Nuclear Medicine

1
Nuclear Medicine

• Imaging and the treatment of Cancer

2

• Gamma photons are the most energetic photons in
  the electromagnetic spectrum. Gamma rays (gamma
  photons) are emitted from the nucleus of some
  unstable (radioactive) atoms.

3
Gamma Radiation

• What are the properties of gamma radiation

• Gamma radiation is very high-energy ionizing
  radiation.
• Gamma photons have no mass and no electrical
  charge--they are pure electromagnetic energy.

4
Gamma Radiation

• Because of their high energy gamma photons
  travel at the speed of light and can cover
  hundreds to thousands of meters in air before
  spending their energy. They can pass through many
  kinds of materials including human tissue

5
Gamma Radiation

• What is the difference between gamma rays and
  x-rays
• Gamma rays and x-rays like visible infrared
  and ultraviolet light are part of the
  electromagnetic spectrum. While gamma rays and
  x-rays differ in their origin. Gamma rays
  originate in the nucleus. X-rays originate in the
  electron fields surrounding the nucleus.

6
Gamma Radiation

• How do we use gamma emitters
• The penetrating power of gamma photons has many
  applications. Gamma rays penetrate many
  materials they do not make them radioactive. The
  three radionuclides by far most useful are
  cobalt-60 and cesium-137 and technetium-99m.

7
Gamma Radiation

• Uses of Cesium-137
• cancer treatment
• Uses of Cobalt-60
• sterilize medical equipment in hospitals
• treat cancer

8
Gamma Radiation

• Uses of Technetium-99m
• TC-99m is the most widely used radioactive
  isotope for diagnostic studies. (Technetium-99m
  is a shorter half-life version of technetium-99.)
  Different chemical forms are used for brain
  bone liver spleen and kidney imaging and also
  for blood flow studies.

9
Radioactive Measurements

• 1. Competitive Binding Assays
• 2. Time Dependent Measurements
• 3. Radio Nucleotide Imaging
• Gamma Camera scintillation camera
• 4. Tomography
• SPECT imaging
• PET imaging

10
1. Competitive Binding Assays

• No radioactive substance is given to the patient
• Blood from a patient is mixed with a radioactive
  substance in the laboratory
• Radioimmunoassay
• Thyroid Hormone and Iron Binding Sites most
  common.

11
1. Competitive Binding Assays
12
2. Time Dependent Measurements

• Radioactive Tracers are to the patient
  administered.
• Allows the volume of a compartment to be measured.

13
Intravenous Pyelogram

• An Intravenous Pyelogram (IVP) is an x-ray
  examination of the kidneys ureters and urinary
  bladder.

14
Intravenous Pyelogram
15

• HIDA Scan
• This is a test done to diagnose obstruction of
  the bile ducts (for example by a gallstone or a
  tumor) disease of the gallbladder and bile
  leaks.

16
Cardiac Angiography

• Coronary angiography is performed to detect
  obstruction in the coronary arteries of the
  heart. During the procedure a catheter is
  inserted into an artery in your groin and then
  threaded carefully into the heart. The blood
  vessels of the heart are then studied by
  injection of contrast media through the catheter.
  A rapid succession of X-rays is taken to view
  blood flow.

17
(No Transcript)
18

• The arrow indicates a blockage in the right
  coronary artery.

19
(No Transcript)
20
(No Transcript)
21

• Cerebral Angiogram
• This image taken before angioplasty This patient
  had episodes of weakness leading to the
  angiogram. The angiogram shows a very narrowed
  artery supplying the right side of brain. This
  vessel is within the skull on the surface of the
  brain

22

• Cerebral angiogram taken after angioplasty The
  narrowing is less severe and the branches beyond
  the narrowing fill better

23
3. Radionucleotide Imaging

• Image is generated using radioactive decay from
  an organ
• Usually a function of time.
• Provide functional information

24
3. Radionucleotide Imaging

• Single detectors are used for thyroid studies.

25
3. Radionucleotide Imaging

• Scintillation Camera
• Shows two dimensional data
• Studies physiologic function

26

• Ventilation-Perfusion Scan of a lung looking for
  a blood clot.

27

• A bone scan is used to find bone problems such
  as cancer infections or fractures to check
  joint replacements and to find joint problems
  such as arthritis. 
• A small amount of injected radioactive matter
  (tracer) and a camera to form an image.   

• Bone scan looking for
• metastatic bone cancer.

28

• Looking for fibrous dysplasia that is a
  congenital non-hereditary skeletal disorder
• Patients are often asymptomatic. Others
  experience pain pathologic fractures and bone
  deformity

29

• Imaging of Acute Osteomyelitis in the Diabetic
  Foot
• A 65 year old male with a history of non-insulin
  dependent diabetes mellitus alcohol abuse and
  severe peripheral vascular disease presented with
  a non-healing ulcer of the left first toe.

30

• This Indium White Blood Cell Scan demonstrates
  areas of infection in the abdomen after surgery
  for colon cancer.

31
4. Tomography

• The fourth class of imaging is the tomographic
  reconstruction of body slices.
• Single-photon emission computer tomography -
  SPECT scan
• Position Emission Tomography PET scan

32
SPECT SCANNER
33
SPECT Imaging

• The use of a brain SPECT scan is based on the
  principal of blood flow. 
• Areas of increased blood flow take up more
  Radioactive tracer than areas of less blood flow.
• Blood flow in the brain is directly related to
  brain activity.

34

• COMMON DISEASES EVALATED BY SPECT
• Attention Deficit Hyperactive Disorder
• Autism  Aspergers syndrome
• Unipolar and Bipolar Depression
• Anxiety states - Panic
• Obsessive-Compulsive Disorder
• Epilepsy and Non-epileptic seizure equivalents
• Post Traumatic Stress Disorder
• Migraine and common headaches 
• Schizophrenia
• Dementia and memory loss- Stroke- Multiple
  Sclerosis- Parkinsons Disease

35
SPECT Image
36

• Blood flow to the brain is represented on a
  color scale dark areas have no flow and bright
  yellow areas have good blood flow. 
• The dark butterfly-shaped area in the center of
  the brain is normal but the dark area on the
  right of each picture is the region of impaired
  blood supply (ischemia) that corresponds to the
  patients acute stroke.

37

• Prior to t-PA the SPECT scan showed a large area
  of the brain that has lost its blood supply
  (arrow).
• Several hours after treatment with t-PA the
  blood flow has dramatically improved although
  there is still a small area ischemia (arrow).

38
PET Scanner
39

• Image of heart which has had a mycardial
  infarction. The arrow points to dead myocardial
  tissue. Therefore the patient will not benefit
  from heart surgery but may have other forms of
  treatment prescribed.

• Normal PET scan of a heart.

40

• PET image showing malignant breast mass that was
  not revealed by conventional imaging techniques
  such as CT MRI and mammogram

• PET image of same patient with enlarged left
  axillary lymph nodes (indicated by arrows) which
  through biopsy were found to be metastatic. The
  whole body scan reveals a mass in the left breast
  (indicated by arrow) that was malignant and
  subsequently removed

41

• Normal Brain

• Image of the brain of a 9 year old female with a
  history of seizures poorly controlled by
  medication. PET imaging identifies the area
  (indicated by the arrows) of the brain
  responsible for the seizures. Through surgical
  removal of this area of the brain the patient is
  rendered seizure-free.

42

• PET measurements of cerebral blood flow (CBF) and
  oxygen extraction by the brain (OEF) before (top
  row)and after (bottom row) angioplasty of a focal
  severe stenosis of an artery at the base of the
  brain (supraclinoid internal carotid artery).

43

• 65 year old male with brain tumors imaged
  
• here with a PET scan.

44
(No Transcript)
45
Treatment of Cancer

• Radioactivity is very effective in the treatment
  of certain cancers.
• The choice is basically do you administer the
  radiotherapy externally or internally.

46
External Beam Therapy

• External beam therapy (EBT) is a method for
  delivering a beam of high-energy x-rays to the
  location of the patients tumor.
• The beam is generated outside the patient and is
  targeted at the tumor site.
• These x-rays can destroy the cancer cells and
  careful treatment planning allows the surrounding
  normal tissues to be spared.

47

• These cancers are commonly treated.
• Breast Cancer
• Colorectal Cancer (Bowel Cancer)
• Head and Neck Cancer
• Lung Cancer
• Prostate Cancer

48
(No Transcript)
49
High Energy X-Rays
50
Linear Particle Accelerator
51
(No Transcript)
52

• Zapping Cancer Proton Beam Therapy Proves
  Effective in Targeting Tumors Aug. 17 2004
  A new kind of radiation is proving effective in
  the fight against cancer. Proton beam therapy
  according to doctors zeroes in on tumors with
  impressive results and without the devastating
  side effects of traditional radiation therapy.
• We can shape the beam more accurately hitting
  targets with more precision said Dr. Jerry
  Slater clinical director of Loma Lindas Proton
  Therapy Center in Southern California.
• You dont feel any pain said Ron Leuck who is
  being treated for prostate cancer with the new
  therapy.
• During the treatment a rotating scaffold three
  stories high aims computerized ray guns directly
  at his tumor.
• .

53
Proton Beam Radiotherapy

• This form of external beam irradiation involves
  directing radiation through the front of the eye
  in order to reach the intraocular tumor.
• When compared to low-energy eye-plaque radiation
  therapy It is easier to treat tumors that are
  surrounding the optic nerve with protons.

54
Brachytherapy

• Brachytherapy is where radioactive seeds or
  sources are placed in or near the tumor itself
  giving a high radiation dose to the tumor while
  reducing the radiation exposure in the
  surrounding healthy tissues.
• The term brachy is Greek for short distance.

55
Brachytherapy

• Brachytherapy is not new. Throughout this
  century several types and routes of implantation
  of radioactive seeds have been used to treat
  cancer.
• Radioactive Iodine seeds were widely used during
  the 1970s and 1980s.

56

• Brachytherapy sources can be divided into
  permanent and temporary groups.
• Permanent sources tend to have lower energy and
  shorter half-lives.
• The advantage of these lower energies is enhanced
  safety.
• The disadvantage is that anatomical adjustments
  cannot be made once the sources are placed.

57

• Currently temporary implants consist primarily
  of 192Ir and 137Cs.

58

• Currently the 2 most common permanent
  radioactive sources for brachytherapy seeds are
  125I and 103Pd.
• The lower the energy emitted by the photons the
  higher the energy transfer.
• The higher the energy transfer the higher the
  radiobiologic effect which can lead to lower
  total doses.

59
Prostate Cancer

• The prostate gland is just beneath the male
  bladder.

• Cancer is common.

60

• The prostate gland can be felt with a digital
  rectal exam Cancer is sometimes detected this
  way.

61
(No Transcript)
62

• 67 year old male with metastatic
  prostate cancer.

63

• Iridium 192 is used for highdose rate treatment
  of prostate cancer. During the implantation
  hollow needles are inserted transperineally. The
  needles are then connected to an automated
  remote-controlled loading machine. The total
  irradiation time is usually only 5-10 minutes.

64
(No Transcript)
65

• Temporary seed placement is shown here.