Toward the Use of Implanted Cardiac Leads or the Diaphragm for Active Respiratory Motion Management in Stereotactic Arrhythmia Radioablation
Bibliographic record
Abstract
PURPOSE: To investigate the utility of implanted cardiac leads or the diaphragm for active respiratory motion management in stereotactic arrhythmia radioablation by quantifying the relationship between their motions. METHODS AND MATERIALS: Seven patients treated with stereotactic arrhythmia radioablation were imaged using 5-Hz biplanar, kV x-ray fluoroscopy for 15-20 seconds under both abdominal compression (AC) and free breathing (FB) conditions. Three-dimensional motion traces for different regions of the heart were acquired by tracking and triangulating the position of all implanted cardiac leads. The heart's respiratory motion was extracted from the total motion (respiratory + cardiac) using a low-pass filter and described in optimized coordinates using principal component analysis. The existence of a relationship between the respiratory motion of different cardiac leads or the diaphragm was quantified using the Spearman rank correlation coefficient. Polynomial correlation models relating PC1 cardiac lead motion to the diaphragm were created and evaluated on the resultant errors. RESULTS: Eighty-one respiratory motion correlations between different positions of the heart or diaphragm were calculated under both AC and FB. Consistently strong correlations between the respiratory motion of different positions in the heart and the diaphragm required accounting for phase shifts between motions. When accounting for phase shifts, the proportion of strong (>0.7) PC1 respiratory motion correlations was 100% under FB and 92.6% under AC. Linear fitting of cardiac lead motion with the diaphragm resulted in mean absolute PC1 tracking errors of (1.0 ± 0.6) mm under FB and (0.7 ± 0.4) mm under AC. CONCLUSIONS: The respiratory motion of all combinations of implanted cardiac leads and the diaphragm are moderately to strongly correlated after accounting for phase shifts between motion traces. These phase shifts should be carefully considered to ensure patient safety during respiratory tracking or gating during stereotactic arrhythmia radioablation using cardiac leads or the diaphragm as internal surrogates.
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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 | 0.002 | 0.005 |
| 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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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".