Radiosensitivity testing

SHORT VERSION

The aim of a radiosensitivity test is to assess each patient’s risk of developing early or late toxicities before treatment initiation. For routine clinical use, the test must be performed using easily accessible samples and must provide rapid results that do not delay the treatment.

Since the 1990s, clinical and basic research groups have been working to develop tests to predict the patients’ radiosensitivity. These tests evaluate, before treatment, the individual risk of developing complications following radiotherapy.

It is important to distinguish the two side effect types that can occur during or after radiotherapy: early or acute complications and latecomplications.

  • Acute complications usually appear during treatment and disappear within 3 months after the treatment end.
  • Late complications appear between 3 months and 3 years after the treatment end and are irreversible. These complications occur in less than 10% of all patients treated with radiotherapy.

Because of their irreversible nature and the impact they can have on the patient quality of life, much effort has been focused on developing tests to predict the occurrence of late complications.

Currently, there are two tests based on different techniques and sample types (blood or skin) They have very different levels of clinical evidence.