Yttrium 90 Half Life

Understanding the Yttrium-90 Half-Life: Implications in Medicine and Beyond

Yttrium-90 (⁹⁰Y) is a radioactive isotope of the element yttrium. Its most significant characteristic, and the focus of this article, is its relatively short half-life. Understanding this half-life is crucial for comprehending its applications, primarily in nuclear medicine, as well as its associated safety considerations. This article will delve into the specifics of ⁹⁰Y's half-life, explaining its meaning, implications, and practical applications.

What is Half-Life?

Radioactive decay is a spontaneous process where unstable atomic nuclei lose energy by emitting radiation. This process transforms the original atom into a different isotope or element. Half-life is the time it takes for half of the atoms in a given sample of a radioactive substance to decay. It's a crucial concept because it dictates how long a radioactive material remains hazardous and how its radioactivity diminishes over time. It's important to note that half-life is a constant; it doesn't depend on the initial amount of the substance or any external factors (excluding extreme pressures or temperatures).

The Half-Life of Yttrium-90

The half-life of yttrium-90 is approximately 64 hours, or roughly 2.67 days. This relatively short half-life is a key factor determining its suitability for certain medical procedures. After 64 hours, half of the initial ⁹⁰Y atoms will have decayed into Zirconium-90 (⁹⁰Zr), a stable, non-radioactive isotope. After another 64 hours (128 hours total), half of the remaining ⁹⁰Y will decay, leaving only one-quarter of the original amount. This exponential decay continues, with progressively smaller fractions remaining over time.

Decay Process and Radiation Emitted

Yttrium-90 undergoes beta decay. This means it emits a beta particle (a high-energy electron) and an antineutrino. Beta particles are relatively easily stopped by matter, typically requiring only a few millimeters of shielding like plastic or aluminum. This is a significant factor in its medical applications because it limits radiation exposure to surrounding healthy tissue. Crucially, ⁹⁰Y does not emit gamma radiation, which is highly penetrating. The absence of gamma emission simplifies shielding and handling procedures.

Medical Applications of Yttrium-90

The short half-life and beta emission characteristics make ⁹⁰Y ideally suited for targeted radiotherapy. It's frequently used in radioembolization, a procedure where microscopic beads containing ⁹⁰Y are injected into arteries supplying tumors, delivering radiation directly to the cancerous tissue while minimizing damage to surrounding healthy organs. This is particularly effective in treating liver cancer and other inoperable tumors. Another application is radioimmunotherapy, where ⁹⁰Y is attached to antibodies that specifically target cancer cells, delivering radiation to those cells with greater precision.

Safety Considerations

While the absence of gamma radiation simplifies shielding, the beta radiation emitted by ⁹⁰Y still poses a risk if ingested or inhaled. Appropriate handling and disposal protocols are crucial to minimize exposure. Medical personnel administering ⁹⁰Y-based treatments follow strict procedures to protect themselves and patients. The short half-life helps mitigate long-term risks, as the radioactivity decreases significantly within a few days.

Comparison with Other Radionuclides

Comparing ⁹⁰Y's half-life to other radionuclides highlights its unique properties. For instance, Iodine-131, used in thyroid cancer treatment, has a half-life of approximately 8 days. This longer half-life means it remains radioactive for a longer period. On the other hand, Technetium-99m, used in various diagnostic imaging procedures, has a much shorter half-life of about 6 hours. The choice of radionuclide for a specific application depends on factors like the desired radiation type, half-life, and the biological characteristics of the target tissue.

Summary

Yttrium-90's 64-hour half-life is a defining characteristic that dictates its applications and safety considerations. Its beta decay, coupled with the absence of gamma emission, makes it particularly valuable in targeted cancer therapies. The relatively short decay period minimizes long-term exposure risks while allowing for effective treatment. Understanding the nuances of ⁹⁰Y's half-life is fundamental for comprehending its role in modern medicine and appreciating the intricate balance between therapeutic benefit and radiation safety.

FAQs

1. What happens to the Zirconium-90 (⁹⁰Zr) produced after ⁹⁰Y decay? ⁹⁰Zr is a stable, non-radioactive isotope, posing no health risks. It's metabolically inert and is typically excreted from the body.

2. How is the radiation dose from ⁹⁰Y controlled in medical procedures? The dose is precisely calculated based on the patient's weight, tumor size, and other factors. The short half-life and targeted delivery methods ensure that most of the radiation is concentrated at the tumor site, minimizing exposure to healthy tissues.

3. Are there any long-term health risks associated with ⁹⁰Y exposure? The primary risk is associated with acute radiation exposure, particularly from ingestion or inhalation. The short half-life significantly minimizes the risk of long-term effects from low-level exposure.

4. How is ⁹⁰Y stored and transported? ⁹⁰Y, due to its short half-life, is typically stored and transported in shielded containers to minimize external radiation exposure. The transportation is regulated to ensure safety.

5. What are the alternative treatments available if ⁹⁰Y therapy is not suitable? Alternative treatments for cancer depend on the type and stage of cancer and may include surgery, chemotherapy, external beam radiation therapy, or other targeted therapies. A physician will determine the most appropriate course of action for each patient.

Search Results:

Yttrium-90 - Wikipedia Yttrium-90 is produced by the nuclear decay of strontium-90 which has a half-life of nearly 29 years and is a fission product of uranium used in nuclear reactors. As the strontium-90 decays, chemical high-purity separation is used to isolate the yttrium-90 before precipitation.

Yttrium-90 - Oncology Medical Physics Yttrium-90 (90 Y) is a beta (electron) emitter with an average energy of 0.9267 MeV and a half-life of 2.67 days. Over 90% of emitted energy is absorbed within 5.3mm and the maximum range of emitted electons is 11mm.

Yttrium-90 - (Intro to Chemistry) - Fiveable Yttrium-90 has a half-life of 64.1 hours, which makes it suitable for medical applications that require a relatively short-lived radioisotope. The beta particles emitted by yttrium-90 have a maximum energy of 2.28 MeV, which allows for deep tissue penetration and effective treatment of …

Radioactive Yttrium 90: A review of its properties, biological … Yttrium 90 has a half life of 64.2 hours. It decays to stable zirconium 90 by the emission of beta particles only, whose maximum energy is 2.25 million electron volts (MeV).

Half-Life of Yttrium-90 - NASA/ADS A series of determinations on the half-life of yttrium-90 have been made, resulting in an average value of 64.24+/-0.30 hours. Y 90 was separated from its Sr 90 mother by either a carbonate or phosphate precipitation, followed by conversion to oxalate as the final counting vehicle.

Yttrium-90 hepatic radioembolization: clinical review and current ... 90 Y is a beta emitter with a 64.2-h physical half-life, in which up to 94% of the 90 Y microspheres radiation dose can be delivered during the first 11 days following treatment, after which it decays into stable zirconium.

Theranostic Imaging of Yttrium-90 - PMC - PubMed Central (PMC) Although challenges remain for 90 Y imaging, continued clinical demand for predictive imaging response assessment and target/nontarget dosimetry will drive research and technical innovation to provide greater clinical utility of 90 Y as a theranostic agent. 1. Yttrium-90 and Its Role in Targeted Radiotherapy.

Yttrium-90 | Radiology Reference Article - Radiopaedia.org 5 Aug 2023 · Yttrium-90 (90Y) is a radioisotope derived from the decay of 90 Sr. Yttrium-90 decays due to the emission of β- particles, with a half-life of 2.67 days 5. It has no gamma energy emission, but may be imaged through the use of bremsstrahlung interactions with planar or SPECT imaging.

Phys. Rev. 97, 102 (1955) - Half-Life of Yttrium-90 A series of determinations on the half-life of yttrium-90 have been made, resulting in an average value of 64.24±0.30 hours. Y90 was separated from its Sr90 mother by either a carbonate or phosphate precipitation, followed by conversion to oxalate as the final counting vehicle.

Phys. Rev. 93, 1029 (1954) - The Half-Life of Yttrium-90 Radioactive yttrium-90 separated from two aged samples of fission product strontium was allowed to decay. The change in activity was followed for more than 650 hours with standard mica-window beta counters. From the observed changes, the mean half-life of yttrium-90 was calculated to be 64.60±0.43 hours. Received 5 November 1953

YTTRIUM-90 - mirdsoft.org YTTRIUM-90 SUMMARY DATA GENERAL CLASSIFICATION Isotope: Y-90 Atomic number (Z): 39 Mass number (A): 90 Neutron number (N): 51 RADIOACTIVE DECAY Decay modes: β- Half-life: 64.1 [h] Decay constant: 3.0038e-06 [1/s] Daughters: Zr-90 (100.0%) Radioactive daughters: None DOSIMETRIC CONSTANTS Mean alpha energy: 0.0 [MeV]

Yttrium-90 - (General Chemistry II) - Fiveable Yttrium-90 has a half-life of about 64 hours, which allows for effective treatment while minimizing prolonged exposure to radiation. The isotope emits beta radiation, which is particularly useful in targeting and destroying cancer cells without significantly affecting surrounding normal tissue.

Yttrium-90 - isotopic data and properties - ChemLin Half-life T ½ = 64.05 (5) h (hours) respectively 2.30580 × 105 seconds s. Direct parent isotope is: 90 Sr. Nuclear isomers or excited states with the activation energy in keV related to the ground state.

NHS England radiation therapy (SIRT) with ytrrium-90 … beta emitting isotope with a half-life of 64.2 hours. The emissions from 90Y have an average/maximal penetration range in tissue of 2.5 mm and 11 mm, respectively, thus limiting the

Radiation Safety Issues in Y-90 Microsphere Selective Hepatic ... Yittrium-90 is a pure beta-emitter, with a decay energy of 0.94 MeV and the average penetration depth in human tissue is 2.4 mm. In the form of microspheres, it is suitable for selective arterial injection. The physical half-life of Y-90 is 64.2 h.

Yttrium 90 - an overview | ScienceDirect Topics 3 Jan 2010 · The high energy β − particles of 90 Y are suited for treating the bigger tumors and performing radiation synovectomy of large joints. Though the half-life of 90 Y is relatively short, this problem can be solved by availing 90 Y from a 90 Sr/ 90 Y generator which yields nca 90 Y.

Yttrium Y-90 | Y | CID 104760 - PubChem 20 Nov 2024 · Exposure to yttrium-90 and yttrium-91 from radioactive fallout is not expected to be important, because of the short half-lives of these yttrium radionuclides, half-lives for yttrium-90 and -91 are 2.67 and 58.5 days, respectively, and the low concentrations of these substances in the environment. (SRC)

Yttrium-90m - isotopic data and properties - ChemLin Half-life T ½ = 3.19 (6) h (hours) respectively 1.1484 × 104 seconds s. Nuclear isomers or excited states with the activation energy in keV related to the ground state. The following table shows the atomic nuclei that are isotonic (same neutron number N = 51) and isobaric (same nucleon number A = 90) with Yttrium-90m.

Yttrium-90 (Y-90) - Advancing Nuclear Medicine The product that comes out of the reactor has a half-life of 2.66 days and it decays to the stable isotope zirconium-90. This makes it a suitable isotope for Selective Internal Radiation Therapy (SIRT).

Yttrium-90 – Spectrum | Nuclear radiation isotope library Yttrium-90 (Y-90) is a radioactive isotope of yttrium with a half-life of approximately 64.1 hours. It decays by beta emission to stable zirconium-90, releasing high-energy beta particles. Y-90 is artificially produced as a decay product of strontium-90 or through neutron irradiation of yttrium-89 in nuclear reactors.