NICE: Neutron spectral measurements using the Nested Neutron Spectrometer

Non-therapeutic neutron radiation that is produced as a byproduct of high-energy radiation therapy poses a carcinogenic risk to cancer patients. Assessment of this risk requires accurate measurement of the spectrum of secondary neutrons that is produced during treatment. Our research team has validated an efficient, active detector called the Nested Neutron Spectrometer (NNS) for use in radiation therapy environments. We are now able to use the NNS to compare neutron spectra produced for a variety of clinically-relevant treatment scenarios. Previous investigations have included comparison of the neutron spectra produced by modern flattening-filter-free (FFF) beams with conventional flattened beams and an extensive analysis of the impact of various treatment parameters (e.g. field size, beam energy, etc.) on neutron spectra produced by megavoltage electron beams.