Oxygen-Enhanced MRI Detects Incidence, Onset, and Heterogeneity of Radiation-Induced Hypoxia Modification in HPV-Associated Oropharyngeal Cancer
Bibliographic record
Abstract
PURPOSE: Hypoxia mediates treatment resistance in solid tumors. We evaluated if oxygen-enhanced MRI-derived hypoxic volume (HVMRI) is repeatable and can detect radiotherapy-induced hypoxia modification in human papillomavirus-associated oropharyngeal head and neck squamous cell cancer. EXPERIMENTAL DESIGN: A total of 27 patients were recruited prospectively between March 2021 and January 2024. HVMRI was measured in primary and nodal tumors prior to standard-of-care (chemo)radiotherapy and then at weeks 2 and 4 (W2 and W4) into therapy. Two pretreatment scans assessed biomarker within-subject coefficient of variation and repeatability coefficient (RC). Cohort treatment response was measured using mixed-effects modeling. Responding lesions were identified by comparing HVMRI change with RC limits of agreement. RESULTS: Oxygen-enhanced MRI identified hypoxia in all lesions. The HVMRI within-subject coefficient of variation was 24.6%, and RC limits of agreement were -45.7% to 84.1%. A cohort median pretreatment HVMRI of 11.3 cm3 reduced to 6.9 cm3 at W2 and 5.9 cm3 at W4 (both P < 0.001). HVMRI was reduced in 54.5% of individual lesions by W2 and in 88.2% by W4. All lesions with W2 hypoxia reduction showed persistent modification at W4. HVMRI reduced in some lesions that showed no overall volume change. Hypoxia modification was discordant between primary and nodal tumors in 50.0% of patients. CONCLUSIONS: Radiation-induced hypoxia modification can occur as early as W2, but onset varies between patients and was not necessarily associated with overall size change. Half of all patients had discordant changes in primary and nodal tumors. These findings have implications for patient selection and timing of dose de-escalation strategies in human papillomavirus-associated oropharyngeal carcinoma. See related commentary by Mason, p. 5503.
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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 | 0.000 | 0.001 |
| 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 | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".