Radiation biology

Investigating the action of ionising radiation on living things

Radiotherapy is the most cost-effective cancer treatment strategy applied to more than 60% of cancer patients and is responsible for over 50% of cancer cures. Technological improvements in the last couple of decades have allowed delivery of doses with much greater conformality to the tumour volumes. However, damage to the surrounding healthy tissue is unavoidable and remains one of the major limiting factors in how much radiation dose can be prescribed to a patient.

Current radiotherapy practice aims to maximise the radiation dose delivered to the tumour volume whilst minimising that absorbed by the healthy tissues.  However, absorbed dose is only a surrogate for the response of cells and tissues exposed to ionizing radiation and radiation effects are the result of complex interplay between physical, chemical and biological processes. There is therefore an increasing drive to take into consideration not just the physical dose but also the biologically intrinsic characteristics of patients and tumours, to provide additional parameters with which to optimise treatments.  Improved knowledge of the response of both normal and cancer cells/tissues to radiation is significant in the move towards more personalised radiotherapy treatments.

NPL is supporting the development and clinical implementation of biologically optimised radiotherapy through the following activities:  

• Definition and methodology for measurement of biologically relevant dosimetric quantities. In collaboration with EU National Measurement Institutes, we are interested in nano- and micro-dosimetry development for clinical applications. This includes development and validation of existing and innovative devices, definition of microdosimetric quantities and their relationship to biological response.
• Optimisation of radiobiological assays, particularly those which aim to provide recommendations and development of new clinical and pre-clinical protocols.
• Validation of robustness of biologically optimised radiotherapy plans by accounting for propagation of physical and biological uncertainties to TCP & NTCP (Tumour Control Probability & Normal Tissue Complication Probability) models.