How to destripe the thermal band in SLC_off LandSat 7 ETM+ data?

I am working on a special study in one of my subject. My study would require me to extract land surface temperature each year for 2007-2014. Since LandSat 5 ceaseed to operate last 2011, my 2012-2014 data are from LandSat 7 with SLC_off. How will I destripe the thermal band? I have ENVI 5.1.