Efficiency comparison between radiotherapy alone and in the presence of radio- or photo- sensitizers on viability of DFW and HT29 cell lines: from simulations to experimental results

Document Type : Original Paper


1 Department of Electrical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

2 Medical Physics Dept., Mashhad University of Medical Sciences

3 Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, Iran



Introduction: Radiotherapy (RT) is a traditional cancer treatment method, which address needs of most cancerous patients. However, toxicity of high X-ray energies increases side effects to the normal tissues. Combination of X-ray with agents like radiosensitizers and photosensitizers has improved RT efficiency.

Material and Methods: In this study, we have developed X-ray induced photodynamic therapy (XPDT) with TiO2 nanoparticles as nanoscintillators and PpIX as photosensitizers. Moreover, a simulated multi-scale physicochemical model of XPDT incorporates the key role of molecular oxygen during PDT component efficiency of XPDT. Also, we have compared XPDT and RT outcomes in the presence and absence of radisensitizers and validated them with the experimental data of two radioresistant cell lines include DFW and HT29.

Results: In accordance with experimental results, simulations showed that XPDT was efficiently abled to destroy cancer cells in comparison with RT alone and RT in the presence of TiO2 radiosensitizers. Simulations estimated a mean drop of 45.28% in DFW and 59.02% in HT-29 cell viabilities after XPDT respect to RT alone under specified conditions. Modeling the contribution of RT and PDT components of XPDT enabled us to estimate apoptotic and necrotic death of the cells as well as cell numbers synchronously targeted by both of them called as minimum XPDT efficiency. Simulations estimated at least 13.22% of DFW cells and 21.23 % of HT-29 cells will destroy after XPDT with irradiation of 4 Gy and nanocomplex concentration of 4 mg/ml. Moreover, RT in the presence of TiO2 nanoparticles had the most effects in cell killing during XPDT.

Conclusion: Although results showed a better XPDT efficiency in targeting cancer cells respect to RT and PDT, more studies are required to explain unpredicted cellular behavior at specific treatment conditions.


Main Subjects

Articles in Press, Accepted Manuscript
Available Online from 08 June 2024
  • Receive Date: 18 January 2024
  • Revise Date: 28 May 2024
  • Accept Date: 08 June 2024