Radiosurgery dosimetry using CaSO4:Eu OSLD film-a feasibility study

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Materials Science

Background:

• Optically stimulated luminescence (OSL) systems offer fast and simple 2D dose evaluation with submillimeter resolution.
• Existing OSL methods may lack cost-effectiveness or reusability for widespread application.

Purpose of the Study:

• To develop and characterize a novel, reusable optically stimulated luminescence dosemeter (OSLD) film for 2D dose mapping.
• To assess the dosimetric properties and feasibility of CaSO4:Eu embedded in a silicone elastomer matrix for radiation therapy applications.

Main Methods:

• Fabrication of a CaSO4:Eu-embedded silicone elastomer film using a low-cost methodology.
• Evaluation of dosimetric properties including repeatability, homogeneity, dose response, and signal fading using a TL/OSL Risø reader.
• Application of the OSLD film for 2D dose distribution mapping in a 6 MV photon beam for radiosurgery.

Main Results:

• The reusable OSLD film demonstrated repeatability within 3% and linearity from 5 to 25 Gy.
• Observed a sensitivity change of nearly 12% within a 5x5 cm2 film, indicating room for homogeneity improvement.
• Reported significant OSL signal fading (approx. 50% in the first week), followed by stabilization.
• Successfully mapped dose distribution in radiosurgery, proving the film's practical utility.

Conclusions:

• The developed CaSO4:Eu OSLD film presents a feasible, reusable, and low-cost solution for 2D dosimetry.
• The film's performance in mapping dose distribution in radiosurgery highlights its potential in clinical radiation oncology.
• Further optimization for homogeneity and fading characteristics could enhance the OSLD film's applicability.