Such correlation can be used to diagnose a tumor or monitor {HEAD ~ the progression} of {TAIL ~ a previously diagnosed tumor} 
of
Such correlation can be used to diagnose a tumor or monitor { HEAD ~ the progression } of { TAIL ~ a previously diagnosed tumor }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL