 Cordotomy involves cutting into the spinothalamic tracts, which run up the front/side (anterolateral) quadrant of the spinal cord, carrying heat and pain signals to the brain.Pancoast tumor pain has been effectively treated with dorsal root entry zone (DREZ) lesioning – damaging a region of the spinal cord where peripheral pain signals cross to spinal cord fibers.This is major surgery, carrying the risk of significant neurological side effects.