Radiation induced optic neuropathy: Does treatment modality influence the risk?

Area of Science:

• Ophthalmology
• Radiation Oncology
• Medical Physics

Background:

• Radiation-induced optic neuropathy (RION) is a severe complication of radiation therapy for periorbital tumors.
• Accurate incidence data for modern photon and proton therapy modalities are crucial for risk assessment.

Purpose of the Study:

• To investigate and compare the incidence of RION in patients treated for periororbital tumors using Intensity Modulated Radiotherapy (IMRT) and Proton Beam Therapy (PBT).

Main Methods:

• Systematic literature search of PubMed for studies published between 1992 and 2017 on periorbital tumors treated with IMRT or PBT.
• Inclusion criteria focused on photon and proton therapy, excluding specific tumor types, pediatric cases, and non-English/French publications.
• Analysis of 31 studies reporting optic nerve/chiasm doses and RION incidence.

Main Results:

• RION incidence was reported comparably across both IMRT and PBT modalities.
• Multiple factors, including patient, tumor, and irradiation parameters, influence RION development.
• Dose to the optic nerve (ON) and optic chiasm (OC) were key factors analyzed.

Conclusions:

• Optimizing treatment planning and selecting appropriate radiation modalities are essential for reducing RION.
• Adherence to dose constraints for critical structures, regular follow-up, and managing comorbidities are vital.
• Early intervention strategies can further mitigate the risk and impact of RION.