Research on CT Imaging and Radiotherapy of Breast Cancer with Bi-DTPA

Background: High z number element is advanced in Computed Tomography (CT) imaging and the sensibilization of radiotherapy because of higher mass energy absorption coefficients. Bi-Diethylene triamine pentaacetic acid (Bi-DTPA), structured on Bi element, is advanced in CT imaging ability and advantages of strong water solubility, good biocompatibility, low cost and mass production. So in this study, Bi-DTPA was used in CT imaging and radiotherapy of breast cancer to explore its feasibility and effect in CT imaging of mouse breast cancer model, and whether it had sensitization radiation characteristics through radiotherapy. Methods The characterization of Bi-DTPA was detected by FT-IR, 1 H-NMR and HR-MS. Compared the tumor CT imaging effect of Bi-DTPA with I 370 on 4T1 tumor bearing mouse model. The radiosensitization mechanism of Bi-DTPA was investigated by CCK-8 assay, clonogenic assay, ROS detection, DNA double strand break detection, flow cytometry for the detection of cell apoptosis, and treatment of 4T1 tumor bearing mouse model. Result The Bi-DTPA’s CT imaging signal was higher than I 370 at a safe concentration which synthesized by the one-pot method. During radiotherapy with Bi-DTPA, the viability of cells was reduced and the sensitization rate was 1.51. The level of ROS generated, DNA damage sites and the proportion of cell apoptosis was significantly higher than that in the radiotherapy group. The results of in vivo treatment showed that Bi-DTPA had better inhibitory effect on tumors. Conclusion The synthesized Bi-DTPA was advanced and applicable in CT imaging and possessed sound capacity in radiation therapy (RT) sensitization which can effectively kill tumor cells by ROS and inhibit tumor proliferation. Therefore, it has great potential in the future application of tumor integrated diagnosis and treatments.