The Dose from Secondary Neutrons during the Operation of Modern Medical Accelerators

Resumo

A review of the experiments performed to date and calculations on the study of doses from secondary neutrons during the operation of medical electron accelerators of various manufacturers is presented. The fundamental differences between the heads of the three largest manufacturers (Varian, Elekta, and Siemens) are given. This article contains data on flux densities and doses for different accelerator models and operating modes. The data analysis showed that the dose from secondary neutrons when irradiating patients on a linear medical accelerator with bremsstrahlung should be taken into account, since its contribution can reach 2.04% at a maximum energy of up to 24 MeV. The contribution to the absorbed dose of secondary neutron fluxes must be evaluated when planning radiation therapy; all other things being equal, it is also necessary to choose modes of operation with the lowest rated energy for treating patients.