title: Assessment of radiation exposure outside the radiotherapeutic room during medical accelerator beam emission with the use of TL detectors (radiation exposure outside a LINAC room).
abstract: Photon and neutron soft tissue absorbed doses near the entrance door to the medical LINAC treatment room were measured with the use of thermoluminescent detectors LiF:Mg,Cu,P in the anthropomorphic phantom. Two different therapeutic beams (6 and 15 MV) and four treatment techniques were involved in the present study. This allowed one to investigate the contribution of scattered X rays, secondary neutrons and gamma rays to the radiation field. Photon absorbed dose rates 50 cm away from the LINAC room door during emission of 15-MV X rays varied between 4.1×10(-4) and 5.6×10(-4) Gy h(-1), depending on the gantry position and the irradiation field size, whereas in the case of 6-MV therapeutic irradiation these doses are ∼1.5 times lower. In the case of 15-MV beam emission, a mixed radiation field near the bunker door is observed with the photon radiation as the main component, which includes a 33.1 % contribution of the induced gamma radioactivity and ∼2.1 % contribution of the neutron radiation.
authors.affiliation: Department of Medical Physics, University of Silesia, Uniwersytecka 4, Katowice 40-007, Poland.
authors.forename: Kinga
authors.initials: K
authors.lastname: Polaczek-Grelik
authors.forename: Beata
authors.initials: B
authors.lastname: Kozłowska
authors.forename: Marcin
authors.initials: M
authors.lastname: Dybek
authors.forename: Barbara
authors.initials: B
authors.lastname: Obryk
authors.forename: Aleksander
authors.initials: A
authors.lastname: Ciba
mesh_terms: D000886:Anthropometry; D003198:Computer Simulation; D005720:Gamma Rays; D006801:Humans; D009502:Neutrons; D010315:Particle Accelerators; D019047:Phantoms, Imaging; D017785:Photons; D011829:Radiation Dosage; D020266:Radiotherapy, Conformal / Q000379:methods*; D018570:Risk Assessment; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation*; D014965:X-Rays