Changing of the Guard

(The Sodium Fluoride Bone Scan)

By Karen Wiki Sponsored by Cyclotek

What is

18

F-Sodium Fluoride (NaF)

• Half Life = 109mins • Energy = 511 keV • Highly sensitive bone seeking tracer • Uptake mechanism resembles 99m Tc MDP • Excellent pharmacokinetic characteristics

History

 Recognised in the late 60’s Early 70’s 18 F as an excellent tracer for skeletal imaging  Limitations = short half life, high energy level, poor scanner design and availability

99m

Tc Bone Scan

PET/CT

18 F NaF

99m Tc BS 18 F NaF

Radioisotope Half Life Dose Prep Uptake delay Scan duration

Imaging HDP

6hrs 740-900 MBq Hydration 2-4hrs 60 min (WB+SPECT/CT) 30 min (L Spine SPECT/CT)

NaF

109mins 150-250 MBq Hydration 45-60mins 25 min (WB ± contrast) 10 min (L Spine)

GE Infinia Hawkeye SPECT/CT GE Discovery VCT 64 slice 64 SLICE

Combined Total Bone Scan Referrals NaF Tc BS 2010 2011 2012 2013

Oncology Referrers 2010 2011 2012 2013 NaF Tc BS

Ca Breast 2010 2011 2012 2013 NaF Tc BS

Case Study 1

Case Study 2

99m Tc BS

18 F NaF

18 F NaF

Advantages of NaF PET/CT

• Superior pharmacokinetics • Sensitive for lytic lesions • Better resolution and sensitivity • Routine tomographic data • Routine use of CT improves specificity • Shorter total examination time

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One stop shop

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References

The SNM Practice Guideline For Sodium 18F-Fluoride PET/CT Bone Scans 1.1

Grant FD, Fahey FH, Packard AB, Davis RT, Alvai A, and Treves ST. Skeletal PET with 18-Fluoride: Applying New Technology to an Old Tracer. JNM 2008;49:68-78.

Apostolova I, Brenner W. Measuring Bone Metabolism with Fluoride PET: Methodological Considerations. PET Clin 2010;5:247-257.

Abikhzer G, Kennedy J. 18F NaF PET/CT and conventional Bone Scanning in Routine Clinical Practice; Compartive Analysis of Tracers, Clinical Acquisition Protocols, and Performance Indices. PET Clin 2012;:315-328.

Czernin J, Satyamurthy N, Schiepers C. Molecular Mechanisms of Bone 18F NaF Deposition. JNM 2010;51:1826-1829 Klaus Strodel, Reza Vali. 18F NaF PET/CT Versus Conventional Bone Scanning in the Assessment of Benign Bone Disease. PET Clin 2012 Mosci C, Lagaru A. 18F NaF PET/CT in the Assessment of Malignant Bone Disease. PET Clin 2012 Southern Cross Health Insurance Eligibility criteria PET/CT

Breast Cancer

• Initial Staging in high risk Breast Cancer(Clinical Stage lllA or higher) or • Initial Staging in Clinical l-llB Breast Cancer with symptoms of bone pain or elevated alkaline phosphatase levels suggesting the presence of bone metastases • Restaging of all stage disease with symptoms of bone pain or elevated alkaline phosphatase levels strongly suggestive of the presence of bone metastases Southern Cross Health Insurance

Comparison of pharmacokinetic properties MDP

~ 64%

NaF

Nearly 100% First-pass clearance Protein binding % Bone uptake Urinary excretion 50% at 4 hr 35%-50% 70% after 6 hr Negligible 50% 50% after 6 hr PET 2012Clin 7 () 315-328

Dose Comparison Chart

99m Tc Bone Scan with SPECT/CT 750MBq (70kg pt) Low Dose CT = 2.5 mSv = 2 mSv 18 F NaF Lumbar Spine

Total = 4.5 mSv

200 MBq (70kg pt) Low Dose CT = 4.5 mSv = 3 mSv 18 F NaF WB with Diagnostic CT

Total = 7.5 mSv

200 MBq (70kg pt) Diagnostic CT = 4.5 mSv = 13 mSv

Total = 17.5 mSv

By Dr Alex Mitchell QHP

CT Parameters Scan Type Thick Speed DFOV kV mA Recon Type

Full Diagnostic CT with Chest WB Low Dose CT Helical Full 0.5s

3.75

0.984:1 70 Helical Full 0.5s

3.75

0.984:1 70 120 Auto Max 600 Min 150 Bone+ 120 Auto Max 110 Min 40 Bone+

Limitations of

99m

Tc Bone Scan

• Inferior spatial resolution and sensitivity of gamma cameras • Longer uptake time • Longer scan times • SPECT/CT isn’t routinely used

Advantages of

99m

Tc Bone Scan

• Wide availability • Generator produced/daily elution • Longer physical half-life • Flow, blood pool and delayed • Lower radiation dose (0.0057mSv/MBq)

Limitations of NaF PET/CT

• Cyclotron produced • Availability • Higher radiation exposure • Lack of flow and blood pool capabilities