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Skeletal PET with 18F-Fluoride: Applying New Technology to an Old Tracer

Frederick D. Grant, Frederic H. Fahey, Alan B. Packard, Royal T. Davis, Abass Alavi and S. Ted Treves
Journal of Nuclear Medicine January 2008, 49 (1) 68-78; DOI: https://doi.org/10.2967/jnumed.106.037200

Article Figures & Data

Figures

  • FIGURE 1. 
    FIGURE 1. 

    Normal 18F-fluoride PET skeletal findings for patients aged 5 y (A), 11 y (B), 15 y (C), 19 y (D), and 30 y (E). Pattern of 18F− uptake in skeleton is similar to pattern seen with more familiar 99mTc-labeled bisphosphonate bone scans and illustrates changes that occur with maturation of skeleton. Compared with 99mTc-MDP SPECT, 18F-fluoride bone PET provides higher-quality images, better ratios of bone uptake to soft-tissue uptake, and shorter studies. MIP = maximum-intensity projection.

  • FIGURE 2. 
    FIGURE 2. 

    In 8-y-old patient with Ewing's sarcoma of right distal fibula, 18F-fluoride PET projection image shows extent of primary tumor and absence of skeletal metastases.

  • FIGURE 3. 
    FIGURE 3. 

    Compared with 99mTc-MDP scintigraphy (left, arrows indicate sites of thoracic and lumbar spine disease), both 18F-FDG PET (middle) and 18F-fluoride PET (right) show higher sensitivity for detecting skeletal lesions. Compared with 18F-FDG PET, 18F-fluoride PET demonstrates minimal soft-tissue uptake, which increases sensitivity for detecting bone lesions that are adjacent to sites of physiologic 18F-FDG uptake or sites of 18F-FDG–avid soft-tissue disease (Reprinted with permission of (23).).

  • FIGURE 4. 
    FIGURE 4. 

    From left to right: posterior and anterior 99mTc-MDP planar scintigraphy, 99mTc-MDP multiple-field-of-view SPECT, and 18F-fluoride PET of 82-y-old patient with numerous bone metastases. As in this patient, more lesions are typically detected by SPECT than by planar imaging, and 18F-fluoride PET detects more lesions than does SPECT.

  • FIGURE 5. 
    FIGURE 5. 

    In 2-y-old girl with stage IV neuroblastoma, uptake in multiple soft-tissue tumors on 18F-fluoride PET bone scan demonstrates 18F-fluoride avidity for sites of soft-tissue calcification. A = anterior; R = right.

  • FIGURE 6. 
    FIGURE 6. 

    In 18-y-old female marathon runner with severe lower leg and foot pain, projection PET image shows increased 18F-fluoride uptake in tibiae and both feet, indicating multiple sites of stress injury.

  • FIGURE 7. 
    FIGURE 7. 

    (A) In 12-y-old female gymnast with lower back pain, 18F-fluoride PET image shows increased focal uptake indicating stress changes in posterior elements of L5 vertebra (arrow). (B) In 21-y-old runner, 18F-fluoride PET image shows stress changes in left sacroiliac region (arrow).

  • FIGURE 8. 
    FIGURE 8. 

    (A) Fusion of 18F-fluoride PET and CT images of 17-y-old male athlete with back pain that worsened on hyperextension. 18F-Fluoride PET had identified focally increased tracer uptake in region of right pars interarticularis of L5 vertebra. Fusion image demonstrates correlation of site of 18F− uptake with nondisplaced fracture of pars that was identified by CT. (B) From top to bottom, sagittal 18F-fluoride PET, CT, and fusion images of 15-y-old female athlete with back pain after landing from high jump. Increased 18F-fluoride uptake and deformity on PET correlates to wedge compression fracture of L3 vertebra (arrows) identified on CT.

  • FIGURE 9. 
    FIGURE 9. 

    In 18F-fluoride PET bone scan without attenuation correction (top row, with coronal, sagittal, and transverse slices appearing from left to right), streak artifact caused by activity in renal collecting system leads to apparent loss of signal in right lumbar spine (solid arrows). Apparent increased signal in thoracic spine results from reduction of attenuation in lung region (open arrow). Both artifacts are greatly reduced when attenuation correction is applied using rotating rod sources of 68Ge/68Ga (middle row). After patient voided, repeated image (bottom row) acquired in single bed position shows resolution of artifact caused by activity in renal collecting system.

Tables

  • TABLE 1

    Radiation Dosimetry of 99mTc-MDP Scintigraphy vs. 18F-Labeled NaF PET

    Type of imagingAdult (70 kg)15-y-old child (55 kg)10-y-old child (32 kg)5-y-old child (19 kg)1-y-old child (9.8 kg)
    99mTc-MDP*
     Administered activity (MBq)51840723714173
     Effective dose in mSv/MBq (mSv)0.0057 (3.0)0.0070 (2.8)0.0110 (2.6)0.0140 (2.0)0.0270 (2.0)
     Bladder wall in mGy/MBq (mGy)0.048 (24.9)0.060 (24.4)0.088 (20.9)0.073 (10.3)0.130 (9.5)
     Bone surfaces (mGy)0.063 (32.6)0.082 (33.4)0.130 (30.8)0.220 (31.0)0.53 (38.7)
     Red marrow (mGy)0.0092 (4.8)0.010 (4.1)0.017 (4.0)0.033 (4.7)0.067 (4.9)
    18F-labeled NaF†
     Administered activity (MBq)148116684021
     Effective dose in mSv/MBq (mSv)0.027 (4.0)0.034 (3.9)0.052 (3.5)0.086 (3.4)0.170 (3.6)
     Bladder wall in mGy/MBq (mGy)0.22 (32.6)0.27 (31.3)0.40 (27.2)0.61 (24.4)1.10 (23.1)
     Bone surfaces in mGy/MBq (mGy)0.040 (5.9)0.050 (5.8)0.079 (5.4)0.130 (5.2)0.300 (6.3)
     Red marrow in mGy/MBq (mGy)0.040 (5.9)0.053 (6.1)0.088 (6.0)0.180 (7.2)0.380 (8.0)

    • ↵* Derived from ICRP Report 80. Ann ICRP. 1999;28:75.

    • ↵† Derived from ICRP Report 53. Ann ICRP. 1987;17:74.

    • Values in parentheses are doses in mGy (mSv for effective dose) for administered activity listed in table for that patient size.

  • TABLE 2

    Indications for 18F-Fluoride Skeletal PET

    Type of diseaseType of assessmentSpecific goal
    OncologicMetastatic disease in skeleton (e.g. prostate, lung, breast, neuroblastoma)Perform initial evaluation (staging)
    Assess response of skeletal metastases to therapy
    Detect skeletal metastases during follow-up
    Bone pain in patients with known cancer
    Primary bone tumorsIdentify sites of disease (initial staging)
    Assess response to therapy
    Differentiate postoperative changes from residual/recurrent disease
    Detect recurrent/metastatic disease during follow-up
    Benign bonePediatric/young adult back painAssess vertebral spondylolysis
    Assess other stress injuries
    Bone viabilityAssess femoral head avascular necrosis
    Assess bone graft viability (long bones, mandible)
    Paget's diseaseAssess extent of disease
    Monitor response to therapy
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