Minimizing eye lens radiation exposure using lens tracking in neurointerventional procedures: retrospective clinical and phantom study.

Background: The eye lens is particularly vulnerable to radiation during endovascular treatments for intracranial aneurysms due to prolonged exposure under high magnification. This study presents a lens tracking method to monitor lens positions during procedures and estimate radiation doses using a phantom.

Methods: A consecutive series of patients treated between January and March 2023 were retrospectively reviewed. A lens tracking method was used to mark lenses on three-dimensional source images to track their positions on two-dimensional working views. An anthropomorphic head phantom and photoluminescent glass dosimeters were used to estimate lens exposure under simulated conditions. We also evaluated potential radiation reduction with collimation based on the lens position.

Results: Among 42 patients, 20 (48%) had their eye lens in the field of view (FOV). In 10 of these cases, collimation could have prevented direct exposure. The phantom study showed a median lens dose of 7.32 (5.02-9.59) mGy. Lenses within the anterior-posterior (AP) plane FOV received higher doses compared with those outside it (4.32 mGy vs 1.76 mGy, P<0.001). In the lateral plane, lenses outside the FOV showed significant dose differences (left lens: 5.02 mGy vs right lens: 2.45 mGy, P<0.001). Collimation reduced lens doses by 60% in the AP plane and 52% in the lateral plane (P<0.001 and P=0.001, respectively) with greater reductions for lenses initially in the FOV.

Conclusion: In this study, lenses were often included in the FOV, thereby receiving higher radiation doses. This underscores the importance of tracking and excluding lenses from the FOV to reduce radiation exposure during procedures.