Development of a mailed dosimetry audit system for radiation therapy in Canada
Bibliographic record
Abstract
The aim of this work was to develop and trial a mailed audit system for external beam radiation therapy, traceable to the Canadian National Metrology Institute, with an overall uncertainty comparable to calibrated secondary standard reference detectors. Alanine was chosen as the dosimeter to be used for the audit system. After a detailed investigation of influence quantities, a complete uncertainty budget was constructed, indicating a relative standard uncertainty in the desired quantity – absorbed dose to water – of around 0.9 %. The complete system was then validated by comparison with the standard maintained by the National Physical Laboratory in the UK. The comparison between the two alanine systems at the two laboratories showed agreement at the 0.5 % level. A hermitically-sealed dosimeter holder was developed for simplicity of use and to reproduce the geometry of standard clinical dosimeters. Eleven cancer centres across Canada participated in the initial trial. The mean ratio of the dose measured using alanine, relative to the dose delivered was found to be 1.010 with a relative standard uncertainty of 0.6 %. These investigations have confirmed the suitability of the alanine system, both in terms of ease-of-use and accuracy, for mailed audit dose measurements in Canada.
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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 | 0.005 | 0.007 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 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".