Performance Improvement of Acrylic Acid Polyvinyl Alcohol Gel Dosimeter with Organic Additive for Radiation Oncology Applications
Abstract
Purpose
To develop and characterize a novel polymer gel dosimeter for 3D radiation dosimetry. This study introduces a formulation based on polyvinyl alcohol (PVA) and acrylic acid (ACA), with the inclusion of glucose as an organic sensitizer to enhance performance.
Methods
An acrylic acid–glucose PVA (ACAGLPVA) polymer gel was prepared. The dosimeter samples were irradiated using a 6-MV medical linear accelerator with absorbed doses ranging from 0 to 60 Gy. The radiation-induced polymerization was quantified by measuring the spin-spin relaxation rate (R2) using a nuclear magnetic resonance spectroscopy. The dosimeter's dependence on dose rate (200–600 cGy/min), photon beam energy (6–15 MV), and irradiation temperature (5°C–35°C) was systematically investigated.
Results
The R2-dose response of the ACAGLPVA gel was linear over a wide and clinically relevant dose range of 0 to 30 Gy (R² = 0.9979). The dosimeter exhibited a dose sensitivity of 0.1766 Gy⁻¹s⁻¹ in the linear range. The response was found to be independent of dose rate, beam energy, and irradiation temperature within the ranges studied. Unlike conventional gels, the formulation is stable at room temperature, simplifying storage and measurement procedures.
Conclusion
A novel, tissue-equivalent polymer gel dosimeter with glucose as an additive has been successfully formulated and characterized. Its linear dose response, high sensitivity, and independence from key irradiation parameters make it a promising tool for accurate 3D dose verification in advanced radiotherapy applications.