The three-dimensional scintillation dosimetry method: test for a 106Ru eye plaque applicator

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Optical Imaging

Background:

• Radiation therapy requires accurate 3D dosimetry for quality assurance, but current techniques are often slow.
• Developing faster and high-resolution 3D dosimetry methods is crucial for advancing radiation therapy.

Purpose of the Study:

• To introduce and evaluate a novel three-dimensional scintillation dosimetry (3DSD) method for radiation dose measurement.
• To assess the feasibility of using liquid scintillators as both phantom material and dose detector.

Main Methods:

• The 3DSD method utilizes visible light images of a liquid scintillator volume taken from multiple angles.
• A tomographic algorithm reconstructs the scintillation light emission density, correlating it with absorbed dose.
• The method was applied to a Ruthenium-106 eye plaque, with results compared to radiochromic film and diode measurements.

Main Results:

• The 3DSD method showed agreement within 25% or 2 mm distance to agreement with film and diode measurements in specific regions outside the plaque.
• Agreement was observed in unobstructed, high-gradient dose areas.
• Accuracy was limited near the plaque's edge and beyond 10 mm from its surface.

Conclusions:

• Three-dimensional scintillation dosimetry (3DSD) presents a promising, potentially fast method for 3D dose reconstruction in radiation therapy.
• Further improvements are needed for enhanced accuracy, particularly near brachytherapy applicators.
• The method could provide a quicker 3D dose profile check for brachytherapy quality assurance.