2026-10-14T14:55:37Z https://api.figshare.com/v2/oai

oai:figshare.com:article/33827632 2026-09-16T04:31:04Z category_388 portal_316 item_type_3 month_year_09_2026

Data Sheet 1_Beyond mean heart dose: differentiated electrocardiographic manifestations and dosimetric mechanisms of cardiac injury in left-sided versus right-sided breast cancer after intensity-modulated radiotherapy.docx Yanjun Zhang (168997) Xiaochen Han (16921096) Feifei Wang (195514) Ruoling Han (18543733) Yasi Zhang (16904230) Ziqi Zhao (8491905) Dan Liu (108669) Zifeng Chi (18558103) Oncology and Carcinogenesis not elsewhere classified breast cancer cardiac substructures intensity-modulated radiotherapy (IMRT) laterality heterogeneity sinoatrial node (SAN) Objective<p>To investigate dosimetric exposure variations to the whole heart and substructures between left- and right-sided breast cancer patients receiving intensity-modulated radiotherapy (IMRT), and to evaluate their relationships with post-radiotherapy (post-RT) electrocardiogram (ECG) alterations.</p>Methods<p>Clinical and dosimetric data of 91 breast cancer patients (54 left-sided, 37 right-sided) undergoing postoperative free-breathing IMRT were retrospectively analyzed. Twelve-lead ECGs were regularly monitored during follow-up. Kaplan-Meier analysis evaluated ECG abnormality-free survival. Receiver operating characteristic (ROC) curves compared the predictive values of mean heart dose (MHD) and left ventricular mean dose (LV D_mean) for new-onset repolarization abnormalities in left-sided patients, utilizing mathematically derived population-specific split-points.</p>Results<p>Target volume configurations (comprehensive regional and internal mammary node irradiation) drove distinct substructure exposure patterns between sides. In left-sided patients, MHD, LV, and left anterior descending artery (LAD) doses were significantly higher than those in right-sided patients (all P < 0.001). Conversely, right-sided patients sustained significantly higher doses to the sinoatrial node (SAN) and right coronary artery (RCA) (all P < 0.001). Left-sided patients had a significantly shorter median ECG abnormality-free survival than right-sided patients (7.0 vs. 12.0 months, P = 0.038). Among the 60 patients developing post-RT ECG modifications (incidence: 81.5% in left-sided cases), left-sided cases predominantly exhibited repolarization abnormalities (68.2%), whereas right-sided cases primarily presented rhythm abnormalities (62.5%, P = 0.032). In the left-sided subgroup, LV dosimetric parameters (LV D_mean, LV V₅–V₈₀) were significantly higher in the repolarization group than in the rhythm group (all P < 0.01). ROC analysis indicated that LV D_mean outperformed MHD in predicting early repolarization changes (AUC: 0.776 vs. 0.715).</p>Conclusion<p>Early post-RT cardiotoxicity follows a laterality-specific “dual-mechanism model.” Left-sided modifications manifest primarily as acute/subacute repolarization surrogates driven by diffuse LV exposure, whereas right-sided modifications present as rhythm-based stress from focal SAN exposure.</p> 2026-09-16T04:31:04Z Dataset Dataset 10.3389/fonc.2026.1901038.s001 https://figshare.com/articles/dataset/Data_Sheet_1_Beyond_mean_heart_dose_differentiated_electrocardiographic_manifestations_and_dosimetric_mechanisms_of_cardiac_injury_in_left-sided_versus_right-sided_breast_cancer_after_intensity-modulated_radiotherapy_docx/33827632 CC BY 4.0