Anticancer Effects of radiation dose and dose fractionation on X-ray-induced photodynamic therapy

Preclinical research has established X-ray-induced photodynamic therapy (X-PDT) as a highly acknowledged antitumor therapy. X-rays play an important role in the X-PDT process. It is crucial to understand the impact of both the total dose and dose fractionation on the effectiveness of X-PDT. For the first time, a systematic study has been conducted on the effects of radiation dose and dose fractionation mode on the efficacy of X-PDT deeply. In vitro and in vivo results showed that there is an optimum dose threshold for the anti-tumor efficacy of X-PDT within the range of 0–6 Gy radiation dose. Additionally, the anti-tumor effect of a single exposure mode is significantly superior to that of a hyperfractionated radiation mode in 4T1 tumor-bearing mice. Notably, X-PDT significantly inhibited the invasion and migration of tumor cells and significantly inhibited lung metastasis of breast cancer. These new findings are significant for the clinical application of X-PDT and offer valuable insights for the development of future X-PDT radiation plans.