Optimisation of a polyvinyl alcohol–silver nitrate color dosimeter for 3D dose measurement in clinical radiotherapy

This study aims to optimize a polyvinyl alcohol–silver nitrate (PVA/AgNO 3 ) color dosimeter for potential application in three-dimensional (3D) dose verification in clinical radiotherapy. Formulations comprising varying concentrations of PVA (70%, 80%, 90%) and silver nitrate (1M, 2M, 3M) were prepared and irradiated with 6 MV and 10 MV photon beams across a dose range of 1–30 Gy. The optical dose response was evaluated using UV-Vis spectrophotometry. Among all formulations, 2M70P demonstrated the highest sensitivity (0.00703) and excellent linearity (R 2 = 0.99259). The dosimeter showed minimal dose rate dependence and stable optical response over 32 days. However, a notable decrease in sensitivity was observed at higher photon energy (10 MV), indicating energy dependence. Incorporating zinc oxide (ZnO) nanoparticles led to marginal enhancement in sensitivity but limited impact on overall performance. The findings support the potential use of the optimized PVA/AgNO 3 dosimeter as a reliable tool for 3D dose distribution assessment in radiotherapy quality assurance.