Abstract:Objective To evaluate the changes in the right ventricular function via velocity vector imaging (VVI) in patients with middle and lower esophageal cancer, left lung cancer and left breast cancer before and after radiotherapy.Methods From May 2020 to May 2021, thirty patients with middle and lower esophageal cancer, left lung cancer and left breast cancer in the Affiliated Hospital of Yanbian University were examined by echocardiography within 1 week before and after radiotherapy. The right ventricular basal diameter (RVD1), right ventricular middle diameter (RVD2), right ventricular longitudinal dimension (RVD3), fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), peak systolic velocity (S'), myocardial performance index (Tei), isovolumic acceleration (IVA) were evaluated. The VVI was applied to measure the right ventricular global longitudinal strain (RVGLS), and right ventricular free wall longitudinal strain of the basal (RVLSbas), mid (RVLSmid), and apical (RVLSapi) segments, which were used for calculating the right ventricular free wall longitudinal strain (RVLSfw). The general parameters and strain parameters were compared before and after radiotherapy, and the correlations of RVGLS and RVLSfw with the general parameters measured via conventional echocardiography and strains of each segment of free walls were analyzed.Results There was no statistically significant difference in RVD1, RVD2, RVD3, or S' before and after the radiotherapy (P > 0.05). Following the radiotherapy, FAC, TAPSE, and IVA were decreased, while Tei was increased (P < 0.05). Besides, RVLSbas, RVLSmid, RVLSapi, RVLSfw, and RVGLS were also increased after the radiotherapy (P < 0.05). RVGLS was negatively correlated with FAC, TAPSE, and IVA (r = -0.563, -0.398 and -0.373, P = 0.001, 0.030 and 0.042), but was positively correlated with S' (r = 0.387, P = 0.035). RVLSfw was negatively correlated with TAPSE (r = -0.489, P = 0.006), but was positively correlated with RVLSbas and RVLSmid (r = 0.582 and 0.378, P = 0.001 and 0.040).Conclusions VVI can be used to evaluate the early changes of the right ventricular function in patients with middle and lower esophageal cancer, left lung cancer and left breast cancer after thoracic radiotherapy.