Radioisotopes (pt1)

Radioisotopes

are unstable atoms that emit radiation during decay used for diagnostic and therapeutic purposes in medicine.

RADIOISOTOPE

They emit alpha particles, beta particles, or gamma rays during their decay process.

Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) scans.

Radioisotopes like Technetium-99m are crucial in imaging techniques such as

Technetium-99m

These help visualize organs, detect abnormalities, and diagnose conditions non-invasively.

hyperthyroidism and certain types of cancer

Radioisotopes like Iodine-131 are used in the treatment of

Iodine-131

They deliver targeted radiation to destroy diseased tissues without significant damage to surrounding healthy tissue

Technetium-99m

Radioisotopes like ____ are crucial in imaging techniques such as Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) scans

Iodine-131

Radioisotopes like ____ are used in the treatment of hyperthyroidism and certain types of cancer.

Americium-241

for uniform thickness when rolling steel and paper, determine location of oil wells

Sodium-24

Oil well studies and to located leaks in pipe lines

Iridium-192

Test integrity of boilers and aircraft parts

Uranium-235

Nuclear power plant and naval propulsion systems fuel, production of fluorescent glassware and colored wall tiles

Californium-252

Determine moisture content of soil important for road construction and building industries

Nuclear reactors, Cyclotrons, Linacs, Generator System

NUCLEAR MEDICINE SOURCES (4)

Nuclear reactors

are the primary source for producing many radioisotopes, such as Molybdenum-99 (Mo-99), which decays to produce Technetium-99m (Tc-99m), a widely used isotope in diagnostic imaging

Molybdenum-99 (Mo-99)

which decays to produce Technetium-99m (Tc-99m),

Technetium-99m (Tc-99m)

a widely used isotope in diagnostic imaging

nuclear fission reaction

Nuclear reactors produce large amounts of neutrons by sustaining a controlled ____. These neutrons are essential for converting stable isotopes into radioactive ones

uranium or molybdenum targets

Stable isotopes, such as _____, are placed in the reactor and bombarded with neutrons. This neutron bombardment induces nuclear reactions, producing radioisotopes like Mo-99.

Mo-99

NUCLEAR REACTORS

Production Process

Stable isotopes, such as uranium or molybdenum targets, are placed in the reactor and bombarded with neutrons. This neutron bombardment induces nuclear reactions, producing radioisotopes like ____

radioisotope

NUCLEAR REACTORS

Production Process

After irradiation, the targets are processed to extract the ____. For example, Mo-99 is separated and distributed to medical facilities, where it is used in generators to produce Tc-99m

Tc-99m

NUCLEAR REACTORS

Medical Applications

produced from Mo-99, is essential for Single Photon Emission Computed Tomography (SPECT) scans, which are used for imaging the heart, liver, bones, and other organs

Samarium-153 (Sm-153)

NUCLEAR REACTORS

Medical Applications

is also produced used in pain relief for bone cancer patients

Iodine-131 (I-131)

used for treating hyperthyroidism and thyroid cancer.

High Flux Reactor (HFR) in the Netherlands

One of the key suppliers of Mo-99 for global medical use

OPAL Reactor in Australia

Known for producing a variety of medical radioisotopes, including Mo-99 and Lutetium-177

National Research Universal (NRU) Reactor in Canada

Historically played a significant role in supplying Mo-99 before its shutdown in 2018.

nuclear technology

In the Philippines,  ____ is not widely developed, but the country has made some use of research reactors and has explored nuclear energy options over the years.

Philippine Research Reactor-1 (PRR-1)

was the first and only research reactor in the Philippines, located in Quezon City.

Philippine Research Reactor-1 (PRR-1)

was established primarily for training, research, and isotope production for various applications, including medical use.

1980s

The PRR-1 was shut down in the late ___ and has since been in a state of decommissioning

PRR-1 Subcritical Assembly for Training, Education, and Research (SATER)

Recent initiatives have focused on possibly refurbishing or upgrading it into a subcritical assembly for continued research and training purposes under the project ______

Bataan Nuclear Power Plant (BNPP)

This facility was constructed in the 1970s as a potential source of nuclear energy for the country.

Bataan Nuclear Power Plant (BNPP)

However, it was never activated due to safety concerns following the Chernobyl disaster, geopolitical issues, and public opposition. The plant remains intact but has not been operational.

CYCLOTRONS

s a circular particle accelerator that propels charged particles, such as protons, at high speeds in a spiral pathway.

CYCLOTRONS

This acceleration enables the particles to bombard target materials, inducing nuclear reactions that produce radioisotopes

CYCLOTRONS

consist of two hollow “D”-shaped electrodes placed in a vacuum chamber and subjected to a strong magnetic field and alternating electric fields.

CYCLOTRONS

This configuration accelerates the particles in a spiral path until they reach the required energy to collide with the target.

Cyclotron-produced isotope

are usually neutron deficient and decay by electron capture or positron emission

Iodine-123, Fluorine-18, Gallium-67, Indium-111, Thallium-201

Some common examples of cyclotron-produced isotopes include (5)

Fluorine-18 (F-18):

Widely used for Positron Emission Tomography (PET) imaging, particularly in the form of fluorodeoxyglucose (FDG), which is crucial for cancer diagnostics and metabolic studies

Carbon-11 (C-11), Nitrogen-13 (N-13), Oxygen-15 (O-15)

These are other short-lived positron emitters used in various specialized PET scans

Linear Accelerators (LINACs) in Nuclear Medicine

are machines that use electromagnetic waves to accelerate charged particles, such as electrons, to high energies in a straight line.

Linear Accelerators (LINACs) in Nuclear Medicine

These high-energy particles can be used to generate x-rays or, when directed at a target, to produce specific radioisotopes

Linear Accelerators (LINACs) in Nuclear Medicine

are primarily known for their role in external beam radiation therapy to treat cancer by precisely targeting tumors with high-energy x-rays or electron beams

Linear Accelerators (LINACs)

can be utilized to produce certain radioisotopes. This makes them valuable for diversifying the sources of medical isotopes.

Linear Accelerators (LINACs)

can be used to produce isotopes like Copper-67 (Cu-67) and Yttrium-90 (Y-90), which are beneficial for targeted radiotherapy

Copper-67 (Cu-67), Yttrium-90 (Y-90)

LINACs can be used to produce isotopes like ____ and ____, which are beneficial for targeted radiotherapy

GENERATOR SYSTEM

These are systems that allow hospitals and clinics to extract Tc-99m from parent isotope Mo-99 on-site.

GENERATOR SYSTEM

It is portable and convenient, allowing for the regular use of Tc-99m without needing direct access to a reactor.

₉₉Mo – ^99mTc Generator

most common generator

₉₉Mo – ^99mTc Generator

A radionuclide “parent” with a relatively long half-life is firmly affixed to an ion exchange column

^99mTc

The parent isotope decays to its radioactive daughter, ____, which is different element with shorter half-life.

Wet system

has a saline reservoir and a vacuum vial that draws saline across the column.

Wet system

most common in commercial radiopharmacies

Dry system

most common in imaging clinics

Dry system

a specific amount of saline in a vial is placed on the generator entry port and drawn across by a vacuum vial.

breakthrough

Uncommonly, some of the parent isotope (99Mo) or alumina is removed from the column during elution and appears in the eluate containing the daughter isotope. This is termed _____

parent isotope (⁹⁹Mo) or alumina

Uncommonly, some of the _____ is removed from the column during elution and appears in the eluate containing the daughter isotope. This is termed breakthrough

transient equilibrium

When the parent isotope has a half-life somewhat greater than that of the daughter, the equilibrium attained is said to be 

Transient Equilibrium

Parent isotope has a much longer half-life than the daughter, but equilibrium is not permanent

Secular Equilibrium

Parent isotope has a much longer half-life than the daughter, and the daughter’s activity remains constant over time.

Physical Equilibrium

Both parent and daughter isotopes have similar half-lives and activity levels remain constant

Chemical Equilibrium

Related to the balance between chemical reactions, not specific to radioactivity, but can influence isotope behavior in a system.

Radionuclide in nuclear medicine

Are short-lived isotopes that emit only gamma rays and decay by isomeric transition

isomeric transition.

Radionuclide in nuclear medicine are short-lived isotopes that emit only gamma rays and decay by

^99mTc, ^113mIn, ^81mKr, ⁸²Rb, ^87mSr, and ⁶⁸Ga

Isotopes that are available from generators include: (6)

particulate bombardment or nuclear fission

Most radioactive material that does not occur naturally can be produced by

neutron-to-proton ratio (N/Z ratio)

is the ratio of the number of neutrons (N) to the number of protons (Z) in an atomic nucleus.

neutron-to-proton ratio (N/Z ratio)

It is a key factor in determining the stability of an atom.

Physically separated

Daughter isotope must be;

____from any remaining and unchanged target nuclei

Fission isotope

are simply the daughter products of nuclear fission of uranium-235 or plutonium-239 in a reactor and represent a multitude of radioactive materials in the range of roughly half of uranium-235.

iodine-131, xenon-133, strontium-90, molybdenum- 99, and cesium-137

Fission isotope