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Transcript of PDF 8.3 Medicine
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A Look at NuclearScience and Technology
Larry Foulke
Atomic and Nuclear Physics Radioisotopes
8.3 Medical Use of Radioisotopes
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This material includes excerpts from apresentation by Alan Waltar at the World
Nuclear University in 2012-2103.
Used by permission from World Nuclear
Association and Alan Waltar.
NOTE: Dr. Waltar is the author of the book, RADIATION AND MODERN LIFE:Fulfilling Marie Curie's Dream, Prometheus Books, 2005
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Numbers of Patients
Benefiting from NuclearMedical Techniques
Over 18 million/year in the U.S. Over 30 million/year globally 1 in 3 patients entering U.S. hospitals
or medical clinics benefit from
nuclear medical techniques
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MEDICINE
Sterilization of Medical Products Surgical dressings, sutures, catheters, syringes
New Drug Testing Over 80% of all new drugs tested withradioactive tagging before approval Between 200 and 300 radiopharmaceuticals
in routine use
Medical Imaging (~90%)Diagnose the ailment
Therapy (~10%) Cure the ailment or ease the pain
Image Source: See Note 1
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Types of Medical Imaging
X-ray(teeth, broken bones, mammograms)(Diagnostics ~ 90% of nuclear procedures)
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Radiography involves the use of an X-
ray tube and a photographic plate.
The patient is placed between the twoand an image is produced on the filmof the area exposed.
A common chest X-ray is an
example of a radiographic X-ray.
Image Source: See Note 2
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Types of Medical Imaging
X-ray(teeth, broken bones, mammograms) CT (Computerized Tomography, 3D X-ray) Radiotracers
SPECT (single photon emission computerizedtomography)
PET (positron emission tomography)MRI (Magnetic Resonance Imaging)
(Diagnostics ~ 90% of nuclear procedures)
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CT Scan
Image Source: See Note 3
Image Source: See Note 4
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Radionuclides are used to determine theextent of a medical problem in a patient.
The radionuclide is attached to a
pharmaceutical, which has the properties todeposit the radioisotope in the organ ofconcern for a patient.
External radiation detectors are used to
determine abnormalities in the organ.
Image Source: See Note 5
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Different parts of the human body absorb different
elements but do not discriminate between differentisotopes.
In tracer techniques a radioactive isotope of an element,such as iodine or technecium-99m, is injected into the body.
The signals coming from the ensuing radiation then give
a picture of the size and location of the area where the
isotope was absorbed. Usually isotopes of a relatively short half-life, of the
order of minutes or days, are used to minimize long-termradiation damage.
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Image Source: See Note 6
PET (positron emission tomography)
scans involve the injection into the
body of an isotope which decays by
positron emission.
When this positron encounters an
electron they annihilate each other,
emitting two photons.
The energy and path of these photons
leaving the body can then be used to
give an accurate picture of the area
where the isotope was absorbed.
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PET (positron emission tomography)
The multitude of allthese lines of
response is used
to calculate a slice
image in a certain
plane.
When a pair of detectors detects simultaneously one 511keV
photon each, a positron must have annihilated on a straightline connecting those two detectors the so called line of
response.
Image Source: See Note 7
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PET IMAGE OF THE BRAIN
Image Source: See Note 8
oSlice of the brain of a56 year old man taken
with positron emission
tomography (PET).
o Image was generatedfrom a 20 minute
measurement with a
PET Scanner.
o Red areas show moreaccumulated tracer
substance and blue
areas are regions wherelow to no tracer have
been accumulated
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Uses gamma cameras, or multi-heads slowly rotated around the
patient.
Able to provide true 3D
information.
Information presented as cross-
sectional slices.
85% of all nuclear medicine
examinations use Mo/Tc Generators
for diagnostics of liver, lungs,
bones.
Image Source: See Note 9
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Mo-99 is the most in demand medical isotope
Mo-99 is shipped to point of use (66 hrs half life)
itsdecay product
Technetium-99m is used as
tracer (6-hour half life)
Comes easily from a handful of existing,
publicly funded nuclear research reactors Reactors are getting old and are being shut down
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Magnetic resonance imaging
generates pictures of the
arteries to evaluate them for
abnormal narrowing or
vessel wall dilatations, at risk
of rupture. MRI technology is
often used to evaluate the
arteries of the neck and
brain, the thoracic and
abdominal aorta, the renal
arteries, and the legs
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Medical Therapy
First applied to Thyroid Cancer(20,000 patients/year)Blood IrradiationOther Cancer(prostate, breast, brain, liver, etc.)
External External Beam Radiation
Protons X-rays
Internal BNCT (boron neutron capture) Cell Directed
Placed inside the body Smart bullets
Decrease pain of bone cancer
~ 10 % of nuclear procedures
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The CyberKnife or
Gamma Knife system is
a method of delivering
radiotherapy, with theintention of targeting
treatment more
accurately than standard
radiotherapy.
Image Source: See Note 11
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Production and distribution of125I seeds and 192Ir wires
BRACHYTHERAPY
Image Source: See Note 13
Image Source: See Note 12
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Take Away Points Nuclear medicine uses radiation to provide
diagnostic information about human health.
Radiotherapy can be used to treat medicalconditions, especially cancer, using radiation to
weaken or destroy particular targeted cells.
Millions of nuclear medicine procedures areperformed each year, and demand for radioisotopes
is increasing rapidly.
Medical Therapy Using Radiation Technology NowGrowing Rapidly
Materials based on RADIATION AND MODERN LIFE:Fulfilling Marie Curies Dream by Alan Waltar,
Prometheus Books, Nov. 2004Image Source: See Note 14
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1. Public domain:http://www.nrc.gov/reading-rm/doc-collections/nuregs/brochures/br0217/r1/br0217r1.pdf
2.
Creative CommonsAttribution Share-Alike 3.0 Unported. ThomasBjorkan.http://en.wikipedia.org/wiki/File:Xraymachine.JPG
3. Creative CommonsAttribution Share-Alike 3.0 Unported.rosiescancerfund.com.http://en.wikipedia.org/wiki/File:Rosies_ct_scan.jpg
4. Public domain:http://en.wikipedia.org/wiki/File:CT_ScoutView.jpg
5. Public domain:http://commons.wikimedia.org/wiki/File:PET-
Image Source Notes
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6. Public domain:http://en.wikipedia.org/wiki/File:ECAT-Exact-HR--PET-Scanner.jpg
7.
Public domain:http://en.wikipedia.org/wiki/File:PET-schema.png
8. Public domain:http://en.wikipedia.org/wiki/File:PET-image.jpg
9. Creative CommonsAttribution Share-Alike 3.0 Unported. Ytrottier.http://en.wikipedia.org/wiki/File:SPECT_CT.JPG
10.Creative CommonsAttribution Share-Alike 3.0 Unported. Ofirglazer.http://en.wikipedia.org/wiki/File:Mra1.jpg
Image Source Notes
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11. Public domain:http://en.wikipedia.org/wiki/File:Gamma_Knife_Graphic.jpg
12.Creative CommonsAttribution Share-Alike 3.0 Unported. Rock mc1.http://en.wikipedia.org/wiki/File:Clinical_applications_of_brachytherapy.jpg
13.Public domain:http://en.wikipedia.org/wiki/File:Brachytherapy.jpeg
14.Public domain:http://en.wikipedia.org/wiki/File:Marie_Curie_c1920.png
Image Source Notes