Immunomodulation by radiotherapy in tumour control and normal tissue toxicity

Area of Science:

• Oncology
• Immunology
• Radiation Biology

Background:

• Radiotherapy (RT) is a cornerstone cancer treatment with known cytotoxic effects.
• Emerging evidence suggests RT also exerts immunomodulatory effects, influencing systemic anti-tumor immunity.
• The precise mechanisms and full scope of RT-induced immune changes, including in normal tissues, are not fully understood.

Purpose of the Study:

• To discuss the current understanding of RT-induced immune effects.
• To highlight the role of RT in generating abscopal responses.
• To explore RT's impact on normal tissues, specifically the lungs and gut, and potential immune crosstalk.

Main Methods:

• Literature review and synthesis of existing research on radiotherapy and immunology.
• Discussion of immune cell, extracellular matrix, and cytokine involvement in RT-induced responses.
• Focus on immune changes in normal tissues following RT exposure.

Main Results:

• RT induces not only direct tumor cell killing but also significant immunomodulatory effects.
• These immune changes can lead to abscopal responses, where RT generates systemic anti-tumor immunity.
• RT can cause acute and chronic immune changes in normal tissues, potentially leading to toxicity and organ dysfunction.

Conclusions:

• RT's immunomodulatory capacity is a critical aspect of its anti-cancer efficacy and can induce systemic immunity.
• Understanding RT-induced immune effects in both tumors and normal tissues is essential for optimizing cancer therapy and mitigating long-term side effects.
• Further research into immune crosstalk between tissues like the lungs and gut post-RT is warranted.