inaya medical college (imc)image tracers by virtue of the gamma rays they emit. • this was...

DR. MOHAMMED MOSTAFA EMAM

INAYA MEDICAL COLLEGE

(IMC)RAD 243- LECTURE 2

Nuclear Medicine Treatments and Clinical Applications

Next Lectures Outlines

• Introduction to Nuclear Physics

• Physics of Radioactivity

• Radiation measurement Units

• Interaction of Radiation with Matter

• Radiation Detectors (Gas-filled and Scintillation

Detectors)

• Imaging Systems

• Applications of Nuclear Medicine Imaging in

Diagnosis and Therapy

Nuclear Medicine Treatments and Clinical Applications _ PART I2

References

• "Advancing Nuclear Medicine ThroughInnovation". Committee on State of the Scienceof Nuclear Medicine, National ResearchCouncil, USA. National Academies Press, 2007.

• K. Maher: "Basic Physics of Nuclear medicine".Wikibooks, 2006.

• W.D. Leslie, I.D. Greenberg: “NuclearMedicine”. Landes Bioscience, 2003.

• J. D. Bronzino: “The Biomedical EngineeringHandBook”. 2nd Edn., CRC Press, 2000.

• D.J. Dowsett, P.A. Kenny, R.E. Johnston: “ThePhysics of Diagnostic Imaging”. Chapman &Hall Medical, 1998.


Introduction


Definition

• Nuclear medicine is a highly multi-

disciplinary specialty that develops

and uses instrumentation and

radiopharmaceuticals to study

physiological processes and non-

invasively diagnose and treat

diseases.


Radiopharmaceuticals

A radiopharmaceutical is either;

• a radionuclide (also called radioisotope)

alone, such as iodine-131

• or a radionuclide that is attached to a

carrier molecule (a drug, protein, or

peptide)

• or particle, which when introduced into

the body by injection, swallowing, or

inhalation accumulates in the organ or

tissue of interest.Nuclear Medicine Treatments and Clinical Applications _ PART I

6

Radionuclides

• Radionuclides are chemical elements that

are radioactive.


Radionuclides

• Radionuclides are chemical elements that

are radioactive.

As we know,

• The nucleus of an unstable radionuclide becomes

stable by emitting particles, such as alpha or beta.

• The nucleus may also emit energy in the form of

electromagnetic radiation known as gamma rays.


Radionuclides

• Although radionuclides can be found in

nature, all radionuclides used in nuclear

medicine are produced in linear

accelerators, cyclotrons, or nuclear

reactors.


Radionuclides

• Although radionuclides can be found in

nature, all radionuclides used in nuclear

medicine are produced in linear

accelerators, cyclotrons, or nuclear

reactors.

• Each radionuclide has unique properties

that make it useful for certain diagnostic

and therapeutic tools.


EXTRACT

Commonly Used Radionuclides in ImagingImaging

Technique Used

Type of Emitted

Radiation

Half-LifeRadionuclide

PETPositron 20.33 minCarbon-11

PETPositron 9.97 minNitrogen-13

PETPositron 2.04 minOxygen-15

PETPositron 109.75 minFluorine-18

SPECTgamma6.02 hoursTechnetium-99m

SPECTgamma2.8 daysIndium-111

SPECTgamma13 hoursIodine-123


Commonly Used Radionuclides in Therapy

Type of Emitted

Radiation

Half-LifeRadionuclide

beta8 daysIodine-131

beta2.7 daysYttrium-90


Nuclear Medicine Scans

• In a nuclear medicine scan, a

radiopharmaceutical is administered to

the patient, and an imaging instrument

that detects radiation is used to show

biochemical changes in the body.

Nuclear Medicine Treatments and Clinical Applications _ PART I13EXTRACT

Nuclear Medicine Scans

• Nuclear medicine imaging, in contrast toimaging techniques that mainly show anatomy (e.g.,conventional ultrasound, computed tomography [CT],or magnetic resonance imaging [MRI])*, canprovide important quantitativefunctional information about normaltissues or disease conditions in livingsubjects.

* Exceptionally with the emergence of advanced(functional) MRI methods the pure anatomicalrole of these traditional imaging techniques isslowly reaching an end.


Nuclear Medicine Treatment

• For treatment, highly targeted

radiopharmaceuticals may be used to

deposit lethal radiation at tumor sites.


The Power of Nuclear Medicine

• The power of nuclear medicine in

clinical diagnosis rests with its ability

to detect altered function with great

sensitivity.


The Power of Nuclear Medicine

• The power of nuclear medicine in

clinical diagnosis rests with its ability

to detect altered function with great

sensitivity.

For this reason nuclear medicine hascontributed not only to clinical diagnosisbut, to an extent unmatched by otherimaging methods, to an understanding ofdisease mechanisms.


Research and Development (R&D)

Activities in the Nuclear Medicine Field

Toward improve disease diagnosis

• Development of new radionuclide production facilities and technologies, such as• nuclear reactors

• particle accelerators

• Development of chemical processes that synthesize new radiopharmaceuticals used • to improve understanding of how specific organs

function.

• for imaging and treatment

• Development of • imaging instruments

• enabling technologies

• multimodality imaging devices, such as PET/CT and PET/MRI


EXTRACT

Research and Development (R&D)

Activities in the Nuclear Medicine Field

Toward improve disease diagnosis

• Design and development of instruments which can

detect radiation emitted from the radionuclides that

accumulate in the human body.

• Development and use of targeted radionuclide

therapeutics that will allow cancer treatments to be

tailored for individual patients.

• Use of nuclear medicine imaging as a tool in the

discovery and development of new drugs.


EXTRACT

Current Clinical Applications of Nuclear Medicine

• Diagnosis of diseases to permit earlier initiation of treatment as well as reduced morbidity and mortality. Examples include:• cancer

• neurological disorders (e.g., Alzheimer’s and Parkinson’s diseases),

• cardiovascular disease in their initial stages

• Non-invasive assessment of therapeutic response, thus reducing patients’ exposure to the toxicity of ineffective treatments and allowing alternative treatments to be started earlier.

• Provision of molecularly targeted treatment of cancer and certain endocrine disorders (e.g., thyroid disease and neuro-endocrine tumors).


EXTRACT

Emerging Opportunities in Nuclear Medicine

• Understanding the relationship between

brain chemistry and behavior (e.g., addictive

behavior, eating disorders, depression).

• Assessment of the atherosclerotic

cardiovascular system.

• Understanding the metabolism and

pharmacology of new drugs.


EXTRACT


• Assessment of the efficacy of new drugs and other forms of treatments, thus speeding their introduction into clinical practice.

• Application of targeted radionuclide therapeutics to individualize treatment for cancer patients by tailoring the properties of the targeting vehicle and the radionuclide.

• Development of new technology platforms (e.g., integrated micro-fluidic chips and other automated screening technologies) that would accelerate and lower the cost of discovering and validating new molecular imaging probes, biomarkers, and radio-therapeutic agents.


EXTRACT


• Development of higher resolution, more sensitive imaging instruments to detect and quantify disease faster and more accurately.

• Further development and exploration of hybrid imaging instruments, such as positron emission tomography/magnetic resonance imaging (PET/MRI), to improve disease diagnosis and treatment.

• Improvement of radionuclide production, chemistry, and automation to lower the cost and increase the availability of radiopharmaceuticals by inventing a new miniaturized particle accelerator and associated technologies to produce short-lived radionuclidesfor local use in research and clinical programs.


EXTRACT

A Brief History

• Henri Becquerel discovered natural radioactivity in February 1896.

• The story was that he placed lumps of pitchblende on sealed photographic film in sunlight, with the intent of finding out if the rays of the sun induced any penetrating fluorescence in the mineral.

• By chance, on developing the film after a cloudy day he was surprised to find as much blackening of the photographic emulsion as had occurred in bright sunlight.

• He realized that the pitchblende itself was a source of the energetic rays.


A Brief History

• Later Mme. (Dr.) Marie and Dr. Pierre Curie

working in Paris described natural radioactivity

and discovered radium.

• Subsequently Mme. (Dr.) Irène Curie was to

observe the artificial induction of radioactivity.

• Rutherford, a British-educated, New Zealand

physicist working at McGill University in Montreal

went on to discover the structure of the atom.

• All won Nobel prizes—Becquerel and Curie jointly.

Next>Nuclear Medicine Treatments and Clinical Applications _ PART I

25

A stamp commemorating Becquerel’s discovery of radioactivity for which he received a Nobel Prize.

<BackNuclear Medicine Treatments and Clinical Applications _ PART I

26

A Brief History

• Another important insight came when a Hungarian scientist — George de Hevesy (a former student of Rutherford)—first used the tracer principle.

• He experimented with a plant having its roots in a water bath containing a radioactive isotope of lead.

• Hevesy was able to follow the rate of passage of the tracer through the stem of the plant with an instrument capable of detecting and measuring radioactivity.

• This use of radioactive atoms, present in minute amounts but acting as a marker of other, non-radioactive atoms came to be called the tracer principle.

• It only required that Hevesy’s insight be translated to people instead of plants, and for the tracer to be administered by injection instead of through a plant’s root system, for the power of nuclear medicine to become clear.

Next>


A stamp celebrating the anniversary of the Nobel Prize awarded to de Hevesy for the discovery of the tracer principle.

<BackNuclear Medicine Treatments and Clinical Applications _ PART I28

A Brief History

• Without a capacity to image the distribution of radiotracers in the body, the importance of nuclear medicine might be of little value.

• Dr. Benedict Cassen developed the first rectilinear scanner to image tracers by virtue of the gamma rays they emit.

• This was followed by the development of the gamma camera, able to image both static and changing distributions of radioactive tracers in the body, by Dr. Hal Anger.

• Then, Dr. David Kuhl and others went on to develop the concept of tomographic sectional imaging in nuclear medicine.

• Nuclear medicine, while beginning in the late nineteenth century, gained momentum through the twentieth.

• Medicine in the twenty-first century will continue to be fundamentally changed by the insights that nuclear medicine provides.


Comparative imaging and the Role of Nuclear Medicine

• Classical radiology had been rooted in

studies of structure.

• Another decisive advantage of nuclear

medicine is its capacity to be used in whole

body imaging.


Next Lecture

PART_II

Physics of Radioactivity

DR. MOHAMMED MOSTAFA EMAM

INAYA MEDICAL COLLEGE

(IMC)RAD 243- LECTURE 3

Nuclear Medicine Treatments and Clinical Applications (PART II)

inaya medical college (imc)image tracers by virtue of the gamma rays they emit. • this was...

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