FBX aqueous chemical dosimeter for measurement of virtual wedge profiles

Abstract

The FBX aqueous chemical dosimeter has been used to measure virtual (dynamic) wedge profiles on a linear accelerator. The lay-out for irradiation of the FBX filled tubes mimicked a conventional linear detector array. A comparison of these measurements with film measured profiles shows that in the main beam region, the difference between the FBX and the film system is within ±2% and that in the penumbra region the difference varies from ±1 mm to ±2.5 mm, in terms of positional equivalence, depending upon the size of dosimeter tubes. Considering  its inherent advantage of energy independent response, and with improvement in efficiency by way of some additional modifications, the FBX system can serve as a cost-effective alternative for routine quality assurance dosimetry of virtual wedges.