Lung tumors are the leading cause of cancer death and are difficult to treat. Radiotherapy has proven to be a successful treatment for lung cancer. Nanoparticles with a high Z, or atomic number, can augment the effectiveness of radiation and increase the localization of radiation doses at the site of the tumor The photoelectric effect is dependent on beam energy and Z value. Radiation can cause generation of reactive oxygen species, or ROS, by interacting with H2O2 present within biological systems. Nanoparticles act as radiosensitizers through the photoelectric effect to cause radiation enhancement when a photon interacts with high Z particles and leads to a greater production of secondary electrons, such as Auger electrons, which generate direct DNA damage or ROS. Double stranded breaks lead to the DNA damage and incurs an additional immune response to target cancer cells. This project seeks to determine differences in radiosensitization enhancement of four formulations of silica-based bismuth gadolinium nanoparticles in vitro in non-small cell lung cancer cell lines after irradiation by using a variety of assays, like survivability and ROS generation. The preclinical implications will help determine the optimum bismuth-gadolinium ratio of nanoparticles for further clinical radiation. Increased ROS is associated with reduced cell survival, suggesting that high Z nanoparticles, like silica-based bismuth gadolinium can enhance the effects of radiation therapy as a lung cancer treatment.