$re = '/\s*\([^()]+\)$/m';
$str = 'Data/3d/Maps/28_rock_rc/SpeedTree/palms/images/palm_trunk.dx11.dds.dvpl (80.79 KiB)
Data/3d/Maps/28_rock_rc/stones/images/karelia_tiletex_blue.dx11.dds.dvpl (595.11 KiB)
Data/3d/Maps/28_rock_rc/stones/images/karelia_tiletex_blue.tex.dvpl (42 B)
Data/3d/Maps/29_skit_sk/work
Data/3d/Maps/29_skit_sk/work/images
Data/3d/Maps/29_skit_sk/work/images/yamato_01.dx11.dds.dvpl (153.60 KiB)
Data/3d/Maps/29_skit_sk/work/images/yamato_01.tex.dvpl (42 B)
Data/3d/Maps/29_skit_sk/work/images/yamato_02.dx11.dds.dvpl (145.80 KiB)
Data/3d/Maps/29_skit_sk/work/images/yamato_02.tex.dvpl (42 B)
Data/3d/Maps/34_forgecity_fc/buildings/images/bld_metlife.dx11.dds.dvpl (507.31 KiB)
Data/3d/Maps/34_forgecity_fc/buildings/images/bld_tower_plant.dx11.dds.dvpl (164.39 KiB)
Data/3d/Maps/34_forgecity_fc/buildings/images/build_1.dx11.dds.html (586.68 KiB)
Data/3d/Maps/34_forgecity_fc/buildings/images/build_2.dx11.dds.txt (145.84 KiB)
Data/3d/Maps/34_forgecity_fc/buildings/images/build_3.dx11.dds.gif (152.02 KiB)
Data/3d/Maps/34_forgecity_fc/buildings/images/build_4.dx11.dds.dvpl (148.57 KiB)
Data/3d/Maps/34_forgecity_fc/buildings/images/chrysler_building.dx11.dds.dvpl (515.44 KiB)
Data/3d/Maps/34_forgecity_fc/landscape/grass/forgecity_GrassMap.dx11.dds.dvpl (184.37 KiB)
Data/3d/Maps/hangar_prem_2018_birthday_6
Data/3d/Maps/hangar_prem_2018_birthday_6/birthday_5';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php