Application of nuclear track detectors as sensors for photoneutrons generated by medical accelerators

We report on a positive attempt on the applicability of PM-355 solid-state nuclear track detectors as integrated neutron fluence sensors for monitoring the level of neutrons during full radiotherapy treatment of prostate cancer patients using the IMRT technique with 15 MeV X rays. We also report on the applicability of the activation detector 58Ni(n,p)58Co as an integrated fluence detector for the same purpose.Studies were performed at different positions in the treatment room of the Varian Clinac 2300 accelerator at the Oncology Centre in Warsaw.Both detectors were calibrated in the field of a 252Cf neutron source. The results of neutron fluence measurements at different points from the conversion target are around 106 n/cm2 Gy. The same results were obtained from the activity readings of the Ni detector. It can be concluded that both types of detectors are suitable for monitoring the integrated neutron fluence for the purposes of estimating the epidemiological risk of the treated patients.

► PM-355 detectors were used to measure neutrons around a Clinac medical accelerator.
► The detectors were equipped with PE radiators and calibrated using a 252-Cf source.
► To verify the results a nickel sample were irradiated together with the PM-detectors.
► The neutron fluence can be normalized to a dose of photons of 1.2.·106 neutrons/cm2 Gy.
► This test study with track detectors agree with findings of other dosimetry methods.