Thank you Sander.
I tried to use
ContourPlot3D[{h == 0, g == 0}, {x, -2, 2}, {y, -2, 2}, {z, -2, 2},
MeshFunctions -> {Function[{x, y, z, f}, h - g]},
MeshStyle -> {{Thick, Blue}}, Mesh -> {{0}},
ContourStyle ->
Directive[Orange, Opacity[0.5], Specularity[White, 30]]]
but in order to build a MeshFunction you have to interpolate the matrices. I have already solved the problem in the following way using Interpolation functions:
ReI=ListInterpolation[RE]
ImI=ListInterpolation[IM]
ContourPlot3D[{ReI[x,y,z] == 0, ImI[x,y,z]== 0}, {x, 25, 65}, {y, 30, 70}, {z, 30,70}, ContourStyle -> Opacity[0.1], Mesh -> None,BoundaryStyle -> {{1,2} -> {{Green,Tube[0.5]}}}, AxesLabel->{x,y,z},PlotPoints -> 16]
However, as soon as I increase the number of points in 'PlotPoints' (the quality of the graph), the memory used is too much and Mathematica quits after few hours.