The concept of lost alpha measurement by 4.44 MeV gamma ray detection produced by the nuclear reaction 9Be(α,nγ)12C was examined for ITER. A MCNP calculation was carried out to evaluate the neutron flux in the port plug, where a gamma-ray detector is supposed to be located. The results showed the total neutron flux was at least 1011 ∼ 1012 cm-2s-1 at the detector location. One of the candidate detectors for the 4.44 MeV gamma-ray measurement is a Ce:LSO scintillator. The response of Ce:LSO to neutrons was estimated for each neutron energy region, and then they are convoluted with the neutron flux at the detector location. It was found that an additional neutron shield layer is needed to reduce neutron fluxes by a factor of 103 at least.