Ultra-widefield fundus photography for radiation therapy planning of ocular tumours.
Fonte: Thibaud Mathis, et all
Fundus photography of the same eye with choroidal melanoma using standard-field (SF) and ultra-widefield (UWF) imaging. SF (A–C) and UWF (D–F) were used to evaluate the differences in distances measured between 2 lengths. The optic disc was assumed to equal 1.5 mm in both techniques (A, D). The distance between a blood vessel branch near the tumour and the point it crossed the optic disc border were measured (B, E). A second measure ≥90° from the latter was also made (C, F).
Purpose: The use of planar ultra-widefield fundus photography (UWF) may result in distortions and inaccurate measurement. The aim of the study was to evaluate the accuracy of UWF instead of the standard narrow field (SF) for the treatment planning phase of ocular tumours. Methods: Distortions between conformal SF and UWF were assessed in 43 patients with choroidal melanoma treated with either proton therapy or brachytherapy. IMAGEJ software was used to measure distortion. Results: The median interquartile range ([IQR]) distortion for all cases was 3.7% [1.7–10.8]. For cases with tumours within 6 mm of the optic disc, distortions appeared clinically nonsignificant. For peripheral and/or large tumours, significantly larger distortions were observed on UWF (median 4.4% [2.7–22.6] for tumours ≥6 mm from the optic disc versus 3.3% [1.6–9.9] for those