A Phase I–II, Open-Label, Multicenter Trial to Determine the Dosimetry and Safety of <sup>99m</sup>Tc-Sestamibi in Pediatric Subjects
Bibliographic record
Abstract
UNLABELLED: Myocardial perfusion imaging has long been used off label by practitioners attending for children with cardiac aliments. To provide clinicians with evidence-based dosage recommendation, a phase I-II, open-label, nonrandomized, multicenter trial was therefore designed using (99m)Tc-sestamibi in pediatric subjects (registered under www.clinicaltrials.gov identifier no. NCT00162045). METHODS: Safety and pharmacokinetic data were collected from 78 subjects using either a 1-d imaging protocol (3.7-7.4 MBq/kg, followed by 11.1 MBq/kg) or a 2-d protocol (7.4 MBq/kg for both rest and stress). Anterior and posterior planar images were collected at 15 min, 1.5 h, 4 h, and 8 h. Blood and urine samples were collected at predetermined times. RESULTS: Subjects included 39 children (mean age ± SD, 8.5 ± 2.04 y) and 39 adolescents (mean age ± SD, 13.6 ± 1.39 y). Mean estimated organ-absorbed doses to the upper large intestine, small intestine, gallbladder wall, and lower large intestines were 0.082, 0.043, 0.042, and 0.035 mSv/MBq, respectively. All patients tolerated the radiotracer without serious adverse effects. Significant differences were observed in the liver, upper large intestine contents, and small intestine contents between rest and stress imaging. The effective dose equivalent and effective dose averages were lower in adolescents than younger children (0.011 and 0.019 mSv/MBq, respectively; P < 0.0001). Percentage injected doses (%IDs) corrected for radioactive decay in all dosimetry-evaluable subjects at 15 min and 4 h were 1.9% and 1.2% in the myocardium. Similarly in the lungs, the %ID for all dosimetry-evaluable subjects was 4.9% at 15 min after injection. At rest, the %ID in the liver decreased from a maximum of about 26% at 15 min to less than 9% at 90 min. With stress, values decreased from 15% to 7%, respectively. CONCLUSION: The estimates of radiation dosimetry, pharmacokinetic parameters, and safety profile in this study population are similar to published studies based on body-mass extrapolations from studies in adults. As such, applying current (99m)Tc-sestamibi dosing regimens for 1- and 2-d protocols based on those extrapolations will result in the expected radiation dose in children and adolescents.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.002 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".