CONTINUOUSLY VARIABLE COLLIMATOR FOR RADIATION THERAPY

THE GOAL OF THIS RESEARCH IS TO DEVELOP AND TEST A NEW TYPE OF SHAPED-FIELD COLLIMATOR SYSTEM TO MOUNT ON EXISTING ONCOLOGY THERAPY LINEAR ACCELERATORS AND COBALT UNITS. THE COLLIMATOR ALLOWS THE RADIATION BEAM TO BE SHAPED IN ARBITRARY IRREGULAR PATTERNS TO MATCH THE SIZE AND SHAPE OF THE TUMOR SO THAT THE DOSE TO THE TUMOR REGION WILL BE MAXIMIZED RELATIVE TO THE DOSE RECEIVED BY SURROUNDING NORMAL TISSUE. THE SHAPING OF THE RADIATION FIELD IS ACHIEVED THROUGH AN ARRAY OF MOVABLE BUT PERMANENTLY MOUNTED TUNGSTEN RODS, THE POSITION OF THE RODS BEING SET AUTOMATICALLY BY EASY-TO-FABRICATE STYROFOAM PATTERNS. MEDICAL TECHNICIANS ARE RELIEVED OF THE BURDEN (AND OF THE FREQUENT MINOR INJURIES) ASSOCIATED WITH THE HANDLING OF HEAVY CAST-METAL COLLIMATORS, WHICH ARE AT PRESENT IN FREQUENT USE FOR THE SHAPING OF IRREGULAR FIELDS. THE NEW "ROD-TYPE" COLLIMATOR WILL REDUCE OPERATING COSTS, IMPROVE STAFF WORKING CONDITIONS, AND INCREASE THE NUMBER OF PATIENTS THAT A FACILITY CAN HANDLE. THE RESEARCH PLAN INVOLVES COLLECTING DATA ON COLLIMATOR ATTACHMENT ARRANGEMENTS FOR FOUR TO SIX OF THE MOST FREQUENTLY USED THERAPY DEVICES, DESIGNING COLLIMATORS FOR THESE DEVICES, PERFORMING LIFE-CYCLE TESTS ON CRITICAL ELEMENTS, UPGRADING AN EXISTING PROTOTYPE TO FULLY AUTOMATED STATUS, AND INSTALLING THIS PROTOTYPE FOR WEEKEND DEBUGGING PERIODS ON AN EXISTING THERAPY UNIT.