might result in an estimated absorbed dose of 24.27 mGy to the total body and the highest effective absorbed dose was in kidneys, 28.39 mSv. The promising results of this study emphasises the importance of absorbed doses in humans estimated from data on rats.
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Affiliation(s)
- Afsaneh Lahooti
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, 16 Azar Street, Tehran, Iran
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Pereira MDO, Pinto NDS, Monteiro MDOB, Santos-Filho SD, Carmo FS, Diniz CL, Marin PJ, Bernardo-Filho M. Influence of whole-body vibration on biodistribution of the radiopharmaceutical [99mTc]methylene diphosphonate in Wistar rats. Int J Radiat Biol 2012; 89:668-72. [PMID: 22849312 DOI: 10.3109/09553002.2012.715790] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE The radionuclide bone scan is the basis of skeletal nuclear medicine imaging. Bone scintigraphy is a highly sensitive method for indicating disease in bone. Mechanical stimulation in the manner of whole-body vibration (WBV) appears beneficial to the maintenance and/or enhancement of skeletal mass in individuals. The aim of this work was to evaluate the effect of WBV on the biodistribution of the radiopharmaceutical [99mTc]methylene diphosphonate (99mTc-MDP) in Wistar rats. MATERIALS AND METHODS In the biodistribution analysis, animals were anesthetized with sodium thiopental, the radiopharmaceutical (99m)Tc-MDP was administered via ocular plexus and after 10 min the animals were submitted to vibration of 20 Hz (1 min) in an oscillatory platform. Following, the animals were sacrificed, the organs were isolated, the radioactivity determined in a well counter, and the percentages of radioactivity per gram (%ATI/g) in the organs were calculated. An unpaired t-test following Welch test (p < 0.05) was done for statistical analysis of the results. RESULTS The biodistribution was significantly (p < 0.05) decreased in kidney, bone, lung, stomach, prostate and bowel. CONCLUSION The analysis of the results indicates that the vibration could produce metabolic alterations with influence in the uptake of the radiopharmaceutical 99mTc-MDP in bone, stomach, bowel, prostate, kidney and bladder.
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A radionuclide dosimetry toolkit based on material-specific Monte Carlo dose kernels. Nucl Med Commun 2009; 30:504-12. [DOI: 10.1097/mnm.0b013e3283299a11] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Aqueous extract of the medicinal plant Mentha crispa alters the biodistribution of the radiopharmaceutical sodium pertechnetate in Wistar rats. Med Chem Res 2007. [DOI: 10.1007/s00044-007-9026-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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