Dose Assessment of Phosphorus-32 (32P) for the Treatment of Recurrent Pterygium

Abstract

Introduction Pterygium is a wing-shaped, vascular, fleshy growth that originates from the conjunctiva and can spread into the corneal limbus and beyond. Beta irradiation after bare sclera surgery of primary pterygium is a simple, effective, and safe treatment, which reduces the risk of local recurrence. Materials and Methods Dosimetric components of strontium-90 (90Sr), phosphorous-32 (32P), and ruthenium-106 (106Ru), in form of ophthalmic applicators, were evaluated, using the Monte Carlo method. Results The obtained results indicated that 32P applicator could deliver higher doses (about 10 Gy) to a target, located within a close distance from the surface, compared to 90Sr and 106Ru; it also delivered a lower dose to normal tissues. Conclusion The risk of pterygium has increased given the geographical location and climate of Iran. Spread of dust in the country over the past few years has also contributed to the rising rate of this condition. Our results showed that using 32P applicator is a cost-effective method for pterygium treatment.

Keywords

• Pterygium
• 32P applicator
• Monte Carlo Method
• MCNP