  Secondary radiation in a radiation therapy environment is considered a cause
for post-treatment side effects including secondary carcinogenesis. In a
proton-therapy setup, neutrons deliver a considerable extra dose to the
patient. Various measurements and calculations of neutron dose suggest a wide
range of values for this quantity. This paper provides a comparison between the
previously published values and analyzes the Monte Carlo calculated neutron
dose from the present work using the neutron cross-section data. The purpose is
to provide a range for the convergence of several neutron-absorbed dose data
points (e.g. 3.94 mSv/Gy in a Bonner sphere measurement and 0.4 mSv/Gy in a
SWENDI measurement) in previous works of other authors.
