Radiation dosimetry of technetium-99m-DMSA in children.
Radiation dosimetry was performed on 24 children (aged 5 wk to 14.8 yr) who were undergoing routine diagnostic investigation of renal impairment with 99mTc-DMSA.


METHODS
Organ doses were calculated using MIRDOSE 3 with biokinetic data obtained in previously described studies, and effective doses and effective dose equivalents were estimated. Interpolation by inverse weight between pediatric anthropomorphic phantoms was compared with age-matching to discrete phantoms. Administered activities were scaled by body surface area from the adult activity of 100 MBq and the resulting radiation doses in normal children were compared with those that would have resulted from a schedule based on body weight.


RESULTS
The effective doses estimated by interpolation differed by up to 46% from those based on discrete phantoms and showed less variation. In children with normal bilateral renal function, the mean effective dose per administered activity was 0.91 +/- 0.08 mSv or 0.98 +/- 0.29 mSv by the two methods, respectively. Renal pathology reduced the effective dose, on average, by 15% of the value for normal patients.


CONCLUSIONS
Over the pediatric age range, the uniformity of effective dose values was improved by scaling the administered activity according to body surface area rather than to body weight.
Smith
T
T
Department of Medical Physics and Radiology, Great Ormond Street Hospital for Children NHS Trust, London.
Evans
K
K
Lythgoe
M F
MF
Anderson
P J
PJ
Gordon
I
I
D000293:Adolescent; D001830:Body Surface Area; D001835:Body Weight; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007668:Kidney / Q000000981:diagnostic imaging; D007676:Kidney Failure, Chronic / Q000000981:diagnostic imaging*; D008297:Male; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011835:Radiation Protection; D011877:Radionuclide Imaging; D004113:Succimer / Q000493:pharmacokinetics; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D014018:Tissue Distribution
D015609:Organotechnetium Compounds; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D004113:Succimer