Bone Scintigraphy Department of Nuclear Medicine Dr (2023)

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Title: Bone Scintigraphy Department of Nuclear Medicine Dr

1
Bone Scintigraphy

• Department of Nuclear Medicine
• Dr. Pei-Shan Wu

2
Radiopharmaceuticals

• Sr-85 high radiation absorbed dose, poor imaging
  characteristics, and delayed imaging time (57
  days)
• Sr-87m Low target-to-background ratios
• Fluorine 18 positron emission
• Tc-99m MDP 140 KeV, 6-hour half-life
• distributed rapidly throughout the extracellular
  fluid space
• rapid uptake in bone
• clearance from the body via the kidneys
• the skeleton-to-background tissue ratio improves
  with time

3
Technique

• 1. Patient preparation and follow-up
• be well hydrated
• void immediately before study
• remove metal objects
• 2. Dosage and route of administration
• 20 mCi (740MBq) Tc-99m MDP
• intravenous injection
• adjust dosage for pediatric patients, minimum 2
  mCi
• 3. Time of imaging
• 24 hr after tracer administration
• 4. Images three-phase, whole body, SPECT

4
Normal bone scan

• 1. Areas with normally increased activity
  include acromioclavicular joints,
  sternoclavicular joints, scapular tips,
  costochondral junctions, sacroiliac joints, lower
  neck, sternum, renal pelves and bladder
• 2. Pediatric patients growth centers and cranial
  sutures
• 3. Pitfalls
• - Patient rotation
• - Urine retained in calyx may overlie lower rib
• - Urine contamination
• - Belt buckles, earrings, necklaces, and the like
  frequently create cold defects
• - Recent dental procedures
• - Radiopharmaceutical problems breakdown of tag
  leading to free pertechnetate causes activity in
  thyroid and GI tract

5
Abnormal bone scans

• A. Metastatic disease
• Tumors most likely to metastasize to bone
  include breast, lung, prostate, lymphoma,
  thyroid, renal and neuroblastoma
• Tumors in which falsely normal bone scan can be
  expected include multiple myeloma, some
  anaplastic tumors, and pure lytic lesions
• Location of metastases axial skeleton 80,
  skull 10, long bones 10
• Super scan diffuse symmetrical increased uptake
• _ tumors frequently causing super scan prostate,
  breast, lung bladder and lymphoma
• _ nontumor causes of super scan
  hyperparathyroidism, osteomalacia, Pagets
  disease, and fibrous dysplasia

6
Abnormal bone scans

• B. Primary malignant bone tumors
• Osteogenic sarcoma, chondrosarcoma, Ewings
  sarcoma
• C. Benign primary tumors
• Osteoid osteoma, bone islands, bone cysts,
  fibrous cortical defects, and others
• D. Osteomyelitis and septic arthritis

7
Abnormal bone scans

• E. Fracture
• 1. Traumatic fracture
• positive within 24 hours
• 2/3 return to normal by 1 year
• child abuse
• _will not detect old, healed fx
• _difficult to evaluate around metaphyseal/epiphyse
  al region
• _may miss some skull fractures

8
Abnormal bone scans

• 2. Stress fractures
• Fatigue fracture caused by repeated abnormal
  stress on normal bone
• _fusiform, longitudinal shape, most often
  involving posterior tibial cortex
• _focal, less than 1/5 length of tibia
• _common located in junction of middle and distal
  third of tibia
• Insufficiency fracture resulting from normal
  stress on abnormal bone
• _seen in such diseases as osteoporosis,
  osteomalacia, pagets disease, fibrous dysplasia,
  and status postirradiation

9
Abnormal bone scans

• F. Metabolic bone disease
• 1. Osteoporosis normal or decreased uptake
• 2. Osteomalacia
• _vitamin D deficiency
• _results in failure of bone matrix to calcify
• _generalized increased skeletal uptake
• 3. Pagets disease
• _increased uptake in bone scan
• _distribution of lesions pelvis (7080),
  lumbar-thoracic vertebrae, femur, skull, scapula,
  tibia, and humerus

10
Abnormal bone scans

• 4. Hyperparathyroidism
• a. Primary caused by hyperplasia or tumor of
  parathyroids
• 5080 normal bone scan
• abnormal uptake at calvarium, mandible,
  acromioclavicular joint, sternum, lateral humeral
  epicondyles and hands
• soft-tissue calcification in lungs, stomach,
  kidneys, heart and periarticular
• b. Secondary associated with chronic renal
  failure
• usually have abnormal bone scan
• super scan
• focal abnormalities

11
Abnormal bone scans

• G. Avascular necrosis
• result of fracture, metabolic disorder, fat
  embolization, steroids, hemolytic anemia, and
  vasculitis
• plain film is normal in early stage (6 months)
• bone scan normal for first 48 hr ? decreased
  activity ? increased activity ? develop
  degenerative joint disease (increased uptake in
  the acetabulum)
• Legg-Calve-Perthes disease afftects boys aged
  48 years

12
Abnormal bone scans

• H. Heterotopic ossification
• _associated with paraplegia and quadriplegia
• _increased activity in soft tissue
• I. Arthritides
• 1. Degenerative joint disease - most common
  locations hands, feet, hips, knees, SI joints
  and shoulders
• 2. Rheumatoid arthritis - symmetrical increased
  uptake hands feet, knees and cervical spine

13
Radionuclide inflammation scan and tumor scan

• Department of Nuclear Medicine
• Dr. Pei-Shan Wu

14
Application of Radionuclide Imaging in Infection

• Radionuclide imaging for detection of infection
• Ga-67 scan
• Tc-99m (V) DMSA scan
• Tc-99m HMPAO labeled WBC scan
• Tc-99m labeled IgG scan
• Utility in specific diseases
• Osteomyelitis
• Painful prosthesis
• AIDS

15
Gallium-67

• Cyclotron produced
• Half-life 78 hrs
• Biological behavior similar to ferric ion
• Binding to iron-binding molecules, including
  transferrin, lactoferrin, ferritin, siderophores

16
Gallium-67 scan Mechanism

• Not thoroughly understood
• Ga-67 citrate binds to transferrin in the blood
• gt transported to site of inflammation/infection
  
• Localization depends on a number of factors
• Adequate blood supply
• Increased vascular permeability
• Leaking into areas inflammation/infection
• Ga-67 can be used in leukopenic,
  immunocompromised patients
• Within 12-24 hours Ga-67 firmly bound within
  lesion

17
Ga-67 scan Technique

• Dose
• Inflammation 3-5 mCi
• Tumor 5-10 mCi
• Imaging time
• 48-72 hr to 1 week
• Inflammation 24 hr Earlier images high
  background false-negative
• Imaging parameters
• Energy 93, 185, 296 keV peaks
• Total body scan, focal view, SEPCT
• Medium energy collimator
• Bowel activity bowel preparation

18
Ga-67 scan Normal distribution

• Liver greatest Ga-67 uptake
• Other Spleen, nasopharynx, lacrimal and salivary
  glands, bone marrow, scrotum, testes
• First 24 hours kidneys, bladder
• - 48-72 hours kidneys only faintly visualized
• After 24 hours, biological clearance through
  bowel
• Breast uptake variable, womans hormonal cycle
• Thymus children

19
Ga-67 scan image interpretation

• Abnormal uptake
• liver or spleen ? abscess
• liver ? clinical important inflammation
• lt bone marrow ? low-level inflammation
• No difference in sensitivity fro acute or chronic
  infection
• Less sensitivity in tuberculosis, fungal infection

20
Ga-67 scan Advantages

• Whole body survey
• Sensitive for detection of all inflammatory
  process whether or not they are discretely
  defined anatomically
• For detecting source of sepsis
• Leukopenic, immunocompromised patients
• Tumor detection

21
Ga-67 scan Disadvantages

• Time delay between injection and imaging
• Poor spatial definition of anatomically discrete
  lesions
• Potential misinterpretation as a result of
  gallium uptake in adjacent organ (e.g. liver)
• Bowel activity
• Infection vs tumor

22
Tc-99m (V) DMSA scan

• A tumor scan e.g. medullary carcinoma of
  thyroid, soft tissue tumor
• Mechanism
• unknown
• hypothesis resemble phosphate ion distribution
• Biodistribution Cardiovascular system, kidneys
• Technique
• 20 mCi Tc-99m (V) DMSA iv injection
• Imaging 4 hr post-injection

23
Tc-99m (V) DMSA scan Advantages

• Good availability
• High resolution
• Low price
• Low radiation dose
• Preparation technique Easy
• Imaging 4 hr post-injection

24
Tc-99m (V) DMSA scan Disadvantages

• GU tract infection
• Infection vs tumor
• Chronic infection
• Further study

25
Scintigraphic diagnosis of osteomyelitis

• ESR Sensitive, but nonspecific
• Blood culture 40 negative
• X-ray
• First imaging study
• Not detectable until 10-21 days after onset of
  symptoms
• Scintigraphic methods
• Three-phase bone scan
• Ga-67 scan
• Tc-99m (V) DMSA scan
• WBC scan
• IgG scan

26
Three-phase bone scan Osteomyelitis

• Blood flow study Imaging at 3-5 sec intervals
  throughout the 1st-2nd minutes after radiotracer
  administration
• Blood pooling study Obtain 5-20 min after
  injection
• Delayed scan 2-4 hr post-injection
• DD osteomyelitis and cellulitis
• Cellulitis diffuse hyperemia, delayed negative
• Osteomyelitis focal hyperemia, delayed positive
  
• Positive
• 24-48 hr after onset of symptoms
• Remain positive for months after resolution
• Sensitivity 90-100, specificity 75-90

27
Ga-67 scan Osteomyelitis

• Positive
• within 24-48 hr of symptomatic onset
• Return to baseline quickly following successful
  treatment
• Sensitivity 80-90, specificity 70
• Sequential bone and gallium scans
• Positive Ga-67 uptake is incongruent with the
  bone scan
• Negative low-trade uptake
• Equivocal intense congruent uptake

28
Neonatal osteomyelitis

• Diffuse nature, propensity for complications,
  paucity of associated signs gt whole body image
• Three-phase bone scan
• 22-68 falsely normal or cold defects
• Resolution
• Cold lesion subperiosteal abscess
• Bone scan negative, clinically suspected gt
  Ga-67 scan

29
Scintigraphic diagnosis of painful prosthesis

• Three-phase bone scan
• Focally increased uptake loosening
• Diffuse, uniformly distribution infection
• Not very specific
• Ga-67 scan
• Differential between pure mechanical loosening
  and infection
• Sequential bone-gallium imaging
• Incongruent image Ga uptake exceed Tc-99m MDP
  bone radiotracer uptake (spatial, intensity of
  uptake)
• sensitivity 70, specificity 90, Accuracy
  80

30
Infection in immunosuppressed patients

• Diffuse pulmonary uptake
• PCP
• CXR bilateral diffuse infiltrate from hilum to
  peripheral
• Ga-67 diffuse bilateral pulmonary uptake without
  nodal or parotid uptake (often before CXR)
• Severe in CXR but decreased uptake in Ga-67 ?
  deficient immune response ? poor prognosis

31
Infection in immunosuppressed patients

• CMV
• Low-grade diffuse lung uptake, perihilar
• Maybe with ocular(retinitis), adrenal, renal
  uptake, persistent colon uptake(diarrhea)
• Lymphoid interstitial pneumonia
• Low-grade diffuse lung uptake, without nodal
  uptake, and symmetrically increased parotid uptake

32
Infection in immunosuppressed patients

• Focal pulmonary uptake
• Bacterial pneumonia a lobar like, without nodal
  and parotid uptake
• Actinomyces, Nocardia and Aspergillus multiple
  sites of focal accumulation, frequently with
  local bone invasion
• Nodal uptake
• Mycobacterium avium-intracellulare (MAI),
  tuberculosis, cryptococcal, HSV infection and
  lymphadenitis, lymphoma
• MAI 2550 of AIDS, patchy lung uptake with
  hilar and nonhilar nodal uptake

33
AIDS Radionuclide Studies

• Ga-67 scan
• Infection, Tumor (lymphoma)
• Thallium-201 scan
• tumor (Kaposis sarcoma, lymphoma)
• Tc-99m HMPAO brain SPECT
• Dementia

34
AIDS Ga-67 scan and Tl-201 scan

• Kaposis sarcoma
• Ga-67 (-), Tl-201 ()
• Infection
• Ga-67 (), Tl-201 (-)
• Lymphoma
• Ga-67 (), Tl-201 ()

35
Overview of Tumor Scintigraphy

• Organ-specific tumor imaging radionuclides
• Cold spot Thyroid scan, Liver scan
• Hot spot Bone scan, conventional brain scan
• Non-specific tumor imaging radionuclides
• Ga-67
• Tl-201
• Tc-99m sestamibi
• Tc-99m (V) DMSA
• PET (F-18 FDG)

• Tumor-type specific radionuclides
• Thyroid cancer I-131
• Adrenal tumors I-131 MIBG or NP-59
• Hepatocyte origin tumors Tc-99m DISIDA
• Hemangioma Tc-99m RBC

36
Ga-67 scan

• Mechanism of tumor localization
• Adequate blood supply
• Vascular premeability
• Specific tumor-associated transferrin receptor
• Tumor metabolism

37
Ga-67 scan image interpretation

• Salivary gland uptake is noted after C/T or R/T
• Faint symmetrical hilar uptake may be seen
  normally and is common after C/T
• Faint or absent liver uptake
• Extensive tumor metastases
• Hepatic failure
• C/T (vincristine) given within 24 hrs of Ga-67
  injected
• Iron overload

38
Ga-67 scan tumor detectability

• Histology high grade
• Lesion size
• Location superficial gt deep
• Tumor detection lymphoma, HCC, soft tissue
  sarcoma, melanoma, lung cancer, head and neck
  tumors

39
Tl-201 Chloride tumor scan

• Thallium-201 a potassium analog
• Factors determining tumor cell uptake
• Blood flow
• Tumor viability
• Tumor type
• Sodium-potassium ATPase system
• Cotransport system
• Calcium ion channel system
• Clearance by kidney, half-life 73 hrs

40
Tl-201 Chloride tumor scan
- Clinical application

• Brain tumor
• Correlated with gliomas grade
• Post-op or post-R/T recurrent
• Therapeutic effectiveness
• In AIDS pt D.D. lymphoma and toxoplasmosis
• Bone and soft tissue tumor
• Correlation between Tl-201 uptake and response to
  C/T
• Lack of Tl-201 uptake ? tumor necrosis

41
Tl-201 Chloride tumor scan
- Clinical application

• Thyroid cancer
• Advantage
• Continue thyroid hormone
• Localized thyroid ca (when I-131 negative, but TG
  elevated)
• Disadvantage
• Not specific
• Not predict the potential therapeutic
  effectiveness
• Kaposis sarcoma Ga(-), Tl()

42
Tc-99m sestamibi

• A lipophilic cationic complex
• Factors determining tumor cell uptake
• Blood flow
• Tumor viability
• Tumor type
• Lipophilic cation
• Large negative transmembrane potential

43
Tc-99m sestamibi

• Localized in liver, kidney, heart and skeletal
  muscle
• Difficult imaging
• Sub-diaphragmatic tumor ? liver uptake and
  urinary clearance
• Brain tumor ? choroid plexus uptake

44
Tc-99m sestamibi -
Clinical application

• Breast cancer
• Sensitivity 85, specificity 81
• Higher in palpable, lower for lesion lt 1cm
• Fibroadenoma is commonest false positive
• Diffuse uptake is nonspecific and usually not
  malignancy
• Useful in
• Non-diagnostic mammogram
• Dense breast or anatomical changed
• Fibrocystic disease

45
F-18 FDG tumor imaging

• F-18 FDG
• F-18 FDG enters the metabolic cycle like glucose,
  but it is trapped in the tissue in the form of
  F-18 FDG-6-phosphate without further metabolism
• Increased glycolysis associated with malignancy
• Excreted by kidney
• Clinical lung cancer, colorectal cancer,
  lymphoma, breast cancer etc.

46
Lymphoscintigraphy

• Clinical applications of lymphoscintigraphy
• Distinguish lymphatic from venous edema,
  myxedema, lipedema, or other etiology
• Assess pathways of lymphatic drainage
• Identify sentinel nodes in patients with
  melanoma, breast, or genitourinary cancer
• Identify patients at high risk for development of
  lymphedema after axillary lymph node dissection
• Quantify lymphatic flow

47
Lymphoscintigraphy

• Methodology
• Radiotracers colloidal gold(198Au), Tc-99m
  labeled tracers (antimony sulfide colloid, sulfur
  colloid, albumin colloid, HSA)
• Tracer injected into the tumor or surrounding
  tissue to identify the nodes receiving the
  lymphatic drainage of that tumor subcutaneous,
  Intradermal, and Subfascial Injection

48
Sentinel lymph node detection and imaging

• Lymphatic effluent of a tumor drains initially to
  one or two lymph nodes before other nodes receive
  the tumoral drainage
• Sentinel node develops lymphatic metastases
  before other nodes
• Careful examination of the sentinel node can be a
  more accurate predictor of regional nodal
  metastases than examination of adjacent nodes
  even if they are located in the same drainage
  basin as the sentinel node

49
Sentinel lymph node detection and imaging

• If the sentinel node is negative for tumor, then
  other nodes are not likely to contain metastases,
  and the patient can be spared the unnecessary
  morbidity and expense of a more extensive node
  dissection
• To localize the proximal or initial portion of
  the lymphatic chain, efferent from the tumor, for
  subsequent surgical excision and histologic
  diagnosis

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