PO-0755: Can dose proximal to the PTV influence the risk of distant metastases in SBRT lung cancer patients?
Bibliographic record
Abstract
We report on the results from second interim analysis on toxicity from the Danish NARLAL2 trial (Novel Approach on Radiotherapy for LA-NSCLC). Material and MethodsNARLAL2 is a multi-centre, randomized phase III trial testing an isotoxic FDG-PET driven, inhomogeneous dose escalation in 33 fractions (F) against standard homogenous RT 66 Gy in 33 F (NCT02354274).There is an extended QA-program along with this protocol including procedure before recruitment, during, and after treatment.This includes workshops, on-site visit, dose plan uploading to dose-planning bank, daily imaging, adaptive strategy etc (Moeller el al, Radiother Oncol.2017 Aug;124(2):311-317 ).In order to avoid excess toxicity with this dose escalation we planned interim analysis to evaluate acute and semi acute toxicity when the first 20, 40, and 60 patients (pts) enrolled in the dose escalated arm had three months follow-up.Observation of ≥10% acute radiation related non-hematologic toxicity of grade ≥4 in the escalated arm was regarded unacceptable, and the study would be stopped for further assessment.Using the method of O´Brien-Flemming, the stopping rules are activated if 7 of first 20 pts in the dose-escalated arm experienced toxicity as described.Likewise, 9 of the first 40 pts etc.Late toxicity would be evaluated after a minimum of 12 months potential follow-up after end of RT, but up to 5% grade ≥4 is considered acceptable.Enrolment for this trial started on 2015 with planned 330 pts. ResultsFour centres are currently enrolling pts and another 4 centres are to start.A number of 101 pts have been randomized Oct 2017, with 53 pts treated in the escalated arm.At the first interim analysis on acute/ semi acute toxicity, 2 pts experienced grade ≥4 (haemoptysis and infection), but neither of these were related to the RT.At the second interim analysis, one further patient experienced grade ≥4 (vena cava superior syndrome), which might be related to the RT.The point for the first interim analysis on late toxicity has not yet been reached.Conclusion PET-FDG driven inhomogeneous dose escalation in LA-NSCLC pts seems safe according to acute-semi acute toxicity in this isotoxic setting evaluated in 2 interim analyses for acute/semi-acute toxicicty.
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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 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 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".