Characterization of a practically designed plastic scintillation plate dosimeter.

Area of Science:

• Medical Physics
• Radiotherapy Technology
• Dosimetry

Background:

• Radiotherapy advancements enable precise irradiation but face challenges in resolution, measurement area, and repeatability.
• Current clinical practice often requires multiple dosimetry systems to overcome measurement limitations.
• A need exists for a high-resolution, repeatable dosimeter for accurate dose distribution measurements.

Purpose of the Study:

• To design a practical scintillation plate dosimeter.
• To evaluate the dosimetric characteristics of the designed system.
• To assess its suitability for use with linear accelerator x-ray beams.

Main Methods:

• A scintillation plate dosimeter was constructed using a 0.2 cm scintillation plate and two 2.0 cm Polymethyl methacrylate (PMMA) plates.
• A Complementary Metal Oxide Semiconductor (CMOS) camera detected scintillation light for dose measurement.
• Evaluations included dose linearity, reproducibility, temperature and angle dependencies, dose-rate, and x-ray energy dependencies using various linear accelerator beams.

Main Results:

• Dose linearity error was a maximum of 0.4% over 10–1000 MU.
• Dose reproducibility showed a coefficient of variation of ±0.062%.
• Temperature dependency was 0.07%/°C, angular variations were within ±1.3% (post-Cherenkov removal), and x-ray energy dependency ranged from -2.1% to +1.4%.

Conclusions:

• The developed scintillation plate dosimeter exhibits favorable dose characteristics.
• The system is suitable for patient-specific quality assurance in radiotherapy.
• It shows particular promise for volumetric modulated arc therapy applications.