The q-Gaussian Tsallis distribution has been proposed by Silva Jr et al.,1998, for being applied to the q-Doppler broadening of spectral lines. Silva Jr and coworkers discussed the Doppler effect "using the q-Maxwellian velocity distribution". However, the q-Gaussian is a function which can be able of expressing not only the Doppler (inhomogeneous) limiting case, but also the (homogeneous) collisional limiting case. Therefore, the q-Gaussian profile needs to be considered in a more general framework.