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Significance high tumor markers: CEA, M protein, AFP, S100, PSA?
- CEA = colorectal
- M protein = multiple myeloma
- AFP = hepatocellular cancer or testicular
- S100 = Melanoma
- PSA = Prostate.
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Identify normal sites of 18FDG uptake?
brain, heart, muscle, kidneys, bladder, liver.
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How is 18FDG metabolized in tumors cells?
brought in by GLUT-1 Hexokinase converts FDG to FDG-6P
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Pattern of 18FDG thymus uptake
inverted v
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Is FDG secreted in breast milk? Explain uptake seen in the lactating breast
- no.
- Uptake by GLUT-1 which is activated by suckling.
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What are the patient preps in IDDM & NIDDM for FDG PET imaging?
- IDDM(Insulin-Dependent Diabetes Mellitus) patients, no insulin for 2hrs prior to FDG.
- NIDDM should not take med within 4hrs of FDG.
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What is the typical blood sugar levels ideal for FDG PET imaging?
15-150mg/dl
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What are the types of PET studies for which anxyolytics are given & why?
used for breast, head and neck, and thyroid. it is sedation to keep Pt still and calm to reduce muscle uptake.
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How does the fasting state & fed state affect myocardial uptake of FDG? Why?(
in the fasting state the heart uses fatty acids for energy. in the fed state the heart uses glucose.
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Why is temperature control of PET suite important?
cold can cause uptake in brown fat.
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What is brown fat and how s it different from white fat?
brown fat has lots of mitochondria, and capillaries. in new borns brown fat is more promenant and helps keep them warm..
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What type of lymphomas are covered for PET imaging?
- hodgkins - HL
- non hodgkins - NHL
- cutaneous T-cell lymphoma - CTL
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Difference between HL, NHL & CTL
- HL: Systemic spread, mostly above diaphram, extranodal in marrow, liver and lung. mostly in young adults.
- NHL: B-cell related, less systemic than HL, mostly in adults, most common form.
- CTL: NHL with mutation of T-cells with subcutaneous nodules.
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Identify the default imaging areas for NHL, HL & CTL & Why?
- arms up
- base of skull to pelvis
- for CTL head to toe, because it spreads throughout body
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What is myeloma and how is it imaged using PET?
- Myeloma is marrow cancer.
- arms to sides
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What is ABN and name a PET study that would need it.
- advance beneficiary notice.
- leukemia
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What type of thyroid cancer is indicated in PET imaging?
poorly differentiated thyroid cancers.
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How does NaF imaging differ from FDG/MDP imaging?
no advanced prep needed.
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How does FDG brain uptake mechanism differ from brain SPECT Rps’?
FDG uptake is proportional to brain glucose utilization. Spect uptake is based on cerebral blood flow.
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How will you prepare the patient for FDG brain imaging?
- fast 6hrs
- run IV 10min before inj
- Pt sits quietly in armchair with legs and arms crosssd
- no reading or talking
- low light, quiet
- after 5-10min inj tracer.
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Identify the image pattern of ictal vs. inter-ictal FDG imaging & CVAs
- Ictal imaging has hot Focus.
- Inter-icatal has reduced activity in affected area.
- cerebrovascular accident (CVA) lack of glucose metabolic uptake.
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FDG PET is approved by medicare for what purpose in epilepsy?
Pre sugical eval of patients with refractory seizures.
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What pattern of FDG localizaton is expected in Dementia patients? Why?
decreased due to neuron death.
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What is FDG PET approved for in Alzheimer’s imaging?
evaluation, but not diagnosis.
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PET radiopharmaceutical conditionally approved for amyloid plaque imaging?
18F-AV-45 Fluorbetapir (Amyvid)
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What does Fluorbetapir bind to and what is it used for?
binds to beta amyloid in brain. is used for Alzheimers.
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What is the effect of anesthesia and high blood glucose on FDG brain imaging?
reduces uptake in cerebral cortex.
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