The Estimation of 99mtc DMSA Absorbed Dose in Renal Scintigraphy of Pediatric Patients Using MIRDOSE Software and Planar/SPECT Hybrid Method

Abstract

Introduction: 99mTc–Dimercaptosuccinic Acid (DMSA) as evaluation of pediatric genitourinary abnormalities has an important role in pediatric nuclear medicine. The aim of this study was to estimate organs absorbed dose for children injected by 99mTc DMSA using MIRDOSE software and hybrid planar/SPECT method. Methods: After injection of 99mTc-DMSA, ten children with genitourinary abnormalities underwent 3-5 planar scans and single SPECT scan (at 1 to 20 h post injection). Also for anatomical reference of patients’ organs, MRI scans were performed for each patient. A hybrid planar/SPECT method was used to plot time activity curves for obtain source organs cumulated activity and then to calculate obserbed doses of organs MIRDOSE software was used. Results: Mean absorbed dose due to 99mTc-DMSA in pediatric for kidneys (200 ± 160), adrenals (15.1 ± 9.5), urinary bladder wall (14.7 ± 9.8), spleen (12.7 ± 7.8), gonads (12.4 ± 11.2), pancreas (10.5 ± 6.2), gall bladder wall (9.8 ± 5.7) , , , , , micro Sivert per MegaBequrel, respectively. Also, the mean effective doses was 10.01 ± 6.03 µSv/MBq. Conclusion: The difference between the radiation doses received by the various organs of the patients caused by different amounts of radiopharmaceutical uptake in organs for different patients. Image quantities practical method using planar/SPECT hybrid method can be utilized with acceptable accuracy in determination of cumulative activity.

Keywords

• Internal Absorbed dose
• Combined SPECT/planar method
• MIRDOSE software
• Cumulated activity