Diffuse choroidal hemangioma: IMRT versus episcleral plaque brachytherapy

Area of Science:

• Ophthalmology
• Radiation Oncology
• Medical Physics

Background:

• Diffuse choroidal hemangioma (DCH) is a rare vascular tumor that can affect vision.
• Traditional management often involves radiation therapy, with varying techniques and associated risks.
• Intensity-modulated radiation therapy (IMRT) and 3D-conformal radiotherapy (3D-CRT) are advanced external beam radiation techniques.

Purpose of the Study:

• To evaluate the safety and procedural aspects of IMRT and 3D-CRT for DCH management.
• To compare the dosimetric outcomes of IMRT/3D-CRT with simulated episcleral plaque brachytherapy.
• To assess potential long-term risks to critical visual structures.

Main Methods:

• Retrospective review of 10 patients (11 eyes) with Sturge-Weber syndrome-associated DCH treated with IMRT (20 Gy in 10 fractions).
• Simulated episcleral plaque brachytherapy plans were created for the same patients.
• Doses to the fovea, optic disc, and lens were collected and compared between techniques.

Main Results:

• IMRT and 3D-CRT achieved effective target volume coverage with low doses to critical structures.
• External beam radiotherapy (EBRT) doses to the fovea, disc, and lens were uniform.
• Simulated brachytherapy resulted in highly variable and potentially higher radiation doses to these critical structures.

Conclusions:

• IMRT and 3D-CRT provide a safe and uniform treatment plan for DCH, with good sparing of the lens, fovea, and optic disc.
• Simulated brachytherapy showed a higher risk of radiation exposure to critical visual structures, potentially leading to vision-threatening toxicity.
• Treatment decisions for DCH should be individualized based on dosimetric parameters, considering EBRT or brachytherapy on a case-by-case basis.