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This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Muzik, O. Articles by Chugani, H. PubMed Articles by Muzik, O. Articles by Chugani, H.

Pediatric radiation dose estimates for the tracer [C-11]PK-11195 based on in vivo PET imaging

¹ Pediatrics, Wayne State University Medical School, Detroit, Michigan

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Objectives: The PET tracer [C-11]PK11195 (PK) is an antagonist of the peripheral-type benzodiazepine binding site and allows the non-invasive imaging of microglial activation common to a number of neurological disorders affecting the developing brain. The objective of this study was to determine accurate in vivo radiation dose estimates in children.

Methods: We studied 7 children ages 5 – 14 years (mean 8.3 ± 3.3 years) who underwent dynamic PET imaging using the Exact HR PET scanner for detecting brain inflammation in various pediatric disorders. Initially, two 15min transmission scans were performed, one for the brain and the other for the torso at the location of the liver. The PK tracer (17MBq/kg) was administered and a dynamic image sequence was initiated alternating between the brain (0–20, 30-40, 50-60 min) and torso (20-30, 40-50, 60-70 min) with short 60s scans interleaved for patient repositioning. Time-activity curves were generated for the brain, heart, lungs, kidneys, liver, gallbladder and red marrow and dose estimates calculated based on the obtained residence times and the OLINDA software.

Results: For children 5-8 years of age, the average Effective Dose Equivalent (EDE) was determined as 0.0102 ± 0.006 mSv/MBq whereas for children 8-14 years of age the EDE was determined as 0.0068 ± 0.0004 mSv/MBq. These values were about 25% lower than those previously calculated based on rat data. The dose to the critical organ gallbladder wall decreased from 0.019 mSv/MBq at 5 years to 0.0079 mSv/MBq at 14 years. The average total EDE of PK PET studies was 0.11 ± 0.01mSv (0.38 ± 0.04rem).

Conclusions: Dose calculations based on rat data are a valid approach to estimate radiation dose in children. Pediatric PK PET studies yield images with good quality and are within safe dose limits.

This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Muzik, O. Articles by Chugani, H. PubMed Articles by Muzik, O. Articles by Chugani, H.