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