Pergascript orange-based polymeric solution as a dosimeter for radiotherapy dosimetric validation.

Area of Science:

• Medical Physics
• Radiation Chemistry
• Polymer Science

Background:

• Accurate dosimetry is crucial for effective radiotherapy.
• Existing dosimeters like Fricke gel and polymer gels have limitations.
• Development of novel, energy-independent dosimeters is needed.

Purpose of the Study:

• To investigate the potential of a novel Pergascript Orange (PGO) based dosimeter for radiotherapy.
• To evaluate the radiation sensitivity, dose response, and energy dependence of the PGO-P dosimeter.
• To compare the performance of the PGO-P dosimeter with established dosimetry methods.

Main Methods:

• Preparation of a polyvinyl butyral solution containing PGO dye and hexachloroethane (HCE).
• Irradiation of the dosimeter with ⁶⁰Co, 6 MV, and 15 MV photons.
• Spectroscopic analysis (FTIR) to confirm PGO ring opening.
• Dose response and sensitivity measurements at varying HCE concentrations.
• Energy dependence and water equivalence assessment.

Main Results:

• The PGO-P dosimeter exhibited a linear dose response from 1-20 Gy.
• Increasing HCE concentration enhanced radiation sensitivity by approximately 58%.
• The dosimeter showed an energy-independent response (≈1.2% variation) across the tested beam qualities.
• Theoretical studies indicated water equivalence from 80 keV to 10 MeV.
• Overall uncertainty was determined to be 4.5% at 95% confidence.

Conclusions:

• The PGO-P dosimeter demonstrates a promising linear and energy-independent response for radiotherapy dosimetry.
• Its performance is comparable to Fricke gel and superior to some polymer gel dosimeters.
• The PGO-P dosimeter offers a viable option for conventional radiotherapy dose verification.