Abstract
Purpose :
Blue wave fundus autofluorescence (FAF) imaging is well established for the investigation of various ocular diseases and has also been used to describe FAF phenomena of choroidal melanomas. In this retrospective clinical case series we assessed FAF changes in the surrounding irradiation field after ruthenium-106 brachytherapy (RBT) for choroidal melanoma to identify FAF characteristics for monitoring effects of RBT.
Methods :
Consecutive patients with choroidal melanoma were included and treated with RBT at a single institution. Tumor height was documented by B-scan ultrasonography. As part of their routine examination patients underwent fundus photography and FAF imaging (HRA2/Spectralis, Heidelberg Engineering, Heidelberg, Germany, excitation at 488 nm, barrier filter > 500 nm). FAF images were analyzed for changes in the irradiation field surrounding the choroidal melanoma.
Results :
27 patients (12 male, 15 female; mean age 66,1 years), underwent plaque radiotherapy for unilateral, posterior choroidal melanoma. Mean tumor thickness before therapy was 2,8 mm. Mean follow-up time was 21,9 months (range 3-49 months). Changes in FAF outside the choroidal melanoma included increased FAF with maximum intensity at the border of the irradiation field, which was clearly defined like a foot print of the ruthenium plaque. At later stages a granular FAF pattern was associated with pigment mottling, whereas reduced FAF occurred with progression to atrophy of the retinal pigment epithelium (RPE).
Conclusions :
FAF imaging is a potential non-invasive tool to visualize FAF characteristics in the irradiation field following RBT for treatment of choroidal melanoma. Increased FAF in the irradiation field may be due to increased metabolic activity of the RPE with following lipofuscin accumulation whereas granular or decreased FAF indicates RPE atrophy. FAF changes may occur before radiation effects are clearly identifiable in fundus photography. Therefore, FAF imaging is helpful to monitor therapeutic effects of RBT and may be a convenient application to assess tumor control after brachytherapy. Further longitudinal studies are needed to investigate influence of irradiation dose and the temporal occurrence of FAF changes.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.