Tumour and normal tissue radiosensitivity: 2025 update.

Area of Science:

• Oncology
• Radiation Oncology
• Biomarkers

Background:

• Personalized oncology and radiation treatments are crucial for patient care.
• Numerous assays exist to predict tumor response and radiation toxicity but aren't in routine use.
• Advances in radiation oncology enable personalized strategies considering tumor recurrence and normal tissue reactions.

Purpose of the Study:

• To review the current status of assays for predicting tumor radiosensitivity and normal tissue toxicity.
• To highlight promising biomarkers and their evidence levels for clinical integration.
• To discuss the potential for personalized radiotherapy based on individual radiosensitivity.

Main Methods:

• Review of existing literature on radiosensitivity prediction assays.
• Assessment of evidence levels for tumor and normal tissue radiosensitivity tests.
• Discussion of emerging biomarkers like radiomics and their potential.

Main Results:

• No tumor radiosensitivity tests are in clinical use; Radiosensitivity Index and Genome-based Model for Adjusting Radiotherapy Dose show promise (Level II evidence).
• Radiomics offers potential for new biomarkers, with ongoing prospective studies.
• Normal tissue radiosensitivity prediction has Level I evidence for single nucleotide polymorphisms (SNPs) in prostate and head/neck cancers, and CD8 T-lymphocyte apoptosis assay for breast and prostate cancers.

Conclusions:

• Personalized radiotherapy can be tailored using assays predicting both tumor and normal tissue radiosensitivity.
• Level I and II evidence supports specific tests for normal tissue and tumor radiosensitivity, respectively.
• These predictive tests can guide radiotherapy decisions before treatment initiation.