Novel frameless LINAC radiosurgery solution for uveal melanoma

Area of Science:

• Ophthalmology
• Radiation Oncology
• Medical Imaging

Background:

• Uveal melanoma (UM) treatment has shifted towards organ-preservation, with radiation therapy replacing enucleation.
• Fractionated stereotactic radiosurgery (fSRS) is a key organ-preservation technique for UM.
• Novel, non-invasive delivery methods are needed to improve fSRS for ocular tumors.

Purpose of the Study:

• To develop and evaluate a novel non-invasive, frameless LINAC-based solution for fSRS treatment of uveal melanoma.
• To assess the feasibility, tolerability, and setup accuracy of the developed system.

Main Methods:

• A stereotactic ocular localization box was designed and 3D-printed, featuring adjustable LED lights and a CCD camera for eye position monitoring.
• The system incorporates infrared spheres compatible with the ExacTRAC image-guided radiation therapy (IGRT) system.
• Treatment plans involved conformal dynamic arcs with a 6MV flattening filter-free photon beam, delivering 50Gy in 5 fractions, with real-time eye movement tracking.

Main Results:

• The stereotactic ocular localization box demonstrated high setup accuracy, with residual setup errors in lateral, longitudinal, and vertical directions below 0.3 mm.
• Rotational errors were also minimal, with pitch, roll, and couch rotation errors below 0.3 degrees.
• All 10 treated patients successfully completed the fSRS treatment, indicating feasibility and tolerability.

Conclusions:

• A novel non-invasive, frameless LINAC-based solution for fSRS of uveal melanoma and other ocular tumors has been successfully developed.
• The system is well-tolerated and achieves high setup accuracy, offering a promising organ-preservation approach.
• Future multi-center trials are warranted to assess the efficacy and reproducibility of this innovative therapeutic solution.