ArticleRadiation oncology (London, England)2026
Tissue-level RBE determination and normal lung responses along the proton SOBP.
Article in Radiation oncology (London, England), 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundTo determine proton relative biological effectiveness (RBE) across the spread-out Bragg peak (SOBP) in rat lung using a histological endpoint, with emphasis on changes associated with increasing linear energy transfer (LET). Histological alterations in alveolar epithelial cells (ATI and ATII) and inflammatory responses involving [Formula: see text] and mast cells were also evaluated.
methodsThe rat lung was irradiated with single-dose proton irradiation delivered to four different regions (dose-mean LET 1.89-3.68 keV/μm) along a 9 cm SOBP or with 6 MV photon irradiation as a reference. Lung tissues were harvested 4 weeks after irradiation and subjected to histological analysis. Lung injury was scored using the American Thoracic Society-recommended system (endpoint [Formula: see text]), from which [Formula: see text] (effective dose for 50% response) and RBE values were derived. Cellular and inflammatory responses were evaluated at dose levels of 16 and 20 Gy using immunohistochemical staining for AQP5 (ATI), SFTPC (ATII), and [Formula: see text] as an inflammatory marker, while mast cells were identified by toluidine blue staining.
resultsAlong the SOBP, the RBE values increased from [Formula: see text] to [Formula: see text] as [Formula: see text] values decreased from [Formula: see text] Gy to [Formula: see text] Gy, respectively. All irradiated groups showed altered ATI-positive cell proportion, [Formula: see text] expression, and mast cell number compared with controls. In the low-LET regions (proximal and central SOBP), these changes were comparable to those in the photon group, whereas the distal high-LET SOBP region exhibited more pronounced alterations, including reduced ATI-positive cell proportion and increased [Formula: see text] expression and mast cell accumulation. Although ATII-positive cell proportion was reduced in all irradiated groups, no regional differences were observed along the SOBP; however, morphological alterations were evident in the distal region.
conclusionsTissue-level RBE calculations revealed an increase toward the distal region of the proton SOBP. Proton-induced lung injury was spatially heterogeneous along the SOBP, with distal high-LET regions showing the most severe epithelial damage and inflammation. These findings suggest that the use of a constant generic RBE may underestimate biological effects, highlighting the need for LET-informed proton therapy planning.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.