Room: AAPM ePoster Library
Purpose: rare abscopal effect describes observed response in untreated metastatic tumors when only the primary tumor is treated using radiotherapy (RT). Gold nanoparticles (GNPs) are radiosensitizers with potential to enhance cancer treatment via the photoelectric effect, with radiation-induced emission of photoelectrons boosting. DNA damage in tumor cells. Immunoadjuvants (IA) are proven to enhance the abscopal effect. The purpose of this study is to examine the combination effect of GNP, IA, and RT on a pancreatic tumor model to enhance the abscopal effect.
Methods: mice were used to create pancreatic cancer in syngeneic murine models from Taconic. Both flanks were injected with Panc-02 cell line and one was treated after 2 weeks once tumors were treatable size. GNP (0.5mg/kg), IA (20µg, Anti-CD 40 antibody) and RT (5 Gy) was used to treat one tumor and the second untreated tumor was monitored for the abscopal effect. Cohorts were treated two weeks after tumor inoculation with a single fractionated dose of 5 Gy (image guided RT-IGRT), 20ug of Anti-CD40 and 1mg/ml of GNP. A Small Animal Radiation Research Platform (SARRP) was used on the initial date of treatment. Mice were euthanized 6 weeks post treatment for tumor collection.
Results: significant difference was observed between treatment cohorts and the control. The tumor weight for 5 Gy alone was less than the control and Anti-CD-40 alone was slightly smaller than 5 Gy radiation. Adding anti-CD40 showed the tumor weight decreased in a higher rate compared to the 5 Gy radiation alone and Anti-CD40 alone. A combination of GNP + 5Gy RT + Anti-CD40 showed the largest decrease in tumor weight compared to the other treatments.
Conclusion: results indicate that the combination of 5 Gy radiation + Anti-CD40 and GNP is an effective treatment combination.
Not Applicable / None Entered.