Program Information
A Novel 3D Printed Ophthalmic Applicator for Conjunctival Melanoma Brachytherapy
C Lee*, J Mikell , K Lam , University of Michigan, Ann Arbor, MI
Presentations
SU-H4-GePD-T-5 (Sunday, July 30, 2017) 4:30 PM - 5:00 PM Room: Therapy ePoster Lounge
Purpose: To design and manufacture a novel 3D printed ophthalmic brachytherapy applicator for the treatment of conjunctival melanoma to overcome the dosimetric limitations of the commonly used Collaborative Ocular Melanoma Study (COMS) eyeplaques.
Methods: A commercial benchtop 3D resin printer (Form 2, FormLabs Inc., Somerville, MA) was used to print a custom brachytherapy applicator that was previously developed in-house. The plaque was designed to deliver a torus-shaped radiation along the conjunctival tissues of eye, which is difficult to achieve with conventional COMS plaque. A class 1 biocompatible resin (Dental SG Resin, FormLabs) was chosen to provide 1) required resolution and rigidity to house 12 low dose I-125 seeds (model IAI-125A, IsoAid, LLC, Port Richey, FL) and 2) medical grade biocompatibility and sterility. The printing time and curing process were investigated for optimal clinical application. Dose distribution is estimated with TG43 formalism and MCNP Monte Carlo simulation.
Results: It took 2.5 hours to print two identical custom plaques. Complete curing process required three hours of optical exposure from a custom UV light box. Supporting structures that were necessary during 3D printing was carefully removed to make smooth surface, avoiding any potential damage to the soft tissues that are in direct contact. A torus shaped 3D dose distribution was achieved for conjunctival tissue irradiation.
Conclusion: A high resolution custom eyeplaque can be designed and printed via a commercial benchtop 3D resin printer. A relatively short turnaround time makes it possible to manufacture personalized plaque design cost effectively. The availability of medical grade biocompatible resin opened opportunities of printing various custom brachytherapy applicators.
Contact Email: