UV/Vis dose response of a reusable PMMA-NaCl polymer composite

Two-dimensional dosimeters are convenient tools for quickly checking the radiation profile in radiotherapy. The currently used solution is costly, especially in busy institutions with extensive quality control procedures. This study fabricates a reusable 2-mm-thick PMMA-NaCl polymer composite sheet and assesses its dosimetric properties.

The PMMA-NaCl composite sheets were prepared using hot melting procedures. For dosimetric evaluations, the samples were irradiated using 6 MV X-ray photons from a medical linac. The absorbed doses were measured as changes in the optical absorption spectrum using a UV-Vis spectrometer.

The lowest dose detected by the samples was 5 Gy, with a linear dose response of at least 20 Gy. The repeatability of the measurements was good, with a standard deviation of 5.03%. The signal was bleachable by using a 100 W filament-type lamp for dosimetric reuse.

The 2-mm-thick PMMA-NaCl polymer-composite sheet could measure absorbed radiation doses from 6 MV X-ray photons down to 5 Gy. Because the sample is reusable, it can be used in a cost-effective two-dimensional radiation dosimeter to ensure the quality of medical linacs.