Subject(s)
Radiometry/instrumentation , Radiotherapy Dosage , Calibration , Evaluation Studies as Topic , HumansABSTRACT
The dose distribution pattern from a Delta-25 head scanner was evaluated experimentally in a 17.5-cm-diam cylinder water phantom for different scan speed and slice thickness combinations. TLD chips were used to measure the dose at different points across the scan section. The isodose curves thus obtained were found to be asymmetric, with the regions of maximum and minimum dose near the surface on the opposite sides of the phantom. The effect of changing the scan thickness and speed on dose was evaluated and a linear increase in dose with the increase of slice thickness was observed. This was consistent with the design of the line focus and the beam collimators used in this system. The effect of multiple slice scan on the dose was also evaluated.
