SU‐FF‐T‐89: Comparison of RADPOS 4D in Vivo Dosimetry System with Phillips Bellows and Varian RPM Systems
Bibliographic record
Abstract
Purpose: To present the latest data on the newly‐developed RADPOS 4D in vivo dosimetry system including comparisons with the Phillips Bellows and Varian RPM systems. Methods and Materials: A 4D Quasar phantom was set‐up on the couch of a Phillips Brilliance CT scanner and set to move in a sinusoidal pattern with amplitude of 1 cm. The Phillips Bellows belt was secured around the moving translation stage and was used to record the motion of the stage. The same motion was also measured by a RADPOS detector. This procedure was repeated on the couch of a PET/CT scanner using the Varian RPM system. A RADPOS detector and the RPM optical block were placed on top of the phantom's translation stage and the motion was recorded by both systems. The feasibility of using the RAPDOS system for in vivo dosimetry during daily external beam radiation therapy is also being studied. Results: When used to measure simulated breathing motion on a 4D Quasar phantom, the RADPOS‐measured displacements were on average within 0.13 and 0.05 mm of those recorded by the Phillips Bellows and Varian RPM systems, respectively. The correlation between the RADPOS displacements and those measured by the Bellows and RPM systems were 0.96 and 0.99, respectively. Initial results for clinical use in radiation therapy treatments show that the RADPOS system can be set‐up quickly, requiring minimal additional time for each scheduled treatment fraction. Conclusions: In conclusion, the RADPOS system agrees well with currently accepted position monitoring systems and provides sufficient information to identify changes in the patients breathing pattern and other patient motion. Acknowledgements: This project is supported by grants from HTX and ORCC Foundation. Financial and technical support from Best medical Canada is also acknowledged.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".