Radiodynamic therapy promises improving cancer treatment

Cancer is the second leading cause of death globally. Currently, the main cancer treatment modalities are surgery, chemotherapy and radiotherapy. Increasing attention is being paid to radiodynamic therapies, because they provide targeted, localized therapy as well as regional therapy for malignancies.

Radiotherapy uses external beam energies, like X-rays or gamma rays, to cause ionizing damage at tumor sites. Photodynamic therapy employs an external beam of photons to activate a photosensitizer drug, giving rise to surrounding cellular damage.

Chong et al. present a review of the current development and benefits of radiotherapy, including photon beam therapy and proton beam therapy, and photodynamic therapy.

“Over the last four decades, photodynamic therapy has proven to be effective in the treatment of superficial and flat lesions in a variety of oncological indications,” said author Yong Zhang. “But it has not gained clinical acceptance as a first-line treatment option in most cases, mainly due to the limited penetration of the excitation light in biological tissues.”

Combining radiotherapy and photodynamic therapy in conjunction with high energy radiation overcomes these current challenges and can provide targeted treatment to deep tissues.

“The future direction will be to combine radiotherapy and photodynamic therapy, leading to the generation of new techniques, such as X-ray photodynamic therapy, proton-induced photodynamic therapy and even hybrid approaches, such as intensity and fluence modulated photodynamic therapy,” said Zhang.

Advances in radiodynamic therapy allows for increased tumoricidal capabilities while limiting toxicities to healthy tissues. It has the potential to achieve increased conformality in the treatment of cancer, paving the way for new advances in precision medicine.

Source: “Recent advances in radiation therapy and photodynamic therapy,” by Li Ming Chong, Danny Tng, Laura Tan, Melvin Chua, and Yong Zhang. Applied Physics Reviews (2021). The article can be accessed at https://doi.org/10.1063/5.0060424 .