Clinical application of radiophotoluminescent glass dosimeter for dose verification of prostate HDR procedure
Schematic of a GD-302M glass dosimeter. On the left hand side (marked “123” in the figure) is the serial number end. The readout area is on the opposite end, in length. The diameter of the incident laser beam is .
(a), (b) Front and lateral views of the in-house prostate water phantom. Geometrical configurations of MCNP simulations indicate the misplacement of dosimeters vertically ( axis) and (c) horizontally ( axis) (d), where represents dosimeter; represents source. (e) Dosimeter locations for single source dwell position. TLDs or RPLGDs are placed in PMMA tubes, Nos. 1–8. (f) Dosimeter locations for multiple source dwell positions. Three dosimeters were placed inside each of the five PMMA tubes, the rest of the 12 PMMA tubes were for placing the radiation sources. Source dwell positions and dwell times were determined by the treatment planning system.
Source is located at the central PMMA tube. is given to the outer ring of the phantom (see arrow), the 100% isodose curve.
The reproducibility study for GD-302M glass dosimeters and rod TLD-100 dosimeters readout. The relative response is the variation among the individual dosimeter and is the individual reading divided by the average of the 50 readings. The error bars represent one standard deviation of six measurements.
Linearity study of the GD-302M glass dosimeter and the rod TLD-100. The coefficients of variation for each dosimeter were less than 3%.
Energy response curves for the GD-302M and the rod TLD-100. The coefficients of variation of each dosimeter were less than 3%.
MCNP simulations of the effects of the dose deviation by misplacing the dosimeter in vertical and horizontal directions. The MCNP calculation errors are within 2%.
The measured dose and TPS calculated results for single source dwell position.
The measured doses and calculated results for multiple source dwell positions. The rod TLD dosimeter is not sensitive enough to measure the dose at high dose gradient positions. (Its spatial resolution is inadequate.)
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