MRI enables accurate diagnosis and follow-up in uveal melanoma patients after vitrectomy

Abstract

Uveal melanoma (UM), the most common primary intraocular tumour, is often complicated by exudative retinal detachment (RD). Sometimes, this exudative RD is mistaken for a rhegmatogenous detachment and is subsequently treated with vitrectomy with silicone oil (SiOil) tamponade. As SiOil prevents ultrasound imaging, the diagnosis, treatment planning and/or follow-up of UM underlying the detachment are often severely hindered by the SiOil. We aim to develop and evaluate new MRI methods to image UM patients with a SiOil tamponade and evaluate this in vivo. A dedicated MRI protocol for 3 and 7 T was developed and subsequently evaluated in three patients. The MRI protocol developed was evaluated in three patients. In the first patient, SiOil hindered follow-up and therefore MRI was indicated. No tumour recurrence was found after two follow-up scans. The second and third patient underwent vitrectomy with SiOil for assumed rhegmatogenous RD in another hospital, during which a mass was found. In these cases, MRI was used to determine whether the lesion was UM and perform measurements to plan brachytherapy treatment. In general, the proposed workflow is more complicated on 7 T than on 3 T as the off-resonance effects scale linearly with field strength. For example, the shimming procedure needed modifications at 7 T, whereas at 3 T, the automatic shimming sufficed. However, at 7 T, higher resolution images were obtained compared with 3 T (0.6 vs. 0.8 mm3). A dedicated MRI protocol enables high-resolution imaging of vitrectomized eyes with SiOil tamponade, enabling treatment planning or follow-up in UM patients.

MRI of Uveal Melanoma

“…However, recent developments on MRI make it a promising diagnostic imaging modality in ophthalmology, due to its excellent soft tissue contrast and spatial resolution, as well as its possibility for generating functional images such as diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) [5,6,9]. UM is therefore more and more being evaluated with MRI [5,6,9,10,11]. The purpose of our study was to optimize the MRI technique of the globe and in particular of uveal melanomas.…”

Diagnostic methods and therapeutic options of uveal melanoma with emphasis on MR imaging—Part I: MR imaging with pathologic correlation and technical considerations

“…In particular, the isotropic spatial resolution of 3D acquisitions enables MR sequences to be reformatted into high-resolution images with countless orientations [ 10 , 35 ]. Additionally, using a properly modified MR protocol it is possible to image patients previously treated for retinal detachment with silicon oil, the eyes of whom in the past needed to be enucleated because of the impossibility to perform a correct follow-up [ 36 ]. For these reasons, the inclusion of an MR examination in the diagnostic management of selected patients with uveal melanoma may positively impact the therapeutic planning, thus changing treatment procedure from enucleation to proton beam therapy or to the less expensive plaque brachytherapy.…”

New Perspectives in Imaging of Uveal Melanoma

“…MR imaging can also be essential in patients who underwent vitrectomy. In these cases, the replacement of the vitreous body with silicon oil (SiOil) tamponade, causes difficulties for UM diagnosis and assessing treatment follow-up with imaging methods such us US, where sound waves reflect at the SiOil-water interface [137]. SiOil by principle does not hinder MR imaging [137,138], although some strong artifacts may appear in the conventional protocols as the result of the off resonance of the SiOil.…”

“…In these cases, the replacement of the vitreous body with silicon oil (SiOil) tamponade, causes difficulties for UM diagnosis and assessing treatment follow-up with imaging methods such us US, where sound waves reflect at the SiOil-water interface [137]. SiOil by principle does not hinder MR imaging [137,138], although some strong artifacts may appear in the conventional protocols as the result of the off resonance of the SiOil. Dedicated MRI protocols such as 3 T and 7 T might be able to provide high-resolution images of vitrectomized eyed with SiOil tamponade [137].…”