Sci-Fri PM: Planning-08: Zero diffusion radiochromic genipin-gelatin dosimeter

Area of Science:

• Materials Science
• Medical Physics
• Biomedical Engineering

Background:

• Accurate three-dimensional (3-D) radiation dosimetry is crucial for effective radiotherapy.
• Existing dosimetry methods may face challenges with diffusion and image stability over time.
• Development of novel, stable, and non-toxic dosimetry materials is an ongoing need.

Purpose of the Study:

• To develop a novel zero-diffusion radiochromic hydrogel for 3-D radiation dosimetry.
• To utilize gelatin and genipin cross-linking for creating a stable dosimetry material.
• To assess the suitability of the developed hydrogel for optical computed tomography (CT) based dosimetry.

Main Methods:

• Gelatin and genipin were cross-linked in an aqueous solution with sulfuric acid to optimize gel sensitivity.
• The hydrogel's response to photon beams (4 MV x-rays) was evaluated using optical CT at 590 nm.
• Zero diffusion was confirmed by sequential 3-D scans over 18 hours and photobleaching experiments.

Main Results:

• The radiochromic bleaching process was rapid, completing within seconds of irradiation.
• Dose sensitivity was found to increase with cross-linking density and sulfuric acid concentration.
• The hydrogel demonstrated image stability for up to six months at 4°C and ten months at 23°C when protected from light.

Conclusions:

• Genipin-cross-linked gelatin hydrogels form permanent and stable images, suitable for 3-D dosimetry.
• The developed radiochromic hydrogel is a new, non-toxic material for radiation dosimetry applications.
• This material shows promise for accurate and reliable 3-D dose distribution measurements.