Thyroid radionuclide imaging and therapy in thyroid cancer
Demetrius Pertsemlidis, William B. Inabnet III, Michel Gagner in Endocrine Surgery, 2017
Iodine-123, with a half-life of 13.3 hours, decays with principal gamma emission of 159 keV energy, and is imaged 4 hours after oral ingestion. Iodine-123 is also used in some centers for whole body imaging of thyroid cancer. Tc-99m, with a half-life of 6.02 hours and principal gamma energy of 140 keV, is inexpensive and readily available as a starting point for other Tc-99m-based radiotracers in routine nuclear medicine imaging. Tc-99m pertechnetate, a +7 anionic form of Tc-99m combined with four oxygen atoms, has a net valence of −1 and shows biologic behavior similar to that of iodide. Following intravenous administration, it is trapped in the thyroid gland in the same manner as iodide [5]. Unlike iodide, Tc-99m pertechnetate does not undergo organification, and washes out of the thyroid gland after 30 minutes. Imaging of the thyroid gland is done usually at 20–30 minutes after injection [6].
Applications of Radioisotopes in the Diagnosis and Treatment of Thyroid Disorders
Madan Laxman Kapre in Thyroid Surgery, 2020
Historical background: The suggestion by Enrico Fermi about the potential use of radioactive isotopes of iodine-127, the naturally occurring iodine isotope, in medicine began consequently to his group's production of new radioisotopes by neutron bombardment of natural elements in 1934 [1]. The first radioactive isotope of iodine, iodine-128, was produced by Robert Evans at the Massachusetts Institute of Technology [2]. Herz et al. suggested that RAI could be used for studying the physiology of the thyroid gland and for therapy [3]. Iodine-123 was discovered by I. Pearlman at the Crocker Medical Cyclotron at Berkeley in 1949 [4]. In the mid-1940s, the U.S. Atomic Energy Commission provided a plentiful supply of I-131, and the first human subject received RAI at MIT in 1946 [2].
Monte Carlo Simulation in Nuclear Medicine
Richard L. Morin in Monte Carlo Simulation in the Radiological Sciences, 2019
With the demonstration of a correlation between radiation dose to the thyroid and thyroid cancer, the importance of performing thyroid uptakes with a minimum radiation dose to the thyroid is apparent. Iodine-123 provides an almost ideal solution; due to its short half life and limited availability, however, many laboratories still use 131I or 99mTc. Thyroid uptakes using 99mTc may be clinically indicative of thyroid condition, but experience with thyroid imaging using this radionuclide demonstrates an incomplete correlation with images produced using radioiodine, and uptake results are equally difficult to interpret. The typically low uptake (about 2%) and high background levels in the circulating blood pool complicate matters technically. Iodine-131 is still widely used but, as is well known, produces a radiation dose to the thyroid substantially greater than the other radionuclides mentioned above.
Theranostic approaches in nuclear medicine: current status and future prospects
Published in Expert Review of Medical Devices, 2020
Luca Filippi, Agostino Chiaravalloti, Orazio Schillaci, Roberto Cianni, Oreste Bagni
As previously mentioned, radioactive iodine therapy (RAI) has represented the oldest example of theranostic approach to cancer. Iodine is an essential element for thyroid production of hormones thyroxine (T4) and triiodothyronine (T3). Two iodine radioisotopes are routinely used in nuclear medicine practice. The former is iodine-123 (123I), that has a half-life of 13.22 hours and emits predominant energy of 159 keV and can be applied for obtaining high-quality pre- and post-therapeutic imaging. The latter is the already cited 131I which presents the characteristics of both a beta (β−, approximately 90% of the radiation, mean: 192 keV, mean tissue penetration: 0.4 mm) and gamma (approximately 10% of the radiation, mean: 383 keV) emitter. In 1946, the radionuclide 131I was successfully applied for the treatment of thyroid carcinoma. DTC includes malignancies originating from cells delimiting thyroid follicles with three well-studied histotypes: follicular (FTC), papillary (PTC) and Hurtle cell carcinoma (HTC) [9]. Surgery, especially total thyroidectomy, represents the first choice of treatment: in such a case, the optimal surgical approach takes into account several factors such as histology, disease extent, and the presence of lymph node involvement. It is of crucial importance of preserving the neighboring anatomical structures such as nerves and blood vessels [10].
Efficacy of arterial spin labeling magnetic resonance imaging with multiple post-labeling delays to predict postoperative cerebral hyperperfusion in carotid endarterectomy
Published in Neurological Research, 2021
Hidenori Endo, Miki Fujimura, Atsushi Saito, Toshiki Endo, Kazumasa Ootomo, Teiji Tominaga
All patients were scanned using an Infinia Hawkeye 4 (GE Healthcare, Tokyo, Japan) to evaluate pre- and postoperative CBF. We used a dual-table autoradiographic method to measure CBF and CVR [11]. The subjects received 2 doses of iodine 123 (123I)–iodoamphetamine (IMP) (111MBq each) by constant infusion for 1 minute at the beginning of and 30 minutes into SPECT, and ACZ injection 7 minutes before the second injection of IMP. Arterial blood sampling was performed 13 minutes after the first IMP administration. The CVR to ACZ was calculated as follows:
Diagnosis and management of hurthle cell carcinoma, a rare case report
Published in Acta Oto-Laryngologica Case Reports, 2020
Marlinda Adham, Ferucha Moulanda, Agnes Harahap, Krishna Pandu, Em Yunir
An ipsilateral neck lymphadenectomy is recommended for clinically/radiologically/biopsy-proven lymphadenopathy. Radioiodine scan should be done three to four months after surgery. The iodine-123 scan was a diagnostic scan to see any residual thyroid tissue. If there is residual thyroid tissue, I-131 ablation with 100 mCi should be considered, followed by a whole body scan [20].
Related Knowledge Centers
- Electron Capture
- Gamma Camera
- Gamma Ray
- Iodine
- Radioactive Decay
- Nuclear Medicine
- Single-Photon Emission Computed Tomography
- Half-Life
- Iodide
- Ion