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Iodine is needed to maintain health
Published in Tatsuo Kaiho, Iodine Made Simple, 2017
Typical radioactive iodine isotopes include iodine 123, iodine 125, and iodine 131 (see the table). There are 15 radioactive iodine drugs, constituting one-third of all radioactive drugs. Iodine 123 has a half-life (13.2 hours) and γ ray (159 keV) energy suitable for diagnostic imaging. Iodine 123 is used for 12 diagnostic radiopharmaceuticals including ioflupane [123I]. Iodine 125 has a long half-life of 59.4 days and emits weak γ ray energy (27.5 keV), and is suitable for radiation treatment. For example, an iodine 125 seed (125I encapsulated in a 5 mm long, 1 mm diameter titanium capsule) is sold commercially. It is embedded into the focus of a prostate cancer patient using a dedicated needle.
Examples of Accelerators
Published in Volker Ziemann, ®, 2019
Whereas Synchrotrons and larger cyclotrons are used to treat patients, smaller cyclotrons are used to create radionuclides that are used both for diagnostics and for patient treatment. The latter is based on implanting radioactive material in the tumor. This treatment method, called brachytherapy, uses iodine 125I, 103Pd, 106Ru, and a number of other radio-isotopes. For diagnostic purposes, radioactive isotopes, such as 123I, can replace the stable isotope 127I and are used as tracers for metabolic pathways. 123I decays with the emission of a very hard photon with energy 159 keV that is detected in Single PhotonEmission Computed Tomography (SPECT) cameras. They allow us to reconstruct the location where the isotope decays. Using isotopes that decay by emitting a positron, allows us to detect photons created in the annihilation of the positrons with nearby electrons. Two photons with an energy of E=511keV, equal to the electron’s rest mass, are emitted back-to-back and from recording them in coincidence, the locus of the decay can be determined. This method is called Positron emission tomography (PET). The needed isotopes are created in small cyclotrons, typically producing protons with energies between 7 and 70 MeV. Nowadays the Penning ion sources [13.2.2] in the center of the cyclotrons are optimized to produce H− ions and the cyclotron accelerates them. Once they reach their maximum energy, a stripper foil [13.3] converts the H− ions to protons that are deflected in the opposite direction and easily extracted and guided to the target. The target material and beam energy determine the type of radioactive isotope generated in the process. The high demand for radionuclides caused more than 1000 of these small cyclotrons to be built and operate world-wide [118].
Radar reflector guided axillary surgery in node positive breast cancer patients
Published in Expert Review of Medical Devices, 2022
Joshua A. Feinberg, Deborah Axelrod, Amber Guth, Leonel Maldonado, Farbod Darvishian, Nakisa Pourkey, Jenny Goodgal, Freya Schnabel
We demonstrated a 100% success rate for localization and retrieval of preoperatively biopsied axillary nodes using radar reflector guidance, with no associated adverse events. Excision of the RRL node resulted in a refined surgical approach with fewer axillary lymph nodes removed. In the setting of upfront surgery, the median number of lymph nodes removed in patients who underwent preoperative reflector placement versus those who did not was 7 and 15, respectively. Of the 10 patients who were treated with NAC, 5 patients achieved an axillary pCR and were spared a cALND. Among the entire cohort, RRL resulted in a 53% reduction in the number of lymph nodes removed. Radar reflectors were placed an average of 39 days prior to surgery, which is longer than the median of 8 days reported by Sun et al. in their study evaluating RRL for TAD after NAC [18]. The longer duration from reflector placement to surgery provides patients with scheduling flexibility and does not appear to impact the ability to successfully localize and retrieve the clipped node. Uncoupling of reflector placement time and retrieval presents one advantage over the Iodine-125 radioactive seed localizer, which must be placed 5–7 days preoperatively due to decay in signal over time [10].
Efficient removal of iodine-131 from radioactive waste by nanomaterials
Published in Instrumentation Science & Technology, 2021
The uses in scientific, industrial and medical areas of radioactive materials, also known as radionuclides is increasing day by day for research, development, and innovation.[1] These materials emit alpha (α), beta (β) and gamma (γ) radiation with high energies that are harmful for humans, animals and plants. Since many radionuclides, such as Y-90, iodine-125, iodine-131, Sr-89, Ir-192, Co-60 and Cs-137, are used for diagnosis and treatment in medicine, it is necessary to manage and store radioactive waste safely and economically in a hospital.[2] In addition, the storage of radioactive wastewater in medical applications has become a serious environmental problem due to their long-term radiological and chemical toxicity.
Prostate cancer high dose-rate brachytherapy: review of evidence and current perspectives
Published in Expert Review of Medical Devices, 2018
Sunil W. Dutta, Clayton E. Alonso, Bruce Libby, Timothy N. Showalter
Brachytherapy can be delivered at a LDR or high dose-rate (HDR). For prostate brachytherapy, LDR typically refers to permanent seed implantation, usually with iodine-125, palladium-103, or cesium-131 [13]. HDR brachytherapy for prostate cancer refers to temporary implants, usually with iridium-192 [14]. This article aims to review the medical literature regarding the clinical application of HDR brachytherapy for prostate cancer. Since HDR brachytherapy has the potential to improve urinary outcomes compared to LDR brachytherapy, based upon the ability to reduce urethral doses through volume-based optimization of dwell times, it is particularly promising as a brachytherapy boost strategy to reduce the rates of adverse urinary effects as observed in the ASCENDE-RT trial.