will frusemide administered to horses prior to scintigraphic examinations reduce the radiation dose...
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Will frusemide administered to horses prior to scintigraphic examinations reduce the radiation dose rate?
Erichsen C*, Falck-Andersen H*, Lønning M*, Bjørnstad A*, Eksell P #
*Norwegian School of Veterinary Science, Oslo – Norway # Private practice, Ôrbyhus - Sweden
Introduction
Scintigraphy has high sensitivity for lesions in bone
Scintigraphy is commonly used in equine practice
Introduction
Radiation safety
The radiation dose from the horse has been claimed to be reduced after administration of frusemide.
No published data to support this.
Introduction
Pilot study at SLU, Uppsala 31 horses in two groups
3 measurepoints Measured at 2, 6 and 24
hours post injection No difference between groups
Present study with improved method at NVH, Oslo
More horses 1 measurepoint 2 and 24 hours post
injection
Purpose
To determine if administration of frusemide prior to scintigraphic examinations reduce the radiation dose rate from the horse at 2 and 24 h post injection.
Material
74 HorsesReferred to NVH for scintigraphic examination
32 horses
Group F (Frusemide)Group C (Control)
42 horses
Material
Group F Horses referred for scintigraphic examinations including the
pelvis
Group C All horses referred for scintigraphic examinations of areas
other than the pelvis
Material
Group F Group C
Age 7,4 8,1
BW (kg) 517 522
Dose 99mTc-HDP(MBq/kg BW)
10,3 10,1
Dose frusemide(mg/kg BW)
0,33 -
Material
Group F Group C
Age 7,4 8,1
BW (kg) 517 522
Dose 99mTc-HDP(MBq/kg BW)
10,3 10,1
Dose frusemide(mg/kg BW)
0,33 -
Method
All horses injected with radiopharmaceutical 99mTc HDP (10 MBq/kg BW)
Placed in a dedicated stableControlled area
Method
Group F Frusemide i.v. one hour post injection
Group C Control horses
Method
Geiger Müeller survey meter Canberra Military
Pocket Radiac
Accumulated Radiation
dose during minimum 30
min was registered
beginning
2 hours post injection 24 hours post injection
Method
Highest radiation dose 15 cm cranial to the tuber coxae against the skin
Method
Highest radiation dose 15 cm cranial to the tuber coxae against the skin
Method
Material and Methods
All measurements werecorrected for time relatedto the time of injectionand converted into Sv/hour.
Minimum level of significance was set to p0.05
Results
No significant differences in measured radiation dose between the groups
Hours after injection
Sv/h
0
10
20
30
40
50
60
70
80
2 24
F C
Results
Radiation dose (Sv/hour)
Mean Range
2 hours 63,6 39-100
24 hours 3,4 2-7
Results
Radiation dose (Sv/hour)
Mean Range
2 hours 63,6 39-100
24 hours 3,4 2-7
Myocard scan 100 60-160
Bone scan 31 30-38
Results
Significant correlations:
1. Dose 99mTc-HDP and radiation dose Higher dose gives higher
radiation dose
2. Bodyweight and radiation dose Increased BW gives lower
radiation dose
Discussion
Claimed Advantages
Encourage urination
Improve image quality
Less radiation dose to personell
Claimed Disadvantages
Possible increased restlessness during
examination
Increases the risk of contamination by radioactive
urine
Discussion
Claimed Advantages
Encourage urination
Improve image quality
Less radiation dose to personell
Claimed Disadvantages
Possible increased restlessness during
examination
Increases the risk of contamination by radioactive
urine
Conclusion
Dose 99mTc & Horse size matters
Conclusion
For radiation safety reasons it should not be
recommended to administer frusemide to all
horses that undergo scintigraphy.
Administration of frusemide should only be
recommended when pelvic imaging is performed,
because of the increased risk of radioactive
contamination due to urination.
Acknowledgements
The three students that did
most of the measurements
during 2006
Technicians at the Equine
section, NVH
Anders Unoson
Thank you for your attention!
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