ABSTRACT
X-ray images used for radio-diagnosis are very useful to evaluate the progress of a treatment or to have a better diagnosis. However, during the interaction between the incoming X-ray beam and the body surface, part of the radiation is scattered out reaching other parts of the body delivering an undesirable dose. In this work the dose in eye lenses, thyroid, and gonads of a solid water phantom was measured using thermoluminescent dosimeters, while a Computer Tomography of the torso was obtained. With the measured absorbed dose the effective dose was calculated. Thus, the effective dose in the eye lens, thyroid, and gonads is approximately 57, 214 and 9⯵Sv respectively. The largest effective dose was on that area located nearest to the region where the radiation is scattered.
Subject(s)
Gonads/radiation effects , Lens, Crystalline/radiation effects , Radiation Dosage , Thyroid Gland/radiation effects , Tomography, X-Ray Computed , Humans , Scattering, RadiationABSTRACT
The ambient dose equivalent has been measured on the walls of a bunker with a 6â¯MV TomoLINAC, which was designed to have a conventional 18â¯MV LINAC. The ambient dose equivalent is due to scattered photons on patient bodies during cancer treatment. Measurements were carried out with thermoluminescent dosimeters that were fixed, at the isocentre plane, on the primary and secondary barriers, the maze, and on the TomoLINAC surface. Measurements were repeated three times, in each time dosimeters were on place during seven working days, where approximately 50 patients were treated per day. Ambient dose equivalent at each location was normalized to the total dose applied during the measuring time. The primary and secondary concrete barriers are thick enough to reduce the dose to safe values.