Patient positioning in static beams for boron neutron capture therapy of malignant glioma.

PURPOSE To develop a procedure for the optimum patient positioning and immobilization during boron neutron capture therapy (BNCT) of glioblastoma multiforme (GBM) at the Brookhaven medical research reactor (BMRR). METHODS A replica of the treatment room in the BMRR was constructed to simulate patient position. A unique feature is a transparent opening in wall to simulate the location of the beam port and to provide a beam-eye view of the head. A portable stereotactic frame was built to facilitate head markings. These marking provide critical reference points for determining the entry point of the central beam axis and patient positioning coordinates calculated relative to these points. RESULT This patient positioning and immobilization system has proven to be satisfactory in minimizing the variations from the planned BNCT radiation doses. CONCLUSION The approach described herein has been satisfactory in treating patients with GBM. These patients are minimally sedated during BNCT lasting from 38 to 73 minutes.