TH-E-BRB-02: Linearization of Dose Response Curve for the Radiochromic Film Dosimetry System
Bibliographic record
Abstract
Purpose: In order to measure relative dose distribution with radiochromic film, one need to first measure an absolute dose (following previously established reference dosimetry protocol) and then convert measured absolute dose into relative dose. We present here result of our efforts to establish a functional form that converts the inherently non-linear dose response curve of the radiochromic film dosimetry system into liner one. Methods: In order to test the invariance of the proposed functional form with respect to the film or scanner model used, we have tested it on film pieces from three different GAFCHROMICTM film models (EBT, EBT-2, and EBT-3) irradiated to various doses and scanned on a single scanner. for one of the film models we have also tested it by scanning with three different flatbed scanner models (Epson V700, 1680, and 10000XL). To test our hypothesis that the proposed functional argument linearizes the response of the radiochromic film dosimetry system, we performed a measurement of percent depth dose (PDD) curves in Cobalt-60 beam. Results: Obtained R2 values indicate that the choice of the functional form of the new argument (ζ) appropriately linearizes the dose response of the radiochromic film dosimetry system we used. The linear behavior was insensitive to both film model and flatbed scanner model used. Measured PDD values using the green channel response of the GAFCHROMICTM EBT-3 film model are well within ±2% window of the local relative dose value when compared to the tabulated Cobalt-60 data. Conclusions: We demonstrate the use of a unique functional argument to linearize the inherently non-linear response of a radiochromic film based reference dosimetry system. In this way, relative dosimetry can be conveniently performed using radiochromic film dosimetry system without the need of establishing an absolute calibration curve. One author is from GAFCHROMICTM films manufacturer
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".