Figures & data
Figure 1. Photo of the tube containing ten encapsulated TLD rods. The tube extends several centimetres beyond the tungsten “end markers” only for the purpose of the patients' comfort. The total length of the tube is approximately 30 cm but depends on anatomy and diagnose. Inserted picture (lower left) shows an EPID image with TLD rods (white crosses) interspaced with lead markers. The black arrow marks the isocentre.
Figure 2. Top view and front view of the polystyrene phantom used for TLD measurements and MC simulation of absorbed dose in the points a to d.
Figure 3. TLD readings of two measurements performed on a rhinopharynx patient with one-week interval. The solid lines represent upper and lower tolerance levels (dosimetric + geometric).
Figure 4. Results of calculated to measured dose ratio from 10 patients and 177 measurements. Error bars plotted for the fist 121 points represent combined geometric and dosimetric tolerance.
Figure 5. Results of TLD measurements (diamond with error bars) plotted together with TPS calculations (dotted lines) and MC simulations (solid lines) for the four points of measurement, a–d, described in . Points a–c were given a symmetrical 10×10 cm2 field whereas point d was given a half beam 5×10 cm2 (X×Z) field (the X1 = 0 jaw along the long axis of the cavity in ).
