Assessment of the potential of radiosensitizers to improve the efficacy of Radiation Therapy

Cancer is a disease characterized by uncontrolled growth of cells, with breast cancer being one of the most common types, predominantly affecting women. Among the available therapeutic modalities, radiotherapy stands out as one of the most widely used, although it presents limitations due to irradiation of healthy tissues. In this context, the use of radiosensitizing particles has been extensively investigated, aiming to enhance the dose delivered to the tumor while reducing side effects in surrounding tissues.

In this study, breast cancer cells were incubated with different concentrations of gold nanoparticles and subsequently irradiated with a clinical X-ray beam (6 MV) and a Cobalt-60 gamma rays beam at various dose points. Immediate biological effects were assessed through fluorescence assays, analysing DNA damage, lipid metabolism alterations, and reactive oxygen species production. Late effects were quantified by clonogenic assays, enabling the construction of survival curves based on the linear-quadratic model. Additionally, gold nanoparticles were incorporated into a radiotherapy treatment plan for a breast cancer patient to evaluate the potential clinical impact of this strategy.

The results demonstrated a significant radiosensitizing effect of gold nanoparticles, leading to a substantial reduction in cell survival, particularly under clinical X-ray irradiation. It was also observed that including these radiosensitizers in treatment planning contributes to reduced doses to organs at risk, increasing the likelihood of tumor control.