title: FBX aqueous chemical dosimeter for measurement of virtual wedge profiles.
abstract: We investigated the ferrous sulfate-benzoic acid-xylenol orange (FBX) aqueous chemical dosimeter for measurement of virtual (dynamic) wedge profiles on a linear accelerator. The layout for irradiation of the FBX-filled tubes mimicked a conventional linear detector array geometry. A comparison of the resulting measurements with film-measured profiles showed that, in the main beam region, the difference between the FBX system and the film system was within +/-2% and that, in the penumbra region, the difference varied from +/-1 mm to +/-2.5 mm in terms of positional equivalence, depending on the size of the dosimeter tubes. We thus believe that the energy-independent FBX dosimetry system can measure virtual wedge profiles with reasonable accuracy at reasonable cost. However, efficiency improvement is required before this dosimetry system can be accepted into routine practice.
authors.affiliation: Department of Radiotherapy, All India Institute of Medical Sciences, New Delhi.
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Semwal
authors.affiliation: Army Hospital Research and Referral, Department of Radiotherapy, All India Institute of Medical Sciences, New Delhi.
authors.forename: Anil K
authors.initials: AK
authors.lastname: Bansal
authors.affiliation: Department of Radiotherapy, University of Pune, Pune, India.
authors.forename: Pradeep K
authors.initials: PK
authors.lastname: Thakur
authors.affiliation: Command Hospital (Southern Command), and Department of Physics, University of Pune, Pune, India.
authors.forename: Pandit B
authors.initials: PB
authors.lastname: Vidyasagar
mesh_terms: D000465:Algorithms; D019817:Benzoic Acid / Q000032:analysis*; D002138:Calibration; D004867:Equipment Design; D005296:Ferrous Compounds / Q000032:analysis*; D007477:Ions; D010315:Particle Accelerators; D010636:Phenols; D017785:Photons; D011126:Polypropylenes / Q000032:analysis; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D013454:Sulfoxides; D014962:X-Ray Film; D014992:Xylenes / Q000032:analysis*
chemical_list: D005296:Ferrous Compounds; D007477:Ions; D010636:Phenols; D011126:Polypropylenes; D013454:Sulfoxides; D014992:Xylenes; C020748:ferrous sulfate; D019817:Benzoic Acid; C016833:xylenol orange