Trigger-based adaptive proton therapy and changes in target coverage and cardiac dose in esophageal cancer
In brief
Adaptive proton replanning raised coverage 1.9 points or cut heart dose 1 Gy
In a retrospective study of 192 patients, adaptive plans improved target coverage by 1.9 percentage points when replanning was triggered by target underdose. In patients with cardiac overdose, they lowered mean heart dose by 1 Gy and modeled 2-year mortality risk by 1.5 percentage points, without raising lung dose; whether these dose changes improve survival remains unknown.
- Journal
- Physics and imaging in radiation oncology (Q1)
- Published
- 4 October 2026
- Study design
- Retrospective cohort
- Evidence level
- Level 3, Low (CEBM 3b)
- Authors
- Vlad Badiu, Esther Kneepkens, Dominique Reijtenbagh, Maaike Berbée, Richard Canters
- PMID
- 42891019
- DOI
- 10.1016/j.phro.2026.101104
Why clinicians should know about it
- Picked for Medical Physics (paper of the day, 18 October 2026): Trigger-based adaptive IMPT improved target coverage and cardiac sparing
Abstract
BACKGROUND AND PURPOSE: Inter-fractional anatomical variations during proton therapy for esophageal cancer may compromise target coverage and increase dose to surrounding organs. Adaptive replanning can mitigate these effects, but its cumulative dose-based and clinical impact remains insufficiently characterized. We evaluated offline adaptive intensity-modulated proton therapy (IMPT) triggered by target underdose or cardiac overdose using deformable dose accumulation. MATERIALS AND METHODS: A retrospective cohort of 192 esophageal cancer patients treated with IMPT was analyzed. Eighty-five underwent adaptive replanning and 107 were treated non-adaptively. Dose accumulation was performed by assigning each fraction to the closest weekly repeat computed tomography (CT) scan and deformably mapping doses to the planning CT. Accumulated doses from adapted and non-adapted plans were compared for internal target volume (ITV) and gross tumor volume (GTV) coverage, target hotspots, heart and lung dose, and normal tissue complication probability (NTCP) for 2-year post-treatment mortality. RESULTS: Compared with the non-adaptive treatment scenario, the adaptive scenario increased ITV D98% by 1.9 percentage points (pp) and GTV D98% by 0.8 pp. in the target underdose subgroup. In the cardiac overdose subgroup, mean heart dose decreased by 1.0 Gy and heart V40Gy by 1.7 pp., with no increase in mean lung dose. NTCP for 2-year post-treatment mortality decreased by 1.5 pp. in this subgroup. CONCLUSIONS: Trigger-based adaptive IMPT improved cumulative target coverage and cardiac sparing without increasing lung dose. Target underdose and cardiac overdose triggers provided complementary benefits, supporting their use in structured adaptive replanning.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.