Technical note: Consistency of IAEA's TRS‐483 and AAPM's extended TG‐51 protocols for clinical reference dosimetry of the CyberKnife M6 machine
Bibliographic record
Abstract
Abstract Background While IAEA's TRS‐483 code of practice is adapted for the calibration of CyberKnife machines, AAPM's TG‐51 is still the protocol recommended by the manufacturer for their calibration. The differences between both protocols could lead to differences in absorbed dose to water during the calibration process. Purpose The aims of this work are to evaluate the difference resulting from the application of TG‐51 (including the manufacturer's adaptations) and TRS‐483 in terms of absorbed dose to water for a CyberKnife M6, and to evaluate the consistency of TRS‐483. Methods Measurements are performed on a CyberKnife M6 unit under machine‐specific reference conditions using a calibrated Exradin A12 ionization chamber. Monte Carlo (MC) simulations are performed to estimate and using a fully modeled detector and an optimized CyberKnife M6 beam model. The latter is also estimated experimentally. Differences between the adapted TG‐51 and TRS‐483 protocols are identified and their impact is quantified. Results When using an in‐house experimentally‐evaluated volume averaging correction factor, a difference of 0.11% in terms of absorbed dose to water per monitor unit is observed when applying both protocols. This disparity is solely associated to the difference in beam quality correction factor. If a generic volume averaging correction factor is used during the application of TRS‐483, the difference in calibration increases to 0.14%. In both cases, the disparity is not statistically significant according to TRS‐483's reported uncertainties on their beam quality correction factor (i.e., 1%). MC results lead to and . Results illustrate that the generic beam quality correction factor provided in the TRS‐483 might be overestimated by 0.36% compared to our specific model and that this overestimation could be due to the volume averaging component. Conclusions For clinical reference dosimetry of the CyberKnife M6, the application of TRS‐483 is found to be consistent with TG‐51.
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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 | 0.041 | 0.062 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.003 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.002 |
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".