Radioactive Decay: intro to pharm

Radioactivity is relevant in both

therapeutics and diagnostics

all smoke detectors contain _________________ in small amounts

americium- 241

nuclear pharmacy can document an organ’s ____________________ and _________________

structure and function

when and where was the first radiopharmacy lab set up?

chicago 1950

energy in the form of particles or electromagnetic waves

radiation

radiation with sufficient energy to remove an electron from an atom or molecule

ionizing radiation

First radiopharmacy lab set up in _______________ in 1950s

• __________ set up a radiopharmacy in 1958

• First monographs for USP radiopharmaceuticals prepared by Dr. Christian from ___________University in 1950s

• Centralized nuclear hospital pharmacies set up in __________________

• First MS degree in Radiopharmacy established at _______ in 1968

• Section on Nuclear Pharmacy established at APhA in __________

• chiacago

• NIH

• Purdue

• 1969

• US

• 1975

The process by which unstable atoms spontaneously transform to new

atoms* and in the process emit radiation

• The new atom may be the same atom in a _____________energy state

radioactivity

lower

Alpha Decay:

_____________ Nucleus —- very massive and __________ ionized

Only a hazard via ingestion or ______________ of alpha emitter

Is it usually an external radiation hazard?

How can it be stopped?

• Helium, doubly

• inhalation

• NO

• stopped by paper and dead layer of skin

Uranium, Therium, and Radon

are examples of which type of decay?

Alpha decay

In alpha decay what happens to the atomic number? what happens to mass?

take out helium from atom (subtract 2 from atomic number and 4 from mass) to get NEW element

Beta Decay:

energetic electron —_____________ ionized

external hazard to _____ and ______

internal hazard via ______________ and ___________of beta emitter

a 1 MeV beta aan travel up to 12 ft in air and 1 cm in plastic

• singly

• eyes and skin

• inhalation and ingestion

Phosphorus, Tritium, Carbon, Sulfur

are examples of which type of decay

beta

for beta decay what happens to the atomic number and mass?

take away an electron so add 1 to the atomic number

DONT CHANGE MASS

Gamma Decay:

• _____ and ____________ are photons which means they have no charge

• external radiation hazard to _______ and __________

• internal hazard via ingestion or inhalation of gamma emitter

• ____________ is good for shielding X and gamma rays because it has __________ electron density

• ___________125 gamma rays (30 keV) can be easily stopped with 1/8 inch of ________

• x-ray and gamma

• deep organs and tissues

• LEAD high

• IODINE stopped with lead

How do gamma rays impact mass and atomic number?

NO CHANGE to mass or atomic number

____________ shieliding material depends on the energy of ________

neutrons

list in order of most dangerous to least dangerous

gamma (most) —beta —- alpha (least)

what can you use to block each particle

• alpha = paper

• beta = plastic

• gamma = lead

_______________used to detect ionizing radiation, usually beta particles and gamma rays, but certain models can detect alpha particles.

Geiger Muller Counter

• batter check

• range seletion

• nal pronbe

• GM pancake probe

• Typical background of 0.03 mR/hr or 100cpm

Geiger Muller Counter

what do we have THE MOST radiation exposure of

what type of particle is it?

Radon = alpha

in the united states radiation absorbed dose, effective dose, and exposure are measured and atated in units called

rad, rem, roetgen

What is the highest source of radiation that is man-made?

medical xrays

what are different biological effects of exposure to ionizing radiation ?

1. somatic

2. genetic

3. teratogenic

what are some prompt vs delayed somatic effects of radiation exposure

prompt = skin burns + cataracts

how can radiation damage cancer cells?

produce free radicals that can damage DNA

How can you protect yourself from radiation as a pharmacist?

• minimize TIME

• DISTANCE: double distance = decrease exposure by factor of 4

• SHIELDING:

  • gamma = lead, water, or concrete

  • beta = thick plastic (lucite)

Radiation levels decrease as the =INVERSE SQUARE of the __________

distance

what is true about the atomic mass, nuclear charge, and mass of isotopes?

• same atomic mass (protons)

• same nuclear charge

• DIFFERENT MASS

radioisotopes are unstable and undergo radioactive transformations also known as

radionuclides

a drug made with a ______________ is a radiopharmaceutical

radionucleotide

What was the first radionuclide used as a pharmaceutical?

radium

who regulates radiopharmaceuticals used for diagnostics and therapeutics?

• FDA

• Nuclear Regulatory Commission (NRC)

• State Board of Pharmacy

Do all radioisotopes (nuclides) have high half lives?

NO they can range from seconds to years

rate of disintegration (-dN/dt) =

-dN / dt = yN

y= decay constant fraction disentegrating per unit of time

N= # of decomposed atoms and time

how can you find the rate of radioactive decay

N= N0e^-yt

^{N0 = # of original atoms when t=0}

half life equation for radioactive decay

t_{1/2 = 0.693 / y or ln2/k}

_{y= rate of disintegration}

what is the scientific vs system international unit for radioactivity? which is used in pharmacy?

scientific = curie

SI = becquerel (USED IN PHARMACY)

how many micro Curies are in one MBq?

27 micro curies = 1 MBq

the following is a graph of ____________vs time (in half-lives)

percent initial activity (how much isotope left) vs time

the folllwing is a graph of ____________ vs________________

log (initial activity) / time

log of the concentration of radionuclide / time

chemical compounds containing elements of HIGH atomic number which will stop the passage of X rays

radioisotope contrast medium

many radioactive contrast media contain

barium or iodine

______________is the agent of choice for imaging the GI tract

barium sulfate

why is barium sulfate a good agent for imaging the GI tract? what problems arise?

barium sulfate is INSOLUBLE in acidic gastric juices

side effect = constipation

The USP 27-NF 22 lists _______ official radioactiive pharmaceuticals

70

The most commonly used radiopharmaceuticals are

1. technetium

2. strontium

3. ytrium

4. Thallous Chloride

5. Gallium Citrate

6. Sodium Iodide

Sodium Iodide - 123

• _______ capsule and better than I-131 as it delivers _______ radiation and better __________ __________

• used to diagnose and treat ____________ function

• emits only _________ rays

• all drugs that can interfere with _____________ uptake of radionuclide should be withheld prior to I-123 use

• oral lower image quality

• thyroid

• gamma (photon)

• thryoid

Iodine- 131:

• not as good as ____________ BUT

• it is used in diagnostic procedures involving the ________ and also for the treatment of ___________ disorders

• can be administered in __________ or ____________ form

• requires special precautions to be implemented during administration

• sodium iodide - 123

• thyroid thyroid

• solid capsule of liquid solution

Technetium - 99m

• relatively short half life of ____________

• offers an abundance of ___________ ________ for imaging without the hazard of ______ particles

• can be used as a __________ agent for several pharmaceuticals used for imaging

• kits are available to prepare Tc-99m compounds that assist in ___________ imagining (mebrofenin) and ___________ _______ ___________ (sestamibi- cadiolite”, tetrofosmin)

• potential use to label ___________ antibodies

• is it easy to obtain and inexpensive or hard to obtain and expensive?

• 6 hours

• gamma photons beta

• binding

• hepatobiliary ischemic heart disease

• monoclonal

• easy + inexpensive!

Tc- 99m labeled radiopharmaceuticals are easily produced by simply adding _________ to many choices of “cold kits”

TcO4 - 99m

___________ is added to a vial containing a chemical compound that bind to the ___________. The result is a radipharmaceitical which will be taken up in the designated organ for imaging (or analysis) with a _______ camera

• TcO4- 99m

• radionuclide

• gamma

Strontium -89 Chloride (Metastron):

• sterile, non-pyrogenic aqueous solution for ____ use and contains NO preservatives

• decays _________ emission with half life of 51 days

• _______ emission is very harmful to ___________ tissue

• used exclusively for ________ scans (tumors, and metastatic lesions)

• acts like _________ analogs (clears rapidly from bloodstream and selectively localizes in ______ mineral)

• TOXIC: CANT GIVE TO PATIENTS WITH PLATELET COUNTS BELOW __________ and WHITE BLOOD CELL COUNTS BELOW ____________

• IV

• beta

• beta skeletal

• bone

• calcium bone

• RBC = below 60,000 WBC= below 2,400

what does each do (key points only)

1. Sodium Iodide- 123

2. Technetium- 99m

3. Strontium-89 chloride

4. Yttrium- 90

5. Thallous - 201 Chloride

6. Gallium -67 Citrate

1. thyroid

2. bind to nuclide for imaging/ gamma photon w/o beta hazard (hepatobiliary imaging + ischemic heart disease)

3. bone

4. bind to glass microspheres + target liver

5. visualize the difference between ischemic and infarcted heart tissues

6. AIDS, hodgkin’s disease, lymphomas, bronchogenic carcinoma

which radiopharmaceutical : thyroid

sodium iodine - 123 (better alternative)

iodine-131

which radiopharmaceutical: bind to nuclide for imaging/ gamma photon w/o beta hazard (hepatobiliary imaging + ischemic heart disease)

Technetium- 99m

which radiopharmaceutical: bone

Strontium-89 chloride

which radiopharmaceutical: bind to glass microspheres + target liver

Yttrium- 90

which pharmaceutical: visualize the difference between ischemic and infarcted heart tissues

Thallous - 201 Chloride

which pharmaceutical: AIDS, hodgkin’s disease, lymphomas, bronchogenic carcinoma

Gallium -67 Citrate

Yttrium- 90:

• a trivalent radioactive metal, pure _______ emitting radionuclide

• half-life of 2.8 days

• application is in _________________________(RIT) of solid large _______ and _________

• TheraSphere are insoluble glass microspheres that are used for hepatocellular carcinoma and BOND TO ______ and target ______________

• when injected these stay localized in the _____ and minimize the side effects of the radionuclide

• the Y-90 decays to form stable _________-90

• beta

• radioimmunotherapy tumors and lymphomas

• bind to yttrium target liver

• liver

• zirconium

Thallus-201 Chloride

• Sterile, nonpyrogenic solution for ____

• Half-life of 73.1 hours

• the ______________ analog undergoes rapid transport to the myocardium —useful for visualization of __________________________ ___________ or _______ _______ ________ (helpful in differentiating between the two)

• IV

• potassium

• myocardial infarction or ischemic heart disease

Gallium - 67 Citrate

• sterile pyrogen-free from aqueous solution

• drug behaves like the _____ ion and has a half-life of 78 hours

• can localize in variable primary and metastatic tumors and in focal sites of infection

• Useful in __________ , ________, and __________ carcinoma

• used for diagnosis and monitoring of “fever of __________ origin” and for Pneumocystis carinii pneumonia of _______

• Disadvantage: considerable biological variation occurs in patients

• ferric

• hodgkin’s disease, lymphomas, and bronchogenic

• undetermined AIDS

the production of other radionuclides for nuclear medicine (PET) involves the use of a

CYCLOTRON

following administration of the radiopharmaceutical to the patient, a __________ camera is used to image the area of interest

gamma

how are physicians able to check how the radiopharmaceutical distributes itself throughout the body or if it has been taken up by specifically targeted organs

GAMMA CAMERAS

do gamma cameras produce still or dynamic images?

BOTH

which type of camera looks at a patient from many different and is able to demonstrate very precise detail within the patient ?

Single Photon Emission Computed Tomography (SPECT)

• information is presented as a series of planes that coorespond to certain depths within the body

• the planes presented may be a series of cornal, sagittal, transveres and or oblique slices

which type of imaging?

SPECT (single photon emission computed tomography)

Positron Emission Tomography can be used to map ….

• _______ flow and volume

• __________ , __________, ____________metabolism

• __________ ______________

• __________ and ________receptor density

• ___________ gene expression

• pH

• _______________ ____________ transport

1. blood

2. oxygen, glucose, fatty acids

3. bone remodeling

4. tumor and neuroreceptor

5. reporter

6. amino acid transport

what is an extremely sensitive technique to image body chemistry and study physiological and biochemical processes within the body

PET (positron emission tomography)

radionuclides which undergo _________ decay usually have very SHORT half lives

positron

PET ______________ are now adjacent to pharamacies

they can be used in ___________ distribution evaluations and one can check if a drug reaches a specific receptor site

longer lived radionuclides are being investigated as radiolabels for __________ antibody based PET

uses in cancer as well as ____________ disorders

cyclotrons

pharmacokinetics

monoclonal

cardiovascular

For any worker who usually works in a controlled area, and

may receive a significant dose from occupational exposure,

_____________________ ______________________ shall be undertaken where appropriate,

adequate and feasible.

individual monitoring

Thermoiluminescent (TLD) or Optically Stimulated Luminescene (OSL) dosimeters are used to detect what types of radiation?

gamma, X, and beta radiation

a film dosimeter can detect

gamma, X, and beta radiation

• film badge

• electronic dosimeter w or w/o alarm (TLD or OSL)

• ring badge

are all forms of

personal monitoring

Assessing Doses for Internal Radiation

• ______________

• whole body monitor: ________ emitting radioisotopes

• thyroid monitoring: ________ radioisotipes

• urinalysis

• gamma

• iodine

employers and liscensees shall maintain _____________ ______________ for each monitored worker

records are to be maintain as required by the ____________ _____________

is this information confidential or is it shared?

who has access to records?

• exposure records

• regulatory body

• CONFIDENTIAL

• worker, employer, regulatory body, health surveillance professionals