Sensitivity of Magnetic Resonance Imaging in Detection of Choroidal Metastasis
Michael Yu, MD
Michael Yu, MD; Hashem Ghoraba, MD; Prithvi Mruthyunjaya, MD, MHS
Byers Eye Insitute, Stanford University, Palo Alto, CA
Neuroimaging, particularly with magnetic resonance imaging (MRI), assumes greater importance today in the surveillance of patients with systemic malignancy than ever before. Despite this, there exists a paucity of research regarding the sensitivity of MRI in detecting choroidal metastases (CM) from systemic primary cancers. Herein, we investigate the detection rate of CM by MRI and compare its sensitivity to that of visual symptoms alone.
42 eyes from 40 consecutive patients seen at the Byers Eye Oncology Service (Stanford University) between January 2018 and January 2022 were included. All patients were diagnosed with CM by funduscopic evaluation and underwent MRI brain/orbits within three months of CM diagnosis. Demographics, along with primary systemic malignancy, CM, and MRI features, were collected and analyzed (t-test, Fisher exact test).
Of 42 CM, 35 (83%) were visually symptomatic and 21 (50%) were detected by MRI. Comparison by detection vs. non-detection revealed increased tumor basal diameter (12.7 vs. 8.9 mm, respectively; p<0.001) and tumor thickness (3.8 vs. 2.1 mm, respectively; p=0.003) as improving detection sensitivity. These features were associated with increased interval from cancer diagnosis to CM diagnosis (5.95 vs. 2.76 years, respectively; p=0.009) and worse staging of primary cancer (p=0.018). There was no difference between MRI brain and MRI orbits (p=0.410).
MRI cannot reliably exclude the presence of CM. In patients with a known primary systemic malignancy, the incidence of CM in visually asymptomatic patients has been estimated at 0-2%. Thus, the utility of assessing visual symptoms may exceed that of MRI in excluding the presence of CM.