{"doi":"10.1016/j.phro.2025.100730","title":"Investigation of 2D anti-scatter grid implementation in a gantry-mounted cone beam computed tomography system for proton therapy","abstract":"Background and purpose: Robust scatter mitigation by 2D anti-scatter grids (2D-ASG) in proton therapy cone beam computed tomography (CBCT) may improve target visualization and computed tomography (CT) number fidelity, allowing online dose verifications and plan adaptations. However, grid artifact-free implementation of 2D-ASG depends on the CBCT system characteristics. Thus, we investigated the feasibility of 2D-ASG implementation in a proton therapy gantry-mounted CBCT system and evaluated its impact on image quality. Materials and methods: A prototype 2D-ASG and a grid support platform were developed for a proton therapy CBCT system with a 340 cm source to imager distance. The effect of gantry flex on 2D-ASG's wall shadows and scan-to-scan reproducibility of 2D-ASG's wall shadows were evaluated. Experiments were conducted to assess 2D-ASG's wall shadow suppression and the effect of 2D-ASG on image quality. Results: While maximum displacement in 2D-ASG wall shadows was 103 µm during gantry rotation, the drift from baseline over 3 months was 8 µm and 1 µm in the transverse and axial directions. 2D-ASG shadows were successfully suppressed in CBCT images. With 2D-ASG, maximum Hounsfield Unit (HU) nonuniformity decreased from 134 to 45 HU, contrast-to-noise ratio (CNR) increased by a factor of 2.5, and HU errors were reduced from 34 % to 5 %. Conclusions: Proton therapy gantry flex was highly reproducible and did not noticeably affect 2D-ASG wall shadow suppression in CBCT images, supporting its feasibility in proton therapy CBCT system. Improved CT accuracy and artifact reduction with 2D-ASG could enhance CBCT-based proton therapy dose calculations.","journal":"Physics and Imaging in Radiation Oncology","year":2025,"id":551630,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9548,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1214519,"name":"Yawei Zhang","orcid":"0000-0002-0571-8383","position":1,"is_corresponding":false},{"id":1303907,"name":"Ryan Sabounchi","orcid":null,"position":2,"is_corresponding":false},{"id":1109069,"name":"Farhang Bayat","orcid":"0000-0002-6800-0440","position":3,"is_corresponding":false},{"id":1447703,"name":"Sébastien Brousmiche","orcid":null,"position":4,"is_corresponding":false},{"id":1447704,"name":"Curtis Bryant","orcid":null,"position":5,"is_corresponding":false},{"id":672883,"name":"Nancy P. Mendenhall","orcid":"0000-0003-2893-7703","position":6,"is_corresponding":false},{"id":1447705,"name":"Perry Johnson","orcid":null,"position":7,"is_corresponding":false},{"id":1096126,"name":"Cem Altunbas","orcid":"0000-0002-9030-8054","position":8,"is_corresponding":false},{"id":1303906,"name":"Uttam Pyakurel","orcid":null,"position":0,"is_corresponding":true}],"reference_count":45,"raw_metadata":null,"created_at":"2026-07-19T02:54:25.065895Z","pmid":"40026909","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}