PET Approved Tracers - NMTCB 2024
  1. PET radiopharmaceuticals approved for neuroendocrine tumor images (note somatostatin receptors - SSTR)
    1. 68Ga-DOTATATE (FDA approval 2016)
    2. 68Ga-DOTATOC (FDG approval 2019) - DOTATOC "mirrors" DOTANOC1
    3. 64Cu-DOTATATE (FDG approval 2020)
  2. SSTR is over expressed in neuroendocrine tumors (NET) and has improved tumor localization and shorter imaging times when compare to Octreotide


    3. Link

  3. SSTR level show different differentiation levels1
    1. Ki-67 staining/cell differentiation/
      1. Grade 1: <2% ki-67 staining
      2. Grade 2: 3 - 20% ki-67 staining
      3. Grade 3: 20% ki-67 staining
      4. Poorly-differentiation >55% G3 usually has a loss of SSTR and is more metabolically active. Which images represent this type of tumor?
      5. Well differentiated NECs tend to have greater SSRT
  4. Comparing the betas energies
    1. 64Cu beta particles has a max energy and range of 1.9 meV and 3.5 mm
      1. Half-life of 12.7 hours
      2. Has a lower photon yield with greater radiation dosimetry
    2. 68Ga beta particle has a max energy and range of 0.65 meV and 0.56 mm
      1. Half-life of 1.1 hour
      2. Higher photon yield with a lower radiation dosimetry

      3. Here are four different patient with NET that were given both radiopharmaceuticals that show similar results. At present there appears to be evidence that one is better than the other2
  5. Procedure
    1. Patient Prep
      1. D/C short acting somatostatin 12 hours prior to the exam
      2. D/C long acting somatostatin 3 to 4 weeks, however, research indicates that this may not be necessary1
      3. Patient should be well hydrated and continue with liquid intake up to one hour after the procedure
    2. Dose - EANM suggests
      1. 68Ga-DOTATOC- 3 to 5 mCi
      2. 8Ga-DOTATATE - 0.054 mCi/kg and up to 5.4 mCi
      3. 64Cu-DOTATATE - 4 mCi
    3. Uptake time
      1. 68Ga-DOTATOC, start scanning 55-90 minutes
      2. 68Ga-DOTATATE start scanning 40-90 minutes
      3. 64Cu-DOTATATE start scanning at 45-90 minutes
    4. Area of scan can either be head to toe or skull base to mid-thigh

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NMMI Procedures Standards/EANM Practice Guideline for SSTR 1

Choice Is Good at Times: The Emergence of [64Cu]Cu-DOTATATE–Based Somatostatin Receptor Imaging in the Era of [68Ga]Ga-DOTATATE by Jha, A, et al. JNMT (2022)2