Laser Cancer Treatment
     IN THE FIGHT AGAINST CANCER, DOCTORS TEND TO USE BRUTE FORCE. 
CHEMOTHERAPY, FOR EXAMPLE, WORKS BECAUSE IT KILLS CELLS--ALL CELLS.  THE HOPE IS
THAT IT WILL KILL THE CANCEROUS ONES BEFORE KILLING THE HEALTHY ONES.  

     Wachter: "The problem is one of targetting that killing process.  . . .there's no good
way to spaticaly localize or control the area over which the therapy is performed."

     ERIC WACHTER IS A PHYSICAL CHEMIST AT OAK RIDGE NATIONAL LAB AND HE'D
LIKE TO SEE  NEW CANCER THERAPIES THAT USE A LITTLE MORE SUBTLETY.  HE'S
MASTERMINDING A NEW STRATEGY.  THE BATTLE PLAN STARTS BY SENDING IN A HARMLESS
ADVANCE GUARD. (sfx: tiptoeing in music)  THIS IS A DRUG THAT ENTERS ALL THE CELLS IN
YOUR BODY BUT WON'T START FIGHTING UNTIL IT GETS THE RIGHT SIGNAL.  THESE TYPES OF
DRUGS ARE KNOWN AS PHOTODYNAMIC BECAUSE THEY NEED ONE THING AS A CALL TO
BATTLE--PHOTONS OF LIGHT.  WACHTER AIMS A LASER AT THE CANCER CELL AND GIVES
THE DRUG ITS MARCHING ORDERS.  (SFX: trumpet and Charge!) ENERGY FROM THE LASER
ACTIVATES THE DRUG AND IT BEGINS TO KILL THE CANCER.   

     Wachter: "We have every precise control over where that therapeutic agensti
sutrned on.  the material may be throughtout hte body but only at the focus of that light
will it be damaging to cells. . . so we bring that focused light onto the cancerous cells, kill
the cancerous acells and only the cancerous cells with that light."

     ALL A PATIENT WOULD FEEL IS A LITTLE HEAT RIGHT AT THE FOCUS OF THE LASER. 
WACHTER AND HIS COLLEAGUES HAVE TO FINISH TESTING THEIR NEW METHOD BUT HOPE
THAT DOCTOR'S WILL SOON BE ABLE TO COMBAT CANCER WITH AN ALL NEW WEAPON.